Records a timestamp into a field when the entry approval status is changed

gv_approval_timestamp.php

<?php // DO NOT COPY THIS LINE

add_action( 'gravityview/approve_entries/updated', 'gv_approval_timestamp', 10, 2 );
function gv_approval_timestamp($entry_id, $status){

	if( !class_exists( 'GFAPI' ) ) {
		gravityview()->log->error( 'GFAPI does not exist' );
		return false;
	}

	if( !class_exists( 'GravityView_Entry_Approval_Status' ) ) {
		gravityview()->log->error( 'GravityView Entry Approval class not loaded' );
		return false;
	}

	$entry = GFAPI::get_entry( $entry_id );
	$form = GFAPI::get_form( $entry['form_id'] );
	
	if ( 23 !== (int) $form['id'] ) { // replace 23 with your form ID
		return;
	}

	$input_id = 1; // replace 1 with the field ID where you want to store the information

	$action = GravityView_Entry_Approval_Status::get_key( $status );
	$updateDate = gmdate("Y-m-d H:i:s");
	$value = $action.' on '.$updateDate;
  
  	$result = GFAPI::update_entry_field( $entry_id, $input_id, $value );
  	return $result;
}