A Practical Tutorial Of Zend Framework(一)

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:

$ wget http://framework.zend.com/download/tgz
$ tar -xvzf ZendFramework-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:

RewriteEngine on
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:

<?php

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:

<?php

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.