Screen Field Editor: Display Constraints



With Display Constraints, system administrators can control how fields display in screens based on responses entered in other fields. You can use any field as a constraint.

For example, in the system screen 2020 HUD: CoC Standard Project Enrollment, the field [income_individual] is set up with a constraint to display only when the field [income_cash_is] equals “Yes.” 

In this article, we’ll define the terms “constrained field” and “constraining field” as follows:

  • A Constrained field is a field that has a display constraint applied to it. This field will only display in a screen if the conditions established in Display Constraints are met.
  •  A Constraining field is a field that is added as a Display Constraint to another field. All field types except for dates can be used as constraining fields. 

Adding Constraints

To apply a constraint to a field within a screen, create or navigate to the appropriate screen. 


Note: In order to add a constraint to a field, both the constraining field and the constrained fields must be first added to the screen.


Within the screen, add or locate the field you’d like to add a constraint to and click the edit icon.


In the DISPLAY CONSTRAINTS section, click ADD CONSTRAINT and select the appropriate field from the drop-down menu. 


You have the option of indicating if the constraining field should equal, not equal, be greater than, or less than the selected response.


If you add two or more constraints, you must set the And/Or value.

  • Or: when either/any of the constraints are met, the field will display in the screen. 
  • And: all constraints must be met in order for the field to display in the screen.


There is no limit to how many constraints you can apply to a field. The constraints only apply to the screen you’re editing.

After you add a constraint to a field, the icon shown below will appear next to the field in Screen Editor to indicate that at least one constraint has been applied to the field.


Advanced Logic

If desired, you can apply advanced nesting logic to display constraints. This logic operates in the same manner as it does with Assessment Processors.

To add advanced logic, you’ll need at least three constraints added for the field. You can then use parentheses to group conditions and And/Or values. In the example below, the field is setup with constraints to display if either:

Veteran Status equals “Yes,” AND Disabling Condition equals “Yes”


Formerly a Ward of Child Welfare or Foster Care Agency equals “Yes.”



When a screen field is not displayed due to a Display Constraint, no data can be saved for that field in that screen. This is in contrast to hidden fields where, even when a field isn’t displayed in the screen, that hidden field can still accept and store data. 

This has data entry and screen design implications:

  • Data entry: it’s possible for users to enter a value for a field when existing constraints allow, and later change the constraining field, making the constrained field no longer visible. When this happens, the previously entered data for the constrained field will not be saved. 
  • Screen design: if a new constraint is introduced to an existing screen, this has the potential to clear previously saved data for that screen. This occurs when a field that previously displayed in the screen and for which data was entered no longer displays due to the new constraint.