Zend_Rest_Client

Introduction

Using the Zend_Rest_Client is very similar to using SoapClient objects (» SOAP web service extension). You can simply call the REST service procedures as Zend_Rest_Client methods. Specify the service's full address in the Zend_Rest_Client constructor.

Example #1 A basic REST request

  1. /**
  2. * Connect to framework.zend.com server and retrieve a greeting
  3. */
  4. $client = new Zend_Rest_Client('http://framework.zend.com/rest');
  5.  
  6. echo $client->sayHello('Davey', 'Day')->get(); // "Hello Davey, Good Day"

Note: Differences in calling
Zend_Rest_Client attempts to make remote methods look as much like native methods as possible, the only difference being that you must follow the method call with one of either get(), post(), put() or delete(). This call may be made via method chaining or in separate method calls:

  1. $client->sayHello('Davey', 'Day');
  2. echo $client->get();

Responses

All requests made using Zend_Rest_Client return a Zend_Rest_Client_Response object. This object has many properties that make it easier to access the results.

When the service is based on Zend_Rest_Server, Zend_Rest_Client can make several assumptions about the response, including response status (success or failure) and return type.

Example #2 Response Status

  1. $result = $client->sayHello('Davey', 'Day')->get();
  2.  
  3. if ($result->isSuccess()) {
  4.     echo $result; // "Hello Davey, Good Day"
  5. }

In the example above, you can see that we use the request result as an object, to call isSuccess(), and then because of __toString(), we can simply echo the object to get the result. Zend_Rest_Client_Response will allow you to echo any scalar value. For complex types, you can use either array or object notation.

If however, you wish to query a service not using Zend_Rest_Server the Zend_Rest_Client_Response object will behave more like a SimpleXMLElement. However, to make things easier, it will automatically query the XML using XPath if the property is not a direct descendant of the document root element. Additionally, if you access a property as a method, you will receive the PHP value for the object, or an array of PHP value results.

Example #3 Using Technorati's Rest Service

  1. $technorati = new Zend_Rest_Client('http://api.technorati.com/bloginfo');
  2. $technorati->key($key);
  3. $technorati->url('http://pixelated-dreams.com');
  4. $result = $technorati->get();
  5. echo $result->firstname() .' '. $result->lastname();

Example #4 Example Technorati Response

  1. <?xml version="1.0" encoding="utf-8"?>
  2. <!-- generator="Technorati API version 1.0 /bloginfo" -->
  3. <!DOCTYPE tapi PUBLIC "-//Technorati, Inc.//DTD TAPI 0.02//EN"
  4.                       "http://api.technorati.com/dtd/tapi-002.xml">
  5. <tapi version="1.0">
  6.     <document>
  7.         <result>
  8.             <url>http://pixelated-dreams.com</url>
  9.             <weblog>
  10.                 <name>Pixelated Dreams</name>
  11.                 <url>http://pixelated-dreams.com</url>
  12.                 <author>
  13.                     <username>DShafik</username>
  14.                     <firstname>Davey</firstname>
  15.                     <lastname>Shafik</lastname>
  16.                 </author>
  17.                 <rssurl>
  18.                     http://pixelated-dreams.com/feeds/index.rss2
  19.                 </rssurl>
  20.                 <atomurl>
  21.                     http://pixelated-dreams.com/feeds/atom.xml
  22.                 </atomurl>
  23.                 <inboundblogs>44</inboundblogs>
  24.                 <inboundlinks>218</inboundlinks>
  25.                 <lastupdate>2006-04-26 04:36:36 GMT</lastupdate>
  26.                 <rank>60635</rank>
  27.             </weblog>
  28.             <inboundblogs>44</inboundblogs>
  29.             <inboundlinks>218</inboundlinks>
  30.         </result>
  31.     </document>
  32. </tapi>

Here we are accessing the firstname and lastname properties. Even though these are not top-level elements, they are automatically returned when accessed by name.

Note: Multiple items
If multiple items are found when accessing a value by name, an array of SimpleXMLElements will be returned; accessing via method notation will return an array of PHP values.

Request Arguments

Unless you are making a request to a Zend_Rest_Server based service, chances are you will need to send multiple arguments with your request. This is done by calling a method with the name of the argument, passing in the value as the first (and only) argument. Each of these method calls returns the object itself, allowing for chaining, or "fluent" usage. The first call, or the first argument if you pass in more than one argument, is always assumed to be the method when calling a Zend_Rest_Server service.

Example #5 Setting Request Arguments

  1. $client = new Zend_Rest_Client('http://example.org/rest');
  2.  
  3. $client->arg('value1');
  4. $client->arg2('value2');
  5. $client->get();
  6.  
  7. // or
  8.  
  9. $client->arg('value1')->arg2('value2')->get();

Both of the methods in the example above, will result in the following get args: ?method=arg&arg1=value1&arg=value1&arg2=value2

You will notice that the first call of $client->arg('value1'); resulted in both method=arg&arg1=value1 and arg=value1; this is so that Zend_Rest_Server can understand the request properly, rather than requiring pre-existing knowledge of the service.

Warning

Strictness of Zend_Rest_Client

Any REST service that is strict about the arguments it receives will likely fail using Zend_Rest_Client, because of the behavior described above. This is not a common practice and should not cause problems.

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