diff --git a/src/applications/dashboard/paneltype/PhabricatorDashboardPanelTypeQuery.php b/src/applications/dashboard/paneltype/PhabricatorDashboardPanelTypeQuery.php
index bae946d1fb..1b6788dd5e 100644
--- a/src/applications/dashboard/paneltype/PhabricatorDashboardPanelTypeQuery.php
+++ b/src/applications/dashboard/paneltype/PhabricatorDashboardPanelTypeQuery.php
@@ -1,118 +1,119 @@
 <?php
 
 final class PhabricatorDashboardPanelTypeQuery
   extends PhabricatorDashboardPanelType {
 
   public function getPanelTypeKey() {
     return 'query';
   }
 
   public function getPanelTypeName() {
     return pht('Query Panel');
   }
 
   public function getPanelTypeDescription() {
     return pht(
       'Show results of a search query, like the most recently filed tasks or '.
       'revisions you need to review.');
   }
 
   public function getFieldSpecifications() {
     return array(
       'class' => array(
         'name' => pht('Search For'),
         'type' => 'search.application',
       ),
       'key' => array(
         'name' => pht('Query'),
         'type' => 'search.query',
         'control.application' => 'class',
       ),
       'limit' => array(
         'name' => pht('Limit'),
         'caption' => pht('Leave this blank for the default number of items.'),
         'type' => 'text',
       ),
     );
   }
 
   public function initializeFieldsFromRequest(
     PhabricatorDashboardPanel $panel,
     PhabricatorCustomFieldList $field_list,
     AphrontRequest $request) {
 
     $map = array();
     if (strlen($request->getStr('engine'))) {
       $map['class'] = $request->getStr('engine');
     }
 
     if (strlen($request->getStr('query'))) {
       $map['key'] = $request->getStr('query');
     }
 
     $full_map = array();
     foreach ($map as $key => $value) {
       $full_map["std:dashboard:core:{$key}"] = $value;
     }
 
     foreach ($field_list->getFields() as $field) {
       $field_key = $field->getFieldKey();
       if (isset($full_map[$field_key])) {
         $field->setValueFromStorage($full_map[$field_key]);
       }
     }
   }
 
 
   public function renderPanelContent(
     PhabricatorUser $viewer,
     PhabricatorDashboardPanel $panel,
     PhabricatorDashboardPanelRenderingEngine $engine) {
 
     $class = $panel->getProperty('class');
 
     $engine = PhabricatorApplicationSearchEngine::getEngineByClassName($class);
     if (!$engine) {
       throw new Exception(
         pht(
           'The application search engine "%s" is not known to Phabricator!',
           $class));
     }
 
     $engine->setViewer($viewer);
+    $engine->setContext(PhabricatorApplicationSearchEngine::CONTEXT_PANEL);
 
     $key = $panel->getProperty('key');
     if ($engine->isBuiltinQuery($key)) {
       $saved = $engine->buildSavedQueryFromBuiltin($key);
     } else {
       $saved = id(new PhabricatorSavedQueryQuery())
         ->setViewer($viewer)
         ->withEngineClassNames(array($class))
         ->withQueryKeys(array($key))
         ->executeOne();
     }
 
     if (!$saved) {
       throw new Exception(
         pht(
           'Query "%s" is unknown to application search engine "%s"!',
           $key,
           $class));
     }
 
     $query = $engine->buildQueryFromSavedQuery($saved);
     $pager = $engine->newPagerForSavedQuery($saved);
 
     if ($panel->getProperty('limit')) {
       $limit = (int)$panel->getProperty('limit');
       if ($pager->getPageSize() !== 0xFFFF) {
         $pager->setPageSize($limit);
       }
     }
 
