The constraints panel contains options to check the value of form fields, when form fields should be visible and when they can be edited. Some constraints are available only for some element, see the list of element.

Properties

Condition

You can change a form field's visibility and read-only state depending on the value of another form element.

7.2.0+ You can also choose formula, which lets you enter a custom form with your own logic. That formula may reference more than one form element. Please note the following:

• The form must be a valid JavaScript expression, e.g.
  $("[name='tfFirstName']").val() === "John".
  • JavaScript statements cannot be used, e.g.
    var x = $("[name='tfFirstName']").val() ; x === "John" will not work.
  • If still necessary, you can wrap statements in an IIFE (immediately invoked function expression): (function(){var x = $("[name='tfFirstName']").val() ; return x === "John"})()
• You can use form variables to access form values more easily. The variable is replaced with a JavaScript value container the value of the form element. For example:
  [%tfFirstName%]==="John"
  • If the value represents a valid floating point number, the placeholder is replaced with a JavaScript number value, e.g.: [%tf1%]+[%tf2%] < 10 (Sum of both fields < 10). Otherwise, the value is replaced with a JavaScript string, e.g.:
    [%tf1%].toUpperCase() === "JOHN" (Field equals "John", case insensitive).
  • The value depends on the type of form element:
    • For checkboxes, the value when checked is used, as entered in the form designer (default: on).
    • For input fields and text areas, the value as entered by the user is used.
    • For select elements displayed as combo boxes or list boxes, the technical value of the selected option is used.
    • For select elements displayed as checkboxes or radio buttons, the sum of all technical values of all selected options is used. This applies to select elements displayed as questions as well.
    • For upload elements, the file name of the selected fle is used.
    • For appointment pickers, the date and time as shown by the appoinment picker is used.
• You can also use other variables such as system variables: e.g.
  [%$PROJECT_TITLE%] === "My form".
• NO server validation is performed for custom formulas, even if that option is enabled for a form element.

Once you have selected a form element, the following conditions are available for the options hidden if, visible if, read-only if, editable if, and required if:

• has a value
• has no value
• equals
• not equals
• lower than
• lower equal than
• greater than
• greater equal than
• between
• regular expression

You can also select elements with the element picker to the right. Click on the hand-shaped icon and then on the element you would like to use. This comes in handy when editing forms with many form fields.

Clear or reset automatically

For the properties hidden if and read-only if, you may choose whether the form field should be cleared or reset automatically when the form field is hidden or disabled. Clearing a form field means that its value is removed, eg. deleting the entered text for an input field or unchecking all checkboxes for a select field. Resetting a form field, on the other hand, refers to changing its value back to the original or initial value it had when the form was openend. In case the form was opened for the first time and not submitted yet, the original value is the value as set in the formcycle Designer. Otherwise, when the form was already submitted and is opened in the inbox, the original value is the most recently submitted (saved) value.

For example, consider the case of entering an address. The user can choose between a physical address and a post-office box, and only one input field is visible depending on the user's choice. When the form is submitted, a value should be send only for one of both fields. By selecting the empty automatically options, the input field post-office box will be cleared automatically when the user selects a physical address.

When an element is cleared or reset, all the elements it contains are cleared or reset as well. This applies to form elements of type page, container, and fieldset.