Zend Framework 入门教程

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A Practical Tutorial
Last Update: Mar. 11, 2006

The Zend Framework has been unveiled! Although it is still in the early stages of development, this tutorial highlights some of the best of what's available now and guides you through the process of building a simple application.

Zend has chosen to release the framework and involve the community early. In the same spirit, this tutorial is written to showcase the framework as it exists today. Because this tutorial is published online, I'll update it as the framework evolves, so that it remains relevant as long as possible.

Requirements

The Zend Framework requires PHP 5. In order to take full advantage of the code presented in this tutorial, you also need the Apache web server, because the sample application (a news management system) uses mod_rewrite .

The code from this tutorial is available for free download, so you can try it out for yourself. You can download it from the Brain Bulb web site at http://brainbulb.com/zend-framework-tutorial.tar.gz.

Downloading the Framework

Before you can get started with this tutorial, you need to download the preview release of the framework. You can do this manually by visiting http://framework.zend.com/download with a browser and choosing the tar.gz or zip download, or you can use the command line:

$wgethttp://framework.zend.com/download/tgz
$tar-xvzfZendFramework-0.1.2.tar.gz

Note: Zend has plans to offer its own PEAR channel to help simplify the download process.

Once you have the preview release, locate the library directory and place it somewhere convenient. In this tutorial, I rename library to lib to provide a clean and simple directory structure:

app/
views/
controllers/
www/
.htaccess
index.php
lib/

The www directory is the document root, controllers and views are empty directories you'll use later, and the lib directory is from the preview release download.

Getting Started

The first component I want to show you is Zend_Controller . In many ways, it provides the foundation of the application you're developing, and it's also part of what makes the Zend Framework more than just a collection of components. Before you can use it, however, you need to direct all incoming requests to a single PHP script. This tutorial uses mod_rewrite for this purpose.

Using mod_rewrite is an art in itself, but luckily, this particular task is very simple. If you're unfamiliar with mod_rewrite or configuring Apache in general, create a .htaccess file in the document root and add the following directives:

RewriteEngineon
RewriteRule!\.(js|ico|gif|jpg|png|css)$index.php

Note: One of the TODO items for Zend_Controller is to remove the mod_rewrite dependency. In order to provide an example that works with the preview release, this tutorial uses mod_rewrite .

If you add these directives to httpd.conf directly, you must restart the web server. Otherwise, if you use a .htaccess file, you should be good to go. You can quickly test this by placing some identifiable text in index.php and making a request for an arbitrary path such as /foo/bar . For example, if your host is example.org , request the URL http://example.org/foo/bar.

You also want include_path to include the path to the framework library. You can do this in php.ini , or you can just put the following directive in your .htaccess file:

php_value include_path "/path/to/lib"

Zend

The Zend class contains a collection of static methods that are universally useful. This is the only class you must include manually:

include 'Zend.php' ;

?>

Once you've included Zend.php , you have access to all of the methods from the Zend class. Loading other classes is simplified with the loadClass() method. For example, to load the Zend_Controller_Front class:

include 'Zend.php' ;

Zend :: loadClass ( 'Zend_Controller_Front' );

?>

The loadclass() method is include_path aware, and it also understands the organization and directory structure of the framework. I use it to load all other classes.

Zend_Controller

Using the controller is pretty intuitive. In fact, I'm writing this tutorial without the luxury of documentation!

Note: Documentation is now available at http://framework.zend.com/manual/zend.controller.html.

I begin with Zend_Controller_Front , a front controller. In order to begin understanding how it works, place the following code in your index.php file:

include 'Zend.php' ;

Zend :: loadClass ( 'Zend_Controller_Front' );

$controller = Zend_Controller_Front :: getInstance ();
$controller -> setControllerDirectory ( '/path/to/controllers' );
$controller -> dispatch ();

?>

If you prefer object chaining, this can instead be written as:

include 'Zend.php' ;

Zend :: loadClass ( 'Zend_Controller_Front' );

$controller = Zend_Controller_Front :: getInstance ()
-> setControllerDirectory ( '/path/to/controllers' )
-> dispatch ();

?>

Now when you make a request for /foo/bar , you get an error. That's good! It lets you know something is happening. The major complaint is that IndexController.php is not found.

Before you create this file, it's helpful to understand how the framework expects you to organize things. The framework breaks a request down into parts, and in the case of a request for /foo/bar , foo is the controller, and bar is the action. The default value for each is index .

When foo is the controller, the framework looks for a file called FooController.php in the controllers directory. Because this does not exist, the framework falls back to IndexController.php . Not finding either, it reports the error.

To continue, create IndexController.php in the controllers directory (which you set with setControllerDirectory() ):

Zend :: loadClass ( 'Zend_Controller_Action' );

class IndexController extends Zend_Controller_Action
{
publicfunction indexAction ()
{
echo 'IndexController::indexAction()' ;
}
}

?>

The IndexController class handles requests for which the controller is index or for which the indicated controller does not exist, as just explained. The indexAction() method handles requests for which the action is index . Remember that index is the default value for both the controller and the action. If you try a request for / , /index , or /index/index , the indexAction() method is executed. (Trailing slashes do not alter this behavior.) A request for any other resource is going to result in an error.