     $results = $engine->executeQuery($query, $pager);
 
     return $engine->renderResults($results, $saved);
   }
 
 }
diff --git a/src/applications/maniphest/query/ManiphestTaskSearchEngine.php b/src/applications/maniphest/query/ManiphestTaskSearchEngine.php
index 4372996aa8..501e095aba 100644
--- a/src/applications/maniphest/query/ManiphestTaskSearchEngine.php
+++ b/src/applications/maniphest/query/ManiphestTaskSearchEngine.php
@@ -1,554 +1,559 @@
 <?php
 
 final class ManiphestTaskSearchEngine
   extends PhabricatorApplicationSearchEngine {
 
   private $showBatchControls;
   private $baseURI;
   private $isBoardView;
 
   public function setIsBoardView($is_board_view) {
     $this->isBoardView = $is_board_view;
     return $this;
   }
 
   public function getIsBoardView() {
     return $this->isBoardView;
   }
 
   public function setBaseURI($base_uri) {
     $this->baseURI = $base_uri;
     return $this;
   }
 
   public function getBaseURI() {
     return $this->baseURI;
   }
 
   public function setShowBatchControls($show_batch_controls) {
     $this->showBatchControls = $show_batch_controls;
     return $this;
   }
 
   public function getResultTypeDescription() {
     return pht('Tasks');
   }
 
   public function getApplicationClassName() {
     return 'PhabricatorApplicationManiphest';
   }
 
   public function getCustomFieldObject() {
     return new ManiphestTask();
   }
 
   public function buildSavedQueryFromRequest(AphrontRequest $request) {
     $saved = new PhabricatorSavedQuery();
 
     $saved->setParameter(
       'assignedPHIDs',
       $this->readUsersFromRequest($request, 'assigned'));
 
     $saved->setParameter('withUnassigned', $request->getBool('withUnassigned'));
 
     $saved->setParameter(
       'authorPHIDs',
       $this->readUsersFromRequest($request, 'authors'));
 
     $saved->setParameter(
       'subscriberPHIDs',
       $this->readPHIDsFromRequest($request, 'subscribers'));
 
     $saved->setParameter(
       'statuses',
       $this->readListFromRequest($request, 'statuses'));
 
     $saved->setParameter(
       'priorities',
       $this->readListFromRequest($request, 'priorities'));
 
     $saved->setParameter('group', $request->getStr('group'));
     $saved->setParameter('order', $request->getStr('order'));
 
     $ids = $request->getStrList('ids');
     foreach ($ids as $key => $id) {
       $id = trim($id, ' Tt');
       if (!$id || !is_numeric($id)) {
         unset($ids[$key]);
       } else {
         $ids[$key] = $id;
       }
     }
     $saved->setParameter('ids', $ids);
 
     $saved->setParameter('fulltext', $request->getStr('fulltext'));
 
     $saved->setParameter(
       'allProjectPHIDs',
       $this->readPHIDsFromRequest($request, 'allProjects'));
 
     $saved->setParameter(
       'withNoProject',
       $request->getBool('withNoProject'));
 
     $saved->setParameter(
       'anyProjectPHIDs',
       $this->readPHIDsFromRequest($request, 'anyProjects'));
 
     $saved->setParameter(
       'excludeProjectPHIDs',
       $this->readPHIDsFromRequest($request, 'excludeProjects'));
 
     $saved->setParameter(
       'userProjectPHIDs',
       $this->readUsersFromRequest($request, 'userProjects'));
 
     $saved->setParameter('createdStart', $request->getStr('createdStart'));
     $saved->setParameter('createdEnd', $request->getStr('createdEnd'));
     $saved->setParameter('modifiedStart', $request->getStr('modifiedStart'));
     $saved->setParameter('modifiedEnd', $request->getStr('modifiedEnd'));
 
     $limit = $request->getInt('limit');
     if ($limit > 0) {
       $saved->setParameter('limit', $limit);
     }
 
     $this->readCustomFieldsFromRequest($request, $saved);
 
     return $saved;
   }
 
   public function buildQueryFromSavedQuery(PhabricatorSavedQuery $saved) {
     $query = id(new ManiphestTaskQuery());
 
     $author_phids = $saved->getParameter('authorPHIDs');
     if ($author_phids) {
       $query->withAuthors($author_phids);
     }
 
     $subscriber_phids = $saved->getParameter('subscriberPHIDs');
     if ($subscriber_phids) {
       $query->withSubscribers($subscriber_phids);
     }
 
     $with_unassigned = $saved->getParameter('withUnassigned');
     if ($with_unassigned) {
       $query->withOwners(array(null));
     } else {
       $assigned_phids = $saved->getParameter('assignedPHIDs', array());
       if ($assigned_phids) {
         $query->withOwners($assigned_phids);
       }
     }
 
