Require an Existing Value for Submission with Gravity Forms

• February 7, 2017: Fixed issue where submitting the form before AJAX validation had completed resulted in a failure to capture the target field's value.

• February 6, 2017: Fixed two issues with validation; validation did not work correctly on submission; AJAX validation was not validating against the correct source field ID.

• February 5, 2017: Added support for AJAX validation; value is validated as soon as the user exits the input.

• August 29, 2016: Updated article with documentation for "field_map" parameter.

• May 14, 2015: Updated does_value_exist() method to only query active entries.

Let’s say a reference number is generated on Form A (using something like GP Unique ID) for the user’s order (represented by a Gravity Form entry). The reference number is emailed to the user.

On Form B, the user is able to contact you about their order by entering the reference number. If they fail to enter a valid reference number, a validation error is returned and they are unable to submit the form.

The form will generate this error unless a valid reference number is entered.

Getting Started

1. Check requirements
   • Make sure you have Gravity Forms installed and activated.
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2. Install the snippet
   • Copy and paste the entire snippet into your theme’s functions.php file.

3. Configure the snippet

   • Once you have installed the snippet, look at the bottom of the snippet for this block of code:

     	new GW_Value_Exists_Validation( array(
     	'target_form_id' => 613,
     	'target_field_id' => 1,
     	'source_form_id' => 519,
     	'source_field_id' => 1,
     	'validation_message' => 'Hey! This isn\'t a valid reference number.'
     	) );

   • The target form ID and field ID represent the form and field that should be validated and show the validation error when validation fails.
   • The source form ID and field ID represent the form and field that store the existing value that the value submitted in the target form and field should be checked against.
   • The validation message can be updated to any message you would like to indicate that the entered value did not match any existing values in the source form and field.

Parameters

• target_form_id (integer) (required)

  This is the Form ID for the field that you will checking if a value already exists (Form B in the example above). There is no default value.

• target_field_id (integer) (required)

  This is the Field ID for the field that you will checking if a value already exists (Form B in the example above). There is no default value.

• source_form_id (integer) (required)

  This is the Form ID for the field that generated the reference number (Form A in the example above). There is no default value.

• source_field_id (integer) (required)

  This is the Field ID for the field that generated the reference number (Form A in the example above). There is no default value.

• validation_message (string) (optional)

  This is the error message that will be displayed if the value being tested does not already exist. Defaults to "Hey! This isn't a valid reference number."

• field_map (array) (optional)

  An array of target and source field IDs; allows for creating multiple requirements that must match the same entry. Format should be:

  array(
      // TARGET_FIELD_ID1 => SOURCE_FIELD_ID1,
      2 => 3,
      5 => 11
  );

• disable_ajax_validation (bool) (optional)

  Optionally disable AJAX validation. AJAX validation is enabled by default and will add a checkmark or an x-mark depending on whether the value exists.

Any questions?

This snippet is more of a building block rather than a final solution. Let us know how you’re using it and any questions you have about building on top of it to accomplish a more involved solution.

For an example of how this can be combined with other plugins to create a more robust solution, check out the How to Generate and Validate a Reference Number for Gravity Forms with GP Unique ID tutorial.

We hope you find this snippet useful! If you do, show us some love by sharing this article on the social media platform of your choice. Let’s keep the Gravity Wiz pumping out awesome snippets.