Operator Type:
Operator Scope of Action:
Operator Purpose:
Operator First Added:
Operator Altered:
Function [other Function type actions]
Item [operators of similar scope]
Query Boolean [other Query Boolean operators]
Baseline
$AttributeName
In queries and conditional action code expressions, starting an attribute name preceded by a $ character functions as a shortened form of the Boolean test for a true value. Thus the following are functional equivalents:
$MyBoolean==true
$MyBoolean
In both cases the result is true if the value of $MyBoolean is true.
In all other contexts, the $AttributeName syntax implies a reference to that attribute.
Usefully Tinderbox also useful supports such short-form $AttributeName tests for all the other attribute data types, returning true if the attribute has a non-default value. Per data type, this equates to long form tests like:
$MyAction!=""
$MyColor!=""
$MyDate!=never
$MyFile!=""
$MyInterval!="00:00"
$MyList!=""
$MyNumber!=0
$MySet!=""
$MyString!=""
$MyURL!=""
In all these cases a short-form test returns true if the attribute value is not the default for that data type.
A reverse short form test is also offered by !$AttributeName, i.e. the same syntax with a preceding exclamation mark.