Zend Framework

Bertha 。 2022-09-26 01:55 503阅读 0赞

以前有AMFPHP的很好用,最近在搞zend+flex的，E的以后在翻译吧

http://blog.log2e.com/2008/11/26/whats-in-the-zend-framework-for-the-flashflex-developer/

## What’s in the Zend Framework for the Flash/Flex Developer? ##

The 1.7 release of the [Zend Framework][] includes the new [Zend\_Amf][Zend_Amf] package which provides a gateway server implementation for AMF remoting.  By the time of writing this article, there are not many resources available yet (a good starting point is [here][] ), and the few tutorials mostly guide you through the process of setting up the bootstrap file and establishing a MySQL database connection by using `mysql_connect()` directly in the service classes.

I would like to introduce a Zend AMF server setup that makes use of some of Zend’s best practices like configuration files, database adapters and models. If you are a Flash/Flex developer coming from an [AMFPHP][] background and have never worked with the Zend framework before, you may easily feel overwhelmed by the framework’s complexity. This article is not meant to present a thourough overview of all Zend features you could possibly utilize in your Flex/Flash development work, but it might motivate you to dive deeper into the framework’s features.

### The Folder Structure ###

First of all, even if I only need the AMF server from the Zend framework I set up my server directories like I would do with any other Zend/PHP application. If you already have some experience with the Zend framework this folder structure probably looks familiar to you:

[![Zend Framework Folder Structure][] ][Zend Framework Folder Structure]

This is a rudimentary folder structure, of course, because a typical Zend application with an HTML frontend has additional folders for controllers, views, layouts, forms, plugins, helpers, etc. But the basic setup is the same: We have an *application* and a *library* folder that are outside the web server’s root directory (*public* ). The Zend framework packages are inside the *library* folder, and below the *application* folder there are a *config* and a *models* folder. For the special purpose of the AMF gateway, I added a *services* folder which is supposed to contain all service class files.

### The Database and the Configuration File ###

Let’s assume we are working on an application that needs to manage user accounts. A very basic table would look like this:

CREATE TABLE users (

1.    id int ( 11 ) NOT NULL AUTO\_INCREMENT ,
2.    username varchar ( 32 ) NOT NULL DEFAULT '' ,
3.    password varchar ( 32 ) NOT NULL DEFAULT '' ,
4.    email varchar ( 255 ) NOT NULL DEFAULT '' ,
5.    firstname varchar ( 50 ) NOT NULL DEFAULT '' ,
6.    lastname varchar ( 50 ) NOT NULL DEFAULT '' ,
7.    PRIMARY KEY ( id )
8.  ) ;

The database credentials are stored in an INI file (*app.ini* ). In this example there are configuration data for both a production system and a development system. Because the development system configuration data are very similar to those for production, the development section inherits from the production section:

1.  \[ production\]
2.  database. adapter  =  PDO\_MYSQL
3.  database.params. host  =  localhost
4.  database.params. dbname  =  prod\_dbname
5.  database.params. username  =  dbusername
6.  database.params. password  =  dbpassword
7.   
8.  \[ development : production\]
9.  database.params. dbname  =  dev\_dbname

This configuration file also allows you to easily change the database adapter (if needed).

### The Bootstrap File ###

Let’s take a look at the bootstrap file (*index.php* ):

<?php

1.  define ( 'APPLICATION\_PATH' , realpath ( dirname ( \_\_FILE\_\_ ) . '/../application/' ) ) ;
2.   
3.  set\_include\_path (
4.      get\_include\_path ( )
5.      . PATH\_SEPARATOR . APPLICATION\_PATH . '/../library/'
6.      . PATH\_SEPARATOR . APPLICATION\_PATH . '/services/'
7.      . PATH\_SEPARATOR . APPLICATION\_PATH . '/models/'
8.  ) ;
9.   
10. require\_once 'Zend/Loader.php' ;
11. Zend\_Loader :: registerAutoload ( ) ;
12.  
13. $server = new Zend\_Amf\_Server ( ) ;
14. $server \-> setClass ( 'UsersService' ) ;
15. $server \-> setClassMap ( 'UserVO' , 'User' ) ;
16. $server \-> setProduction ( false ) ;
17.  
18. echo ( $server \-> handle ( ) ) ;

This bootstrap file is very similar to the standard bootstrap files you find in other tutorials or in the Zend Reference Guide. It adds some include paths, initializes the Zend autoload feature for classes, and sets up the AMF server.

### The Service Classes ###

Utilizing the *Zend\_Config* and *Zend\_Db* packages, we set up the database connection in a base service class that the actual service classes inherit from. In line 7 in the listing below we provide a default database adapter for all subsequent instances of *Zend\_Db\_Table* objects in our application (for more information, please refer to the [Zend\_Db chapter][Zend_Db chapter] in the Reference Guide). This way we keep the logic of creating a database connection in one central place.