     $statuses = $saved->getParameter('statuses');
     if ($statuses) {
       $query->withStatuses($statuses);
     }
 
     $priorities = $saved->getParameter('priorities');
     if ($priorities) {
       $query->withPriorities($priorities);
     }
 
     $order = $saved->getParameter('order');
     $order = idx($this->getOrderValues(), $order);
     if ($order) {
       $query->setOrderBy($order);
     } else {
       $query->setOrderBy(head($this->getOrderValues()));
     }
 
     $group = $saved->getParameter('group');
     $group = idx($this->getGroupValues(), $group);
     if ($group) {
       $query->setGroupBy($group);
     } else {
       $query->setGroupBy(head($this->getGroupValues()));
     }
 
     $ids = $saved->getParameter('ids');
     if ($ids) {
       $query->withIDs($ids);
     }
 
     $fulltext = $saved->getParameter('fulltext');
     if (strlen($fulltext)) {
       $query->withFullTextSearch($fulltext);
     }
 
     $with_no_project = $saved->getParameter('withNoProject');
     if ($with_no_project) {
       $query->withAllProjects(array(ManiphestTaskOwner::PROJECT_NO_PROJECT));
     } else {
       $project_phids = $saved->getParameter('allProjectPHIDs');
       if ($project_phids) {
         $query->withAllProjects($project_phids);
       }
     }
 
     $any_project_phids = $saved->getParameter('anyProjectPHIDs');
     if ($any_project_phids) {
       $query->withAnyProjects($any_project_phids);
     }
 
     $exclude_project_phids = $saved->getParameter('excludeProjectPHIDs');
     if ($exclude_project_phids) {
       $query->withoutProjects($exclude_project_phids);
     }
 
     $user_project_phids = $saved->getParameter('userProjectPHIDs');
     if ($user_project_phids) {
       $query->withAnyUserProjects($user_project_phids);
     }
 
     $start = $this->parseDateTime($saved->getParameter('createdStart'));
     $end = $this->parseDateTime($saved->getParameter('createdEnd'));
 
     if ($start) {
       $query->withDateCreatedAfter($start);
     }
 
     if ($end) {
       $query->withDateCreatedBefore($end);
     }
 
     $mod_start = $this->parseDateTime($saved->getParameter('modifiedStart'));
     $mod_end = $this->parseDateTime($saved->getParameter('modifiedEnd'));
 
     if ($mod_start) {
       $query->withDateModifiedAfter($mod_start);
     }
 
     if ($mod_end) {
       $query->withDateModifiedBefore($mod_end);
     }
 
     $this->applyCustomFieldsToQuery($query, $saved);
 
     return $query;
   }
 
   public function buildSearchForm(
     AphrontFormView $form,
     PhabricatorSavedQuery $saved) {
 
     $assigned_phids = $saved->getParameter('assignedPHIDs', array());
     $author_phids = $saved->getParameter('authorPHIDs', array());
     $all_project_phids = $saved->getParameter(
       'allProjectPHIDs',
       array());
     $any_project_phids = $saved->getParameter(
       'anyProjectPHIDs',
       array());
     $exclude_project_phids = $saved->getParameter(
       'excludeProjectPHIDs',
       array());
     $user_project_phids = $saved->getParameter(
       'userProjectPHIDs',
       array());
     $subscriber_phids = $saved->getParameter('subscriberPHIDs', array());
 
     $all_phids = array_merge(
       $assigned_phids,
       $author_phids,
       $all_project_phids,
       $any_project_phids,
       $exclude_project_phids,
       $user_project_phids,
       $subscriber_phids);
 
     if ($all_phids) {
       $handles = id(new PhabricatorHandleQuery())
         ->setViewer($this->requireViewer())
         ->withPHIDs($all_phids)
         ->execute();
     } else {
       $handles = array();
     }
 
