Adding the ability to apply or discard a subset of keys

Author: thoov

addon/mixin.js

@@ -3,6 +3,8 @@ import Ember from 'ember';
 var hasOwnProp = Object.prototype.hasOwnProperty;
 var get = Ember.get;
 var set = Ember.set;
+var keys = Ember.keys;
+var isArray = Ember.isArray;
 
 function empty(obj) {
   var key;
@@ -19,8 +21,17 @@ export default Ember.Mixin.create({
     this.hasBufferedChanges = false;
   },
 
-  initializeBuffer: function() {
-    this.buffer = {};
+  initializeBuffer: function(onlyTheseKeys) {
+    if(isArray(onlyTheseKeys) && onlyTheseKeys.length > 0) {
+      keys(this.buffer).forEach(function(key) {
+        if(onlyTheseKeys.contains(key)) {
+          delete this.buffer[key];
+        }
+      }, this);
+    }
+    else {
+      this.buffer = {};
+    }
   },
 
   unknownProperty: function(key) {
@@ -65,28 +76,41 @@ export default Ember.Mixin.create({
     return value;
   },
 
-  applyBufferedChanges: function() {
+  applyBufferedChanges: function(onlyTheseKeys) {
     var buffer = this.buffer;
     var content = this.get('content');
 
-    Ember.keys(buffer).forEach(function(key) {
+    keys(buffer).forEach(function(key) {
+      if (isArray(onlyTheseKeys) && !onlyTheseKeys.contains(key)) {
+        return;
+      }
+
       set(content, key, buffer[key]);
     });
 
-    this.initializeBuffer();
-    this.set('hasBufferedChanges', false);
+    this.initializeBuffer(onlyTheseKeys);
+
+    if (keys(this.buffer).length === 0) {
+      this.set('hasBufferedChanges', false);
+    }
   },
 
-  discardBufferedChanges: function() {
+  discardBufferedChanges: function(onlyTheseKeys) {
     var buffer = this.buffer;
 
-    this.initializeBuffer();
+    this.initializeBuffer(onlyTheseKeys);
+
+    keys(buffer).forEach(function(key) {
+      if (isArray(onlyTheseKeys) && !onlyTheseKeys.contains(key)) {
+        return;
+      }
 
-    Ember.keys(buffer).forEach(function(key) {
       this.propertyWillChange(key);
       this.propertyDidChange(key);
     }, this);
 
-    this.set('hasBufferedChanges', false);
+    if (keys(this.buffer).length === 0) {
+      this.set('hasBufferedChanges', false);
+    }
   }
 });

tests/unit/mixin-test.js

@@ -3,19 +3,19 @@ import Ember from 'ember';
 
 module("ember-buffered-proxy/mixin");
 
-test("exists", function() { 
+test("exists", function() {
   ok(Mixin);
 });
 
 test("that it works", function() {
   var BufferedPorxy = Ember.ObjectProxy.extend(Mixin);
 
   var content = {
-    baz: 1 
+    baz: 1
   };
 
   var proxy = BufferedPorxy.create({
-    content: content                
+    content: content
   });
 
   equal(proxy.get('baz'), 1);
@@ -60,3 +60,99 @@ test("that it works", function() {
   equal(proxy.get('baz'), 1);
   equal(content.baz, 1);
 });
+
+test("that apply only these keys works", function() {
+  var BufferedPorxy = Ember.ObjectProxy.extend(Mixin);
+
+  var content = {
+    baz: 1,
+    world: 'hello'
+  };
+
+  var proxy = BufferedPorxy.create({
+    content: content
+  });
+
+  equal(proxy.get('baz'), 1);
+  equal(content.baz, 1);
+  equal(proxy.get('world'), 'hello');
+  equal(content.world, 'hello');
+
+  ok(!('foo' in content));
+  equal(proxy.get('hasBufferedChanges'), false);
+
+  proxy.set('foo', 1);
+
+  equal(proxy.get('foo'), 1);
+  ok(!('foo' in content));
+  equal(proxy.get('hasBufferedChanges'), true);
+
+  proxy.set('testing', '1234');
+
+  equal(proxy.get('testing'), '1234');
+  ok(!('testing' in content));
+  equal(proxy.get('hasBufferedChanges'), true);
+
+  proxy.applyBufferedChanges(['foo']);
+
+  equal(proxy.get('foo'), 1);
+  ok('foo' in content);
+  ok(!('testing' in content));
+  equal(proxy.get('hasBufferedChanges'), true);
+  equal(content.foo, 1);
+  equal(proxy.get('testing'), '1234');
+
+  proxy.applyBufferedChanges(['testing']);
+
+  equal(proxy.get('testing'), '1234');
+  ok('testing' in content);
+  equal(proxy.get('hasBufferedChanges'), false);
+  equal(content.testing, '1234');
+
+  // Testing discardBufferdChanges with onlyTheseKeys
+
+  proxy.setProperties({
+    bar: 2,
+    example: 123
+  });
+
+  equal(proxy.get('foo'), 1);
+  equal(proxy.get('bar'), 2);
+  equal(proxy.get('example'), 123);
+
+  ok('foo' in content);
+  ok('testing' in content);
+  ok(!('bar' in content));
+  ok(!('example' in content));
+
+  equal(proxy.get('hasBufferedChanges'), true);
+
+  proxy.discardBufferedChanges(['bar']);
+
+  equal(proxy.get('foo'), 1);
+  equal(proxy.get('testing'), '1234');
+  equal(proxy.get('bar'), undefined);
+  equal(proxy.get('example'), 123);
+
+  ok('foo' in content);
+  ok('testing' in content);
+  ok(!('bar' in content));
+  ok(!('example' in content));
+  equal(proxy.get('hasBufferedChanges'), true);
+
+  proxy.discardBufferedChanges(['example']);
+
+  equal(proxy.get('foo'), 1);
+  equal(proxy.get('testing'), '1234');
+  equal(proxy.get('bar'), undefined);
+  equal(proxy.get('example'), undefined);
+
+  ok('foo' in content);
+  ok('testing' in content);
+  ok(!('bar' in content));
+  ok(!('example' in content));
+  equal(proxy.get('hasBufferedChanges'), false);
+
+  equal(proxy.get('baz'), 1);
+  equal(content.baz, 1);
+});