Validate nested sub-properties

[pranavkm]

No description provided.

[guardrex]

@pranavkm Where does HomeAddress come from? Is that supposed to be Address?

[pranavkm]

Fixed

[Rick-Anderson]

@SteveSandersonMS one minute review please.

[SteveSandersonMS]

I'm not sure this approach is quite right. The IValidatableObject technique is going to end up registering error messages with the wrong keys. I think @pranavkm also saw this happening.

Making this work cleanly involves some logic changes inside <DataAnnotationsValidator> to make it recognize the concept of nested objects. I posted a sample of this here: https://gist.github.com/SteveSandersonMS/86a0bd3be0826f57af1ae2d3bd5fa95c. However that is a bit complicated to have in docs! Our intention is to bake this functionality into the framework in 3.1 (probably - cc @danroth27 @mkArtakMSFT).

As for what we should document for 3.0, I'm not sure.

@pranavkm What problems occur due to the incorrect dictionary keys? Is it good enough that we can tell people to do this in 3.0 then change the advice in 3.1?

[pranavkm]

@pranavkm What problems occur due to the incorrect dictionary keys? Is it good enough that we can tell people to do this in 3.0 then change the advice in 3.1?

I should have kept a gif of an app showing the repro. But since the keys are different, you can get field validaton and submit validation duplicated for the same field. In addition, submit validation would not "clear" the state of field validation. Both of these are not issues for top level properties where the keys match.

My plan was to suggest this, since it's a well-known DataAnnotations primitive until we have a better solution in 3.1.

[SteveSandersonMS]

I don't think we should suggest an approach that leads to buggy behavior (e.g., duplicated validation error messages). I'd prefer to hold off on giving any advice until we have a reasonable story for it.

[pranavkm]

Updated the text to point to a sample.

[guardrex]

Is it ready? I'd like to change that so that the sample link is under suitable link text.

... and a few other nits: 2nd person, contraction, "need."

[pranavkm]

The sample is still in PR: aspnet/samples#44. I just want some eyes on it before it's merged.

[guardrex]

I'll stand by until the dust has settled on everything. The changes are nits:

• Proper link for the sample
• Remove 2nd person
• Use a contraction
• Drop 'needs' (i.e., inanimate objects don't have 'needs,' so we use 'requirements or 'specifies or something like that)

I'll fix it up at the end.

[pranavkm]

@guardrex the sample was merged - https://github.com/aspnet/samples/tree/master/samples/aspnetcore/blazor/Validation. All yours

[guardrex]

@pranavkm Tough to describe! 😄 See if the update is sane. If so, .

[pranavkm]

Let's get this merged in 👍