     $assigned_handles = array_select_keys($handles, $assigned_phids);
     $author_handles = array_select_keys($handles, $author_phids);
     $all_project_handles = array_select_keys($handles, $all_project_phids);
     $any_project_handles = array_select_keys($handles, $any_project_phids);
     $exclude_project_handles = array_select_keys(
       $handles,
       $exclude_project_phids);
     $user_project_handles = array_select_keys($handles, $user_project_phids);
     $subscriber_handles = array_select_keys($handles, $subscriber_phids);
 
     $with_unassigned = $saved->getParameter('withUnassigned');
     $with_no_projects = $saved->getParameter('withNoProject');
 
     $statuses = $saved->getParameter('statuses', array());
     $statuses = array_fuse($statuses);
     $status_control = id(new AphrontFormCheckboxControl())
       ->setLabel(pht('Status'));
     foreach (ManiphestTaskStatus::getTaskStatusMap() as $status => $name) {
       $status_control->addCheckbox(
         'statuses[]',
         $status,
         $name,
         isset($statuses[$status]));
     }
 
     $priorities = $saved->getParameter('priorities', array());
     $priorities = array_fuse($priorities);
     $priority_control = id(new AphrontFormCheckboxControl())
       ->setLabel(pht('Priority'));
     foreach (ManiphestTaskPriority::getTaskPriorityMap() as $pri => $name) {
       $priority_control->addCheckbox(
         'priorities[]',
         $pri,
         $name,
         isset($priorities[$pri]));
     }
 
     $ids = $saved->getParameter('ids', array());
 
     $form
       ->appendChild(
         id(new AphrontFormTokenizerControl())
           ->setDatasource('/typeahead/common/accounts/')
           ->setName('assigned')
           ->setLabel(pht('Assigned To'))
           ->setValue($assigned_handles))
       ->appendChild(
         id(new AphrontFormCheckboxControl())
           ->addCheckbox(
             'withUnassigned',
             1,
             pht('Show only unassigned tasks.'),
             $with_unassigned))
       ->appendChild(
         id(new AphrontFormTokenizerControl())
           ->setDatasource('/typeahead/common/projects/')
           ->setName('allProjects')
           ->setLabel(pht('In All Projects'))
           ->setValue($all_project_handles));
 
     if (!$this->getIsBoardView()) {
       $form
         ->appendChild(
           id(new AphrontFormCheckboxControl())
             ->addCheckbox(
               'withNoProject',
               1,
               pht('Show only tasks with no projects.'),
               $with_no_projects));
     }
 
     $form
       ->appendChild(
         id(new AphrontFormTokenizerControl())
           ->setDatasource('/typeahead/common/projects/')
           ->setName('anyProjects')
           ->setLabel(pht('In Any Project'))
           ->setValue($any_project_handles))
       ->appendChild(
         id(new AphrontFormTokenizerControl())
           ->setDatasource('/typeahead/common/projects/')
           ->setName('excludeProjects')
           ->setLabel(pht('Not In Projects'))
           ->setValue($exclude_project_handles))
       ->appendChild(
         id(new AphrontFormTokenizerControl())
           ->setDatasource('/typeahead/common/accounts/')
           ->setName('userProjects')
           ->setLabel(pht('In Users\' Projects'))
           ->setValue($user_project_handles))
       ->appendChild(
         id(new AphrontFormTokenizerControl())
           ->setDatasource('/typeahead/common/accounts/')
           ->setName('authors')
           ->setLabel(pht('Authors'))
           ->setValue($author_handles))
       ->appendChild(
         id(new AphrontFormTokenizerControl())
           ->setDatasource('/typeahead/common/mailable/')
           ->setName('subscribers')
           ->setLabel(pht('Subscribers'))
           ->setValue($subscriber_handles))
       ->appendChild($status_control)
       ->appendChild($priority_control);
 
     if (!$this->getIsBoardView()) {
       $form
         ->appendChild(
           id(new AphrontFormSelectControl())
             ->setName('group')
             ->setLabel(pht('Group By'))
             ->setValue($saved->getParameter('group'))
             ->setOptions($this->getGroupOptions()))
         ->appendChild(
           id(new AphrontFormSelectControl())
             ->setName('order')
             ->setLabel(pht('Order By'))
             ->setValue($saved->getParameter('order'))
             ->setOptions($this->getOrderOptions()));
     }
 
