When using the "Close as Duplicate" relationship action, limit the UI to 1 task

Summary:
Ref T4788. When closing a task as a duplicate of another task, you can only select one task, since it doesn't really make sense to merge one task into several other tasks (this operation is //possible//, but probably not what anyone ever wants to do, I think?).

Make the UI understand this: after you select a task, disable all of the "select" buttons in the UI to make this clear.

Test Plan:
  - Used "Close as Duplicate", only allowed to select 1 task.
  - Used other editors like "Merge Duplicates In", allowed to select lots of tasks.

Reviewers: chad

Reviewed By: chad

Maniphest Tasks: T4788

Differential Revision: https://secure.phabricator.com/D16203

resources/celerity/map.php

@@ -11,7 +11,7 @@ return array(
     'core.pkg.js' => 'f2139810',
     'darkconsole.pkg.js' => 'e7393ebb',
     'differential.pkg.css' => '3e81ae60',
-    'differential.pkg.js' => '01a010d6',
+    'differential.pkg.js' => '634399e9',
     'diffusion.pkg.css' => '91c5d3a6',
     'diffusion.pkg.js' => '3a9a8bfa',
     'maniphest.pkg.css' => '4845691a',
@@ -495,7 +495,7 @@ return array(
     'rsrc/js/core/behavior-lightbox-attachments.js' => 'f8ba29d7',
     'rsrc/js/core/behavior-line-linker.js' => '1499a8cb',
     'rsrc/js/core/behavior-more.js' => 'a80d0378',
-    'rsrc/js/core/behavior-object-selector.js' => '9030ebef',
+    'rsrc/js/core/behavior-object-selector.js' => 'e0ec7f2f',
     'rsrc/js/core/behavior-oncopy.js' => '2926fff2',
     'rsrc/js/core/behavior-phabricator-nav.js' => '56a1ca03',
     'rsrc/js/core/behavior-phabricator-remarkup-assist.js' => '116cf19b',
@@ -658,7 +658,7 @@ return array(
     'javelin-behavior-phabricator-line-linker' => '1499a8cb',
     'javelin-behavior-phabricator-nav' => '56a1ca03',
     'javelin-behavior-phabricator-notification-example' => '8ce821c5',
-    'javelin-behavior-phabricator-object-selector' => '9030ebef',
+    'javelin-behavior-phabricator-object-selector' => 'e0ec7f2f',
     'javelin-behavior-phabricator-oncopy' => '2926fff2',
     'javelin-behavior-phabricator-remarkup-assist' => '116cf19b',
     'javelin-behavior-phabricator-reveal-content' => '60821bc7',
@@ -1608,12 +1608,6 @@ return array(
       'javelin-dom',
       'javelin-request',
     ),
-    '9030ebef' => array(
-      'javelin-behavior',
-      'javelin-dom',
-      'javelin-request',
-      'javelin-util',
-    ),
     '9196fb06' => array(
       'javelin-install',
       'javelin-dom',
@@ -2036,6 +2030,12 @@ return array(
     'df5e11d2' => array(
       'javelin-install',
     ),
+    'e0ec7f2f' => array(
+      'javelin-behavior',
+      'javelin-dom',
+      'javelin-request',
+      'javelin-util',
+    ),
     'e10f8e18' => array(
       'javelin-behavior',
       'javelin-dom',

src/applications/maniphest/relationship/ManiphestTaskCloseAsDuplicateRelationship.php

@@ -53,16 +53,11 @@ final class ManiphestTaskCloseAsDuplicateRelationship
     return false;
   }
 
+  public function getMaximumSelectionSize() {
+    return 1;
+  }
+
   public function willUpdateRelationships($object, array $add, array $rem) {
-
-    // TODO: Communicate this in the UI before users hit this error.
-    if (count($add) > 1) {
-      throw new Exception(
-        pht(
-          'A task can only be closed as a duplicate of exactly one other '.
-          'task.'));
-    }
-
     $task = head($add);
     return $this->newMergeIntoTransactions($task);
   }

src/applications/search/controller/PhabricatorSearchRelationshipController.php

@@ -39,11 +39,23 @@ final class PhabricatorSearchRelationshipController
     $done_uri = $src_handle->getURI();
     $initial_phids = $dst_phids;
 
