Evaluates, calculates the given expression for the given entity.
Target parameters (in) and Activity options
The entity used for the calculation of the expression.
If your expression doesn’t need an entity, you still need to set this parameter to make it valid. Try to set the current user from the start activity.
The expression to evaluate.
Use the left option list with functions, operators, values and more to create the expression. The editor has some supporting features when editing, e.g. try to start writing a “[“.
Double click in the middle list to select and add a value/function to your expression.
For more syntax details see Criteria Language Syntax | Cross-Platform Class Library | DevExpress Documentation.
Source parameters (out)
The result from the evaluation.
Checking that the subject and message aren’t empty in an email message entity:
A simple validation of an e-mail address:
Or create/calculate something else than a boolean expression, like a dynamic string: