Material: Custom validation in md-autocomplete

[calebegg]

We have some custom validation directives that we'd like to be able to use on md-autocomplete, but can't, because it doesn't use ng-model (and the wrapped <md-input-container> has its own ng-model).

[ThomasBurleson]

Great feature for PR from community contributor.

[devversion]

@calebegg What item you want to access from the ngModelController? The selected item or just the search text?

[calebegg]

For our use case, we want the search text. Though, I know other people want the selected item so they can mark it as invalid if there's no selected item.

[enderdickerson]

For our use case we would like to access the selected item as @calebegg said just to ensure an item was selected from the list instead of validating against the presence of search text.

[devversion]

Okay, I just think about the search text too. We should provide both possibilities. But in first, what do you think about mirroring a ngModel, which can be accessed from the custom directives?

[enderdickerson]

Mirroring the ngModel for use with custom directives would be fine

[timruffles]

Great to see this is being discussed!

@DevVersion what does mirroring the ngModel mean? Would it support the standard <md-autocomplete name=someName ng-model=$ctrl.someProp approach (see #7910)?