Validating: Start year <= End year

[Michael Lenaghan]

I created a `Fieldset (Page)` field with two fields, a start year and an end year.

Is there some way to add validation that guarantees start year <= end year?

(If, that is, they're specified at all; both fields should be optional.)

[wbmnfktr]

The easiest way would probably be to use hooks in ready.php - something like the pseudo-code below:

$pages->addHookBefore('Pages::saveReady', function(HookEvent $event) {
  $page = $event->arguments(0);

  // todo: change template name
  if($page->template == "your-template" { 

    // todo: change field names
	$field1 = $page->dateStart;
    $field2 = $page->dateEnd;

	// todo: add validation
    if($field1 > $field2) {
		// show a message
		// whatever
    }
  }
});

This would hook into the save process just before the page would be saved. Therefore you could check if the fields validate.

[Michael Lenaghan]

OK, thanks for that!