| Operator Type: | Function |
| Operator Scope of Action: | Item |
| Operator Purpose: | Boolean (query) |
!$AttributeName
In queries and conditional action code expressions, starting an attribute name preceded by an exclamation mark plus a $ character functions as a shortened form of the Boolean test for a false value. Thus the following are functional equivalents:
$MyBoolean==false
!$MyBoolean
In both cases the result is false if the value of $MyBoolean is false.
Usefully Tinderbox also useful supports such short-form !$AttributeName tests for all the other attribute data types, returning true if the attribute has a default value. Per data type, this equates to long form tests like:
$MyAction==""
$MyColor==""
$MyDate==never
$MyFile==""
$MyList==""
$MyNumber==0
$MySet==""
$MyString==""
$MyURL==""
In all these cases a short-form test returns true if the attribute value is the default for that data type.
This test is the logical opposite of the $AttrbuteName test.
