[#10397] Add frontend validation for feedback submission

[madanalogy]

Fixes #10397

[madanalogy]

@xpdavid The idea I had was that once a constraint component was initialised in a question component, it would emit an Observable<boolean> to be tracked by the question. The question will then update the model whenever there is any change in the form by polling the observable to retrieve the latest isValid: boolean.

This design approach was my answer to "when should the constraint component emit the validity boolean?" because the constraint component doesn't have access to the parent question component's formModelChange.

[xpdavid]

You can make *-contrains component emit isValid event and let question-submission-form.component to change the model.

I think we are also facing a new issue here: There are constraints targeted to a group of responses and also a single response.

• If your isValid is only defined for QuestionSubmissionFormModel, how about the individual response?
• If your isValid is only defined for FeedbackResponseRecipientSubmissionFormModel, how about the group response?

[madanalogy]

You can make *-contrains component emit isValid event and let question-submission-form.component to change the model.

Yes this is what I'm already doing, just that I'm using a single observable emit so the responsibility then becomes on the question component to poll the value whenever necessary, rather than the constraint component constantly emitting at some arbitrary benchmark.

I think we are also facing a new issue here: There are constraints targeted to a group of responses and also a single response.

• If your isValid is only defined for QuestionSubmissionFormModel, how about the individual response?
• If your isValid is only defined for FeedbackResponseRecipientSubmissionFormModel, how about the group response?

isValid here is only define for QuestionSubmissionFormModel because constraints are only defined on a per question basis. Individual responses can easily be validated within their corresponding response component or even on a per response basis prior to sending to the backend and even easily validated at the backend. My only purpose here is to validate the group response (i.e. per-question basis). I do not see individual response validation within the scope of this PR.

[xpdavid]

so the responsibility then becomes on the question component to poll the value whenever necessary

You don't need use EventEmitter<Observable<boolean>> to separate the responsibility. If the constraint component use EventEmitter<boolean>, it is still up to the question component to "listen" to the event or not.

In addition, your end goal is to update isValid attribute in the questionModal which can be easily achieved by EventEmitter<boolean>.

My only purpose here is to validate the group response (i.e. per-question basis). I do not see individual response validation within the scope of this PR.

I think this is not closed for modification. I think we can ask ourselves, how many lines of code shall we change if we want the logic (e.g., disable the submission button or pop up the status message when any response is invalid) for single response also?

[madanalogy]

You don't need use EventEmitter<Observable<boolean>> to separate the responsibility. If the constraint component use EventEmitter<boolean>, it is still up to the question component to "listen" to the event or not.

In addition, your end goal is to update isValid attribute in the questionModal which can be easily achieved by EventEmitter<boolean>.

When should the constraint component emit the value then? It doesn't have access to the parent formModelChange. Unless I set up an emitter in the parent as well possibly?

I think this is not closed for modification. I think we can ask ourselves, how many lines of code shall we change if we want the logic (e.g., disable the submission button or pop up the status message when any response is invalid) for single response also?

Okay noted on this, I will think it through and see how I can make this work for both grouped responses and individual responses

[xpdavid]

Almost there :)

[xpdavid]

💯