Retry failed page anchor navigation

Summary:
When the user loads a page with an anchor on it like #thing, or clicks a link to
#thing, and #thing doesn't exist, keep trying to navigate to #thing for a few
seconds.

This allows anchors to work when the target is in content which is later ajaxed
in. In particular, this affects inline comments in Differential.

Test Plan: Opened inline comment links in a new tab, was in the right place when
I switched tabs.

Reviewers: nh, btrahan, jungejason

Reviewed By: btrahan

CC: aran, btrahan, epriestley

Maniphest Tasks: T492

Differential Revision: https://secure.phabricator.com/D1327

src/__celerity_resource_map__.php

@@ -731,13 +731,14 @@ celerity_register_resource_map(array(
   ),
   'javelin-behavior-phabricator-watch-anchor' =>
   array(
-    'uri' => '/res/96f40736/rsrc/js/application/core/behavior-watch-anchor.js',
+    'uri' => '/res/2a4963c3/rsrc/js/application/core/behavior-watch-anchor.js',
     'type' => 'js',
     'requires' =>
     array(
       0 => 'javelin-behavior',
       1 => 'javelin-stratcom',
       2 => 'javelin-dom',
+      3 => 'javelin-vector',
     ),
     'disk' => '/rsrc/js/application/core/behavior-watch-anchor.js',
   ),
@@ -1729,24 +1730,6 @@ celerity_register_resource_map(array(
       'uri' => '/res/pkg/11a5c52c/differential.pkg.js',
       'type' => 'js',
     ),
-    '4e7acf1a' =>
-    array(
-      'name' => 'core.pkg.js',
-      'symbols' =>
-      array(
-        0 => 'javelin-mask',
-        1 => 'javelin-workflow',
-        2 => 'javelin-behavior-workflow',
-        3 => 'javelin-behavior-aphront-form-disable-on-submit',
-        4 => 'phabricator-keyboard-shortcut-manager',
-        5 => 'phabricator-keyboard-shortcut',
-        6 => 'javelin-behavior-phabricator-keyboard-shortcuts',
-        7 => 'javelin-behavior-refresh-csrf',
-        8 => 'javelin-behavior-phabricator-watch-anchor',
-      ),
-      'uri' => '/res/pkg/4e7acf1a/core.pkg.js',
-      'type' => 'js',
-    ),
     '540effd7' =>
     array(
       'name' => 'typeahead.pkg.js',
@@ -1763,6 +1746,24 @@ celerity_register_resource_map(array(
       'uri' => '/res/pkg/540effd7/typeahead.pkg.js',
       'type' => 'js',
     ),
+    '75c76dab' =>
+    array(
+      'name' => 'core.pkg.js',
+      'symbols' =>
+      array(
+        0 => 'javelin-mask',
+        1 => 'javelin-workflow',
+        2 => 'javelin-behavior-workflow',
+        3 => 'javelin-behavior-aphront-form-disable-on-submit',
+        4 => 'phabricator-keyboard-shortcut-manager',
+        5 => 'phabricator-keyboard-shortcut',
+        6 => 'javelin-behavior-phabricator-keyboard-shortcuts',
+        7 => 'javelin-behavior-refresh-csrf',
+        8 => 'javelin-behavior-phabricator-watch-anchor',
+      ),
+      'uri' => '/res/pkg/75c76dab/core.pkg.js',
+      'type' => 'js',
+    ),
     '8b139246' =>
     array(
       'name' => 'differential.pkg.css',
@@ -1855,7 +1856,7 @@ celerity_register_resource_map(array(
     'javelin-behavior-aphront-basic-tokenizer' => '540effd7',
     'javelin-behavior-aphront-drag-and-drop' => '11a5c52c',
     'javelin-behavior-aphront-drag-and-drop-textarea' => '11a5c52c',
-    'javelin-behavior-aphront-form-disable-on-submit' => '4e7acf1a',
+    'javelin-behavior-aphront-form-disable-on-submit' => '75c76dab',
     'javelin-behavior-differential-accept-with-errors' => '11a5c52c',
     'javelin-behavior-differential-add-reviewers-and-ccs' => '11a5c52c',
     'javelin-behavior-differential-comment-jump' => '11a5c52c',
@@ -1865,16 +1866,16 @@ celerity_register_resource_map(array(
     'javelin-behavior-differential-keyboard-navigation' => '11a5c52c',
     'javelin-behavior-differential-populate' => '11a5c52c',
     'javelin-behavior-differential-show-more' => '11a5c52c',
-    'javelin-behavior-phabricator-keyboard-shortcuts' => '4e7acf1a',
+    'javelin-behavior-phabricator-keyboard-shortcuts' => '75c76dab',
     'javelin-behavior-phabricator-object-selector' => '11a5c52c',
-    'javelin-behavior-phabricator-watch-anchor' => '4e7acf1a',
-    'javelin-behavior-refresh-csrf' => '4e7acf1a',
-    'javelin-behavior-workflow' => '4e7acf1a',
+    'javelin-behavior-phabricator-watch-anchor' => '75c76dab',
+    'javelin-behavior-refresh-csrf' => '75c76dab',
+    'javelin-behavior-workflow' => '75c76dab',
     'javelin-dom' => 'b164acea',
     'javelin-event' => 'b164acea',
     'javelin-install' => 'b164acea',
     'javelin-json' => 'b164acea',
-    'javelin-mask' => '4e7acf1a',
+    'javelin-mask' => '75c76dab',
     'javelin-request' => 'b164acea',
     'javelin-stratcom' => 'b164acea',
     'javelin-tokenizer' => '540effd7',
@@ -1886,14 +1887,14 @@ celerity_register_resource_map(array(
     'javelin-uri' => 'b164acea',
     'javelin-util' => 'b164acea',
     'javelin-vector' => 'b164acea',
-    'javelin-workflow' => '4e7acf1a',
+    'javelin-workflow' => '75c76dab',
     'phabricator-content-source-view-css' => '8b139246',
     'phabricator-core-buttons-css' => 'faf854fc',
     'phabricator-core-css' => 'faf854fc',
     'phabricator-directory-css' => 'faf854fc',
     'phabricator-drag-and-drop-file-upload' => '11a5c52c',
-    'phabricator-keyboard-shortcut' => '4e7acf1a',
-    'phabricator-keyboard-shortcut-manager' => '4e7acf1a',
+    'phabricator-keyboard-shortcut' => '75c76dab',
+    'phabricator-keyboard-shortcut-manager' => '75c76dab',
     'phabricator-object-selector-css' => '8b139246',
     'phabricator-remarkup-css' => 'faf854fc',
     'phabricator-shaped-request' => '11a5c52c',

