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.

<?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.

Performing simple HTTP requests is very easily done using the request() method, and rarely needs more than three lines of code:

<?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).

<?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.

<?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.

<?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.