Yii 1.1 Application Development Cookbook


Yii 1.1 Application Development Cookbook Over 80 recipes to help you master using the Yii PHP framework Alexander Makarov BIRMINGHAM - MUMBAI Yii 1.1 Application Development Cookbook Copyright © 2011 Packt Publishing All rights reserved. No part of this book may be reproduced, stored in a retrieval system, or transmitted in any form or by any means, without the prior written permission of the publisher, except in the case of brief quotations embedded in critical articles or reviews. Every effort has been made in the preparation of this book to ensure the accuracy of the information presented. However, the information contained in this book is sold without warranty, either express or implied. Neither the author, nor Packt Publishing, and its dealers and distributors will be held liable for any damages caused or alleged to be caused directly or indirectly by this book. Packt Publishing has endeavored to provide trademark information about all of the companies and products mentioned in this book by the appropriate use of capitals. However, Packt Publishing cannot guarantee the accuracy of this information. First published: August 2011 Production Reference: 1170811 Published by Packt Publishing Ltd. Livery Place 35 Livery Street Birmingham B3 2PB, UK. ISBN 978-1-849515-48-1 www.packtpub.com Cover Image by Jasmine Doremus (jasdoremus@gmail.com) Credits Author Alexander Makarov Reviewers Anatoliy Dimitrov Antonio Ramirez Cobos SAKURAI, atsushi Kyle Ferreira Acquisition Editor Usha Iyer Development Editor Hyacintha D'Souza Technical Editors Azharuddin Sheikh Conrad Sardinha Copy Editor Neha Shetty Project Coordinator Michelle Quadros Proofreader Steve Maguire Indexers Hemangini Bari Tejal Daruwale Graphics Nilesh Mohite Production Coordinator Aparna Bhagat Cover Work Aparna Bhagat Foreword When Alex told me he was about to write a Yii cookbook about a year ago, I was wondering how original it would be, considering the fact that there was already an online user-contributed cookbook (also known as Yii wiki). It turned out Alex produced a book that is not only full of wisdom about how to use Yii effectively, but also presented in such a systematic way that it can be taken as an essential companion book to the definitive guide to Yii. In fact, Alex has successfully intrigued the interest of every member in the Yii developer team when he asked for reviews and comments on his newly finished book chapters. As the founder and the lead developer of the Yii framework, I feel this book is a must-read for every Yii programmer. While this book does not describe directly the rules set by Yii, it shows how to program with Yii from a practical perspective. People who are driven by tight project schedules will find this book very handy, as it gives ready-to-use solutions to many problems they may face in their projects. People who are already familiar with Yii will also find this book very informative as most problem solutions given in the book can be considered as officially recommended because they have undergone thorough a review by every Yii developer team member. Alex, through this book and his active participation in the Yii project, proved himself to be a great programmer, as well as a good writer. Qiang Xue Lead Developer of the Yii framework About the Author Alexander Makarov graduated from Voronezh State University in 2007 with a master degree in computer science. During his study, he started working on homegrown PHP frameworks and projects trying various design patterns and techniques. During the last year of his study, he spent a year working for Siemens mainly doing Java coding and complex SQL reports and also did many small and medium freelance projects in his free time. In 2007, he joined an outsourcing company, Murano Software, and had a lot of experience with web development in general, J2EE, PHP, and client-side technologies working on projects such as wrike.com and docufide.com. As in previous years he did some notable freelance jobs, including social network for Russia Today built with Yii in 2009 and heavy loaded NNM.ru portal in 2008. Between 2008 and 2010, he helped the Russian CodeIgniter community to grow and started actively to contribute to open source projects. In 2009, Alexander joined Yii camp and started growing the Russian Yii community, translated documentation into Russian and, since May 2010, has become a passionate Yii framework core developer. He has published several articles in Smashing Magazine and a lot more in his Russian blog http://rmcreative.ru/, and has presented numerous talks on Yii and web development in general at various conferences. Alexander currently resides in Voronezh, Russia, with his beloved wife and daughter. Besides the web, he enjoys movies, rock music, travelling, photography, and languages. I would like to thank Qiang Xue, Maurizio Domba, Sebastián Thierer, Alexander Kochetov, Antonio Ramirez Cobos, and all people who reviewed the RAW book. Your suggestions and critics helped to improve this book a lot. I would like to thank Qiang Xue and Wei Zhuo for creating Yii. I would also like to thank Packt Publishing for inviting me to write this book and helping me to actually get it done. I would like to thank all the past and current Yii core team members for keeping Yii in a good shape and making it better and better. You guys rock! About the Reviewers Anatoliy Dimitrov has an O'Reilly certificate in PHP/MySQL programming and he is a great supporter of Yii. Besides that, he is experienced in website security, server hardening, and secure services configuration. He has held senior technical positions for some of the largest hosting companies, payment processors, and many freelance projects. I would like to thank Rali, the love of my life, for everything and especially allowing me to stay late in the evenings working. Antonio Ramirez Cobos (aka tonydspaniard), self-educated programmer, jumped into the world of coding while studying hardware and client support at TAFE, Melbourne. He has more than 12 years of experience and has been working in the field using Javascript, C++, Java, ASP.net (with C#), Visual Basic (COM, COM+), Dynamic DLL, until he met PHP and the wonders of open source. Since then, he has not left that language and specializes in building web applications. A Yii lover, he maintains his blog at www.ramirezcobos.com, which has been lately used to propagate the wonders of such frameworks. He is also a regular user of Yii's forum. SAKURAI, atsushi is a microprocessor expert, as well as a PHP programmer for over 10 years. As a manager of a design team of microprocessors, he has been working to build the support website for their microprocessors. Recently, his efficiency for developing web application is drastically increasing, thanks to Yii. His main contribution to the Yii community includes the translation of the documentations into Japanese. www.PacktPub.com Support files, eBooks, discount offers, and more You might want to visit www.PacktPub.com for support files and downloads related to your book. Did you know that Packt offers eBook versions of every book published, with PDF and ePub files available? You can upgrade to the eBook version at www.PacktPub.com and as a print book customer, you are entitled to a discount on the eBook copy. Get in touch with us at service@packtpub.com for more details. At www.PacktPub.com, you can also read a collection of free technical articles, sign up for a range of free newsletters and receive exclusive discounts and offers on Packt books and eBooks. http://PacktLib.PacktPub.com Do you need instant solutions to your IT questions? PacktLib is Packt's online digital book library. Here, you can access, read, and search across Packt's entire library of books.  Why Subscribe? ff Fully searchable across every book published by Packt ff Copy and paste, print and bookmark content ff On demand and accessible via web browser Free Access for Packt account holders If you have an account with Packt at www.PacktPub.com, you can use this to access PacktLib today and view nine entirely free books. Simply use your login credentials for immediate access. Dedicated to my wife, Eugenia, my daughter, Maya, my entire family, and all my friends. Thanks for your love and support. Table of Contents Preface 1 Chapter 1: Under the Hood 7 Introduction 7 Using getters and setters 7 Using Yii events 10 Using import and autoloading 17 Using exceptions 21 Configuring components 24 Configuring widget defaults 27 Using Yii core collections 28 Working with request 32 Chapter 2: Router, Controller, and Views 37 Introduction 38 Configuring URL rules 38 Generating URLs by path 41 Using regular expressions in URL rules 45 Creating URL rules for static pages 48 Providing your own URL rules at runtime 51 Using base controller 55 Using external actions 57 Displaying static pages with CViewAction 61 Using flash messages 62 Using controller context in a view 64 Reusing views with partials 65 Using clips 68 Using decorators 69 Defining multiple layouts 70 Paginating and sorting data 73 ii Table of Contents Chapter 3: AJAX and jQuery 75 Introduction 75 Loading a block through AJAX 75 Managing assets 81 Including resources into the page 86 Working with JSON 89 Passing configuration from PHP to JavaScript 92 Handling variable number of inputs 94 Chapter 4: Working with Forms 103 Introduction 103 Writing your own validators 103 Uploading files 106 Adding CAPTCHA 110 Customizing CAPTCHA 115 Creating a custom input widget with CInputWidget 117 Chapter 5: Testing your Application 121 Introduction 121 Setting up the testing environment 121 Writing and running unit tests 125 Using fixtures 131 Testing the application with functional tests 137 Generating code coverage reports 142 Chapter 6: Database, Active Record, and Model Tricks 147 Introduction 147 Getting data from a database 148 Defining and using multiple DB connections 153 Using scopes to get models for different languages 158 Processing model fields with AR event-like methods 161 Applying markdown and HTML 163 Highlighting code with Yii 166 Automating timestamps 172 Setting an author automatically 174 Implementing single table inheritance 176 Using CDbCriteria 180 Chapter 7: Using Zii Components 183 Introduction 183 Using data providers 183 Using grids 190 Using lists 198 Creating custom grid columns 203 iii Table of Contents Chapter 8: Extending Yii 209 Introduction 209 Creating model behaviors 209 Creating components 216 Creating reusable controller actions 220 Creating reusable controllers 223 Creating a widget 227 Creating CLI commands 229 Creating filters 233 Creating modules 235 Creating a custom view renderer 241 Making extensions distribution-ready 246 Chapter 9: Error handling, Debugging, and Logging 249 Introduction 249 Using different log routes 250 Analyzing the Yii error stack trace 256 Logging and using the context information 259 Implementing your own smart 404 handler 263 Chapter 10: Security 269 Introduction 269 Using controller filters 269 Using CHtml and CHtmlPurifier to prevent XSS 274 Preventing SQL injections 278 Preventing CSRF 284 Using RBAC 287 Chapter 11: Performance Tuning 295 Introduction 295 Following best practices 295 Speeding up sessions handling 300 Using cache dependencies and chains 304 Profiling an application with Yii 311 Chapter 12: Using External Code 321 Introduction 321 Using Zend Framework from Yii 321 Customizing the Yii autoloader 326 Using Kohana inside Yii 331 Using PEAR inside Yii 339 iv Table of Contents Chapter 13: Deployment 341 Introduction 341 Changing the Yii directories layout 341 Moving an application out of webroot 344 Sharing the framework directory 346 Moving configuration