Manual:WebRequest.php

WebRequest
The WebRequest class which encapsulates getting at data passed in the URL or via a POSTed form, handling remove of "magic quotes" slashes, stripping illegal input characters and normalizing Unicode sequences. You can access the standard WebRequest through the RequestContext. You should not create additional instances of this class. Instead create a DerivativeRequest or use FauxRequest if there is no user request context.

Functions
... many more, this is a partial list.
 * function getVal: get a scalar or null if the parameter was not passed
 * function getInt: same as before, but the value returned is an integer
 * function getBool: same as getVal, but returns a boolean value
 * function getArray: get an array or null if the parameter was not passed. If the parameter is a scalar, it will return an array with a single element.
 * function getCheck: return a boolean whether the parameter was passed, this is useful for checkboxes.
 * function getCookie: get a cookie from the $_COOKIE jar
 * function wasPosted: returns a bool whether the request was posted

FauxRequest
FauxRequest is a class extending WebRequest. Its purpose is to emulate a request with the values passed to the constructor.

Also see API:Calling internally for an example that creates a DerivativeRequest to make an API call.