     $form
       ->appendChild(
         id(new AphrontFormTextControl())
           ->setName('fulltext')
           ->setLabel(pht('Contains Words'))
           ->setValue($saved->getParameter('fulltext')))
       ->appendChild(
         id(new AphrontFormTextControl())
           ->setName('ids')
           ->setLabel(pht('Task IDs'))
           ->setValue(implode(', ', $ids)));
 
     $this->appendCustomFieldsToForm($form, $saved);
 
     $this->buildDateRange(
       $form,
       $saved,
       'createdStart',
       pht('Created After'),
       'createdEnd',
       pht('Created Before'));
 
     $this->buildDateRange(
       $form,
       $saved,
       'modifiedStart',
       pht('Updated After'),
       'modifiedEnd',
       pht('Updated Before'));
 
     if (!$this->getIsBoardView()) {
       $form
         ->appendChild(
           id(new AphrontFormTextControl())
             ->setName('limit')
             ->setLabel(pht('Page Size'))
             ->setValue($saved->getParameter('limit', 100)));
     }
   }
 
   protected function getURI($path) {
     if ($this->baseURI) {
       return $this->baseURI.$path;
     }
     return '/maniphest/'.$path;
   }
 
   public function getBuiltinQueryNames() {
     $names = array();
 
     if ($this->requireViewer()->isLoggedIn()) {
       $names['assigned'] = pht('Assigned');
       $names['authored'] = pht('Authored');
       $names['subscribed'] = pht('Subscribed');
     }
 
     $names['open'] = pht('Open Tasks');
     $names['all'] = pht('All Tasks');
 
     return $names;
   }
 
   public function buildSavedQueryFromBuiltin($query_key) {
 
     $query = $this->newSavedQuery();
     $query->setQueryKey($query_key);
 
     $viewer_phid = $this->requireViewer()->getPHID();
 
     switch ($query_key) {
       case 'all':
         return $query;
       case 'assigned':
         return $query
           ->setParameter('assignedPHIDs', array($viewer_phid))
           ->setParameter(
             'statuses',
             ManiphestTaskStatus::getOpenStatusConstants());
       case 'subscribed':
         return $query
           ->setParameter('subscriberPHIDs', array($viewer_phid))
           ->setParameter(
             'statuses',
             ManiphestTaskStatus::getOpenStatusConstants());
       case 'open':
         return $query
           ->setParameter(
             'statuses',
             ManiphestTaskStatus::getOpenStatusConstants());
       case 'authored':
         return $query
           ->setParameter('authorPHIDs', array($viewer_phid))
           ->setParameter('order', 'created')
           ->setParameter('group', 'none');
     }
 
     return parent::buildSavedQueryFromBuiltin($query_key);
   }
 
   private function getOrderOptions() {
     return array(
       'priority' => pht('Priority'),
       'updated' => pht('Date Updated'),
       'created' => pht('Date Created'),
       'title' => pht('Title'),
     );
   }
 
   private function getOrderValues() {
     return array(
       'priority' => ManiphestTaskQuery::ORDER_PRIORITY,
       'updated' => ManiphestTaskQuery::ORDER_MODIFIED,
       'created' => ManiphestTaskQuery::ORDER_CREATED,
       'title' => ManiphestTaskQuery::ORDER_TITLE,
     );
   }
 
   private function getGroupOptions() {
     return array(
       'priority' => pht('Priority'),
       'assigned' => pht('Assigned'),
       'status' => pht('Status'),
       'project' => pht('Project'),
       'none' => pht('None'),
     );
   }
 
   private function getGroupValues() {
     return array(
       'priority' => ManiphestTaskQuery::GROUP_PRIORITY,
       'assigned' => ManiphestTaskQuery::GROUP_OWNER,
       'status' => ManiphestTaskQuery::GROUP_STATUS,
       'project' => ManiphestTaskQuery::GROUP_PROJECT,
       'none' => ManiphestTaskQuery::GROUP_NONE,
     );
   }
 
   protected function renderResultList(
     array $tasks,
     PhabricatorSavedQuery $saved,
     array $handles) {
 
     $viewer = $this->requireViewer();
 