parts into separate files 348 Using multiple configurations to simplify the deployment 354 Implementing and executing cron jobs 357 Maintenance mode 360 Index 363 Preface Yii is a very flexible and high-performance application development framework written in PHP. It helps building web applications from small ones to large-scale enterprise applications. The framework name stands for Yes It Is. This is often the accurate and most concise response to inquires from those new to Yii: Is it fast? ... Is it secure? ... Is it professional? ... Is it right for my next project? ... The answer is Yes, it is! This cookbook contains 13 independent chapters full of recipes that will show you how to use Yii efficiently. You will learn about the hidden framework gems, using core features, creating your own reusable code base, using test-driven development, and many more topics that will bring your knowledge to a new level! What this book covers Chapter 1, Under the Hood provides information about the most interesting Yii features hidden under the hood: events, import, autoloading, exceptions, component, and widget configuration, and more. Chapter 2, Router, Controller, and Views is about handy things concerning the Yii URL router, controllers, and views: URL rules, external actions and controllers, view clips, decorators, and more. Chapter 3, AJAX and jQuery focuses on the Yii's client side that is built with jQuery—the most widely used JavaScript library out there. It is very powerful and easy to learn and use. This chapter focuses on Yii-specific tricks rather than jQuery itself. Chapter 4, Working with Forms. Yii makes working with forms a breeze and documentation on it is almost complete. Still, there are some areas that need clarification and examples. Some of the topics covered in this chapter are creating own validators and input widgets, uploading files, using, and customizing CAPTCHA. Preface 2 Chapter 5, Testing Your Application covers both unit testing, functional testing, and generating code coverage reports. Recipes follow a test driven development approach. You will write tests for several small applications and then will implement functionality. Chapter 6, Database, Active Record, and Model Tricks is about working with databases efficiently, when to use models and when not to, how to work with multiple databases, how to automatically pre-process Active Record fields, and how to use powerful database criteria. Chapter 7, Using Zii Components covers data providers, grids, and lists: How to configure sorting and search, how to use grids with multiple related models, how to create your own column types, and more. Chapter 8, Extending Yii shows not only how to implement your own Yii extension but also how to make your extension reusable and useful for the community. In addition, we will focus on many things you should do to make your extension as efficient as possible. Chapter 9, Error Handling, Debugging, and Logging reviews logging, analyzing the exception stack trace, and own error handler implementation. Chapter 10, Security provides information about keeping your application secure according to the general web application security principle "filter input escape output". We will cover topics such as creating your own controller filters, preventing XSS, CSRF, and SQL injections, escaping output, and using role-based access control. Chapter 11, Performance Tuning shows how to configure Yii to gain extra performance. You will learn a few best practices of developing an application that will run smoothly until you have very high loads. Chapter 12, Using External Code focuses on using the third party code with Yii. We will use Zend Framework, Kohana, and PEAR but you will be able to use any code after learning how it works. Chapter 13, Deployment covers various tips that are especially useful on application deployment, when developing an application in a team, or when you just want to make your development environment more comfortable. What you need for this book In order to run the examples in this book, the following software will be required: ff Web server: ‰‰ 2.x version of Apache web server is preferred ‰‰ Other versions and web servers will work too, but configuration details are not provided Preface 3 ff Database server: MySQL is recommended ‰‰ MySQL 4+ with InnoDB support, MySQL 5 or higher recommended ff PHP: PHP 5.3 is recommended ‰‰ PHP 5.2 or PHP 5.3, PHP 5.3 recommended ff Yii: ‰‰ latest 1.1.x Additionally, the following tools are not strictly required but are used for specific recipes: ff PHPUnit ff XDebug ff Selenium RC ff PEAR ff Smarty ff memcached Who this book is for If you are a developer with a good knowledge of PHP5, are familiar with the basics of Yii, have checked its definitive guide, and have tried to develop applications using Yii, then this book is for you. Knowledge of the object-oriented approach and MVC pattern will be a great advantage as Yii uses these extensively. Conventions In this book, you will find a number of styles of text that distinguish between different kinds of information. Here are some examples of these styles, and an explanation of their meaning. Code words in text are shown as follows: "We can include view partials through the use of the include directive." A block of code is set as follows: defined('YII_DEBUG') or define('YII_DEBUG', false); defined('YII_TRACE_LEVEL') or define('YII_TRACE_LEVEL', 0); $yii=dirname(__FILE__).'/../framework/yii.php'; $config=dirname(__FILE__).'/../app/config/production.php'; require($yii); Yii::createWebApplication($config)->run(); Preface 4 When we wish to draw your attention to a particular part of a code block, the relevant lines or items are set in bold: defined('YII_DEBUG') or define('YII_DEBUG', false); defined('YII_TRACE_LEVEL') or define('YII_TRACE_LEVEL', 0); $yii=dirname(__FILE__).'/../framework/yii.php'; $config=dirname(__FILE__).'/../app/config/production.php'; require($yii); Yii::createWebApplication($config)->run(); Any command-line input or output is written as follows: cd path/to/protected/tests phpunit unit/BBCodeTest.php Warnings or important notes appear in a box like this. Tips and tricks appear like this. Reader feedback Feedback from our readers is always welcome. Let us know what you think about this book—what you liked or may have disliked. Reader feedback is important for us to develop titles that you really get the most out of. To send book author feedback about the book, simply fill a form at http://yiicookbook. org/feedback. If there is a book that you need and would like to see PACKT publish, please send a note in the SUGGEST A TITLE form on www.packtpub.com or e-mail suggest@packtpub.com. If there is a topic that you have expertise in and you are interested in either writing or contributing to a book, see author guide on www.packtpub.com/authors. Preface 5 Customer support Now that you are the proud owner of a Packt book, we have a number of things to help you to get the most from your purchase. Downloading the example code To get the example code files for this book visit http://yiicookbook.org/code. You can download the example code files for all Packt books you have purchased from your account at http://www.PacktPub.com. 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If you come across any illegal copies of our works, in any form, on the Internet, please provide us with the location address or website name immediately so that we can pursue a remedy. Please contact us at copyright@packtpub.com with a link to the suspected pirated material. We appreciate your help in protecting our authors, and our ability to bring you valuable content. Questions You can contact the book's author using http://yiicookbook.org/feedback if you are having a problem with any aspect of the book, and he will do his best to address it. 1 Under the Hood In this chapter, we will cover: ff Using getters and setters ff Using Yii events ff Using import and autoloading ff Using exceptions ff Configuring components ff Configuring widget defaults ff Using Yii core collections ff Working with request Introduction In this chapter, we will cover the most interesting Yii features that are hidden "under the hood". These are mostly described in the framework API, but since they are not mentioned in the official guide (http://www.yiiframework.com/doc/guide/) or mentioned very briefly, only experienced Yii developers usually use these. Yet, features described here are relatively simple and using them makes development with Yii much more fun and productive. Using getters and setters Yii has many features that came from other languages, such as Java or C#. One of them is defining properties with getters and setters for any of the class extended from CComponent (that is, virtually any Yii class). From this recipe, you will learn how to define your own properties using getters and setters, how to make your properties read-only, and how to hide custom processing behind native PHP assignments. Under the Hood 8 How to do it... 1. As PHP does not have properties at the language level, we can only use getters and setters in the following way: class MyClass { // hiding $property private $property; // getter public function getProperty() { return $this->property; } // setter public function setProperty($value) { $this->property = $value; } } $object = new MyClass(); // setting value $object->setProperty('value'); // getting value echo $object->getProperty(); 2. This syntax is very common in the Java world but it is a bit long to use in PHP. Still, we want to use the same functionality C# properties gives us: calling getters and setters like class members. With Yii, we can do it in the following way: // extending CComponent is necessary class MyClass extends CComponent { private $property; public function getProperty() { return $this->property; } Chapter 1 9 public function setProperty($value) { $this->property = $value; } } $object = new MyClass(); $object->property = 'value'; // same as $object-> setProperty('value'); echo $object->property; // same as $object->getProperty(); 3. Using this feature, you can make properties read-only or write-only while keeping the simple PHP syntax as follows: class MyClass extends CComponent { private $read = 'read only property'; private $write = 'write only property'; public function getRead() { return $this->read; } public function setWrite($value) { $this->write = $value; } } $object = new MyClass(); // gives us an error since we are trying to write to read-only property $object->read = 'value'; // echoes 'read only property' echo $object->read; // gives us an error since we are trying to read to write-only property echo $object->write; // writes 'value' to private $write $object->write = 'value'; Under the Hood 10 4. Yii uses this technique extensively because almost everything is a component. For example, when you are calling Yii::app()->user->id to get the currently logged in user ID, what's really called is Yii::app()->getUser()->getId(). How it works... To use getters and setters like properties, CComponent uses the PHP magic methods: __ get, __set, __isset, and __unset (http://php.net/manual/en/language.oop5. magic.php). The following example shows what Yii 1.1 CComponent::__get looks like: public function __get($name) { $getter='get'.