Changing Client-Side Validation Messages
Frontend (App Interfaces)
Platform Server Release Oct.2019 CP1

There is currently no way to change the error messages that users see specifically for client side validation only. For example, say we have a button. On the button click we allow the validation to be "Client & Server." This means that before the server is hit, it checks client side validation first. The most common client side validation is not filling a value in a mandatory field then clicking the button. The error that will occur is "Required field!" 

Now there is a way to change the error text of all Mandatory fields to something else. The problem with this is that by modifying this text you change it for all Mandatory text that exists.

What I am suggesting is let the user choose what they wish the client side validation messages to say. This can be done in the Properties Pane for a particular input.

Of course the way around this is to only do server side validation and enter in those error responses when something is not done. The problem with this is that it must hit the server each time in order to do this validation.

Changed the category to
Changed the status to
Working on it
expected delivery in Q4 2019

Hi Tim,

That's a great idea. In fact are currently working on the next generation of web apps, which will make validation at the client-side a lot more flexible. In fact they will make everything that is client-side a lot more flexible and maintainable, as you'll be able to create flows in OutSystems that will generate JavaScript code. We'll release an early access version of this soon, and we would love to hear your feedback.

Tiago Simões

Changed the status to
on 02 Oct 2019

Hi Tim,

We are glad to announce that on October 02nd we released a new generation of Web Apps that are much closer to the Mobile model, allowing developers to leverage client-side logic a lot more. You can read all about Reactive Web Apps on our forum post.

With the introduction of Reactive Web Apps, you can now change default input validation messages using Client Actions.

It's, of course, important to keep doing server-side validation, to prevent accepting invalid data because the client-side was tampered with.

Feel free to experiment with the new version and let us know if there's something we can improve.

Thanks again for sharing your idea!


That's fantastic news! Thank you so much for implementing this!