ember-computed-change-gate - npm Package Compare versions

Comparing version 0.0.1 to 0.0.2

addon/change-gate.js

 import Em from 'ember';
 
-var get = Em.get,
-    getMeta = Em.getMeta,
-    setMeta = Em.setMeta;
+var get = Em.get;
 
-var defaultFilter = function(value) { console.log('value', value); return value; }
+var defaultFilter = function(value) { return value; };
 
@@ -12,29 +10,25 @@ export default function(dependentKey, filter) {
 
-  return Em.computed(function(key) {
-    var hasObserverKey = '_changeGate:%@:hasObserver'.fmt(key);
-    var lastValueKey =   '_changeGate:%@:lastValue'.fmt(key);
-    var isFirstRun = !getMeta(this, hasObserverKey);
+  var computed = Em.computed(function handler(key) {
 
-    if(isFirstRun) { //setup an observer which is responsible for notifying property changes
-      // debugger;
-      var value = filter(get(this, dependentKey));
+    var lastValueKey = '__changeGate%@LastValue'.fmt(key);
 
-      setMeta(this, hasObserverKey, true);
-      setMeta(this, lastValueKey, value);
+    var isFirstRun = !this.hasOwnProperty(lastValueKey);
+    if (isFirstRun) { //setup an observer which is responsible for notifying property changes
+      this[lastValueKey] = filter.call(this, get(this, dependentKey));
 
       this.addObserver(dependentKey, function() {
-        var newValue = filter(get(this, dependentKey));
-        var lastValue = getMeta(this, lastValueKey);
+        var newValue = filter.call(this, get(this, dependentKey));
+        var lastValue = this[lastValueKey];
 
         if(newValue !== lastValue) {
-          setMeta(this, lastValueKey, newValue);
+          this[lastValueKey] = newValue;
           this.notifyPropertyChange(key);
         }
       });
+    }
 
-      return value;
-    } else {
-      return getMeta(this, lastValueKey);
-    }
+    return this[lastValueKey];
   });
+
+  return computed;
 }

package.json

 {
   "name": "ember-computed-change-gate",
-  "version": "0.0.1",
+  "version": "0.0.2",
   "directories": {
@@ -5,0 +5,0 @@ "doc": "doc",

README.md

 # ember-computed-change-gate
 
-Observers on Ember.js computed properties are fired regardless of the property value changes or not. `ember-computed-change-gate` only triggers observers when the result of a computed property changes.
+[![Build Status](https://travis-ci.org/GavinJoyce/ember-computed-change-gate.svg)](https://travis-ci.org/GavinJoyce/ember-computed-change-gate)
 
+Observers on Ember.js computed properties are fired if a dependant key changes, regardless of whether the property value changes or not. `ember-computed-change-gate` only triggers observers when the result of a computed property changes.
+
 Consider the following example:
@@ -37,5 +39,5 @@
 
-## [Watch a screencast on how this addon was built >>](https://www.youtube.com/watch?v=PDgvMAyA8ic)
+## Watch a screencast showing how this addon was built below
 
-![Image](https://cloud.githubusercontent.com/assets/2526/4349867/d399b15e-41c9-11e4-8319-43c2e06186aa.png)
+[![Image](https://cloud.githubusercontent.com/assets/2526/4349867/d399b15e-41c9-11e4-8319-43c2e06186aa.png)](https://www.youtube.com/watch?v=PDgvMAyA8ic)
 
@@ -42,0 +44,0 @@ Questions? Ping me [@gavinjoyce](https://twitter.com/gavinjoyce)

tests/unit/change-gate-test.js

@@ -73,1 +73,98 @@ import Em from 'ember';
 });
+
+test('a changeGate on multiple instances of same class', function(){
+
+  var Paragraph = Em.Object.extend({
+    text: 'Hello there',
+    wordCount: changeGate('text', function(value) {
+      return value.split(/\s+/).length;
+    })
+  });
+
+  var p1 = Paragraph.create({text: 'Foo Bar baz'});
+  var p2 = Paragraph.create({text: 'Bar Foo'});
+
+  equal(p1.get('wordCount'), 3);
+  equal(p2.get('wordCount'), 2);
+
+
+  var p1Observer = 0;
+  var p2Observer = 0;
+
+  p1.addObserver('wordCount', function() {
+    p1Observer++;
+  });
+
+  p2.addObserver('wordCount', function() {
+    p2Observer++;
+  });
+
+  p1.set('text', 'Foo Bar Bar Boo');
+  equal(p1Observer, 1, "the observer fires once when the value is changed on p1");
+
+  p2.set('text', "Bar Foo Foo");
+  equal(p2Observer, 1, "the observer fires once when the value is changed on p2");
+
+  p1.set('text', 'Foo Bar Bar Bar Baa');
+  equal(p1Observer, 2, "change to p1 is only recorded on this object, not the other");
+});
+
+test('multiple changeGate properties on same object', function() {
+
+  var Paragraph = Em.Object.extend({
+    text: 'Hello there',
+    wordCount: changeGate('text', function(value) {
+      return value.split(/\s+/).length;
+    }),
+    letterCount: changeGate('text', function(value) {
+      return value.split('').length;
+    })
+  });
+
+  var p = Paragraph.create();
+
+  var wordCountObserverCount = 0;
+  var letterCountObserverCount = 0;
+
+  p.addObserver('wordCount', function() {
+    wordCountObserverCount++;
+  });
+
+  p.addObserver('letterCount', function(){
+    letterCountObserverCount++;
+  });
+
+  equal(p.get('wordCount'), 2); 
+  equal(p.get('letterCount'), 11);
+
+  p.set('text', 'Hello  there');
+  equal(p.get('wordCount'), 2);  
+  equal(p.get('letterCount'), 12);
+  equal(letterCountObserverCount, 1, "uneffected observer does not fire when another observer is fired");
+
+  p.set('text', 'Hello there you');
+  equal(p.get('letterCount'), 15);
+  equal(p.get('wordCount'), 3);
+
+  equal(letterCountObserverCount, 2, "intended observer fires when effected");
+  equal(wordCountObserverCount, 1, "uneffected observer does not fire when another observer is fired");
+
+});
+
+test("changeGate filter is bound to instance that it's attached to", function(){
+
+  expect(1);
+
+  var instance;
+
+  var Paragraph = Em.Object.extend({
+    text: 'Hello there',
+    wordCount: changeGate('text', function(value) {
+      equal(this, instance);
+      return value.split(/\s+/).length;
+    })
+  });
+
+  instance = Paragraph.create();
+  instance.get('wordCount');
+});

No alert changes

Improved metrics

Total package byte prevSize

19541

increased by14.36%

Lines of code

319

increased by24.61%

Number of lines in readme file

55

increased by3.77%

No dependency changes