Expression Builder

The Expression Builder allows you to create simple expressions, which are normally used for binding WebPage elements (typically constructed in the Web Page Editor). Click on the icon of a WebPage element's property to launch the Expression Builder.

For example, in your application, you want to decide whether or not to display an image based on an "if" condition, which marks the threshold between a good or bad product. You can construct a simple expression for this using the Expression Builder Language Elements.

Note:

The Expression Builder dialog's label always marks the field being bound, and the data type for that field.
When starting, the "No binding" error message is present, by default.


Control	Description
Help	Displays the IDE Help file.
Validate	Checks the validity of the expression.
Associations	Maps the expression's return type to the type required by the binding, e.g. a number to a color. Note: For more information, please see the Binding Associations topic.
Tag Selector	Launches the Tag Selector dialog, which displays the list of available tags.
Tag	Shows the list of available tags.
Constant	Shows the list of the available constant values.
Function	Shows the list of the available functions.
...	Shows the list of all functions, tags, and constants.
Result	It attempts to evaluate the expression and returns the resulting value. If there are errors, it provides quick feedback on possible syntax errors. This element is only visible (can be collapsed still) if the entered expression is invalid. If collapsed, the parser error is shown as a tooltip.