The ThingWorx Documentation has a brief description, a video tutorial about how to use a simple expression, and descriptions of the properties. I've copied that content here:
Expression Widget
The Expression widget evaluates an expression and is invisible at run time.checkbox
View the following video tutorial for more information: How to Use an Expression Widget.
NoteProperty Name | Description | Base Type | Default Value | Bindable? (Y/N) | Localizable? (Y/N) |
|---|---|---|---|---|---|
Expression | The expression to evaluate. | STRING | n/a | N | N |
AutoEvaluate | Automatically evaluate the expression when the value of its inputs change. | BOOLEAN | False | N | N |
FireOnFirstValue | A boolean value indicating whether the Changed Event should be fired when the Expression widget is supplied its first value. | BOOLEAN | False | N | N |
DataChangeType | The type of data change that must occur to fire the Changed Event (Value, Always, or Never). | BOOLEAN | Value | N | N |
Output | The output of the expression. | NUMBER | n/a | Y | N |
OutputBaseType | The base type of the output (NOTHING, BOOLEAN, DATETIME, LOCATION, NUMBER, TAGS, or STRING). | STRING | NUMBER | N | N |
Changed | Event. The Event fired by the Expression widget when its output is changed. | n/a | n/a | Y | N |
Evaluate | Service. Evaluates the expression. | n/a | n/a | Y | N |
Visible | Is the widget visible in runtime? | BOOLEAN | True | Y | N |
