From 3f9a4d42f7bf0c90c38834fdb20c3f8361695573 Mon Sep 17 00:00:00 2001
From: Bob Trahan <bob.trahan@gmail.com>
Date: Tue, 13 Aug 2013 16:14:26 -0700
Subject: [PATCH] Better JS for Differential File Collapsing Undo

Summary: take epriestley's feedback 'cuz its good

Test Plan: collapse, expand, use undo like a rockstar. observe proper behavior

Reviewers: epriestley

Reviewed By: epriestley

CC: Korvin, aran

Maniphest Tasks: T2258

Differential Revision: https://secure.phabricator.com/D6748
---
 .../differential/behavior-toggle-files.js     | 30 ++++++++++---------
 1 file changed, 16 insertions(+), 14 deletions(-)

diff --git a/webroot/rsrc/js/application/differential/behavior-toggle-files.js b/webroot/rsrc/js/application/differential/behavior-toggle-files.js
index a680e69c3a..296b6f91b2 100644
--- a/webroot/rsrc/js/application/differential/behavior-toggle-files.js
+++ b/webroot/rsrc/js/application/differential/behavior-toggle-files.js
@@ -18,26 +18,28 @@ JX.behavior('differential-toggle-files', function(config) {
       }
 
       var diff = e.getData().diff[0],
-          data = JX.Stratcom.getData(diff),
-          undo;
+          data = JX.Stratcom.getData(diff);
       if (data.hidden) {
         data.hidden = false;
         JX.DOM.show(diff);
-        undo = JX.DOM.find(diff.parentNode,
-                           'div',
-                           'differential-collapse-undo-div');
-        JX.DOM.remove(undo);
+        JX.DOM.remove(data.undo);
+        data.undo = null;
       } else {
         data.hidden = true;
+        data.undo = render_collapse_undo();
         JX.DOM.hide(diff);
-        undo = render_collapse_undo();
-        JX.DOM.listen(undo, 'click', 'differential-collapse-undo', function(e) {
-          e.kill();
-          data.hidden = false;
-          JX.DOM.show(diff);
-          JX.DOM.remove(undo);
-        });
-        JX.DOM.appendContent(diff.parentNode, undo);
+        JX.DOM.listen(
+          data.undo,
+          'click',
+          'differential-collapse-undo',
+          function(e) {
+            e.kill();
+            data.hidden = false;
+            JX.DOM.show(diff);
+            JX.DOM.remove(data.undo);
+            data.undo = null;
+          });
+        JX.DOM.appendContent(diff.parentNode, data.undo);
       }
       JX.Stratcom.invoke('differential-toggle-file-toggled');
     });