-    $can_edit_priority = PhabricatorPolicyFilter::hasCapability(
-      $viewer,
-      $this->getApplication(),
-      ManiphestCapabilityEditPriority::CAPABILITY);
-
-    $can_bulk_edit = PhabricatorPolicyFilter::hasCapability(
-      $viewer,
-      $this->getApplication(),
-      ManiphestCapabilityBulkEdit::CAPABILITY);
+    if ($this->isPanelContext()) {
+      $can_edit_priority = false;
+      $can_bulk_edit = false;
+    } else {
+      $can_edit_priority = PhabricatorPolicyFilter::hasCapability(
+        $viewer,
+        $this->getApplication(),
+        ManiphestCapabilityEditPriority::CAPABILITY);
+
+      $can_bulk_edit = PhabricatorPolicyFilter::hasCapability(
+        $viewer,
+        $this->getApplication(),
+        ManiphestCapabilityBulkEdit::CAPABILITY);
+    }
 
     return id(new ManiphestTaskResultListView())
       ->setUser($viewer)
       ->setTasks($tasks)
       ->setSavedQuery($saved)
       ->setCanEditPriority($can_edit_priority)
       ->setCanBatchEdit($can_bulk_edit)
       ->setShowBatchControls($this->showBatchControls);
   }
 
 }
diff --git a/src/applications/search/engine/PhabricatorApplicationSearchEngine.php b/src/applications/search/engine/PhabricatorApplicationSearchEngine.php
index 0869739d6d..9dd2519ff0 100644
--- a/src/applications/search/engine/PhabricatorApplicationSearchEngine.php
+++ b/src/applications/search/engine/PhabricatorApplicationSearchEngine.php
@@ -1,812 +1,825 @@
 <?php
 
 /**
  * Represents an abstract search engine for an application. It supports
  * creating and storing saved queries.
  *
  * @task construct  Constructing Engines
  * @task app        Applications
  * @task builtin    Builtin Queries
  * @task uri        Query URIs
  * @task dates      Date Filters
  * @task read       Reading Utilities
  * @task exec       Paging and Executing Queries
  * @task render     Rendering Results
  *
  * @group search
  */
 abstract class PhabricatorApplicationSearchEngine {
 
   private $application;
   private $viewer;
   private $errors = array();
   private $customFields = false;
   private $request;
+  private $context;
+
+  const CONTEXT_LIST  = 'list';
+  const CONTEXT_PANEL = 'panel';
 
   public function setViewer(PhabricatorUser $viewer) {
     $this->viewer = $viewer;
     return $this;
   }
 
   protected function requireViewer() {
     if (!$this->viewer) {
       throw new Exception('Call setViewer() before using an engine!');
     }
     return $this->viewer;
   }
 
+  public function setContext($context) {
+    $this->context = $context;
+    return $this;
+  }
+
+  public function isPanelContext() {
+    return ($this->context == self::CONTEXT_PANEL);
+  }
+
   public function saveQuery(PhabricatorSavedQuery $query) {
     $query->setEngineClassName(get_class($this));
 
     $unguarded = AphrontWriteGuard::beginScopedUnguardedWrites();
     try {
       $query->save();
     } catch (AphrontQueryDuplicateKeyException $ex) {
       // Ignore, this is just a repeated search.
     }
     unset($unguarded);
   }
 
   /**
    * Create a saved query object from the request.
    *
    * @param AphrontRequest The search request.
    * @return PhabricatorSavedQuery
    */
   abstract public function buildSavedQueryFromRequest(
     AphrontRequest $request);
 
   /**
    * Executes the saved query.
    *
    * @param PhabricatorSavedQuery The saved query to operate on.
    * @return The result of the query.
    */
   abstract public function buildQueryFromSavedQuery(
     PhabricatorSavedQuery $saved);
 
   /**
    * Builds the search form using the request.
    *
    * @param AphrontFormView       Form to populate.
    * @param PhabricatorSavedQuery The query from which to build the form.
    * @return void
    */
   abstract public function buildSearchForm(
     AphrontFormView $form,
     PhabricatorSavedQuery $query);
 
   public function getErrors() {
     return $this->errors;
   }
 
   public function addError($error) {
     $this->errors[] = $error;
     return $this;
   }
 
