Expressions

PXML Expressions

PXML expressions are PHP expressions used directly in the PXML. Several rules apply to such expressions:

• they must be enclosed in curly braces and thus should not contain curly braces themselves
• the expression is always executed in the global scope - the PHP lambda functions are created from expressions
• the instance of the document (encapsulating PXML document) in whose context expression is evaluated is reachable by $self variable

The expressions are evaluated several times in view's lifecycle:

• during initialization only static bindings? are evaluated
• just before restoring state binding expressions are evaluated first time
• during execute stage of the view's lifecycle the event expressions are evaluated
• binding expressions can also by evaluated during the update of display list if it results in dynamic creation of the components with bindings assigned
• second time are binding expressions evaluated before saving state