$name; if(method_exists($this,$getter)) return $this->$getter(); … This magic PHP method intercepts all calls to missing real properties, so when we are calling $myClass->property, it receives property as $name parameter. If a method named getProperty exists, then PHP uses its return value as a property value. There's more... For further information, refer to the following URL: http://www.php.net/manual/en/language.oop5.overloading.php#language. oop5.overloading.members See also ff The recipe named Using Yii events in this chapter ff The recipe named Configuring components in this chapter Using Yii events Most Yii classes are extended from CComponent which allows us to achieve great application flexibility by using events. An event is a message indicating that the application did something. We can register several event handlers that will react to certain event types. A handler can get parameters from an event it works with and react accordingly. Using events allows achieving great application flexibility. In this recipe, you will learn how to declare and use both predefined and custom events in your application. Chapter 1 11 How to do it... To declare an event in your CComponent child class, you should add a method with a name starting with on. For example, if you add the onRegister method, you will get a corresponding event declared. A method used to declare an event becomes the default event handler. Typically, events are used like this: ff Declare an event by adding a corresponding method ff Attach one or multiple event handlers ff The component raises an event by using the CComponent::raiseEvent method ff All subscribed handlers are called automatically Let's look at how we can attach an event handler to an event. To achieve it, we can use the CComponent::attachEventHandler method. It accepts the following two parameters: ff $name: Event name ff $handler: Event handler; a standard PHP callback should be used In PHP, we have several ways to define a callback as follows: ff Use a global function and just pass its name as a string, such as 'my_function'. ff Use a static class method. You should pass an array: array('ClassName', 'staticMethodName') . ff Use an object method: array($object, 'objectMethod'). ff Create and pass anonymous function using create_function as follows: $component->attachEventHandler('onClick', create_function('$event', 'echo "Click!";')); ff Since PHP 5.3, you can use anonymous functions without create_function: $component->attachEventHandler('onClick', function($event){ echo "Click!"; }); When you use CComponent::attachEventHandler, event handler is added to the end of the handlers list. Under the Hood 12 ff To keep your code shorter, you can use component properties to manage event handlers as follows: $component->onClick=$handler; // or: $component->onClick->add($handler); ff To manage event handlers more precisely, you can get handlers list (CList) using CComponent::getEventHandlers and work with it. For example, you can attach an event handler the same way as with attachEventHandler using the following code: $component->getEventHandlers('onClick')->add($handler); ff To add an event handler to the beginning of handlers list, use: $component->getEventHandlers('onClick')->insertAt(0, $handler); ff To delete a particular handler you can use CComponent::detachEventHandler as follows: $component->detachEventHandler('onClick', $handler); ff Alternatively, get a list of handlers as shown earlier and delete handlers from it. CComponent::hasEvent checks if event specified is defined in the component. CComponent::hasEventHandler checks if there are handlers attached to the event specified. As we now know how to define and use handlers, let's review some real life examples as follows: ff It is common practice to compress your application output using gzip to save client bandwidth and speed up page loading time. If you have an access to fine-tune your server, then you can instruct it to do so, but in some environments such as shared hosting, you can't. ff Fortunately, PHP can gzip the application output using output buffering and ob_gzhandler. In order to do so, we should start buffering the output when the application starts and releases the gzipped output, when it finishes. ff Yii's application component has two events that will come in handy in this case: CApplication::onBeginRequest and CApplication::onEndRequest. Let's use them. Put the following in index.php after configuring an application but before running it: … require_once($yii); $app = Yii::createWebApplication($config); Chapter 1 13 // attaching a handler to application start Yii::app()->onBeginRequest = function($event) { // starting output buffering with gzip handler return ob_start("ob_gzhandler"); }; // attaching a handler to application end Yii::app()->onEndRequest = function($event) { // releasing output buffer return ob_end_flush(); }; $app->run(); There are many handy events defined inside Yii core classes. You can get them all by searching for "function on" text in the framework folder using your favorite IDE. Now, let's look at another example. In Yii, you can translate strings to different languages using Yii::t. As we all love perfect projects all language translations should be up to date. If they are not, we would like to receive an e-mail about it. Events come in handy again here. In particular, the CMessageSource::onMissingTransl ation event that is called when the translation for a string passed to Yii::t is missing. This time we will use the application configuration file protected/config/main.php to attach an event handler as follows: … 'components' => array( … // messages component class is CPhpMessageSource by default 'messages' => array( // using static class method as event handler 'onMissingTranslation' => array('MyEventHandler', 'handleMissingTranslation'), ), … ) … Under the Hood 14 Now, we should implement our handler. Create protected/components/ MyEventHandler.php as follows: class MyEventHandler { static function handleMissingTranslation($event) { // event class for this event is CMissingTranslationEvent // so we can get some info about the message $text = implode("\n", array( 'Language: '.$event->language, 'Category:'.$event->category, 'Message:'.$event->message )); // sending email mail('admin@example.com', 'Missing translation', $text); } } Let's look at the last example. We have a blog application and we need to send an e-mail when there is a new comment (Comment) to the blog post (Post). Comment is a standard AR model generated with Gii. Post is the same Gii-generated model except some customized methods. We will need a custom event NewCommentEvent to store both Post and Comment models and a handler class Notifier that will do the work. 1. Let's start with protected/components/NewCommentEvent.php: class NewCommentEvent extends CModelEvent { public $comment; public $post; } It is pretty simple. We have just added two properties. 2. Now, let's move on to protected/models/Post.php. All standard AR methods are omitted to emphasize on what was added: class Post extends CActiveRecord { // custom method for adding a comment // to current post function addComment(Comment $comment){ $comment->post_id = $this->id; // creating event class instance $event = new NewCommentEvent($this); $event->post = $this; $event->comment = $comment; Chapter 1 15 // triggering event $this->onNewComment($event); return $event->isValid; } // defining onNewComment event public function onNewComment($event) { // Event is actually triggered here. This way we can use // onNewComment method instead of raiseEvent. $this->raiseEvent('onNewComment', $event); } } 3. Now, it is time to implement a notifier. Create protected/components/ Notifier.php as follows: class Notifier { function comment($event){ $text = "There was new comment from {$event->comment->author} on post {$event->post->title}"; mail('admin@example.com', 'New comment', $text); } } 4. Now, it is time to get these together in protected/controllers/ PostController.php: class PostController extends CController { function actionAddComment() { $post = Post::model()->findByPk(10); $notifier = new Notifier(); // attaching event handler $post->onNewComment = array($notifier, 'comment'); // in the real application data should come from $_POST $comment = new Comment(); $comment->author = 'Sam Dark'; $comment->text = 'Yii events are amazing!'; // adding comment $post->addComment($comment); } } 5. After the comment has been added, admin will receive an e-mail about it. Under the Hood 16 There's more... It is not always necessary to attach an event handler. Let's look at how we can handle an event that is already declared inside an existing component by overriding a base class method. For example, we have a form model UserForm used to collect some information about our application user and we need to get the complete name from the first and the last name entered by the user. Fortunately, in CModel, which is a base class for all Yii models including form models, CModel::afterValidate method is defined. This method is being called after a successful form validation. Let's use it in our protected/models/UserForm.php model: class UserForm extends CFormModel { public $firstName; public $lastName; public $fullName; public function rules() { return array( // First name and last name are required array('firstName, lastName', 'required'), ); } // $event argument here is CEvent instance that // was created passed when an event method was called. // This time it was happened inside of // CModel::afterValidate(). function afterValidate() { // If this method was called then // the model is already filled // with data and data is valid // so we can use it safely: $this->fullName = $this->firstName.' '.$this->lastName; // It's important to call parent class method // so all other event handlers are called return parent::afterValidate(); } } Chapter 1 17 We need to call parent method inside of afterValidate because parent implementation calls onAfterValidate that actually raises events: protected function afterValidate() { $this->onAfterValidate(new CEvent($this)); } An event method name should always be defined as function eventHandler($event){…}, where $event is a CEvent instance. The CEvent class contains just two properties named sender and handled. First property contains an object that called the current event while the second can be used to prevent calling all others not yet executed handlers by setting it to false. The approach described above can be used to customize your Active Record models and implement your own model behaviors. Further reading For further information, refer to the following URLs: ff http://www.yiiframework.com/doc/api/CComponent/#raiseEvent- detail ff http://www.yiiframework.com/doc/api/ CComponent/#attachEventHandler-detail ff http://www.yiiframework.com/doc/api/ CComponent/#getEventHandlers-detail ff http://www.yiiframework.com/doc/api/ CComponent/#detachEventHandler-detail See also ff The recipe named Using getters and setters in this chapter ff The recipe named Configuring components in this chapter Using import and autoloading When programming with PHP, one of the most annoying things is loading additional code with include and require. Fortunately, you can do it automatically using the SPL class loader (http://php.net/manual/en/function.spl-autoload.php). Under the Hood 18 Autoloading is one of the features which Yii relies on. Still, there are many questions about it on the forums. Let's get it clear and show how we can use it. When we are using a class, for example, CDbCriteria, we are not including it explicitly so PHP initially cannot find it and is trying to rely on the autoloading feature; SPL autoloader to be precise. In most cases, Yii default autoloader (YiiBase::autoload) will be used. For the sake of speed and simplicity, almost all core framework classes are loaded when needed without including or importing them explicitly. It's done through YiiBase::$_ coreClasses map, so loading core classes is very fast. Zii classes, such as CMenu, extension classes or your own classes are not loaded automatically, so