   /**
    * Return an application URI corresponding to the results page of a query.
    * Normally, this is something like `/application/query/QUERYKEY/`.
    *
    * @param   string  The query key to build a URI for.
    * @return  string  URI where the query can be executed.
    * @task uri
    */
   public function getQueryResultsPageURI($query_key) {
     return $this->getURI('query/'.$query_key.'/');
   }
 
 
   /**
    * Return an application URI for query management. This is used when, e.g.,
    * a query deletion operation is cancelled.
    *
    * @return  string  URI where queries can be managed.
    * @task uri
    */
   public function getQueryManagementURI() {
     return $this->getURI('query/edit/');
   }
 
 
   /**
    * Return the URI to a path within the application. Used to construct default
    * URIs for management and results.
    *
    * @return string URI to path.
    * @task uri
    */
   abstract protected function getURI($path);
 
 
   /**
    * Return a human readable description of the type of objects this query
    * searches for.
    *
    * For example, "Tasks" or "Commits".
    *
    * @return string Human-readable description of what this engine is used to
    *   find.
    */
   abstract public function getResultTypeDescription();
 
 
   public function newSavedQuery() {
     return id(new PhabricatorSavedQuery())
       ->setEngineClassName(get_class($this));
   }
 
   public function addNavigationItems(PHUIListView $menu) {
     $viewer = $this->requireViewer();
 
     $menu->newLabel(pht('Queries'));
 
     $named_queries = $this->loadEnabledNamedQueries();
 
     foreach ($named_queries as $query) {
       $key = $query->getQueryKey();
       $uri = $this->getQueryResultsPageURI($key);
       $menu->newLink($query->getQueryName(), $uri, 'query/'.$key);
     }
 
     if ($viewer->isLoggedIn()) {
       $manage_uri = $this->getQueryManagementURI();
       $menu->newLink(pht('Edit Queries...'), $manage_uri, 'query/edit');
     }
 
     $menu->newLabel(pht('Search'));
     $advanced_uri = $this->getQueryResultsPageURI('advanced');
     $menu->newLink(pht('Advanced Search'), $advanced_uri, 'query/advanced');
 
     return $this;
   }
 
   public function loadAllNamedQueries() {
     $viewer = $this->requireViewer();
 
     $named_queries = id(new PhabricatorNamedQueryQuery())
       ->setViewer($viewer)
       ->withUserPHIDs(array($viewer->getPHID()))
       ->withEngineClassNames(array(get_class($this)))
       ->execute();
     $named_queries = mpull($named_queries, null, 'getQueryKey');
 
     $builtin = $this->getBuiltinQueries($viewer);
     $builtin = mpull($builtin, null, 'getQueryKey');
 
     foreach ($named_queries as $key => $named_query) {
       if ($named_query->getIsBuiltin()) {
         if (isset($builtin[$key])) {
           $named_queries[$key]->setQueryName($builtin[$key]->getQueryName());
           unset($builtin[$key]);
         } else {
           unset($named_queries[$key]);
         }
       }
 
       unset($builtin[$key]);
     }
 
     $named_queries = msort($named_queries, 'getSortKey');
 
     return $named_queries + $builtin;
   }
 
   public function loadEnabledNamedQueries() {
     $named_queries = $this->loadAllNamedQueries();
     foreach ($named_queries as $key => $named_query) {
       if ($named_query->getIsBuiltin() && $named_query->getIsDisabled()) {
         unset($named_queries[$key]);
       }
     }
     return $named_queries;
   }
 
 
 /* -(  Applications  )------------------------------------------------------- */
 
 
   protected function getApplicationURI($path = '') {
     return $this->getApplication()->getApplicationURI($path);
   }
 
   protected function getApplication() {
     if (!$this->application) {
       $class = $this->getApplicationClassName();
 
       $this->application = id(new PhabricatorApplicationQuery())
         ->setViewer($this->requireViewer())
         ->withClasses(array($class))
         ->withInstalled(true)
         ->executeOne();
 
       if (!$this->application) {
         throw new Exception(
           pht(
             'Application "%s" is not installed!',
             $class));
       }
     }
 
     return $this->application;
   }
 
   protected function getApplicationClassName() {
     throw new Exception(pht('Not implemented for this SearchEngine yet!'));
   }
 
