Manage channel subscriptions inside DataSource

[ovidiuch]

Need

Decouple DataSource from Widgets: We want the DataSource to be a self-sustained encapsulated module. Maybe even a separate OS component.

Deliverables (specs in this case)

• An API for primitive subscribing to a DataSource channel
• DataSource is the only element bound to a channel directly (so we have only one callback for channel)
• When a primitive (Object {} subclass) subscribes to a DS channel, its reference is put into a global mapping within the DS, and not bound directly to the Backbone collection/model. When the DS receives an event for a channel, it traverses the global mapping of subscribers->channels, and dynamically establish which methods of which widget to call. This has a lot of advantages
  • GC is improved crazily! Only the DS is tied directly to a collection/model, the widgets just need to be removed from the DS global mapping.
  • Having a DS global mapping makes debugging widget channels a dream, we can see them in plain text
  • Widgets can change their get_items methods on the fly, we won't need fat arrows, post-initialize states or the backbone_events mambojambo; this isn't a real need, but it sure helps keeping this simple and transparent

    Solution

    Prerequisites

• [required dependency for identifying the problem, scope and then solution for this issue]

  TODO

• [logical step in completing this story]

  Files

• [path to a file involved in this story]

  Notes

• [peculiar aspect relevant this story]

  ETA [0-2]p

[ovidiuch]

@aismail @valentinzberea what do you think? Not really something to implement in a single increment, but something to strive towards maybe? (B plan)

[aismail]

I love it - we're going to be implementing this partially for our next release (due within a few weeks).

[ovidiuch]

:heart: