ExpressionManagerStart

 Hint: This feature is available starting in version 4.0.0

Usage

This event is triggered when the Expression Script engine builds its list of available functions. It allows a plugin to register its own custom Expression Manager function(s).

Input

None.

Possible output

• functions: array of new functions to add to the expression manager.
• packages: array of name => definition pairs, registered via Yii's CClientScript package mechanism, added as a dependency of the expression manager's own JavaScript package.

Function definition

Each function is defined as a zero-indexed array containing, in order:

• PHP callable to execute — can use a fully qualified class name, e.g. \Namespace\Class::method.
• JavaScript function name, or null for a static function (one with no live JavaScript evaluation).
• Short description, shown in the administration GUI.
• Usage syntax, shown in the administration GUI.
• Help URL.
• Number of arguments — trailing elements of the array give the allowed argument count(s):
  • 1, 2: 1 or 2 arguments
  • 1, 2, 3, 4: 1, 2, 3 or 4 arguments
  • 2, 4: 2 or 4 arguments
  • A negative value means "at least N arguments, any number above that": -1 means any number of arguments (minimum 0), -2 means at least 1 argument, -3 means at least 2, and so on (minimum = abs(value + 1)). Only the first value is used in this case — no other trailing elements are read.

Example

• demoAddEmFunction
• statFunctions