deprecation guide: window.global

content/ember/v3/deprecate-window-global.md

@@ -0,0 +1,46 @@
+---
+id: ember-source.window-global
+title: Ember Global
+until: 4.0.0
+since: 'Upcoming Features'
+---
+
+Accessing Ember on the global context (e.g. `window.Ember`, `globalThis.Ember`,
+or just `Ember` without importing it) is no longer supported. Migrate to
+importing Ember explicitly instead.
+
+Before:
+
+```js
+export default class MyComponent extends Ember.Component {
+  // ...
+}
+```
+
+After:
+
+```js
+import Ember from 'ember';
+export default class MyComponent extends Ember.Component {
+  // ...
+}
+```
+
+Alternatively, consider converting to use the Ember modules API equivalent to
+the API you are using:
+
+```js
+import Component from '@ember/component';
+export default class MyComponent extends Component {
+  // ...
+}
+```
+
+If there is no modules API equivalent, consider refactoring away from using that
+API.
+
+For addon authors that need dynamic runtime access where transpiling is not an option,
+this be used:
+```js
+const Ember = require.has('ember') ? require('ember') : window.Ember;
+```