feat(ngName): allow interpolated name for form controls

[Pasvaz]

ngName allows forms' fields to set their name dynamically, especially useful with ngRepeat.
Right now is not possible to validate form controls like this: <input type="text" name="{{field.name}}" ng-model="field.data">
The current work-around is to use one nested form for each field but indeed it's an hack rather than a solution.

This implementation could be moved inside the directive ngModel or within its own directive ngName, I left intentionally it in the NgModelController because it's slightly faster, however I can refactor it as you prefer.

this fixes also the issues #1404 and #2426

[Pasvaz]

for instance

<input type="text" name="{{field.name}}" ng-model="field.data">

with this patch would be:

<input type="text" ng-name="field.name" ng-model="field.data">

[neoasterix]

+1

[lastnico]

Hi,

I think ngForm should also benefit from this improvement, as currently, the ng-form="static-name" and name="static-name" are not interpolated, meaning you cannot define a dynamic name for inner ng-form (again, this is especially needed for ng-form in ng-repeat loops), and, in the end, they won't be populating the parent form exported list of controls.

[damrbaby]

@lastnico see #3115, I wonder if that would take care of your use case

[gregbiv]

👍

[petebacondarwin]

PR Checklist (Minor Feature)

• Contributor signed CLA now or in the past (if you just signed, leave a comment here with your real name for cross reference)
• Feature improves existing core functionality
• API is compatible with existing Angular apis and relevant standards (if applicable)
• PR doesn't contain a breaking change
• PR contains unit tests
• PR contains e2e tests (if suitable)
• PR contains documentation update
• PR passes all tests on Travis (sanity)
• PR passes all tests on ci.angularjs.org (cross-browser compatibility)
• PR is rebased against recent master
• PR is squashed into one commit per logical change
• PR's commit messages are descriptive and allows us to autogenerate release notes (required commit message format)
• All changes requested in review have been implemented

[petebacondarwin]

@Pasvaz - can you make sure you sign the CLA? Thanks

[pkozlowski-opensource]

@petebacondarwin I think we should focus on #3135 while considering this PR. The #3135 has associated unit tests and is not observing the name attribute.

[petebacondarwin]

I agree. Should we close this one?

[pkozlowski-opensource]

Yes imo. Working on 2 very similar prs doesn't make much sense and we shoul promote ones with unit tests.

[petebacondarwin]

@Pasvaz - I think we will close this for now. Thank you for putting this PR together. Perhaps you could help us review and move the other PR forward? Thanks.

[Pasvaz]

@petebacondarwin yes I signed the CLA about a month ago.

What about moving this code into its own directive ngName? I left it inside the ngForm for two reasons, it's faster and it takes care only of the ngName when it is inside a form, however I didn't like this approach, I would rather move it inside its own directive and provide also the feature to change the name of an element regardless if it is inside a form, having a directive ngName would allow me to make tests, docs and everything else.
Let me know what do you think about it.