we need to import them first. To import classes, we will use Yii::import: ff Import does not include a class immediately by default ff It does not include a class if it is not used ff It will not load a class twice, so it is safe to import the same class multiple times How to do it... 1. Let's assume that we have a custom class named LyricsFinder that finds lyrics for a given song. We have put it under protected/apis/lyrics/ and in our protected/controllers/TestController.php, we are trying to use it in the following way: class TestController extends CController { public function actionIndex($song) { $lyric = 'Nothing was found.'; $finder = new LyricsFinder(); if(!empty($song)) $lyric = $finder->getText($song); echo $lyric; } } 2. When executing it, we will get the following PHP error: include(LyricsFinder.php) [function. include]: failed to open stream: No such file or directory. Chapter 1 19 3. Yii helps us there a bit because at the error screen, we can see that autoloader fails because it doesn't know where to look for our class. Therefore, let's modify our code: class TestController extends CController { public function actionIndex($song) { $lyric = 'Nothing was found.'; // importing a class Yii::import('application.apis.lyrics.LyricsFinder'); $finder = new LyricsFinder(); if(!empty($song)) $lyric = $finder->getText($song); echo $lyric; } } Now our code works. The built-in Yii class loader requires that each class should be placed into a separate file named the same as the class itself. How it works... Let's look at application.apis.lyrics.LyricsFinder: application is a standard alias that points to your application protected folder and is translated into a filesystem path. The following table shows some more standard aliases: Alias Path application path_to_webroot/protected system path_to_webroot/framework zii path_to_webroot/framework/zii webroot path_to_webroot ext path_to_webroot/protected/extensions Under the Hood 20 You can define your own aliases using the Yii::setPathOfAlias method. Typically, it can be done as the first lines of protected/config/ main.php, so all other config parts will be able to use these new aliases. apis.lyrics are translated to apis/lyrics and are appended to a path retrieved from the application alias, and LyricsFinder is the class name we want to import. If LyricsFinder requires some additional classes located in its directory, then we can use Yii::import('application.apis.lyrics.*') to import the whole directory. Note that * does not include subfolders, so if you need lyrics/includes, you should add another import statement Yii::import('application.apis.lyrics.includes.*'). For performance reasons, it is better to use explicit paths with a class name instead of * if you are importing a single class. There's more... If you want your classes to be imported automatically like the Yii core classes, then you can configure global imports in your main.php configuration file: return array( // … // global imports 'import'=>array( 'application.models.*', 'application.components.*', 'application.apis.lyrics.*', 'application.apis.lyrics.includes.*', 'application.apis.albums.AlbumFinder', ), Note that using *, with a huge amount of global imports could slow your application down as there will be too many directories to check. Downloading the example code You can download the example code files for all Packt books you have purchased from your account at http://www.PacktPub.com. If you purchased this book elsewhere, you can visit http://www.PacktPub. com/support and register to have the files e-mailed directly to you. Chapter 1 21 Using exceptions Exceptions are a core PHP feature, but they are seldom used fairly. Yii makes exceptions very useful. There are two main areas where Yii exceptions come in handy, which are as follows: 1. Exceptions allow simplifying the process of detecting and fixing application errors and special situations, such as database connection failure or API failure. 2. Exceptions allow generating different HTTP responses in a very clean way. Generally, an exception should be thrown when a component cannot handle a special situation, such as the one said earlier, and needs to leave it to higher-level components. How to do it… 1. Let's assume that we have an application/apis/lyrics/LyricsFinder.php class that makes an HTTP request to an API using CURL and returns song lyrics based on its name. This is how we can use exceptions inside of it: // create some custom exceptions to be able to catch them // specifically if needed // general lyrics finder exception class LyricsFinderException extends CException {} // used when there is a connection problem class LyricsFinderHTTPException extends LyricsFinderException{} class LyricsFinder { private $apiUrl = 'http://example.com/lyricsapi&songtitle=%s'; function getText($songTitle) { $url = $this->getUrl($songTitle); $curl = curl_init(); curl_setopt($curl, CURLOPT_URL, $url); curl_setopt($curl, CURLOPT_RETURNTRANSFER, 1); $result = curl_exec($curl); Under the Hood 22 // if there is an HTTP error, we'll throw an exception if($result===false) { $errorText = curl_error($curl); curl_close($url); throw new LyricsFinderHTTPException($errorText); } curl_close($curl); return $result; } private function getRequestUrl($songTitle) { return sprintf($this->apiUrl, urlencode($songTitle)); } } 2. As we don't know how a specific application needs to handle its API connection, we will leave it to the application itself by throwing a custom LyricsFinderHTTPException. This is how we can handle it in our protected/controllers/TestController.php: class TestController extends CController { public function actionIndex($song) { $lyric = 'Nothing was found.'; // importing api class Yii::import('application.apis.lyrics.LyricsFinder'); $finder = new LyricsFinder(); if(!empty($song)) { // We don't want to show user an error. // Instead we want to apologize and // invite him to try again later. try { $lyric = $finder->getText($song); } // we are looking for specific exception here catch (LyricsFinderHTTPException $e) { Chapter 1 23 echo 'Sorry, we cannot process your request. Try again later.'; } } echo $lyric; } } 3. Another usage of Yii exceptions is the generation of different HTTP responses by throwing CHttpException. For example, an action that displays a blog post represented by a Post model, loaded by its ID will look like this: class PostController extends CController { function actionView() { if(!isset($_GET['id'])) // If there is no post ID supplied, request is definitely wrong. // According to HTTP specification its code is 400. throw new ChttpException(400); // Finding a post by its ID $post = Post::model()->findByPk($_GET['id']); if(!$post) // If there is no post with ID specified we'll generate // HTTP response with code 404 Not Found. throw new CHttpException(404); // If everything is OK, render a post $this->render('post', array('model' => $post)); } } How it works… Yii converts all non-fatal application errors to CException automatically. Additionally, the default exception handler raises either the onError or an onException event. The default event handler writes a log message with error level set to error. Additionally, if your application's YII_DEBUG constant is set to true, unhandled exception or error will be displayed at a handy error screen. This screen includes a call stack trace, a code area where the exception was raised, and the file and line where you can look for the code to fix. Under the Hood 24 There's more... For further information, refer to the following URLs: ff http://php.net/manual/en/language.exceptions.php ff http://www.yiiframework.com/doc/api/CException/ ff http://www.yiiframework.com/doc/api/CHttpException/ Configuring components Yii is a very customizable framework. Moreover, as in every customizable code, there should be a convenient way to setup different application parts. So in Yii, this is provided through a configuration file named main.php located at protected/config/. How to do it… If you have worked with Yii before, then you have probably configured a database connection: return array( … 'components'=>array( 'db'=>array( 'class'=>'system.db.CDbConnection', 'connectionString'=>'mysql:host=localhost;dbname=database_ name', 'username'=>'root', 'password'=>'', 'charset'=>'utf8', ), … ), … ); This way of configuring component is used when you want to use a component across all application parts. With the preceding configuration, you can access a component by its name, such as Yii::app()->db. Chapter 1 25 How it works… When you are using the Yii::app()->db component for the first time directly or through active record model, Yii creates a component and initializes its public properties with the corresponding values provided in db array under the components section of the main.php application configuration file. In the preceding code, 'connectionString' the value will be assigned to CDbConnection::connectionString, 'username' will be assigned to CDbConnection::username, and so on. If you want to find out what 'charset' stands for or want to know what else you can configure in the db component, then you need to know its class. In case of db component, the class is CDbConnection. You can refer to its API page at http://www.yiiframework. com/doc/api/CDbConnection/ and look for its public properties you can set from config. In the preceding code, the 'class' property is a bit special because it is used to specify component class name. It does not exist in the CDbConnection class. Therefore, it can be used to override a class as follows: return array( … 'components'=>array( 'db'=>array( 'class'=>'application.components.MyDbConnection', … ), … ), … ); This way, you can override each application component and it is very useful whenever a standard component does not fit your application. There's more... Now, let's find out which standard Yii application components you can configure. There are two application types bundled with Yii which are as follows: 1. Web application (CWebApplication) 2. Console application (CConsoleApplication) Both are extended from CApplication, so both console and web applications are sharing its components. Under the Hood 26 You can get the component names from API pages (http://www.yiiframework.com/ doc/api/) and the source code of the registerCoreComponents application method, but let's list them here so the list can be used as a reference. Both console and web application components are listed in the following table: Component name Default/suggested component class Description coreMessages CPhpMessageSource This component provides the source for translating Yii framework messages. db CDbConnection This component provides a database connection. messages CPhpMessageSource This component provides the source for translating application messages. errorHandler CErrorHandler This component handles PHP errors and uncaught exceptions. securityManager CSecurityManager This component provides security- related services, such as hashing, encryption, and so on. statePersister CStatePersister This component provides global state persistence methods. format CFormatter This component provides a set of commonly used data formatting methods. cache CFileCache This component provides a caching feature. Additional components available only for web application are listed in the following table: Component name Default component class Description session CHttpSession This component provides the session- related functionalities. request CHttpRequest This component encapsulates the $_SERVER variable and resolves its inconsistency among different web servers. It also manages the cookies sent from and to the user. urlManager CUrlManager URL router; used both to generate and resolve application URLs. Chapter 1 27 Component name Default component class Description assetManager CAssetManager This component manages the publishing of private asset files. user CWebUser This component represents the user session information. themeManager CThemeManager This component manages themes. authManager CPhpAuthManager This component manages role-based access control (RBAC). clientScript CClientScript This component manages client scripts (JavaScript and CSS). widgetFactory CWidgetFactory This component creates widgets and supports widget skinning. You can add your own application components (classes extended from CComponent) by simply adding new configuration items and pointing their class properties to your custom classes. See also ff The recipe named Configuring widget defaults in this chapter Configuring widget defaults In Yii, code pieces commonly used in views are placed into widgets. For example, a widget can render a tag cloud or provide a custom form input type. Core widgets are highly configurable and are used in views as follows: widget('CLinkPager', array( 'pages' => $pages, 'pageSize' => 15, ))?