Deprecate model hooks and events

[bajtos]

Deprecate the following Model hooks:

• beforeValidate
• afterValidate
• beforeCreate
• afterCreate
• beforeSave
• afterSave
• beforeUpdate
• afterUpdate
• beforeDestroy
• afterDestroy

Deprecate the following Model events:

• changed
• deletedAll
• deleted

Closes strongloop/loopback#617.

/to @raymondfeng @ritch please review

[bajtos]

I added one more commit to fix depd in browser. We may want to extract "lib/browser.depd.js" into a standalone module in the future, or perhaps contribute the simpler version to depd. I don't have enough time for that right now.

@raymondfeng @ritch ping, is this good to be merged?

[bajtos]

I made one more change. Initially, event deprecation messages were printed at the time when the deprecated event was emitted. That's a wrong approach, because depd will print a stack showing where the event was emitted, which is not helpful in identifying the place which is listening for this deprecated event. I have reworked the implementation to print the deprecation message from Model.on() and cleaned up the commit history along the way.

The PR is ready for review and merge.

[ritch]

LGTM

[bajtos]

For posterity, the CI build passed on 5 out of 6 machines.

[bajtos]

@crandmck could you please update the docs and reword the warning to a deprecation note? http://docs.strongloop.com/display/LB/Model+hooks

I am not sure if the we have the model events (Model.on('changed'), deleted, deletedAll) documented anywhere. If we do, then please update that page as well.

[crandmck]

Added deprecation notice. I removed

However, afterInitialize is still useful.
Should that stay in?

Also removed the following events from http://docs.strongloop.com/display/LB/Events and http://docs.strongloop.com/display/LB/Basic+model+object:

• changed
• deleted
• deletedAll

@bajtos Please confirm that is correct, and I will also remove from http://apidocs.strongloop.com/loopback/#model.

[bajtos]

@crandmck Thank you.

However, afterInitialize is still useful.

Should that stay in?

Yes please, afterInitialize is not deprecated and still useful. It is also different from the rest of the model hooks because it's synchronous (i.e. there is no callback).

Also removed the following events from http://docs.strongloop.com/display/LB/Events

Can that page mention that there are Operation hooks that should (and can) be used instead of the deprecated events?

Also perhaps the page http://docs.strongloop.com/display/LB/Basic+model+object should link to "Operation hooks" instead of "Model hooks"?

[crandmck]

OK, added note about afterInitialize, and note about using operation hooks instead of the deprecated events.