Some ideas for fetching/finding with spine and callbacks.

gistfile1.coffee

class Model extends Spine.Model
  # This one always pulls the data from the server. 
  @fetchAndThen: (id, callback) ->
    @fetch(id: id)
    @one 'refresh', (docs) -> callback(docs[0])

  # This one pulls the data from the server if it isn't cached locally. 
  @remoteFind: (id, callback) ->
    if @exists? id
      callback @find(id)
    else
      # I have a custom persistence library with now.js that has callbacks, but this
      # could use an ajax callback or even fetchAndThen() above. 
      @fetch {id: id, success: callback}