Merge pull request #2573 from robbiepitts/deprecate-ember-binding

Deprecate Ember.Binding

source/deprecations/v2.x.html.md

@@ -504,6 +504,67 @@ Once view and controller deprecations are removed, you can remove the addons wit
 `Ember.Backburner` was private throughout the Ember 2.x series and will be
 removed _after_ 2.8.
 
+#### Ember.Binding
+
+##### until: 3.0.0
+##### id: ember-metal.binding
+
+`Ember.Binding` has not been needed for some time and is deprecated in favor of
+computed properties and services (depending on what you were binding to). It is
+recommended that you take the following actions:
+
+1. Refactor global bindings to services
+2. Refactor `oneWay` bindings to `readOnly` computed properties
+3. Refactor all other bindings to `alias` computed properties
+
+The [guide on services]
+(https://guides.emberjs.com/v2.5.0/applications/services/) is a good place
+to start for creating and consuming services to replace your global bindings.
+In general though, you will replace your global with a service and consume it
+like this:
+
+```js
+export default Ember.Component.extend({
+  // will load the service in file /app/services/cool-service.js
+  coolService: Ember.inject.service()
+});
+```
+
+This would replace a binding that may have looked like this:
+
+```js
+export default Ember.Component.extend({
+  boringObjectBinding: 'MyApp.boringObject'
+});
+```
+
+Refactoring local bindings to computed properties can be achieved with
+less work:
+
+If you had this:
+
+```js
+export default Ember.Component.extend({
+  thingContainer: …,
+  thingOneBinding: Ember.Binding.oneWay('thingContainer.thingOne'),
+  thingTwoBinding: 'thingContainer.thingTwo'
+});
+```
+
+You could change it to this:
+
+```js
+export default Ember.Component.extend({
+  thingContainer: …,
+  thingOne: Ember.computed.readOnly('thingContainer.thingOne'),
+  thingTwo: Ember.computed.alias('thingContainer.thingTwo')
+});
+```
+
+See the [guide on computed properties]
+(https://guides.emberjs.com/v2.5.0/object-model/computed-properties/) for
+further reading.
+
 ### Deprecations Added in Pending Features
 
 #### Route#serialize