The Front Controller
Zend_Controller
Programmer's Reference Guide

The Request Object

Introduction

The request object is a simple value object that is passed between Zend_Controller_Front and the router, dispatcher, and controller classes. It packages the names of the requested module, controller, action, and optional parameters, as well as the rest of the request environment, be it HTTP, the CLI, or PHP-GTK.

  • The module name is accessed by getModuleName() and setModuleName().

  • The controller name is accessed by getControllerName() and setControllerName().

  • The name of the action to call within that controller is accessed by getActionName() and setActionName().

  • Parameters to be accessible by the action are an associative array of key and value pairs that are retrieved by getParams() and set with setParams(), or individually by getParam() and setParam().

Based on the type of request, there may be more methods available. The default request used, Zend_Controller_Request_Http, for instance, has methods for retrieving the request URI, path information, $_GET and $_POST parameters, etc.

The request object is passed to the front controller, or if none is provided, it is instantiated at the beginning of the dispatch process, before routing occurs. It is passed through to every object in the dispatch chain.

Additionally, the request object is particularly useful in testing. The developer may craft the request environment, including module, controller, action, parameters, URI, etc, and pass the request object to the front controller to test application flow. When paired with the response object, elaborate and precise unit testing of MVC applications becomes possible.

HTTP Requests

Accessing Request Data

Zend_Controller_Request_Http encapsulates access to relevant values such as the key name and value for the controller and action router variables, and all additional parameters parsed from the URI. It additionally allows access to values contained in the superglobals as public members, and manages the current Base URL and Request URI. Superglobal values cannot be set on a request object, instead use the setParam() and getParam() methods to set or retrieve user parameters.

Note: Superglobal Data
 When accessing superglobal data through Zend_Controller_Request_Http as public member properties, it is necessary to keep in mind that the property name (superglobal array key) is matched to a superglobal in a specific order of precedence: 1. GET, 2. POST, 3. COOKIE, 4. SERVER, 5. ENV.

Specific superglobals can be accessed using a public method as an alternative. For example, the raw value of $_POST['user'] can be accessed by calling getPost('user') on the request object. These include getQuery() for retrieving $_GET elements, and getHeader() for retrieving request headers.

Note: GET and POST Data
 Be cautious when accessing data from the request object as it is not filtered in any way. The router and dispatcher validate and filter data for use with their tasks, but leave the data untouched in the request object.

Note: Retrieving the Raw POST Data
 As of 1.5.0, you can also retrieve the raw post data via the getRawBody() method. This method returns FALSE if no data was submitted in that fashion, but the full body of the post otherwise.
This is primarily useful for accepting content when developing a RESTful MVC application.

You may also set user parameters in the request object using setParam() and retrieve these later using getParam(). The router makes use of this functionality to set parameters matched in the request URI into the request object.

Note: getParam() Retrieves More than User Parameters
 In order to do some of its work, getParam() actually retrieves from several sources. In order of priority, these include: user parameters set via setParam(), GET parameters, and finally POST parameters. Be aware of this when pulling data via this method.
If you wish to pull only from parameters you set via setParam(), use the getUserParam().
Additionally, as of 1.5.0, you can lock down which parameter sources will be searched. setParamSources() allows you to specify an empty array or an array with one or more of the values '_GET' or '_POST' indicating which parameter sources are allowed (by default, both are allowed); if you wish to restrict access to only '_GET' specify setParamSources(array('_GET')).

Note: Apache Quirks
 If you are using Apache's 404 handler to pass incoming requests to the front controller, or using a PT flag with rewrite rules, $_SERVER['REDIRECT_URL'] contains the URI you need, not $_SERVER['REQUEST_URI']. If you are using such a setup and getting invalid routing, you should use the Zend_Controller_Request_Apache404 class instead of the default HTTP class for your request object:

  1.  
This class extends the Zend_Controller_Request_Http class and simply modifies the autodiscovery of the request URI. It can be used as a drop-in replacement.

Base Url and Subdirectories

Zend_Controller_Request_Http allows Zend_Controller_Router_Rewrite to be used in subdirectories. Zend_Controller_Request_Http will attempt to automatically detect your base URL and set it accordingly.

For example, if you keep your index.php in a webserver subdirectory named /projects/myapp/index.php, base URL (rewrite base) should be set to /projects/myapp. This string will then be stripped from the beginning of the path before calculating any route matches. This frees one from the necessity of prepending it to any of your routes. A route of 'user/:username' will match URIs like http://localhost/projects/myapp/user/martel and http://example.com/user/martel.

Note: URL Detection is Case Sensitive
 Automatic base URL detection is case sensitive, so make sure your URL will match a subdirectory name in a filesystem (even on Windows machines). If it doesn't, an exception will be raised.

Should base URL be detected incorrectly you can override it with your own base path with the help of the setBaseUrl() method of either the Zend_Controller_Request_Http class, or the Zend_Controller_Front class. The easiest method is to set it in Zend_Controller_Front, which will proxy it into the request object. Example usage to set a custom base URL:

  1. /**
  2. * Dispatch Request with custom base URL with Zend_Controller_Front.
  3. */'./application/controllers''/projects/myapp'); // set the base url!
  4. $response   = $controller->dispatch();

Note: Fully-Qualified URL is not supported
 Passing a fully-qualified URL (ie: http://example.com/) to the setBaseUrl method is not supported, and will cause issues for both the usage describe above and when using the URL view helper. See ticket » ZF-10923 for more details.

Determining the Request Method

getMethod() allows you to determine the HTTP request method used to request the current resource. Additionally, a variety of methods exist that allow you to get boolean responses when asking if a specific type of request has been made:

  • isGet()

  • isPost()

  • isPut()

  • isDelete()

  • isHead()

  • isOptions()

The primary use case for these is for creating RESTful MVC architectures.

Detecting AJAX Requests

Zend_Controller_Request_Http has a rudimentary method for detecting AJAX requests: isXmlHttpRequest(). This method looks for an HTTP request header X-Requested-With with the value 'XMLHttpRequest'; if found, it returns TRUE.

Currently, this header is known to be passed by default with the following JS libraries:

  • Prototype and Scriptaculous (and libraries derived from Prototype)

  • Yahoo! UI Library

  • jQuery

  • MochiKit

Most AJAX libraries allow you to send custom HTTP request headers; if your library does not send this header, simply add it as a request header to ensure the isXmlHttpRequest() method works for you.

Subclassing the Request Object

The base request class used for all request objects is the abstract class Zend_Controller_Request_Abstract. At its most basic, it defines the following methods:

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The request object is a container for the request environment. The controller chain really only needs to know how to set and retrieve the controller, action, optional parameters, and dispatched status. By default, the request will search its own parameters using the controller or action keys in order to determine the controller and action.

Extend this class, or one of its derivatives, when you need the request class to interact with a specific environment in order to retrieve data for use in the above tasks. Examples include the HTTP environment, a CLI environment, or a PHP-GTK environment.

The Front Controller
Zend_Controller
Programmer's Reference Guide