Description
The gform_signature_url_permission_granted filter can be used to perform custom logic to determine if the signature URL will allow access to the file.
Usage
The following would apply to all forms.
add_filter( 'gform_signature_url_permission_granted', 'your_function_name', 10, 3 );
Parameters
Examples
Require the user to have administrative capabilities
The following example shows how you can restrict access to only those users who have permission to activate plugins, but only when the hash has passed validation.
add_filter( 'gform_signature_url_permission_granted', function( $permission_granted, $form_id, $field_id ) { return $permission_granted && current_user_can( 'activate_plugins' ); }, 10, 3 );
Placement
This code should be placed in the functions.php file of your active theme or a custom functions plugin.
Since
This filter was added in version 4.0.
Source Code
This filter is located in GF_Signature_Image::is_permission_granted() in includes/class-gf-signature-image.php.