How to overwrite ember-data reader method? or convert DS.attr to computed property?

I have an endpoint that returns id, name, properties, and properties is a damn string, with comma separated attribute key/value pairs. Yes you read that correctly.

properties = "id:1,name:foobar,phone:123456789,taco:true"

Current Model

import DS from 'ember-data';

export default DS.Model.extend({
  contact: DS.belongsTo("contact"),

  name: DS.attr(),
  phone: DS.attr(),
  properties: DS.attr(),
  eachProperties: function () {
    return this.get('properties').split(",").map(function(propertyKeyValuePair) {
      return propertyKeyValuePair.split(":");
    });
  }.property('properties')
});

properties requires some computation to be helpful on the front-end.

Can you re-use the property named properties instead of creating a new one called eachProperties?

Something like:

export default DS.Model.extend({
  // ... other stuff

  properties: DS.attr(function(model, obj){
    return obj.split(",").map(function(propertyKeyValuePair) {
      return propertyKeyValuePair.split(":");
    });
  });
});

OR how does one change the name of an api property name to something else like rawProperties and then have the computed property called properties?

I know you're thinking "Just fix your damn API" but you know that isn't always possible :)