src/applications/differential/view/inlinecomment/DifferentialInlineCommentView.php

@@ -178,10 +178,13 @@ final class DifferentialInlineCommentView extends AphrontView {
       }
     }
 
+    $anchor_name = 'inline-'.$inline->getID();
+
     $anchor = phutil_render_tag(
       'a',
       array(
-        'name' => 'inline-'.$inline->getID(),
+        'name' => $anchor_name,
+        'id'   => $anchor_name,
       ),
       '');
 

webroot/rsrc/js/application/core/behavior-watch-anchor.js

@@ -3,6 +3,7 @@
  * @requires javelin-behavior
  *           javelin-stratcom
  *           javelin-dom
+ *           javelin-vector
  */
 
 JX.behavior('phabricator-watch-anchor', function() {
@@ -20,9 +21,38 @@ JX.behavior('phabricator-watch-anchor', function() {
   }
 
   // Defer invocation so other listeners can update the document.
-  var fn = function() {
+  function defer_highlight() {
     setTimeout(highlight, 0);
+  }
+
+  // In some cases, we link to an anchor but the anchor target ajaxes in
+  // later. If it pops in within the first few seconds, jump to it.
+  function try_anchor(anchor) {
+    try {
+      // If the anchor exists, assume the browser handled the jump.
+      JX.$(anchor);
+      defer_highlight();
+    } catch (e) {
+      var n = 50;
+      var try_anchor_again = function () {
+        try {
+          window.scrollTo(0, JX.$V(JX.$(anchor)).y - 60);
+          defer_highlight();
+        } catch (e) {
+          if (n--) {
+            setTimeout(try_anchor_again, 100);
+          }
+        }
       };
-  JX.Stratcom.listen('hashchange', null, fn);
-  fn();
+      try_anchor_again();
+    }
+  }
+
+  JX.Stratcom.listen('hashchange', null, try_anchor);
+
+  var anchor = window.location.hash.replace('#', '');
+  if (anchor) {
+    try_anchor(anchor);
+  }
+
 });