[Question] Async validation: what has to be returned?

[chiester]

I'm looking at the documentation at https://uniforms.tools/docs/api-forms/#asynchronous-validation

It seems that onValidate() has to return errors in order for the errors to be rendered in the form. What is the correct way to modify the errors to return them?

I'm making a call to my API to do my async validation and if it fails, it's not clear to me how to pass that response back to the form. I also looked at ajv's recommended approach (https://ajv.js.org/guide/async-validation.html), but couldn't get it working in my bridge.

[radekmie]

Hi @chiester. As with all errors in uniforms, the format of the error is specified by the bridge you're using. So, if you're using JSON schema bridge (I assume so, based on the ajv in your message), you have to return a list of ErrorObject-like objects. (I say ErrorObject-like, as we're not using all of the properties. You can always check the getError implementation to see the details.)

What is the correct way to modify the errors to return them?

In onValidate, you are supposed to return a new error, not modify the one you received. So, for example, in JSON schema, simply add your custom errors to the details array. To make them visible with the showInlineError, make sure that the instancePath is correct.

I'm making a call to my API to do my async validation and if it fails, it's not clear to me how to pass that response back to the form. I also looked at ajv's recommended approach (https://ajv.js.org/guide/async-validation.html), but couldn't get it working in my bridge.

You don't have to use onValidate for that - you can use the validator itself (the function that you pass to the JSONSchemaBridge constructor). The only thing is that you have to return the error in a proper format (and not reject or throw it).

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I hope this answers the question. If not, please do let me know.

[chiester]

I'm returning the error, but it's not clear to me how to show it in the <ErrorField .../>

[radekmie]

To make the error visible in ErrorField, you have to make it understandable for the getError implementation of your bridge. In general, it has to have the name of the field. (For details, refer to the getError implementation in your bridge.)

[mariusrak]

Hi I'm also battling with this. Again. Can we please have noted the exact schema of error object somewhere in documentation? Thanks

[wadamek65]

@mariusrak I believe this is something we already touched upon and we've realized that we most likely can introduce stricter types for the errors inside the bridges directly so this should be an even better improvement. If for some reason that will not come to fruition, we will add a note in the docs.

@kestarumper Can you file an issue for this as IIRC you were the one investigating this? I believe the issue is this one #1158.