Javalin: How to set a custom payload (json) for validation errors?

[davioooh]

I'm trying to apply Javalin validation functionalities in my project and I'd like to ask some questions:

• In Javalin documentation a JavalinValidation.validate() method is mentioned, but I can't find in version 3.9.0. Am I missing something?
• By default a validation error response has a payload of type text/plain containing the error message. Is there a out-of-the-box way to return a custom json object with additional data (and a custom structure)?
• If I should to implement it by myself, could it be a helpful feature to add to the project?

I also noticed there's an open issue about some new validation feature (#998). Maybe there is something not well documented related to my questions?

Thanks!

[tipsy]

Hi @davioooh,

In Javalin documentation a JavalinValidation.validate() method is mentioned, but I can't find in version 3.9.0. Am I missing something?

The JavalinValidation.validate() method is from 2.X, I'll fix the docs.

By default a validation error response has a payload of type text/plain containing the error message. Is there a out-of-the-box way to return a custom json object with additional data (and a custom structure)?

In your browser, or in postman? It should return JSON by default if the client asks for JSON. You can collect the errors manually, as shown here: https://javalin.io/documentation#validator-error-collection

If I should to implement it by myself, could it be a helpful feature to add to the project?

All PRs will be considered :)

[tipsy]

I've removed the outdated info from the docs now.

[davioooh]

In your browser, or in postman? It should return JSON by default if the client asks for JSON.

I'm using Postman for my tests. Sorry, you're right: adding the Accept header to the request I'm a getting a JSON representation.

OK, I'll work on it and if the result worth sharing I'll consider opening a PR.

Thank you very much. :)