jamesarosen/ember-cpm — pull request #18 by rjackson (2014-04-11 03:21:30+00:00)
Title: Add EmberCPM.Macros.sumBy.

Operates on an array of objects, and sums a given property on the object. The implementation is essentially the same as `Ember.computed.sum` with a few changes (to get the value of a given property instead of just adding each item).