Monkey patching Ember Data (when using ember-cli)

Question

Could anyone explain to me how to do monkey patching when using Ember CLI? It's about the following method:

https://github.com/emberjs/data/blob/fba5e5f09824caab3dfaf0e746f760b3eeacd269/packages/ember-data/lib/system/relationships/relationship.js#L284

BelongsToRelationship.prototype.addRecord = function(newRecord) {
  if (this.members.has(newRecord)){ return;}
  var type = this.relationshipMeta.type;
  Ember.assert("You can only add a '" + type.typeKey + "' record to this relationship", newRecord instanceof type);

  if (this.inverseRecord) {
    this.removeRecord(this.inverseRecord);
  }

  this.inverseRecord = newRecord;
  this._super$addRecord(newRecord);
};

I wish to temporarily disable the assert statement but I don't see how to do this without forking the whole project. I would then also need to fork the ember-data bower package project then and create my own distribution.

-- Thomas

I'm curious what's driving you to have to monkey patch ember data in this way. Are you able to elaborate on the use case some? — user239546
It's related to this pull request: github.com/emberjs/data/pull/2345. Basically I want to have a polymorphic belongs to relationship with models of any kind — Thomas Brus

Ramy Ben Aroya Ramy Ben Aroya · Accepted Answer · 2014-12-05T02:24:27

BelongsToRelationship is not defined in a way it can be accessed via the global scope. However you can retrieve it by instantiating a model with DS.belongsTo relation and digging inside of it.

This initializer should do the trick:

// app/initializers/monkey-patch.js

import DS from 'ember-data';
import Ember from 'ember';

//Hacky way to get BelongsToRelationship constructor
var getBelongsToConstructor = function(store) {
  var dummyRecord = store.createRecord(DS.Model.extend({
    dummy: DS.belongsTo(DS.Model.extend())
  }));
  return dummyRecord._relationships.dummy.constructor;
};

export default {
  name: 'monkey-patch',
  after: 'store',
  initialize: function(container, application) {
    var store = container.lookup('store:main'),
      BelongsToRelationship = getBelongsToConstructor(store),
      originalAssert = Ember.assert,
      originalAddRecord = BelongsToRelationship.prototype.addRecord;

    //Overriding assert in order to check Ember.disableAssert flag
    Ember.assert = function() {
      var args = Array.prototype.slice.call(arguments, 0),
        retVal;
      if (!Ember.disableAssert) {
        retVal = originalAssert.apply(this, args);
      }
      return retVal;
    };

    //Overriding BelongsToRelationship - calling super while asserion is disabled
    BelongsToRelationship.prototype.addRecord = function() {
      var args = Array.prototype.slice.call(arguments, 0),
        retVal;
      Ember.disableAssert = true;
      retVal = originalAddRecord.apply(this, args);
      Ember.disableAssert = false;
      return retVal;
    };
  }
};

Monkey patching Ember Data (when using ember-cli)

1 Answers