Gravity Forms - Fill dropdown with custom fields

gravity_forms_fill_product_dropdowns

/*Get the Page id as parameter from the link and fill dropdowns with the custom fields that you need from this page

We use gravity forms, and field Product (type dropdown).

In this example in pages there are parameters as date1, date2 etc and prices like price (default price) price1, price2 etc. 
The form with id 3 will be filled with the above parameters and corresponding prices, if there is no corresponding price default price will be filled in.


*/
add_filter( 'gform_pre_render_3', 'populate_dates' );
add_filter( 'gform_pre_validation_3', 'populate_dates' );
add_filter( 'gform_pre_submission_filter_3', 'populate_dates' );
add_filter( 'gform_admin_pre_render_3', 'populate_dates' );

function populate_dates( $form ) {

  if (isset($_GET['post_id'])) {
    $post_id  = $_GET['post_id'];
  } else {
    $post_id = '0';
  }


 
  foreach ( $form['fields'] as &$field ) {

    if ( $field->type != 'product' || strpos( $field->cssClass, 'populate-dates' ) === false ) {
        continue;
    }
    
    $the_date = array();
    $the_price = array();
    
    $DatesArr = array();


    for($i=0;$i<10;$i++) 
    {
      $the_date[$i] = get_post_meta($post_id, 'date' . $i);

      if(!empty($the_date[$i])) 
      {
        array_push($DatesArr, $the_date[$i][0]);
      }
    }

    $choices = array();

    foreach ( $DatesArr as $Date ) {

      for($i=0;$i<10;$i++)
      {
        if($Date === $the_date[$i][0]) {
          $price = get_post_meta($post_id, 'price' . $i);
        }
       
      }

      if(empty($price))
      {
        $price = get_post_meta($post_id, 'price');
      }
      
      $choices[] = array( 'text' => $Date, 'value' => $Date, 'price' => $price[0] );
      
    }

    $field->placeholder = 'Select a Date';
    $field->choices = $choices;

  }
 
    return $form;
}