Table of Contents
Zend_Http_Client provides an easy interface for preforming Hyper-Text Transfer Protocol (HTTP) requests. Zend_Http_Client supports most simple features expected from an HTTP client, as well as some more complex features such as HTTP authentication and file uploads. Successful requests (and most unsuccessful ones too) return a Zend_Http_Response object, which provides access to the response's headers and body (see Section 15.5, “Zend_Http_Response”).
The class constructor optionally accepts a URL as it's first parameter (can be either a string or a Zend_Uri_Http object), and an optional array of configuration parameters. Both can be left out, and set later using the setUri() and setConfig() methods.
Example 15.1. Instantiating a Zend_Http_Client object
<?php
require_once 'Zend/Http/Client.php';
$client = new Zend_Http_Client('http://example.org', array(
'maxredirects' => 0,
'timeout' => 30));
// This is actually exactly the same:
$client = new Zend_Http_Client();
$client->setUri('http://example.org');
$client->setConfig(array(
'maxredirects' => 0,
'timeout' => 30));
?>
The constructor and setConfig() method accept an associative array of configuration parameters. Setting these parameters is optional, as they all have default values.
Table 15.1. Zend_Http_Client configuration parameters
| Parameter | Description | Expected Values | Default Value |
|---|---|---|---|
| maxredirects | Maximum number of redirections to follow (0 = none) | integer | 5 |
| strictredirects | Whether to strictly follow the RFC when redirecting (see Section 15.2.1, “HTTP Redirections”) | boolean | false |
| useragent | User agent identifier string (sent in request headers) | string | 'Zend_Http_Client' |
| timeout | Connection timeout (seconds) | integer | 10 |
| httpversion | HTTP protocol version | float (1.1 or 1.0) | 1.1 |
| adapter | Connection adapter class to use (see Section 15.3, “Zend_Http_Client - Connection Adapters”) | mixed | 'Zend_Http_Client_Adapter_Socket' |
| keepalive | Whether to enable keep-alive connections with the server. Useful and might improve performance if several consecutive requests to the same server are performned. | boolean | false |
Performing simple HTTP requests is very easily done using the request() method, and rarely needs more than three lines of code:
Example 15.2. Preforming a Simple GET Request
<?php
require_once 'Zend/Http/Client.php';
$client = new Zend_Http_Client('http://example.org');
$response = $client->request();
?>
The request() method takes one optional parameter - the request method. This can be either GET, POST, PUT, HEAD, DELETE, TRACE, OPTIONS or CONNECT as defined by the HTTP protocol [1]. For convenience, these are all defined as class constants: Zend_Http_Request::GET, Zend_Http_Request::POST and so on.
If no method is specified, the method set by the last setMethod() call is used. If setMethod() was never called, the default request method is GET (see the above example).
Example 15.3. Using Request Methods Other Than GET
<?php
// Preforming a POST request
$response = $client->request('POST');
// Yet another way of preforming a POST request
$client->setMethod(Zend_Http_Client::POST);
$response = $client->request();
?>
Adding GET parameters to an HTTP request is quite simple, and can be done either by specifying them as part of the URL, or by using the setParameterGet() method. This method takes the GET parameter's name as it's first parameter, and the GET parameter's value as it's second parameter. For convenience, the setParameterGet() method can also accept a single associative array of name => value GET variables - which may be more comfortable when several GET parameters need to be set.
Example 15.4. Setting GET Parameters
<?php
// Setting a get parameter using the setParameterGet method
$client->setParameterGet('knight', 'lancelot');
// This is equivalent to setting such URL:
$client->setUri('http://example.com/index.php?knight=lancelot');
// Adding several parameters with one call
$client->setParameterGet(array(
'first_name' => 'Bender',
'middle_name' => 'Bending'
'made_in' => 'Mexico',
));
?>
While GET parameters can be sent with every request method, POST parameters are only sent in the body of POST requests. Adding POST parameters to a request is very similar to adding GET parameters, and can be done with the setParameterPost() method, which is similar to the setParameterGet() method in structure.
Example 15.5. Setting POST Parameters
<?php
// Setting a POST parameter
$client->setParameterPost('language', 'fr');
// Setting several POST parameters, one of them with several values
$client->setParameterPost(array(
'language' => 'es',
'country' => 'ar',
'selection' => array(45, 32, 80)
));
?>
Note that when sending POST requests, you can set both GET and POST parameters. On the other hand, while setting POST parameters for a non-POST request will not trigger and error, it is useless. Unless the request is a POST request, POST parameters are simply ignored.
Zend_Http_Client provides methods of accessing the last request
sent and last response received by the client object.
Zend_Http_Client->getLastRequest() takes no parameters
and returns the last HTTP request sent by the client as a string.
Similarly, Zend_Http_Client->getLastResponse() returns
the last HTTP response received by the client as a
Zend_Http_Response object.