> In the preceding code, we are using $this->widget that calls a CLinkPager widget with an array of parameters to display a pagination. pages and pageSize are both assigned to the corresponding public properties of CLinkPager before it is being rendered. Note that we have changed the count of items per page to 15 in our example. If we want our pagination to display 15 items per page on all pages of our application, then we will need to provide a pageSize parameter with value 15 for all CLinkPager widget calls. Is there a better way? Definitely, yes. Under the Hood 28 How to do it… A Yii web application provides a bunch of components. One of them is a widget factory that since Yii 1.1.3 can be used to set widget defaults. 1. Let's use it to set pageSize application-wide. We will need to edit the application configuration file main.php as follows: return array( … 'components'=>array( 'widgetFactory'=>array( 'widgets'=>array( 'CLinkPager'=>array( 'pageSize'=>15, ), … ), ), … ), ); 2. Now, the default value for CLinkPager's pageSize will be 15, so if we omit this parameter for all the application CLinkPagers then it will be 15, application-wide. 3. Moreover, we still can override the pageSize value for a specific widget: widget('CLinkPager', array( 'pages' => $pages, 'pageSize' => 5, ))?> This works much like the CSS cascade. You are setting the default overall style in an external file, but are still able to override this through inline styles for individual widgets. See also ff The recipe named Configuring components in this chapter Using Yii core collections Yii has a set of collection classes used mainly for internal purposes which are not described in the Definitive Guide, but are still very useful for applications: ff Lists: CList, CTypedList ff Maps: CMap, CAttributeCollection Chapter 1 29 ff Queue: CQueue ff Stack: CStack How to do it… All collections implement SPL IteratorAggregate, Traversable, and Countable. Lists and maps also implement SPL ArrayAccess. It allows using collections like a standard PHP construct. The following is a snippet from the CList API: ff The following is the snippet from CList API: // append at the end $list[]=$item; // $index must be between 0 and $list->Count $list[$index]=$item; // remove the item at $index unset($list[$index]); // if the list has an item at $index if(isset($list[$index])) // traverse each item in the list foreach($list as $index=>$item) // returns the number of items in the list $n=count($list); ff CList is an integer-indexed collection. Compared to the native PHP array, it adds stricter checks, can be used in OO fashion, and allows to make a collection read-only: $list = new CList(); $list->add('python'); $list->add('php'); $list->add('java') if($list->contains('php')) $list->remove('java'); $anotherList = new CList(array('python', 'ruby')); $list->mergeWith($anotherList); $list->setReadOnly(true); print_r($list->toArray()); Under the Hood 30 ff There is another list collection named CTypedList that ensures that the list contains only items of a certain type: $typedList = new CTypedList('Post'); $typedList->add(new Post()); $typedList->add(new Comment()); As we are trying to add a comment to a posts list, the preceding code will give you the following exception: CTypedList can only hold objects of Post class. ff CMap allows using every value, integer or not, as a key. Just like in CList, it can also be used in the native PHP style, has almost the same set of OO-methods, and allows making a collection read only: $map = new CMap(); $map->add('php', array('facebook', 'wikipedia', 'wordpress', 'drupal')); $map->add('ruby', array('basecamp', 'twitter')); print_r($map->getKeys()); ff There is also one handy static method named CMap::mergeArray that can be used to recursively merge two associative arrays while replacing scalar values: $apps1 = array( 'apps' => array( 'task tracking', 'bug tracking', ), 'is_new' => false ); $apps2 = array( 'apps' => array( 'blog', 'task tracking', ), 'todo' => array( 'buy milk', ), 'is_new' => true ); $apps = CMap::mergeArray($apps1, $apps2); CVarDumper::dump($apps, 10, true); Chapter 1 31 The result of the preceding code is as follows: array ( 'apps' => array ( '0' => 'task tracking' '1' => 'bug tracking' '2' => 'blog' '3' => 'task tracking' ) 'is_new' => true 'todo' => array ( '0' => 'buy milk' ) ) ff CAttributeCollection includes all CMap functionality and can work with data just like properties: $col = new CAttributeCollection(); // $col->add('name','Alexander'); $col->name='Alexander'; // echo $col->itemAt('name'); echo $col->name; ff CQueue and CStack implement a queue and a stack respectively. A stack works as LIFO: last in, first out, and the queue is FIFO: first in, first out. Same as list and map collections these can be used in native PHP style and have OO style methods: $queue = new CQueue(); // add some tasks $queue->enqueue(new Task('buy milk')); $queue->enqueue(new Task('feed a cat')); $queue->enqueue(new Task('write yii cookbook')); // complete a task (remove from queue and return it) echo 'Done with '.$queue->dequeue(); echo count($queue).' items left.'; // return next item without removing it echo 'Next one is '.$queue->peek(); Under the Hood 32 foreach($queue as $task) print_r($task); $garage = new CStack(); // getting some cars into the garage $garage->push(new Car('Ferrari')); $garage->push(new Car('Porsche')); $garage->push(new Car('Kamaz')); // Ferrari and Porsche can't get out // since there is… echo $garage->peek(); // Kamaz! // we need to get Kamaz out first $garage->pop(); $porsche = $garage->pop(); $porsche->drive(); Working with request You can work with request data directly using PHP superglobals such as $_SERVER, $_GET, or $_POST but the better way is to use Yii powerful CHttpRequest class that resolves inconsistencies among different web servers, manages cookies, provides some additional security, and has a nice set of OO methods. How to do it… You can access the request component in your web application by using Yii::app()- >getRequest(). So, let's review the most useful methods and their usage, methods that return different parts of the current URL. In the following table, returned parts are marked with a bold font. getUrl http://cookbook.local/test/index?var=val getHostInfo http://cookbook.local/test/index?var=val getPathInfo http://cookbook.local/test/index?var=val getRequestUri http://cookbook.local/test/index?var=val getQueryString http://cookbook.local/test/index?var=val Chapter 1 33 The methods that allow us to ensure request type are getIsPostRequest, getIsAjaxRequest, and getRequestType. ff For example, we can use getIsAjaxRequest to serve different content based on request type: class TestController extends CController { public function actionIndex() { if(Yii::app()->request->isAjaxRequest)s $this->renderPartial('test'); else $this->render('test'); } } In the preceding code, we are rendering a view without layout if the request is made through AJAX. ff While PHP provides superglobals for both POST and GET, Yii way allows us to omit some additional checks: class TestController extends CController { public function actionIndex() { $request = Yii::app()->request; $param = $request->getParam('id', 1); // equals to $param = isset($_REQUEST['id']) ? $_REQUEST['id'] : 1; $param = $request->getQuery('id'); // equals to $param = isset($_GET['id']) ? $_GET['id'] : null; $param = $request->getPost('id', 1); // equals to $param = isset($_POST['id']) ? $_POST['id'] : 1; } } Under the Hood 34 ff getPreferredLanguage tries to determine the user's preferred language. It can't be completely accurate, but it is good to use it as a fallback in case the user has not specified a preferred language manually. class TestController extends CController { public function actionIndex() { $request = Yii::app()->request; $lang = $request->preferredLanguage; // trying to get language setting from DB $criteria = new CDbCriteria(); $criteria->compare('user_id', $request->getQuery('userid')); $criteria->compare('key', 'language'); $setting = Settings::model()->find($criteria); if($setting) $lang = $setting->value; Yii::app()->setLanguage($lang); echo Yii::t('app', 'Language is: ').$lang; } } ff sendFile allows to initiate file download as follows: class TestController extends CController { public function actionIndex() { $request = Yii::app()->getRequest(); $request->sendFile('test.txt', 'File content goes here.'); } } This action will trigger a file download and send all necessary headers, including content type (mimetype) and content length. Mimetype, if not set manually as a third parameter, will be guessed based on the filename's extension. ff The last thing we are going to show in this chapter is the getCookies method. It returns a CCookieCollection class instance that allows us to work with cookies. As CCookieCollection extends CMap, we can use some native PHP methods as follows: class TestController extends CController { public function actionIndex() Chapter 1 35 { $request = Yii::app()->request; // getting a cookie $cookie = $request->cookies['test']; if($cookie) // printing cookie value echo $cookie->value; else { // creating new cookie $cookie=new CHttpCookie('test','I am a cookie!'); $request->cookies['test'] = $cookie; } } There's more... If you are working with a lot of cookie values and want to shorten the code provided, then you can use a helper as follows: class Cookie { public static function get($name) { $cookie=Yii::app()->request->cookies[$name]; if(!$cookie) return null; return $cookie->value; } public static function set($name, $value, $expiration=0) { $cookie=new CHttpCookie($name,$value); $cookie->expire = $expiration; Yii::app()->request->cookies[$name]=$cookie; } } Under the Hood 36 After you drop this code into protected/components/Cookie.php, you will be able to perform the following: class TestController extends CController { public function actionIndex() { $cookie = Cookie::get('test'); if($cookie) echo $cookie; else Cookie::set('test','I am a cookie!!'); } } 2Router, Controller, and Views In this chapter, we will cover: ff Configuring URL rules ff Generating URLs by path ff Using regular expressions in URL rules ff Creating URL rules for static pages ff Providing your own URL rules at runtime ff Using base controller ff Using external actions ff Displaying static pages with CViewAction ff Using flash messages ff Using controller context in a view ff Reusing views with partials ff Using clips ff Using decorators ff Defining multiple layouts ff Paginating and sorting data Router, Controller, and Views 38 Introduction This chapter will help you to learn some handy things about Yii URL router, controllers, and views. You will be able to make your controllers and views more flexible. Configuring URL rules Yii URL router is quite powerful and does two main tasks: it resolves URLs into internal routes and creates URLs from these routes. Router rules description is scattered over the official Yii guide and API docs. Let's try to understand how to configure application rules by example. Getting ready 1. Create a fresh Yii application using yiic webapp as described in the official guide (http://www.yiiframework.com/doc/guide/) and find your protected/ config/main.php. It should contain the following: // application components 'components'=>array( … // uncomment the following to enable URLs in path-format /* 'urlManager'=>array( 'urlFormat'=>'path', 'rules'=>array( '/'=>'/view', '//'=>'/', '/'=>'/', ), ), 2. Delete everything from rules as we are going to start from scratch. 