feat(prefixer): add service to prefix attributes

[devversion]

The service contains the following features:

• Check for an element, to have the specified attribute, including the prefixes
• Generate an attribute selector for the specified attribute
• Build a list of all prefixed attributes

Fixes #3258. Fixes #8080. Closes #8121

[Frank3K]

Thumbs up, this is functionality that is often (or should often be) used.

At first it was not clear to me when one should the the prefixer with an initial parameter or when one should call a method on the instantiated prefixer. When reading the code it became clear to me. I do not have a suggestion yet on how to improve this.

In your PR you add the functionality to a number of components, which is good. However, I think not all components are reached. For example md-autofocus in util.js (references #4180).

[ThomasBurleson]

Since most of the examples are prefixing for a querySelector, perhaps this would be better:

$provide.decorator('$mdUtil', ['$delegate', function ($delegate) {
    var prefixer = new MdPrefix();

    // Publish easy alias for 'quick-use'
    $delegate.prefix = angular.bind(prefixer, prefixer.buildList);
    $delegate.prefixForQuery = angular.bind(prefixer, prefixer.buildSelector);

    // Return full prefixer
    $delegate.prefixer = prefixer;
}

[devversion]

Hm, I don't really like it.

Then the actual prefixer() will be only used for hasAttribute.
This will make the whole constructor function unnecessary.

I would rather change the constructor fn to something like that

$mdUtil.prefixer('ng-click', true)

[devversion]

FYI: This comment is already outdated, since @ThomasBurleson and I had a discussion about it and figured out a better solution.

[devversion]

@Frank3K Thanks for the feedback.

Awesome, that the code was enough the clarify the intention. When the code is clear enough to show, how it works, then it's good code (no self-praise 😄)

Yea, I went through the most components and searched for queries, which can be accessed by developers.

Thanks for the alert of the auto-focus directive. I will add some more today, maybe you can help and list some other queries you found ;)

[Frank3K]

I have done a quick search but haven't found more.

[devversion]

@Frank3K Great, thanks for your effort. @ThomasBurleson PTAL.

[ThomasBurleson]

@devversion - merge confict with master. Can you rebase please.