From f9e4a8500aa9e96aa9b73358088625dddfc54bfc Mon Sep 17 00:00:00 2001
From: Daryl Koopersmith <koop@git.wordpress.org>
Date: Tue, 9 Jul 2013 08:50:32 +0000
Subject: [PATCH] Revisions: Move data management into the frame state. See
 #24425.

This helps to solidify the separation between data and UI. We track the diffId internally now, as the property itself was never referenced, and was always derived from the 'from' and 'to' models. This also sets us up for better request debouncing and diff management.



git-svn-id: https://develop.svn.wordpress.org/trunk@24609 602fd350-edb4-49c9-b593-d223f7449a82
---
 wp-admin/js/revisions.js | 61 ++++++++++++++++++++++++----------------
 1 file changed, 36 insertions(+), 25 deletions(-)

diff --git a/wp-admin/js/revisions.js b/wp-admin/js/revisions.js
index a3d58740ab..0747fa65fb 100644
--- a/wp-admin/js/revisions.js
+++ b/wp-admin/js/revisions.js
@@ -209,8 +209,26 @@ window.wp = window.wp || {};
 		// will only be updated once. This is because Backbone updates all of
 		// the changed attributes in `set`, and then fires the `change` events.
 		updateDiff: function() {
-			var from = this.get('from');
-			this.set( 'diffId', (from ? from.id : '0' ) + ':' + this.get('to').id );
+			var from, to, diffId;
+
+			from = this.get('from');
+			to = this.get('to');
+			diffId = ( from ? from.id : 0 ) + ':' + to.id;
+
+			// Check if we're actually changing the diff id.
+			if ( this._diffId === diffId )
+				return;
+
+			this._diffId = diffId;
+			this.trigger( 'update:revisions', from, to );
+
+			this.diffs.ensure( diffId, this ).done( function( diff ) {
+				// Check if the current diff changed while the request was in flight.
+				if ( this._diffId !== diff.id )
+					return;
+
+				this.trigger( 'update:diff', diff );
+			});
 		}
 	});
 
@@ -231,7 +249,7 @@ window.wp = window.wp || {};
 				revisions: this.collection
 			});
 
-			this.listenTo( this.model, 'change:diffId', this.updateDiff );
+			this.listenTo( this.model, 'update:diff', this.renderDiff );
 			this.listenTo( this.model, 'change:compareTwoMode', this.updateCompareTwoMode );
 
 			this.views.set( '.revisions-control-frame', new revisions.view.Controls({
@@ -264,17 +282,10 @@ window.wp = window.wp || {};
 			return this;
 		},
 
-		updateDiff: function() {
-			this.model.diffs.ensure( this.model.get('diffId'), this ).done( function( diff ) {
-				if ( this.model.get('diffId') !== diff.id )
-					return;
-
-				this.views.set( '.revisions-diff-frame', new revisions.view.Diff({
-					model: diff
-				}) );
-
-				this.model.trigger('renderDiff');
-			});
+		renderDiff: function( diff ) {
+			this.views.set( '.revisions-diff-frame', new revisions.view.Diff({
+				model: diff
+			}) );
 		},
 
 		updateCompareTwoMode: function() {
@@ -364,7 +375,7 @@ window.wp = window.wp || {};
 		},
 
 		initialize: function() {
-			this.listenTo( this.model, 'change:diffId', this.updateMeta );
+			this.listenTo( this.model, 'update:revisions', this.updateMeta );
 		},
 
 		restoreRevision: function() {
@@ -372,10 +383,10 @@ window.wp = window.wp || {};
 			document.location = restoreUrl;
 		},
 
-		updateMeta: function() {
+		updateMeta: function( from, to ) {
 			this.$el.html( this.template( this.model.toJSON() ) );
 
-			$('#restore-revision').prop( 'disabled', this.model.get('to').attributes.current );
+			$('#restore-revision').prop( 'disabled', to.attributes.current );
 		}
 	});
 
@@ -481,7 +492,7 @@ window.wp = window.wp || {};
 		},
 
 		ready: function() {
-			this.listenTo( this.model, 'change:diffId', this.disabledButtonCheck );
+			this.listenTo( this.model, 'update:revisions', this.disabledButtonCheck );
 		},
 
 		// Go to a specific modelindex, taking into account RTL mode.
@@ -582,8 +593,8 @@ window.wp = window.wp || {};
 				this.updateSliderSettings();
 			}, this );
 
-			// Listen for changes in the diffId
-			this.listenTo( this.model, 'change:diffId', this.diffIdChanged );
+			// Listen for changes to the revisions
+			this.listenTo( this.model, 'update:revisions', this.updateRevisions );
 		},
 
 		mousemove: function( e ) {
@@ -672,15 +683,15 @@ window.wp = window.wp || {};
 			}
 		},
 
-		diffIdChanged: function() {
-			// Reset the view settings when diffId is changed
+		updateRevisions: function( from, to ) {
+			// Update the view settings when the revisions have changed.
 			if ( this.model.get('compareTwoMode') ) {
 				this.settings.set({ 'values': [
-					this.model.revisions.indexOf( this.model.get('from') ),
-					this.model.revisions.indexOf( this.model.get('to') )
+					this.model.revisions.indexOf( from ),
+					this.model.revisions.indexOf( to )
 				] });
 			} else {
-				this.settings.set({ 'value': this.model.revisions.indexOf( this.model.get('to') ) });
+				this.settings.set({ 'value': this.model.revisions.indexOf( to ) });
 			}
 		},