3. In your protected/controllers, create WebsiteController.php with the following code inside: class WebsiteController extends CController { public function actionIndex() { echo "index"; } Chapter 2 39 public function actionPage($alias) { echo "Page is $alias."; } } This is the application controller we are going to customize URLs for. 4. Configure your application server to use clean URLs. If you are using Apache with mod_rewrite and AllowOverride turned on, then you should add the following lines to the .htaccess file under your webroot folder: Options +FollowSymLinks IndexIgnore */* RewriteEngine on # if a directory or a file exists, use it directly RewriteCond %{REQUEST_FILENAME} !-f RewriteCond %{REQUEST_FILENAME} !-d # otherwise forward it to index.php RewriteRule . index.php How to do it... Our website should display the index page at /home and all other pages at /page/. Additionally, /about should lead to a page with alias about. 1. Add the following to your rules in protected/config/main.php: 'home' => 'website/index', '' => 'website/page', 'page/' => 'website/page', 2. After saving your changes, you should be able to browse the following URLs: ‰‰ /home ‰‰ /about ‰‰ /page/about ‰‰ /page/test Router, Controller, and Views 40 The following screenshot shows part of a page that opens when /about URL is used: How it works... Let's review what was done and why it works. We'll start with the right part of the first rule: 'home' => 'website/index', What is website/index exactly? In the Yii application, each controller and its actions have corresponding internal routes. A format for an internal route is moduleID/controllerID/actionID. For example, the actionPage method of WebsiteController corresponds to the website/page route. So, in order to get the controller ID, you should take its name without the Controller postfix and make its first letter lowercased. To get an action ID, you should take action method name without the action prefix and, again, make its first letter lowercased. Now, what is home? To understand it in a better way, we need to know, at least perfunctorily, what's happening when we access our application using different URLs. When we are using /home, URL router checks our rules one by one starting from the top trying to match URL entered with the rule. If the match is found, then the router is getting controller and its action from an internal route assigned to the rule and is executing it. So, /home is the URL pattern that defines which URLs will be processed by the rule it belongs to. The fewer rules you have, the fewer checks are needed if URL does not match. Less URLs means more performance. There's more... You can create parameterized rules using a special syntax. Let's review the third rule: 'page/' => 'website/page', Here, we are defining an alias parameter that should be specified in URL after /page/. It can be virtually anything and it will be passed as $alias parameter to WebsiteController::actionPage($alias). Chapter 2 41 You can define a pattern for such a parameter. We did it for the second rule: '' => 'website/page', Alias here should match about or else, the rule will not be applied. Further reading For further information, refer to the following URLs: ff http://www.yiiframework.com/doc/guide/en/basics.controller ff http://www.yiiframework.com/doc/guide/en/topics.url ff http://www.yiiframework.com/doc/api/1.1/CUrlManager See also ff The recipe named Generating URLs by path in this chapter ff The recipe named Using regular expressions in URL rules in this chapter ff The recipe named Creating URL rules for static pages in this chapter ff The recipe named Providing your own URL rules at runtime in this chapter Generating URLs by path Yii allows you not only to route your URLs to different controller actions but also to generate a URL by specifying a proper internal route and its parameters. This is really useful because you can focus on internal routes while developing your application and care about real URLs only before going live. Never specify URLs directly and use the Yii URL toolset. It will allow you to change URLs without rewriting a lot of application code. Getting ready 1. Create a fresh Yii application using yiic webapp as described in the official guide and find your protected/config/main.php. Replace rules array as follows: // application components 'components'=>array( … // uncomment the following to enable URLs in path-format /* Router, Controller, and Views 42 'urlManager'=>array( 'urlFormat'=>'path', 'rules'=>array( '' => 'website/page', 'page/about/' => 'website/page', 'page/' => 'website/page', ), 2. In your protected/controllers, create WebsiteController with the following code inside: class WebsiteController extends CController { public function actionIndex() { echo "index"; } public function actionPage($alias) { echo "Page is $alias."; } } This is our application controller that we are going to generate custom URLs for. 3. Configure your application server to use clean URLs. If you are using Apache with mod_rewrite and AllowOverride turned on, then you should add the following lines to the .htaccess file under your webroot folder: Options +FollowSymLinks IndexIgnore */* RewriteEngine on # if a directory or a file exists, use it directly RewriteCond %{REQUEST_FILENAME} !-f RewriteCond %{REQUEST_FILENAME} !-d # otherwise forward it to index.php RewriteRule . index.php How to do it... We need to generate URLs pointing to index and page actions of WebsiteController. Depending on where we need it, there are different ways for doing it, but the basics are the same. Let's list some methods that generate URLs. Chapter 2 43 CHtml::link() and some other CHtml methods such as form, refresh, and ajaxLink all accept URLs and are typically used in views. These are using CHtml::normalizeUrl internally to resolve internal routes. Therefore, you should pass data in one of the following formats: ff URL string: In this case, URL passed will be used as is. ff array(internal route, param => value, param => value, …). In this case, URL will be generated. What is internal route? Each controller and its actions have corresponding routes. A format for a route is moduleID/controllerID/actionID. For example, actionPage method of WebsiteController corresponds to website/page route. To get a controller ID, you should take its name without Controller postfix and make its first letter lowercased. To get an action ID, you should take action method name without action prefix and, again, make its first letter lowercased. Parameters are $_GET variables that will be passed to an action with internal route specified. For example, if we want to create a URL to WebsiteController::actionIndex that passes $_GET['name'] parameter to it, it can be done like this: echo CHtml::link('Click me!', array('website/index', 'name' => 'Qiang')); URLs are also helpful when using controller. Inside the controller, you can use createUrl and createAbsoluteUrl to get both relative and absolute URLs: class WebsiteController extends CController { public function actionTest() { echo $this->createUrl('website/page', 'alias' => 'about'); echo $this->createAbsoluteUrl('website/page', 'alias' => 'test'); } // the rest of the methods } As we have URL rules defined in the router configuration, we will get the following URLs: ff /about ff http://example.com/about Relative URLs can be used inside your application while absolute ones should be used for pointing to locations outside of your website (like other websites) or for linking to resources meant to be accessed from outside (RSS feeds, e-mails, and so on). Router, Controller, and Views 44 When you cannot get controller instance, for example, when you implement a console application, you can use application's methods: echo Yii::app()->createUrl('website/page', 'alias' => 'about'); echo Yii::app()->createAbsoluteUrl('website/page', 'alias' => 'test'); The difference is that when using controller-specific methods, you can omit both controller and module names. In this case, the current module name and the current controller name are used: class MyController extends CController { public function actionIndex() { // As we're inside of controller, createUrl will assume that URL // is for current controller echo $this->createUrl('index'); } } How it works... All URL building tools we have reviewed are internally using the CWebApplication:: createUrl method that is calling CUrlManager::createUrl. It tries to apply routing rules one by one starting from the top. If no rules are matched, then the default URL form is generated. There's more... For further information, refer to the following URLs: ff http://www.yiiframework.com/doc/guide/en/basics.controller ff http://www.yiiframework.com/doc/guide/en/topics.url ff http://www.yiiframework.com/doc/api/CUrlManager ff http://www.yiiframework.com/doc/api/CHtml/#normalizeUrl-detail ff http://www.yiiframework.com/doc/api/CHtml/#link-detail ff http://www.yiiframework.com/doc/api/CController/#createUrl- detail ff http://www.yiiframework.com/doc/api/CWebApplication/#createUrl- detail Chapter 2 45 See also ff The recipe named Configuring URL rules in this chapter ff The recipe named Using regular expressions in URL rules in this chapter ff The recipe named Creating URL rules for static pages in this chapter ff The recipe named Providing your own URL rules at runtime in this chapter Using regular expressions in URL rules One of the "hidden" features of Yii URL router is that you can use regular expressions that are pretty powerful when it comes to strings handling. Getting ready 1. Create a fresh Yii application using yiic webapp as described in the official guide and find your protected/config/main.php. It should contain the following: // application components 'components'=>array( … // uncomment the following to enable URLs in path-format /* 'urlManager'=>array( 'urlFormat'=>'path', 'rules'=>array( '/'=>'/view', '//'=>'/', '/'=>'/', ), ), 2. Delete everything from rules as we are going to start from scratch. 3. In your protected/controllers, create PostController.php with the following code inside: class PostController extends CController { public function actionView($alias) { echo "Showing post with alias $alias."; } Router, Controller, and Views 46 public function actionIndex($order = 'DESC') { echo "Showing posts ordered $order."; } public function actionHello($name) { echo "Hello, $name!"; } } This is our application controller we are going to access using our custom URLs. 4. Configure your application server to use clean URLs. If you are using Apache with mod_rewrite and AllowOverride turned on, then you should add the following lines to the .htaccess file under your webroot folder: Options +FollowSymLinks IndexIgnore */* RewriteEngine on # if a directory or a file exists, use it directly RewriteCond %{REQUEST_FILENAME} !