Implement post editing

ember/app/components/discussions/composer-edit.js

@@ -0,0 +1,48 @@
+import Ember from 'ember';
+
+import TaggedArray from '../../utils/tagged-array';
+
+var precompileTemplate = Ember.Handlebars.compile;
+
+export default Ember.Component.extend(Ember.Evented, {
+	layoutName: 'components/discussions/composer-body',
+
+	submitLabel: 'Save Changes',
+	placeholder: '',
+	content: Ember.computed.oneWay('post.content'),
+	originalContent: Ember.computed.oneWay('post.content'),
+	submit: null,
+	loading: false,
+
+	didInsertElement: function() {
+		var controls = TaggedArray.create();
+		this.trigger('populateControls', controls);
+		this.set('controls', controls);
+	},
+
+	populateControls: function(controls) {
+		var title = Ember.Component.create({
+			tagName: 'h3',
+			layout: precompileTemplate('Editing Post #{{component.post.number}} in <em>{{discussion.title}}</em>'),
+			discussion: this.get('post.discussion'),
+			component: this
+		});
+		controls.pushObjectWithTag(title, 'title');
+	},
+
+	actions: {
+		submit: function(content) {
+			this.get('submit')({
+				content: content
+			});
+		},
+
+		willExit: function(abort) {
+			// If the user has typed something, prompt them before exiting
+			// this composer state.
+			if (this.get('content') !== this.get('originalContent') && ! confirm('You have not saved your post. Do you wish to discard your changes?')) {
+				abort();
+			}
+		}
+	}
+});