Custom form validation on panel field

Kirby 3 Solved ✅
,
1

I’m trying to validate a number field for having a specific min value that I’m reading from another field, therefore I can’t set it in the blueprint.
I tried it with a page.update:after hook, but when I change the page there, the changes only are visible are reloading in the frontend:

'page.update:after' => function (Kirby\Cms\Page $newPage, Kirby\Cms\Page $oldPage) {
   // validation failed, set variable back to what it was before
   $newPage->update([
       'myVar' =>  $myVal
   ]);
}

I also tried adding a validator in a plugin, but there I only have access to the value of the field and not to the other pages I’d need to read too.

How could I achieve such a validation or how can I return an error from the hook?

2

To throw an error, you would have to use a page.update:before hook.

But maybe a custom validator is the better option.

Is the field you want to get the value from in the same page? Or what is the relation?

3

the field is on the same page, yes! How could I do this with the validator? I only got $value there which was the current value, as shown in Validators | Kirby CMS

how could I throw an error from page.update:before?

4

This hook would throw an error if the current value is lower than the value given in the minValue field (change field names as appropriate).

   'hooks' => [
        'page.update:before' => function ($page) {
            $min = $page->minValue()->toInt(); // or use toFloat if you field uses floats
            if ($page->myVar()->toInt() < $min) {
                throw new Exception('Min value must be ' . $min);
            }
        }
    ]

A custom validator indeed would not work because you don’t have access to the current page in this context.

1 Like
5

works like a charm, thank you very much!