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ISBLANK

Use the ISBLANK function check if a value is blank or empty.

Use

ISBLANK( value )
Returns TRUE if the value is blank.

ParameterRequiredDescription
valueYesany type value to test

ReturnsLogical

Examples

Mandatory Field Validation

You can use ISBLANK in an Output Validation Formula to ensure that a user does not leave a required field empty before submitting a form. Because ISBLANK returns TRUE when a field is empty, it is commonly paired with the NOT function to create a "Cannot be empty" rule.

  • Scenario: A user must provide a "Justification" for a high-value purchase request.
  • Formula: NOT(ISBLANK(this))
  • Logic:
    • this: This keyword refers to the value currently being entered in the "Justification" field.
    • ISBLANK(this): This part returns TRUE if the user has typed nothing.
    • NOT(...): Reverses the result so that the validation formula returns TRUE (Valid) only when the field contains text.

Conditional Form Visibility

In the Form Builder, you can use ISBLANK within Conditional Logic to simplify a form by showing or hiding elements based on whether optional information was provided in a previous step.

  • Scenario: A reviewer should only see a "Detailed Instructions" content block if the initial submitter did not provide a "Project Summary" in the trigger form.
  • Formula: ISBLANK(@Trigger.out.ProjectSummary)
  • Logic:
    • @Trigger.out.ProjectSummary: This identifies the specific output data captured from the trigger step.
    • Show when: This formula is placed in the "Show when" property of the content block.
    • Result: If the ProjectSummary is empty, the function returns TRUE, and the instructions are displayed to the reviewer to provide extra guidance.