-f RewriteCond %{REQUEST_FILENAME} !-d # otherwise forward it to index.php RewriteRule . index.php How to do it... We want our PostController actions to accept parameters according to some rules and give "404 not found" HTTP response for all parameters that do not match. In addition, post index should have an alias URL archive. Let's use regular expressions to achieve it: 'post/' => 'post/view', '(posts|archive)' => 'post/index', '(posts|archive)/' => 'post/index', 'sayhello/' => 'post/hello', Now, you can try the following URLs: // success http://example.com/post/test-post // fail Chapter 2 47 http://example.com/post/another_post // success http://example.com/posts // success http://example.com/archive // fail http://example.com/archive/test // success http://example.com/posts/ASC // success The following screenshot shows that the URL http://example.com/post/test-post has run successfully: The following screenshot shows that the URL http://example.com/archive/test did not run successfully and encountered an error: Router, Controller, and Views 48 How it works... You can use regular expressions in both parameter definition and the rest of the rule. Let's read our rules one by one. 'post/' => 'post/view', Alias parameter should contain one or more English letter or a dash. No other symbols are allowed. '(posts|archive)' => 'post/index', Both posts and archive are leading to post/index. '(posts|archive)/' => 'post/index', Both posts and archive are leading to post/index. Order parameter can only accept two values: DESC and ASC. 'sayhello/' => 'post/hello', You should specify the name part but there are no restrictions on what characters are allowed. Note that regardless of the rule used, the developer should never assume that input data is safe. There's more... To learn more about regular expressions, you can use the following sources: ff http://www.php.net/manual/en/reference.pcre.pattern.syntax.php ff Mastering Regular Expressions, by Jeffrey Friedl (http://regex.info/) See also ff The recipe named Configuring URL rules in this chapter ff The recipe named Creating URL rules for static pages in this chapter Creating URL rules for static pages A website typically contains some static pages. Usually, they are /about, /contact, /tos, and so on, and it is common to handle these pages in a single controller action. Let's find a way to create URL rules for these types of pages. Chapter 2 49 Getting ready 1. Create a fresh Yii application using yiic webapp as described in the official guide and find your protected/config/main.php. It should contain the following: // application components 'components'=>array( … // uncomment the following to enable URLs in path-format /* 'urlManager'=>array( 'urlFormat'=>'path', 'rules'=>array( '/'=>'/view', '//'=>'/', '/'=>'/', ), ), 2. Delete everything from rules as we are going to start from scratch. 3. In your protected/controllers, create WebsiteController with the following code: class WebsiteController extends CController { public function actionPage($alias) { echo "Page is $alias."; } } 4. Configure your application server to use clean URLs. If you are using Apache with mod_rewrite and AllowOverride turned on you should add the following lines to the .htaccess file under your webroot folder: Options +FollowSymLinks IndexIgnore */* RewriteEngine on # if a directory or a file exists, use it directly RewriteCond %{REQUEST_FILENAME} !-f RewriteCond %{REQUEST_FILENAME} !-d # otherwise forward it to index.php RewriteRule . index.php Router, Controller, and Views 50 How to do it... The most straightforward way is defining a rule for each page: '' => 'website/page', '' => 'website/page', '' => 'website/page', Using regular expressions, we can compact it to a single rule: '' => 'website/page', Now, what if we want the URL to be /tos and an alias parameter to be terms_of_service? No problem, we can use default parameters to achieve it: 'tos' => array('website/page', 'defaultParams' => array('alias' => 'terms_of_service')), OK. What if we have many pages and want to be able to dynamically create pages without adding more rules or changing existing ones? We can achieve this with the following rule: '' => 'website/page' As this rule matches everything, we need to place it last, so it won't affect all other rules. In addition, default rules with one slug, such as controller name will stop working. To overcome this issue, we need to add default rules which we deleted in the Getting ready section of this recipe. How it works... Let's read rules we just wrote. '' => 'website/page', If the URL is /about, then pass it as the alias parameter to website/page. '' => 'website/page', If the URL is /about or /contact or /tos, then pass it as the alias parameter to website/page. 'tos' => array('website/page', 'defaultParams' => array('alias' => 'terms_of_service')), When the URL is /tos, pass terms_of_service as the alias parameter value. Chapter 2 51 This rule is a bit special because it uses default parameter option. Default parameter allows you to set a value that will be used if parameter with name specified is omitted. When you need to specify an option for the rule, you should use an array notation: 'pattern' => array('internal/route', 'option' => 'value', 'option' => 'value', …), For a list of options you can set, refer to the following API page: http://www.yiiframework.com/doc/api/1.1/CUrlRule See also ff The recipe named Configuring URL rules in this chapter ff The recipe named Using regular expressions in URL rules in this chapter Providing your own URL rules at runtime When you are developing an application with pluggable module architecture, you most likely need to somehow inject your module-specific rules into an existing application. Getting ready 1. Set up a new application using yiic webapp. 2. Add .htaccess, shown in official URL Management guide to your webroot. 3. Add 'showScriptName' => false to your URL manager configuration. 4. Generate the page module using Gii. 5. Don't forget to add your new module to the modules list in your application configuration. Router, Controller, and Views 52 The Yii code generator is shown in the following screenshot: How to do it... 1. Create ModuleUrlManager.php in your protected/components directory with the following code inside: modules)) { foreach(Yii::app()->modules as $moduleName => $config) { $module = Yii::app()->getModule($moduleName); if(!empty($module->urlRules)) { Yii::app()->getUrlManager()->addRules ($module->urlRules); } } } Chapter 2 53 return true; } } 2. In your application configuration, add the following line: 'onBeginRequest' => array('ModuleUrlManager', 'collectRules'), 3. Now, in your page module, you can add custom rules. To do so, open PageModule. php and add: public $urlRules = array( 'test' => 'page/default/index', ); 4. To test if it works, open your browser and go to http://example.com/test. This page should look like the one shown in the following screenshot: This is the view content for action "index". The action belongs to the controller "DefaultController" in the "page" module. 5. You still can override URL rules from your main application configuration file. So, what you specify in module's urlRules is used only when the main application rules are not matching. How it works... Let's review the ModuleUrlManager::collectRules method. If there are modules defined in our application, then we are checking if urlRules public property exists. If it does, then there are some rules defined in the module and they are added using CUrlManager::addRules. Router, Controller, and Views 54 CUrlManager::addRules description says "In order to make the new rules effective, this method must be called before CWebApplication::processRequest". Now, let's check how our application works. In our index.php, we have the following line: Yii::createWebApplication($config)->run(); After being initialized with configuration, we are calling CWebApplication::run(): public function run() { if($this->hasEventHandler('onBeginRequest')) $this->onBeginRequest(new CEvent($this)); $this->processRequest(); if($this->hasEventHandler('onEndRequest')) $this->onEndRequest(new CEvent($this)); } As we can see, there is an onBeginRequest event raised just before calling processRequest. That is why we are attaching our class method to it. There's more... As instantiating all application modules on every request is not good for performance, it is good to cache module rules. Caching strategy can vary depending on your application. Let's implement a simple one: modules)) { $cache = Yii::app()->getCache(); foreach(Yii::app()->modules as $moduleName => $config) { $urlRules = false; if($cache) $urlRules = $cache->get('module.urls.'.$moduleName); if($urlRules===false){ $urlRules = array(); $module = Yii::app()->getModule($moduleName); Chapter 2 55 if(isset($module->urlRules)) $urlRules = $module->urlRules; if($cache) $cache->set('module.urls.'.$moduleName, $urlRules); } if(!empty($urlRules)) Yii::app()->getUrlManager()->addRules($urlRules); } } return true; } } This implementation caches URL rules per module. So, adding new modules is not a problem but changing existing ones requires you to flush cache manually using Yii::app()->cache->flush(). See also ff The recipe named Configuring URL rules in this chapter Using base controller In many frameworks, the concept of a base controller that is being extended by other ones is described right in the guide. In Yii, it is not in the guide as you can achieve flexibility in many other ways. Still, using base controller is possible and can be useful. Getting ready A new application using yiic webapp is to be set up. Let's say we want to add some controllers that will be accessible only when the user is logged in. We can surely set this constraint for each controller separately, but we will do it in a better way. How to do it... 1. First, we will need a base controller that our user-only controllers will use. Let's create SecureController.php in protected/components with the following code: array('@'), ), array('deny', 'users'=>array('*'), ), ); } } 2. Now, go to the Gii controller generator and enter SecureController into the Base Class field. You will get something like this: class TestController extends SecureController { public function actionIndex() { $this->render('index'); } … } 3. Now, your TestController index will be only accessible if the user is logged in, even though we have not declared it explicitly in the TestController class. How it works... The trick is nothing more than a basic class inheritance. If filters or accessRules is not found in TestController, then it will be called from SecureController. Chapter 2 57 Using external actions In Yii, you can define controller actions as separate classes and then connect them to your controllers. This way, you can reuse some common functionality. For example, you can move backend for autocomplete fields to an action and save some time by not having to write it over and over again. Another simple example that we will review is deleting a model. Getting ready 1. Set up a new application using yiic webapp. 2. Create a DB schema with the following script: CREATE TABLE `post` ( `id` int(10) unsigned NOT NULL auto_increment, `created_on` int(11) unsigned NOT NULL, `title` varchar(255) NOT NULL, `content` text NOT NULL, PRIMARY KEY (`id`) ); CREATE TABLE `user` ( `id` int(10) unsigned NOT NULL auto_increment, `username` varchar(200) NOT NULL, `password` char(40) NOT NULL, PRIMARY KEY (`id`) ); 3. Generate Post and User models using Gii. How to do it... 1. Let's write a usual delete action for posts first, as follows: class PostController extends CController { function actionIndex() { $posts = Post::model()->findAll(); $this->render('index', array( 'posts' => $posts, )); Router, Controller, and Views 58 } function actionDelete($id) { $post = Post::model()->findByPk($id); if(!