Component *change events consistency

[rafaelss95]

Bug, feature request, or proposal:

Proposal.

What is the expected behavior?

I'd expect all components to have the same behavior. Or all return a plain object, or all return an instance of a class.

What is the current behavior?

Some components return a plain object, others return an instance of a class.

What components have a different behavior?

Topic 1 (About emit a plain object):

Chip: https://github.com/angular/material2/blob/5210b3e197647381611ec48ddcd99333ec5356e9/src/lib/chips/chip.ts#L183

Paginator: https://github.com/angular/material2/blob/5210b3e197647381611ec48ddcd99333ec5356e9/src/lib/paginator/paginator.ts#L189

Sort: https://github.com/angular/material2/blob/5210b3e197647381611ec48ddcd99333ec5356e9/src/lib/sort/sort.ts#L131

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Topic 2 (Some "change" events are named ...Event, some others are ...Change and others are ...ChangeEvent):
https://github.com/angular/material2/blob/5210b3e197647381611ec48ddcd99333ec5356e9/src/lib/autocomplete/autocomplete.ts#L35
Suffixed by 'Event'.

https://github.com/angular/material2/blob/5210b3e197647381611ec48ddcd99333ec5356e9/src/lib/tabs/tab-group.ts#L43
This is the only event that is suffixed by 'Change' and 'Event'.

https://github.com/angular/material2/blob/5210b3e197647381611ec48ddcd99333ec5356e9/src/lib/chips/chip.ts#L25
Besides being an interface (not a class), it isn't suffixed by 'Change'.

https://github.com/angular/material2/blob/5210b3e197647381611ec48ddcd99333ec5356e9/src/lib/chips/chip-input.ts#L16
Not sure about this. I think this can't be considered inconsistency, but I'll left it here anyway.

https://github.com/angular/material2/blob/5210b3e197647381611ec48ddcd99333ec5356e9/src/lib/paginator/paginator.ts#L30
Suffixed by 'Event'.

https://github.com/angular/material2/blob/5210b3e197647381611ec48ddcd99333ec5356e9/src/lib/sort/sort.ts#L41
Besides being an interface (not a class), it isn't suffixed by 'Change'.

Is there anything else we should know?

Maybe it's a complement of #6677.

[amcdnl]

This is being partly addressed by #6677

[rafaelss95]

Hey @amcdnl, as I said it's a complement of #6677.

There are inconsistencies here that aren't pointed out in that issue.

And, according to your last comment there you've already done all the work for that issue.

[vivian-hu-zz]

Team discussed the options of

1. Omitting the word "Event" from the names and instead suffixing with the type of event (e.g. "Change").
2. Always put "Event" at the end
   The decision is to go with option 2: always put "Event" at the end. It will be clearer to have "MatDatepickerInputEvent" than "MatDatepickerInput"

[rafaelss95]

@vivian-hu Hmm.. any chance to do this before v8?

[jelbourn]

This won't make it in for v8