From 222b3f1b043bf786646efdf70bb099406582ab42 Mon Sep 17 00:00:00 2001
From: Bryan Housel <bryan@mapbox.com>
Date: Tue, 11 Dec 2018 14:54:59 -0500
Subject: [PATCH] Don't render contents of collapsed sections (speeds things up
 if raw tag editor is hidden)

---
 modules/ui/disclosure.js       | 32 ++++++++++++++++++++------------
 test/spec/ui/raw_tag_editor.js |  3 ++-
 2 files changed, 22 insertions(+), 13 deletions(-)

diff --git a/modules/ui/disclosure.js b/modules/ui/disclosure.js
index f50ef2bfa..6b9f3f7c7 100644
--- a/modules/ui/disclosure.js
+++ b/modules/ui/disclosure.js
@@ -51,14 +51,17 @@ export function uiDisclosure(context, key, expandedDefault) {
         var wrap = selection.selectAll('.disclosure-wrap')
             .data([0]);
 
+        // enter/update
         wrap = wrap.enter()
             .append('div')
             .attr('class', 'disclosure-wrap disclosure-wrap-' + key)
-            .merge(wrap);
+            .merge(wrap)
+            .classed('hide', !_expanded);
 
-        wrap
-            .classed('hide', !_expanded)
-            .call(_content);
+        if (_expanded) {
+            wrap
+                .call(_content);
+        }
 
 
         function toggle() {
@@ -78,6 +81,11 @@ export function uiDisclosure(context, key, expandedDefault) {
                     : (textDirection === 'rtl') ? '#iD-icon-backward' : '#iD-icon-forward'
                 );
 
+            if (_expanded) {
+                wrap
+                    .call(_content);
+            }
+
             wrap
                 .call(uiToggle(_expanded));
 
@@ -86,30 +94,30 @@ export function uiDisclosure(context, key, expandedDefault) {
     };
 
 
-    disclosure.title = function(_) {
+    disclosure.title = function(val) {
         if (!arguments.length) return _title;
-        _title = _;
+        _title = val;
         return disclosure;
     };
 
 
-    disclosure.expanded = function(_) {
+    disclosure.expanded = function(val) {
         if (!arguments.length) return _expanded;
-        _expanded = _;
+        _expanded = val;
         return disclosure;
     };
 
 
-    disclosure.updatePreference = function(_) {
+    disclosure.updatePreference = function(val) {
         if (!arguments.length) return _updatePreference;
-        _updatePreference = _;
+        _updatePreference = val;
         return disclosure;
     };
 
 
-    disclosure.content = function(_) {
+    disclosure.content = function(val) {
         if (!arguments.length) return _content;
-        _content = _;
+        _content = val;
         return disclosure;
     };
 
diff --git a/test/spec/ui/raw_tag_editor.js b/test/spec/ui/raw_tag_editor.js
index ac7212ef9..a6ec85bee 100644
--- a/test/spec/ui/raw_tag_editor.js
+++ b/test/spec/ui/raw_tag_editor.js
@@ -5,7 +5,8 @@ describe('iD.uiRawTagEditor', function() {
         taglist = iD.uiRawTagEditor(context)
             .entityID(entity.id)
             .preset({isFallback: function() { return false; }})
-            .tags(tags);
+            .tags(tags)
+            .expanded(true);
 
         element = d3.select('body')
             .append('div')