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
/**
* Connect to framework.zend.com server and retrieve a greeting
*/
$client = new Zend_Rest_Client('http://framework.zend.com/rest');
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:
$client->sayHello('Davey', 'Day');
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
$result = $client->sayHello('Davey', 'Day')->get();
if ($result->isSuccess()) {
echo $result;
// "Hello Davey, Good Day"
}
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
$technorati = new Zend_Rest_Client('http://api.technorati.com/bloginfo');
$technorati->key($key);
$technorati->url('http://pixelated-dreams.com');
$result = $technorati->get();
echo $result->
firstname() .
' '.
$result->
lastname();
Example #4 Example Technorati Response
<?xml version="1.0" encoding="utf-8"?>
<!-- generator="Technorati API version 1.0 /bloginfo" -->
<!DOCTYPE tapi PUBLIC "-//Technorati, Inc.//DTD TAPI 0.02//EN"
"http://api.technorati.com/dtd/tapi-002.xml">
<tapi version="1.0">
<document>
<result>
<url>http://pixelated-dreams.com</url>
<weblog>
<name>Pixelated Dreams</name>
<url>http://pixelated-dreams.com</url>
<author>
<username>DShafik</username>
<firstname>Davey</firstname>
<lastname>Shafik</lastname>
</author>
<rssurl>
http://pixelated-dreams.com/feeds/index.rss2
</rssurl>
<atomurl>
http://pixelated-dreams.com/feeds/atom.xml
</atomurl>
<inboundblogs>44</inboundblogs>
<inboundlinks>218</inboundlinks>
<lastupdate>2006-04-26 04:36:36 GMT</lastupdate>
<rank>60635</rank>
</weblog>
<inboundblogs>44</inboundblogs>
<inboundlinks>218</inboundlinks>
</result>
</document>
</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
$client = new Zend_Rest_Client('http://example.org/rest');
$client->arg('value1');
$client->arg2('value2');
$client->get();
// or
$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.
WarningStrictness 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.