<?php

1.  class BaseService
2.  \{ 
3.      public function \_\_construct ( )
4.      \{   
5.        $configuration = new Zend\_Config\_Ini ( APPLICATION\_PATH . '/config/app.ini' , 'development' ) ;    
6.        $dbAdapter = Zend\_Db :: factory ( $configuration \-> database ) ;  
7.        Zend\_Db\_Table\_Abstract :: setDefaultAdapter ( $dbAdapter ) ;
8.      \}
9.  \}

The only real service class in our example is *UsersService* which extends *BaseService* and invokes the parent class’s constructor by calling `parent::__construct();` . For the sake of simplicity it contains only one method (`getUsers()` ):

<?php

1.  class UsersService extends BaseService
2.  \{   
3.      public function \_\_construct ( )
4.      \{ 
5.        parent :: \_\_construct ( ) ;
6.      \}
7.   
8.      public function getUsers ( )
9.      \{ 
10.       $usersArray = array ( ) ;
11.  
12.       $table = new Users ( ) ;
13.       $result = $table \-> fetchAll ( ) ;
14.  
15.       foreach ( $result as $row )
16.       \{   
17.           $user = new User ( ) ;
18.           $user \-> id = $row \-> id ;
19.           $user \-> username = $row \-> username ;
20.           $user \-> email = $row \-> email ;
21.           $user \-> firstname = $row \-> firstname ;
22.           $user \-> lastname = $row \-> lastname ;
23.           array\_push ( $usersArray , $user ) ;
24.       \}
25.       return $usersArray ;
26.     \}
27. \}

You may wonder what the *Users* class does (line 12 in the above code listing). Here’s the answer: It’s a model class.

### The Model Class ###

Models are another important concept of the Zend framework. Although the classical MVC pattern doesn’t apply in the context of the Zend AMF server, I stick to this concept here because it may come in handy sometimes. Imagine an application that is supposed to support both a Flash and an HTML interface. By following the framework’s MVC guidelines, we are able to build an application engine that uses the same model classes for both the AMF server gateway and the MVC-based HTML frontend.

The class *Users* is located in the *models* folder. It extends *Zend\_Db\_Table* and holds the name of the corresponding database table:

<?php

1.  class Users extends Zend\_Db\_Table
2.  \{ 
3.     protected $\_name = 'users' ;
4.  \}

Remember that we provided an application-wide database adapter for all *Zend\_Db\_Table* objects (see line 7 in the *BaseService* class). By creating an instance of *Users* (which inherits all methods from *Zend\_Db\_Table* ) we are able to use `fetchAll()` to retrieve all rows from the table *users* .

### The Value Object Class ###

The class *User* (see line 17 in the *UsersService* code listing) is a helper class that allows us to send an array of typed objects to the Flash player. This is especially useful in Flex-based applications where you want to use value objects for data-binding, for example. By the way, the class *User* doesn’t look any different than a VO class in an [AMFPHP][] context.

<?php

1.  class User \{ 
2.      public $id = 0 ;
3.      public $username = '' ;
4.      public $password = '' ;
5.      public $firstname = '' ;
6.      public $lastnamne = '' ;
7.      public $email = '' ;
8.  \}

By calling `$server->setClassMap('UserVO','User');` inside the bootstrap file, the *User* objects are mapped to *UserVO* .

I skip the Flex/Flash part here because this topic is well covered in other tutorials. But I hope you caught a glimpse of how you can leverage the power of other components inside the Zend framework – even if you are only interested in the Zend AMF server. There are more scenarios where the Zend framework may come in handy for a Flash/Flex developer (for example, think of generating PDF files on the fly by using *Zend\_Pdf* ).

Tags: [AMFPHP][AMFPHP 1] , [Flash][] , [Flex][] , [Zend][] , [Zend Amf][]

[Zend Framework]: http://framework.zend.com/
[Zend_Amf]: http://framework.zend.com/manual/en/zend.amf.html
[here]: http://diamondtearz.org/blog/zend_amf-collection/
[AMFPHP]: http://www.amfphp.org/
[Zend Framework Folder Structure]: http://blog.log2e.com/wp-content/uploads/2008/11/zend_amf_setup.gif
[Zend_Db chapter]: http://framework.zend.com/manual/en/zend.db.table.html
[AMFPHP 1]: http://blog.log2e.com/tag/amfphp/
[Flash]: http://blog.log2e.com/tag/flash/
[Flex]: http://blog.log2e.com/tag/flex/
[Zend]: http://blog.log2e.com/tag/zend/
[Zend Amf]: http://blog.log2e.com/tag/zend-amf/