Expression Dialog 

The expression associated with a validation, an assignment, or a calculated field is defined and edited using the same expression editor within the applicable expression dialog, as shown in the figure below.

An expression consists of field names, attribute names, qualifier names, lookup values, attribute text values, operators, and functions, which you can type in manually or use the toolbar buttons to enter for you.

If you manually type field, attribute, qualifiers, operators, and function names, MDM automatically tokenizes the text you have just typed when you press Space, and highlights these tokens in blue.

You must use the toolbar buttons to enter lookup values, text attribute values, and measurement values (consisting of a number and a unit of measure). MDM highlights these tokens in magenta.

Expressions now support limited measurement arithmetic addition within the same convertible dimension (MDM uses the unit of the left-hand operator), and multiplication of a scalar with a measurement (for example, Length *2 < 50 ft).

Tokens for the values of lookup fields and text attributes appear as “name [value]” and for virtual fields names (such as [Record], [Depth], [Parent], [Child]) appear insquare brackets ([]).

Expressions are token-based, so that you do not have to type field, attribute, qualifier, operator, or function names, and can instead select them from drop-down lists, reducing the potential for typing error.

The following table describes the toolbar buttons of the Expression dialog for entering tokens into the expression.

Control / Button	Tooltip	Description
	Number	Type the number for a measurement value
	Dimension	Choose from the drop-down list of dimensions
	Unit	Choose from the drop-down list of units
	Enter	Enter the measurement value into the expression
	Cancel	Clear the measurement value
	Fields	Choose from the drop-down list of fields, and for each lookup, from the cascading menu of fields
	Attributes	Choose from the drop-down list of attributes
	Relationships	Choose from the drop-down list of relationships, and then from the cascading menu of fields
	Lookups	Choose from the drop-down list of lookups, and then from the pop-up dialog of lookup values
	Text Values	Choose from the drop-down list of text attributes, and then from the pop-up dialog of text values
	Operators	Choose from the drop-down list of operators
	Functions	Choose from the drop-down list of functions