Joomla! Documentation™

Parameters are one way that data may be stored for a Joomla! Extension. Each parameter consists of two parts:

• A simple text string of the form {NAME} = {VALUE}, in which the parameter value is recorded. The strings are usually concatenated into a single string with other parameter values and stored in a table field.
• A form field in the Extension backend that allows a user to enter the parameter value, and which is defined by an XML <param> element.

Joomla! defines 21 core parameter types, each of which gives a predefined behaviour and appearance in the back-end. This makes it very easy for developers to implement a range of form data entry types (text boxes, radio buttons, calendar selectors and so on) with a minimum of effort. This behaviour and appearance is determined by the type attribute of the <param> element. See J1.5:Standard parameter types for a complete list and details of each type.