Class: PropertyEvaluator

var PropertyEvaluator = system.evaluators.PropertyEvaluator ;

var obj =
{
    message : "hello world" ,
    title   : "my title"    ,
    menu    :
    {
        title : "my menu title" ,
        label : "my label"
    }
}

var evaluator = new PropertyEvaluator( obj ) ;

// valid expressions

trace( evaluator.eval( "message"    ) ) ; // hello world
trace( evaluator.eval( "title"      ) ) ; // my title
trace( evaluator.eval( "menu.title" ) ) ; // my menu title
trace( evaluator.eval( "menu.label" ) ) ; // my label

// invalid expressions

trace( evaluator.eval( ""            ) ) ; // null
trace( evaluator.eval( "unknow"      ) ) ; // null
trace( evaluator.eval( "menu.unknow" ) ) ; // null

// change the "undefineable" value returns in the eval() method when the evaluation failed.

evaluator.undefineable = "empty" ;
trace( evaluator.eval( "unknow" ) ) ; // empty ;

evaluator.undefineable = undefined ;
trace( evaluator.eval( "unknow" ) ) ; // undefined ;

// activate the throwError mode.

evaluator.throwError = true ;

try
{
    evaluator.eval( "test" ) ;
}
catch( e )
{
    trace( e ) ; // ##EvalError: [object PropertyEvaluator] eval failed with the expression : test##
}

Extends

• system.Evaluable

Members

---

separator :string

The separator character of the expression evaluator.

Type:

• string

Default Value:

• '.'

---

target :object

The target reference use in the evaluator.

Type:

• object

---

throwError :boolean

Indicates if the eval() method throws errors or return null when an error is throwing.

Type:

• boolean

Default Value:

• false

---

undefineable :object

Defines the value returns from the eval() method if the expression can't be evaluate.

Type:

• object

Default Value:

• null

Methods

---

eval(value)

Evaluates the specified object.

Parameters:

Name	Type	Description
value	*	The object to evaluates.

Overrides:

• system.Evaluable#eval

Returns:

The result of the evaluation.

---

toString()

Returns the string representation of this instance.

Overrides:

• system.Evaluable#toString

Returns:

the string representation of this instance.