There is another useful method to add to IndexController before continuing. The noRouteAction() method is called whenever a request is made for a controller that doesn't exist. For example, a request for /foo/bar executes noRouteAction() if FooController.php does not exist. However, a request for /index/foo still results in an error, because foo is the action, not the controller.

Add noRouteAction() to IndexController.php :

Zend :: loadClass ( 'Zend_Controller_Action' );

class IndexController extends Zend_Controller_Action
{
publicfunction indexAction ()
{
echo 'IndexController::indexAction()' ;
}

publicfunction noRouteAction ()
{
$this -> _redirect ( '/' );
}
}

?>

This example uses $this->_redirect('/') to illustrate a possible action to take in noRouteAction() . This causes requests for nonexistent controllers to be redirected to the root document (front page).

Now create FooController.php :

Zend :: loadClass ( 'Zend_Controller_Action' );

class FooController extends Zend_Controller_Action
{
publicfunction indexAction ()
{
echo 'FooController::indexAction()' ;
}

publicfunction barAction ()
{
echo 'FooController::barAction()' ;
}
}

?>

If you again request /foo/bar , you should see that barAction() is being executed, because bar is the action. Not only can you already support friendly URLs, but you can also do so in a very organized way with just a few lines of code. Cool!

You can also create a __call() method to handle requests for undefined actions such as /foo/baz :

Zend :: loadClass ( 'Zend_Controller_Action' );

class FooController extends Zend_Controller_Action
{
publicfunction indexAction ()
{
echo 'FooController::indexAction()' ;
}

publicfunction barAction ()
{
echo 'FooController::barAction()' ;
}

publicfunction __call ( $action , $arguments )
{
echo 'FooController:__call()' ;
}
}

?>

Now that you can elegantly handle incoming requests with just a few lines of code, you are ready to continue.

Zend_View

Zend_View is a class that helps you organize your view logic. It is template-system agnostic, and for the sake of simplicity, I don't use a template system in this tutorial. You're free to use one if you prefer.

Keep in mind that all incoming requests are now handled by the front controller. Therefore, the framework of the application already exists, and further additions must conform to it. In order to demonstrate a very basic use of Zend_View , change the code in IndexController.php as follows:

Zend :: loadClass ( 'Zend_Controller_Action' );
Zend :: loadClass ( 'Zend_View' );

class IndexController extends Zend_Controller_Action
{
publicfunction indexAction ()
{
$view =new Zend_View ();
$view -> setScriptPath ( '/path/to/views' );
echo $view -> render ( 'example.php' );
}

publicfunction noRouteAction ()
{
$this -> _redirect ( '/' );
}
}

?>

Create a file called example.php in the views directory:

Thisisanexample.

Now, when you request your web site's root resource, you should see the contents of example.php . This isn't very useful yet, but keep in mind that you're working toward a very structured and organized way to develop web applications.

In order to make the use of Zend_View a bit clearer, modify your template ( example.php ) to include some data:

echo $this -> escape ( $this -> body ); ?>

Two additional features have been added. The $this->escape() method must be used on all output. Even if you create the output yourself, which is going to be the case in this example, escaping all output is a very good habit that can help you prevent cross-site scripting (XSS) vulnerabilities by default.

The $this->title and $this->body properties exist to demonstrate dynamic data. These should be defined in the controller, so modify IndexController.php to assign them:

Zend :: loadClass ( 'Zend_Controller_Action' );
Zend :: loadClass ( 'Zend_View' );

class IndexController extends Zend_Controller_Action
{
publicfunction indexAction ()
{
$view =new Zend_View ();
$view -> setScriptPath ( '/path/to/views' );
$view -> title = 'DynamicTitle' ;
$view -> body = 'Thisisadynamicbody.' ;
echo $view -> render ( 'example.php' );
}

publicfunction noRouteAction ()
{
$this -> _redirect ( '/' );
}
}

?>

Now you should see these values being used by the template when you again visit your web site's root directory. The reason you use $this in the template is that it is executed within the scope of the Zend_View instance.

Keep in mind that example.php is just an ordinary PHP script, so you can do anything you want. Just try to be disciplined enough to limit your use of templates to only what is required to display data. Your controller (or a module to which the controller dispatches) should handle all of your business logic.

I want to make one final note about Zend_View before continuing. Instantiating the $view object within each method of the controller requires a lot of extra typing, and our primary goal is to make it easier to quickly develop web applications. It's also a hassle to call setScriptPath() in each case if all of the templates reside in a single directory.

Luckily, the Zend class includes a registry that helps you eliminate this overhead. You can store your $view object in the registry by using the register() method:

Zend :: register ( 'view' , $view );

?>

To retrieve it, use the registry() method:

$view = Zend :: registry ( 'view' );

?>

From this point forward, this tutorial uses the registry.

Zend_InputFilter

The last component this tutorial covers is Zend_InputFilter . This class provides a simple but rigid approach to input filtering. You instantiate it by passing an array of data to be filtered:

$filterPost =new Zend_InputFilter ( $_POST );

?>

This sets the array ( $_POST ) to NULL , so direct access is no longer possible. Zend_InputFilter instead provides a small, focused collection of methods that filter data according to specific criteria. For example, if you want the alphabetic characters of $_POST['name' ], you can use the getAlpha() method:

/*$_POST['name']='John123Doe';*/

$filterPost =new Zend_InputFilter ( $_POST );

/*$_POST=NULL;*/