+    $maximum = $relationship->getMaximumSelectionSize();
+
     if ($request->isFormPost()) {
       $phids = explode(';', $request->getStr('phids'));
       $phids = array_filter($phids);
       $phids = array_values($phids);
 
+      // The UI normally enforces this with Javascript, so this is just a
+      // sanity check and does not need to be particularly user-friendly.
+      if ($maximum && (count($phids) > $maximum)) {
+        throw new Exception(
+          pht(
+            'Too many relationships (%s, of type "%s").',
+            phutil_count($phids),
+            $relationship->getRelationshipConstant()));
+      }
+
       $initial_phids = $request->getStrList('initialPHIDs');
 
       // Apply the changes as adds and removes relative to the original state
@@ -175,6 +187,7 @@ final class PhabricatorSearchRelationshipController
       ->setHeader($dialog_header)
       ->setButtonText($dialog_button)
       ->setInstructions($dialog_instructions)
+      ->setMaximumSelectionSize($maximum)
       ->buildDialog();
   }
 

src/applications/search/relationship/PhabricatorObjectRelationship.php

@@ -104,6 +104,10 @@ abstract class PhabricatorObjectRelationship extends Phobject {
     return "/search/rel/{$type}/{$phid}/";
   }
 
+  public function getMaximumSelectionSize() {
+    return null;
+  }
+
   public function canUndoRelationship() {
     return true;
   }

src/view/control/PhabricatorObjectSelectorDialog.php

@@ -11,6 +11,7 @@ final class PhabricatorObjectSelectorDialog extends Phobject {
   private $selectedFilter;
   private $excluded;
   private $initialPHIDs;
+  private $maximumSelectionSize;
 
   private $title;
   private $header;
@@ -87,6 +88,15 @@ final class PhabricatorObjectSelectorDialog extends Phobject {
     return $this->initialPHIDs;
   }
 
+  public function setMaximumSelectionSize($maximum_selection_size) {
+    $this->maximumSelectionSize = $maximum_selection_size;
+    return $this;
+  }
+
+  public function getMaximumSelectionSize() {
+    return $this->maximumSelectionSize;
+  }
+
   public function buildDialog() {
     $user = $this->user;
 
@@ -190,6 +200,8 @@ final class PhabricatorObjectSelectorDialog extends Phobject {
       $dialog->addHiddenInput('initialPHIDs', $initial_phids);
     }
 
+    $maximum = $this->getMaximumSelectionSize();
+
     Javelin::initBehavior(
       'phabricator-object-selector',
       array(
@@ -202,6 +214,7 @@ final class PhabricatorObjectSelectorDialog extends Phobject {
         'exclude' => $this->excluded,
         'uri'     => $this->searchURI,
         'handles' => $handle_views,
+        'maximum' => $maximum,
       ));
 
     $dialog->setResizeX(true);

webroot/rsrc/js/core/behavior-object-selector.js

@@ -10,11 +10,13 @@ JX.behavior('phabricator-object-selector', function(config) {
   var n = 0;
 
   var phids = {};
+  var display = [];
+
   var handles = config.handles;
   for (var k in handles) {
     phids[k] = true;
   }
-  var button_list = {};
+
   var query_timer = null;
   var query_delay = 50;
 
@@ -41,37 +43,82 @@ JX.behavior('phabricator-object-selector', function(config) {
       return;
     }
 
-    var display = [];
-    button_list = {};
+    display = [];
     for (var k in r) {
       handles[r[k].phid] = r[k];
-      display.push(renderHandle(r[k], true));
+      display.push({phid: r[k].phid});
     }
 
