Add option for templateManipulator to ignore specific ng-model

[mikejpeters]

Sometimes custom templates may involve multiple directives referring to the same ng-model. For example:

<div class="dropdown">
    <input ng-model="model[options.key]">
    <a data-toggle="dropdown">Click here to show calendar</a>
    <ul class="dropdown-menu">
        <datetimepicker ng-model="model[options.key]"></datetimepicker>
    </ul>
</div>

In this situation, formly adds the same attributes to both the input and datetimepicker.

We can tell the manipulator to skip ALL attributes using skipNgModelAttrsManipulator, but what we really want is to just ignore the one on datetimepicker.

It would be great to be able to add an attribute to the actual element so it is ignored:

<datetimepicker ng-model="model[options.key]" formly-skip-ng-model-attrs-manipulator>

[kentcdodds]

Very good. I like the suggestion. I'd be happy to pull this concept in. I'll try to get to it as soon as I am able. If you want to try your hand at a PR, see CONTRIBUTING.md and the changes will likely be around here: https://github.com/formly-js/angular-formly/blob/master/src/run/formlyNgModelAttrsManipulator.js#L17

[kentcdodds]

Like with #343, I've created tests for this feature and I'm going to give someone a shot at contributing to open source for the first time :-) So I will only accept a PR from someone who's never contributed to open source before.

Instructions:

• Watch this video to learn what you need to do to get things setup
• Go to these tests and change it.skip to it.only
• Run $ npm test
• Notice that all the tests are failing
• Update the formlyNgModelAttrsManipulator to make the tests pass. (hint, what you'll want to do is construct the query sent into querySelectorAll to add :not for both the special attribute as well as the specified selector, so you can potentially have two :nots in your query.)
• Once they're passing, change the it.onlys to its so all the tests run.
• Commit your changes to the src/ directory mentioning issue Add a hook to transform field config before forms are compiled #343 (notice it runs all the tests... twice)
• Push your changes to your fork, create a PR, get merged, celebrate 🎉

I'm happy to hold your hand through this if you need help. Catch me on gitter.

[kentcdodds]

P.S. I've already developed the solution, I just haven't committed it because I want to give someone else a first shot at contributing to open source 👍

[kentcdodds]

@douglas-mason committed this! Thanks!

[kentcdodds]

This will be released as soon as I'm able