How to catch Validator error

[kirill-ratkin]

In case of validation error a log message appears in console.
But example says no about how to catch the exception.
Could you add such logic to example or say couple words here how to do it?

I try to override method validated_message in my custom validator class inherited from Validator.
It doesn't work :(.

[kirill-ratkin]

How I see function: wrap_function_by_validator(self, function, validator) intercepts ValidationError exception itself and print message.
So ... there is no way to detect validation error on application level, right?

[kirill-ratkin]

I just did minimal changes in pull request - #225 .
It's very simple soluton. Maybe it doesn't work for all cases. But it solves my problem with validation quite complicated messages come thru NATS and maybe helps you.

[artas728]

Hello @kirill-ratkin
Indeed, catching a validator exception looks like a useful feature.
I'll check your PR soon

[artas728]

@kirill-ratkin just checked PR #225
The thing is such implementation breaks all listener functions that don’t have an argument validation_report.
I would consider adding validation_error_cb as an argument for the listener decorator. For example:

async def custom_validation_error_cb(msg):
    # custom msg handling
    log.error(f"something wrong")

@app.listen("some.subject", validator=SomeValidator, validation_error_cb=custom_validation_error_cb)
async def foo(msg):
    # msg handling if everything allright
    log.info(f"got message {msg.data}")

What do you think? Would it be convenient for your case?

[kirill-ratkin]

Hi.
Yes. Good idea to add decorator parameter. It's better than mine solution.
What do you think to do with wrapped function call in case of validation error happened?

For my perpective wrapped functoin should not be called in this case and custom_validation_error_cb should be responsible for error handling. In my case I'll inform sender in reply about validation error.

Good idea!

[artas728]

We will think about a wrapped function.

I can't guarantee but i think we will release the new version by the end of next week, the new version will include the validation error callback feature.

[artas728]

#227 Update in new panini release - v0.7.1