onBeforeAttach and onAttach for CollectionView child views

[ianmstew]

Fixes #2526. Cherry-pick of #2481 for 2.4.2.

[ianmstew]

Pinging @ahumphreys87 and @jasonLaster -- you guys thumbs-upped the original PR against next. :)

[ianmstew]

The main difference between this and the original PR is that, instead of calling Marionette.triggerMethodMany(), I'm calling this._triggerMethodMany(), which is actually Jason's code from next that I dropped into CollectionView for backward-compatibility.

The second difference is the once('render' approach to firing before:attach within _addChildView() that we agreed on strictly for 2.4.2 here: #2481 (comment).

Obviously, both of these workarounds do not exist in the original code already merged into next.

[jasonLaster]

Is it safe to drop addEmptyView? Sorry Ian if yhis is more work.

[ahumphreys87]

That's my only questions also, tricky as its one of those methods that probably should never have been "public" as it does so much that people shouldn't mess with but because it was it will be a breaking change :(

[ianmstew]

Ahh, I overlooked that. No problem at all.

[ianmstew]

There we go. I wanted to cry bumping maxstatements and maxcomplexity just because of addEmptyView()...

[ahumphreys87]

yeah it's ok we can kill it in 3.0 :)

👍

[jasonLaster]

💥