-    if (!display.length) {
-      display = renderNote('No results.');
-    }
-
-    JX.DOM.setContent(JX.$(config.results), display);
+    redrawList(true);
   }
 
   function redrawAttached() {
-    var display = [];
+    var attached = [];
 
     for (var k in phids) {
-      display.push(renderHandle(handles[k], false));
+      attached.push(renderHandle(handles[k], false).item);
     }
 
-    if (!display.length) {
-      display = renderNote('Nothing attached.');
+    if (!attached.length) {
+      attached = renderNote('Nothing attached.');
     }
 
-    JX.DOM.setContent(JX.$(config.current), display);
+    JX.DOM.setContent(JX.$(config.current), attached);
     phid_input.value = JX.keys(phids).join(';');
   }
 
-  function renderHandle(h, attach) {
+  function redrawList(rebuild) {
+    var ii;
+    var content;
 
+    if (rebuild) {
+      if (display.length) {
+        var handle;
+
+        content = [];
+        for (ii = 0; ii < display.length; ii++) {
+          handle = handles[display[ii].phid];
+
+          display[ii].node = renderHandle(handle, true);
+          content.push(display[ii].node.item);
+        }
+      } else {
+        content = renderNote('No results.');
+      }
+
+      JX.DOM.setContent(JX.$(config.results), content);
+    }
+
+    var phid;
+    var is_disabled;
+    var button;
+
+    var at_maximum = !canSelectMore();
+
+    for (ii = 0; ii < display.length; ii++) {
+      phid = display[ii].phid;
+
+      is_disabled = false;
+
+      // If this object is already selected, you can not select it again.
+      if (phids.hasOwnProperty(phid)) {
+        is_disabled = true;
+      }
+
+      // If the maximum number of objects are already selected, you can
+      // not select more.
+      if (at_maximum) {
+        is_disabled = true;
+      }
+
+      button = display[ii].node.button;
+      JX.DOM.alterClass(button, 'disabled', is_disabled);
+      button.disabled = is_disabled;
+    }
+
+  }
+
+  function renderHandle(h, attach) {
     var some_icon = JX.$N(
       'span',
       {className: 'phui-icon-view phui-font-fa ' +
@@ -111,15 +158,10 @@ JX.behavior('phabricator-object-selector', function(config) {
           meta: {handle: h, table:table}},
         cells));
 
-    if (attach) {
-      button_list[h.phid] = select_object_button;
-      if (h.phid in phids) {
-        JX.DOM.alterClass(select_object_button, 'disabled', true);
-        select_object_button.disabled = true;
-      }
-    }
-
-    return table;
+    return {
+      item: table,
+      button: select_object_button
+    };
   }
 
   function renderNote(note) {
@@ -138,6 +180,18 @@ JX.behavior('phabricator-object-selector', function(config) {
       .send();
   }
 
+  function canSelectMore() {
+    if (!config.maximum) {
+      return true;
+    }
+
+    if (JX.keys(phids).length < config.maximum) {
+      return true;
+    }
+
+    return false;
+  }
+
   JX.DOM.listen(
     JX.$(config.results),
     'click',
@@ -151,10 +205,13 @@ JX.behavior('phabricator-object-selector', function(config) {
         return;
       }
 
-      phids[phid] = true;
-      JX.DOM.alterClass(button_list[phid], 'disabled', true);
-      button_list[phid].disabled = true;
+      if (!canSelectMore()) {
+        return;
+      }
 
+      phids[phid] = true;
+
+      redrawList(false);
       redrawAttached();
     });
 
@@ -170,13 +227,7 @@ JX.behavior('phabricator-object-selector', function(config) {
 
       delete phids[phid];
 
-      // NOTE: We may not have a button in the button list, if this result is
-      // not visible in the current search results.
-      if (button_list[phid]) {
-        JX.DOM.alterClass(button_list[phid], 'disabled', false);
-        button_list[phid].disabled = false;
-      }
-
+      redrawList(false);
       redrawAttached();
     });
 
@@ -205,6 +256,7 @@ JX.behavior('phabricator-object-selector', function(config) {
     });
 
   sendQuery();
-  redrawAttached();
 
+  redrawList(true);
+  redrawAttached();
 });