Validation Rules aren't run in Server Action for server-side binding

Wappler General Bugs
1

Wappler v7.3.4

NodeJS

Validation Rules aren't run in Server Action for server-side binding

  1. Create a page
  2. Attach a Server Action to the page, for server-side binding
  3. In the Server Action, place a validation rule on $_GET.hello parameter, make it required
  4. You should’ve seen an error or something, instead page proceeds normally
2

Just curious, how are you displaying the validation on the page?

3

You're right on being curious :slight_smile:

To give you a little context, imagine I send an email to a user and there's an unsubscribe link:

/unsubscribe?id=123

I made an unsubscribe page that has attached a Dababase Update query, so the validation is just for that, I don't care much what the user sees if validation fails, at least for a minimum viable implementation

4

Hi Apple,

My understanding is that only $_POST parameters with Linked Fields can show an error in the UI. I haven't used validations for $_GET parameters when submitting a form in the UI. Try by adding the Linked Field property, matching the input field ID, to check whether it shows the error message.

5

Thanks guptast for your suggestion, it didn’t work either

Validate Data step is not working either

6

In this example, you have a query parameter id=123. This query parameter can be used to populate a hidden input field value in a server connect form when user clicks on the unsubscribe link. This way you can use $_POST variables with proper validation for both server and UI, and show an error message if validation fails.

7

Validating a GET input seems to work fine in my tests:

Screenshot 2025-09-29 at 8.34.54
Screenshot 2025-09-29 at 8.34.54422×215 7.14 KB

Same for validate data step in the server action. Maybe show some screenshots explaining what you're doing.

8

You forgot to attach the Server Action to a page for server-side binding:

CleanShot 2025-09-29 at 16.39.27@2x
CleanShot 2025-09-29 at 16.39.27@2x666×674 18.1 KB

And then you try to load the page, Validation isn’t processed

1 Like
10

The validation is only executed if the server action is accessed directly, when it is called as a sub action the validation in not run. This is for sub actions you include or execute from an action and for templates which execute them as a sub action for the template. Executing validation after other steps already have run and output is already generated will result in server errors.

I will check if there is perhaps another way to do validation in templates but with the current implementation it is not possible.