J1.5

Retrieving and Filtering GET and POST requests with JRequest::getVar

From Joomla! Documentation

The "J1.5" namespace is an archived namespace. This page contains information for a Joomla! version which is no longer supported. It exists only as a historical reference, it will not be improved and its content may be incomplete and/or contain broken links.



Summary[edit]

When writing any web application, it is crucial that you filter input data before using it. Joomla! provides a set of filtering libraries to help you accomplish this.


JRequest 'getVar' method[edit]

To retrieve GET/POST request data, Joomla! uses the getVar method of the JRequest class (JRequest::getVar()).

Retrieving Data

If you have a form variable named 'address', you would want to use this code to get it:

EXAMPLE:

$address = JRequest::getVar('address');

Unless other parameters are set, all HTML and trailing whitespace will be filtered out.

The DEFAULT Parameter

If you want to specify a default value in the event that 'address' is not in the request or is unset, use this code:

$address = JRequest::getVar('address', 'Address is empty');
echo $address;  // Address is empty

The SOURCE Parameter

Frequently, you will expect your variable to be found in a specific portion of the HTTP request (POST, GET, etc...). If this is the case, you should specify which portion; this will slightly increase your extension's security. If you expect 'address' to only be in POST, use this code to enforce that:

EXAMPLE:

$address = JRequest::getVar('address', 'default value goes here', 'post');

The VARIABLE TYPE Parameter

The fourth parameter of getVar() can be used to specify certain filters to force validation of specific value types for the variable.

EXAMPLE:

$address = JRequest::getVar('address', 'default value goes here', 'post','variable type');

Here is a list of types you can validate:

  • INT
  • INTEGER
  • FLOAT
  • DOUBLE
  • BOOL
  • BOOLEAN
  • WORD
  • ALNUM
  • CMD
  • BASE64
  • STRING
  • ARRAY
  • PATH
  • USERNAME

The FILTER MASK Parameter

Finally, there are some mask constants you can pass in as the fifth parameter that allow you to bypass portions of the filtering: EXAMPLE:

$address = JRequest::getVar('address', 'default value goes here', 'post','validation type','mask type');
  • JREQUEST_NOTRIM - prevents trimming of whitespace
  • JREQUEST_ALLOWRAW - bypasses filtering
  • JREQUEST_ALLOWHTML - allows most HTML. If this is not passed in, HTML is stripped out by default.

Definition[edit]

The class JRequest is defined in the following location.

libraries\joomla\environment\request.php