$post) throw new CHttpException(404); if($post->delete()) $this->redirect('post/index'); throw new CHttpException(500); } } We have defined two actions. One lists all posts and another deletes a post specified if it exists and redirects back to index action. 2. Now, let's do the same in a separate action class. Create DeleteAction.php in your protected/components directory as follows: class DeleteAction extends CAction { function run() { if(empty($_GET['id'])) throw new CHttpException(404); $post = Post::model()->findByPk($_GET['id']); if(!$post) throw new CHttpException(404); if($post->delete()) $this->redirect('post/index'); throw new CHttpException(500); } } 3. Let's use it inside our controller. Delete actionDelete, we will not need it anymore. Then, add the actions method: class PostController extends CController { function actions() { Chapter 2 59 return array( 'delete' => 'DeleteAction', ); } … } 4. OK. Now, we are using external delete action for post controller, but what about the user controller? To use our DeleteAction with UserController we need to customize it first. We do this as follows: class DeleteAction extends CAction { public $pk = 'id'; public $redirectTo = 'index'; public $modelClass; function run() { if(empty($_GET[$this->pk])) throw new CHttpException(404); $model = CActiveRecord::model($this->modelClass) ->findByPk($_GET[$this->pk]); if(!$model) throw new CHttpException(404); if($model->delete()) $this->redirect($this->redirectTo); throw new CHttpException(500); } } 5. Now, we can use this action for both post controller and user controller. For post controller, we do this as follows: class PostController extends CController { function actions() { return array( 'delete' => array( Router, Controller, and Views 60 'class' => 'DeleteAction', 'modelClass' => 'Post', ); ); } … } 6. For user controller, we do this as follows: class UserController extends CController { function actions() { return array( 'delete' => array( 'class' => 'DeleteAction', 'modelClass' => 'User', ); ); } … } 7. This way, you can save yourself a lot of time by implementing and reusing external actions for tasks of a similar type. How it works... Every controller can be built from external actions like a puzzle from pieces. The difference is that you can make external actions very flexible and reuse them in many places. In the final version of DeleteAction, we defined some public properties. As DeleteAction is a component, we can set its properties through config. In our case, we pass config into the actions controller method used to add actions to a module. There's more… For further information, refer to the following URLs: ff http://www.yiiframework.com/doc/api/CAction/ ff http://www.yiiframework.com/doc/api/CController#actions-detail Chapter 2 61 Displaying static pages with CViewAction If you have a few static pages and aren't going to change them very frequently, then it's not worth querying database and implementing a page management for them. Getting ready Set up a new application using yiic webapp. How to do it... 1. We just need to connect CViewAction to our controller. class SiteController extends CController { function actions() { return array( 'page'=>array( 'class'=>'CViewAction', ), ); } } 2. Now, put your pages into protected/views/site/pages. Name them about.php and contact.php. 3. Now, you can try your pages by typing: http://example.com/index.php?r=site/page&view=contact Alternatively, you can type the following: http://example.com/site/page/view/about If you have configured clean URLs with path format. How it works... We are connecting external action named CViewAction that simply tries to find a view named the same as the $_GET parameter supplied. If it is there, it displays it. If not, then it will give you 404 Not found page. Router, Controller, and Views 62 There's more... There are some useful CViewAction parameters we can use. These are listed in the following table: Parameter name Description basePath It is a base path alias that is prepended to a view name. Default is pages. That means a page named faq.company will be translated to protected/views/pages/faq/company.php. defaultView It is a name of a page to render when there is no $_GET parameter supplied. Default is index. layout Layout used to render a page. By default, controller layout is used. If it is set to null, then no layout is applied. renderAsText If set to true, then the page will be rendered as is. Else, PHP inside will be executed. viewParam The name of the $_GET parameter used to pass page name to CViewAction. Default is view. Further reading For further information, refer to the following URL: http://www.yiiframework.com/doc/api/CViewAction See also ff The recipe named Using external actions in this chapter Using flash messages When you are editing a model with a form, when you are deleting a model, or doing any other operation, it is good to tell users if it went fine or if there was an error. Typically, after some kind of action, such as editing a form, a redirect will happen and we need to display a message on the page we want to go to. However, how to pass it from the current page to the redirect target and clean afterwards? Flash messages will help us. Getting ready Set up a new application using yiic webapp. Chapter 2 63 How to do it... 1. Let's create a protected/controllers/WebsiteController.php controller as follows: class WebsiteController extends CController { function actionOk() { Yii::app()->user->setFlash('success', 'Everything went fine!'); $this->redirect('index'); } function actionBad() { Yii::app()->user->setFlash('error', 'Everything went wrong!'); $this->redirect('index'); } function actionIndex() { $this->render('index'); } } 2. Additionally, create the protected/views/website/index.php view as follows: user->hasFlash('success')):?>
user->getFlash('success')?>
user->hasFlash('error')):?>
user->getFlash('error')?>
3. Now, if we go to http://example.com/website/ok, we'll be redirected to http://example.com/website/index and a success message will be displayed. Moreover, if we go to http://example.com/website/bad, we will be redirected to the same page, but with an error message. Refreshing the index page will hide the message. Router, Controller, and Views 64 How it works... We are setting a flash message with Yii::app()->user->setFlash('success', 'Everything went fine!'), for example, calling CWebUser::setFlash. Internally, it is saving a message into a user state, so in the lowest level, our message is being kept in $_SESSION until Yii::app()->user->getFlash('success') is called and the $_SESSION key is deleted. There's more… The following URL contains an API reference of CWebUser and will help you to understand flash messages better: http://www.yiiframework.com/doc/api/CWebUser Using controller context in a view Yii views are pretty powerful and have many features. One of them is that you can use controller context in a view. So, let's try it. Getting ready Set up a new application using yiic webapp. How to do it... 1. Create a controller as follows: class WebsiteController extends CController { function actionIndex() { $this->pageTitle = 'Controller context test'; $this->render('index'); } function hello() { if(!empty($_GET['name'])) echo 'Hello, '.$_GET['name'].'!'; } } Chapter 2 65 2. Now, we will create a view showing what we can do:

pageTitle?>

Hello call. hello()?>

widget('zii.widgets.CMenu',array( 'items'=>array( array('label'=>'Home', 'url'=>array('index')), array('label'=>'Yiiframework home', 'url'=>'http://yiiframework.ru/', ), ))?> How it works... We are using $this in a view to refer to a currently running controller. When doing it, we can call a controller method and access its properties. The most useful property is pageTitle which refers to the current page title and there are many built-in methods that are extremely useful in views such as renderPartials and widget. There's more… The following URL contains API documentation for CController where you can get a good list of methods you can use in your view: http://www.yiiframework.com/doc/api/CController Reusing views with partials Yii supports partials, so if you have a block without much logic that you want to reuse or want to implement e-mail templates, partials are the right way to look. Getting ready 1. Set up a new application using yiic webapp. 2. Create a WebsiteController as follows: class WebsiteController extends CController { function actionIndex() { $this->render('index'); } } Router, Controller, and Views 66 How to do it... We will start with a reusable block. For example, we need to embed a YouTube video at several website pages. Let's implement a reusable template for it. 1. Create a view file named protected/views/common/youtube.php and paste an embed code from YouTube. You will get something like: 2. Now, we need to make it reusable. We want to be able to set video ID, width, and height. Let's make width and height optional, as follows: 3. Now, you can use it in your protected/views/website/index.php like this: renderPartial('////common/youtube', array( 'id' => '8Rp-CaIKvQs', // you can get this id by simply looking at video URL 'width' => 320, 'height' => 256, ))?> Looks better, right? Note that we have used // to reference a view. This means that Yii will look for a view starting from protected/views not taking controller name into account. 4. Now, let's send some e-mails. As we are unable to write unique letters to thousands of users, we will use a template but will make it customized. Let's add a new method to protected/controllers/WebsiteController.php as follows: class WebsiteController extends CController { function actionSendmails() Chapter 2 67 { $users = User::model->findAll(); foreach($users as $user) { $this->sendEmail('welcome', $user->email, 'Welcome to the website!', array('user' => $user)); } echo 'Emails were sent.'; } function sendEmail($template, $to, $subject, $data) { mail($to, $subject, $this->renderPartial ('//email/'.$template, $data, true)); } } 5. Here is our template protected/views/email/welcome.php: Hello name?>, Welcome to the website! You can go check our new videos section. There are funny raccoons. Yours, Website team. How it works... CController::renderPartial does the same template processing as CController::render except the former does not use layout. As we can access current controller in a view using $this, we can use its renderPartial to use view within another view. renderPartial is also useful when dealing with AJAX as you don't need layout rendered in this case. There's more… For further information, refer to the following URL: http://www.yiiframework.com/doc/api/CController/#renderPartial-detail See also ff The recipe named Using controller context in a view in this chapter Router, Controller, and Views 68 Using clips One of the Yii features you can use in your views is clips. The basic idea is that you can record some output and then reuse it later in a view. A good example will be defining additional content regions for your layout and filling them elsewhere. Getting ready Set up a new application using yiic webapp. How to do it... 1. For our example, we need to define two regions in our layout: beforeContent and footer. Open protected/views/layouts/main.php and insert the following just before the content output (): clips['beforeContent'])) echo $this->clips['beforeContent']?> Then, insert the following into
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