[FEATURE ds-rollback-attribute] Add rolling back of a single model at…

…tribute
emberjs · Mar 18, 2016 · c5a8a0b · c5a8a0b
1 parent 3e32efe
commit c5a8a0b
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Showing 4 changed files with 99 additions and 1 deletion.
diff --git a/addon/-private/system/model/internal-model.js b/addon/-private/system/model/internal-model.js
@@ -435,6 +435,7 @@ InternalModel.prototype = {
     this.record._notifyProperties(dirtyKeys);
 
   },
+
   /*
     @method transitionTo
     @private
@@ -855,3 +856,16 @@ if (isEnabled('ds-references')) {
   };
 
 }
+
+if (isEnabled('ds-rollback-attribute')) {
+  InternalModel.prototype.rollbackAttribute = function rollbackAttribute(attributeName) {
+    var attrs = this._attributes;
+    var dirtyKeys = Object.keys(attrs);
+    if (dirtyKeys.indexOf(attributeName) !== -1) {
+      delete this._attributes[attributeName];
+      this.send('propertyWasReset', attributeName);
+      this.record.notifyPropertyChange(attributeName);
+    }
+  }
+}
+
diff --git a/addon/-private/system/model/model.js b/addon/-private/system/model/model.js
@@ -977,6 +977,30 @@ if (isEnabled("ds-references")) {
 
 }
 
+if (isEnabled('ds-rollback-attribute')) {
+  Model.reopen({
+    /**
+      Discards any unsaved changes to the given attribute.
+
+      Example
+
+      ```javascript
+      record.get('name'); // 'Untitled Document'
+      record.set('name', 'Doc 1');
+      record.get('name'); // 'Doc 1'
+      record.rollbackAttribute('name');
+      record.get('name'); // 'Untitled Document'
+      ```
+
+      @method rollbackAttribute
+    */
+    rollbackAttribute(attributeName) {
+      this._internalModel.rollbackAttribute(attributeName);
+    }
+  });
+}
+
+
 Model.reopenClass(RelationshipsClassMethodsMixin);
 Model.reopenClass(AttrClassMethodsMixin);
 

diff --git a/config/features.json b/config/features.json
@@ -3,5 +3,6 @@
   "ds-references": null,
   "ds-transform-pass-options": null,
   "ds-pushpayload-return": null,
-  "ds-serialize-ids-and-types": null
+  "ds-serialize-ids-and-types": null,
+  "ds-rollback-attribute": null
 }
diff --git a/tests/unit/model-test.js b/tests/unit/model-test.js
@@ -382,6 +382,65 @@ test("changedAttributes() works while the record is being updated", function(ass
   });
 });
 
+if (isEnabled('ds-rollback-attribute')) {
+  test("rollbackAttribute() reverts a single attribute to its canonical value", function(assert) {
+    assert.expect(5);
+    env.adapter.shouldBackgroundReloadRecord = () => false;
+
+    run(function() {
+      store.push({
+        data: {
+          type: 'person',
+          id: '1',
+          attributes: {
+            name: 'Peter',
+            isDrugAddict: true
+          }
+        }
+      });
+
+      store.findRecord('person', 1).then(function(person) {
+        assert.equal(person.get('hasDirtyAttributes'), false, "precond - person record should not be dirty");
+        person.setProperties({
+          name: 'Piper',
+          isDrugAddict: false
+        });
+        assert.equal(person.get('hasDirtyAttributes'), true, "record becomes dirty after setting property to a new value");
+        person.rollbackAttribute('isDrugAddict');
+        assert.equal(person.get('isDrugAddict'), true, "The specified attribute is rolled back");
+        assert.equal(person.get('name'), 'Piper', "Unspecified attributes are not rolled back");
+        assert.equal(person.get('hasDirtyAttributes'), true, "record with changed attributes is still dirty");
+      });
+    });
+  });
+
+  test("Rolling back the final value with rollbackAttribute() causes it to become clean again", function(assert) {
+    assert.expect(3);
+    env.adapter.shouldBackgroundReloadRecord = () => false;
+
+    run(function() {
+      store.push({
+        data: {
+          type: 'person',
+          id: '1',
+          attributes: {
+            name: 'Peter',
+            isDrugAddict: true
+          }
+        }
+      });
+
+      store.findRecord('person', 1).then(function(person) {
+        assert.equal(person.get('hasDirtyAttributes'), false, "precond - person record should not be dirty");
+        person.set('isDrugAddict', false);
+        assert.equal(person.get('hasDirtyAttributes'), true, "record becomes dirty after setting property to a new value");
+        person.rollbackAttribute('isDrugAddict');
+        assert.equal(person.get('hasDirtyAttributes'), false, "record becomes clean after resetting property to the old value");
+      });
+    });
+  });
+}
+
 test("a DS.Model does not require an attribute type", function(assert) {
   var Tag = DS.Model.extend({
     name: DS.attr()