 
 /* -(  Constructing Engines  )----------------------------------------------- */
 
 
   /**
    * Load all available application search engines.
    *
    * @return list<PhabricatorApplicationSearchEngine> All available engines.
    * @task construct
    */
   public static function getAllEngines() {
     $engines = id(new PhutilSymbolLoader())
       ->setAncestorClass(__CLASS__)
       ->loadObjects();
 
     return $engines;
   }
 
 
   /**
    * Get an engine by class name, if it exists.
    *
    * @return PhabricatorApplicationSearchEngine|null Engine, or null if it does
    *   not exist.
    * @task construct
    */
   public static function getEngineByClassName($class_name) {
     return idx(self::getAllEngines(), $class_name);
   }
 
 
 /* -(  Builtin Queries  )---------------------------------------------------- */
 
 
   /**
    * @task builtin
    */
   public function getBuiltinQueries() {
     $names = $this->getBuiltinQueryNames();
 
     $queries = array();
     $sequence = 0;
     foreach ($names as $key => $name) {
       $queries[$key] = id(new PhabricatorNamedQuery())
         ->setUserPHID($this->requireViewer()->getPHID())
         ->setEngineClassName(get_class($this))
         ->setQueryName($name)
         ->setQueryKey($key)
         ->setSequence((1 << 24) + $sequence++)
         ->setIsBuiltin(true);
     }
 
     return $queries;
   }
 
 
   /**
    * @task builtin
    */
   public function getBuiltinQuery($query_key) {
     if (!$this->isBuiltinQuery($query_key)) {
       throw new Exception("'{$query_key}' is not a builtin!");
     }
     return idx($this->getBuiltinQueries(), $query_key);
   }
 
 
   /**
    * @task builtin
    */
   protected function getBuiltinQueryNames() {
     return array();
   }
 
 
   /**
    * @task builtin
    */
   public function isBuiltinQuery($query_key) {
     $builtins = $this->getBuiltinQueries();
     return isset($builtins[$query_key]);
   }
 
 
   /**
    * @task builtin
    */
   public function buildSavedQueryFromBuiltin($query_key) {
     throw new Exception("Builtin '{$query_key}' is not supported!");
   }
 
 
 /* -(  Reading Utilities )--------------------------------------------------- */
 
 
   /**
    * Read a list of user PHIDs from a request in a flexible way. This method
    * supports either of these forms:
    *
    *   users[]=alincoln&users[]=htaft
    *   users=alincoln,htaft
    *
    * Additionally, users can be specified either by PHID or by name.
    *
    * The main goal of this flexibility is to allow external programs to generate
    * links to pages (like "alincoln's open revisions") without needing to make
    * API calls.
    *
    * @param AphrontRequest  Request to read user PHIDs from.
    * @param string          Key to read in the request.
    * @param list<const>     Other permitted PHID types.
    * @return list<phid>     List of user PHIDs.
    *
    * @task read
    */
   protected function readUsersFromRequest(
     AphrontRequest $request,
     $key,
     array $allow_types = array()) {
 
     $list = $this->readListFromRequest($request, $key);
 
     $phids = array();
     $names = array();
     $allow_types = array_fuse($allow_types);
     $user_type = PhabricatorPHIDConstants::PHID_TYPE_USER;
     foreach ($list as $item) {
       $type = phid_get_type($item);
       if ($type == $user_type) {
         $phids[] = $item;
       } else if (isset($allow_types[$type])) {
         $phids[] = $item;
       } else {
         $names[] = $item;
       }
     }
 
     if ($names) {
       $users = id(new PhabricatorPeopleQuery())
         ->setViewer($this->requireViewer())
         ->withUsernames($names)
         ->execute();
       foreach ($users as $user) {
         $phids[] = $user->getPHID();
       }
       $phids = array_unique($phids);
     }
 
     return $phids;
   }
 
 
   /**
    * Read a list of generic PHIDs from a request in a flexible way. Like
    * @{method:readUsersFromRequest}, this method supports either array or
    * comma-delimited forms. Objects can be specified either by PHID or by
    * object name.
    *
    * @param AphrontRequest  Request to read PHIDs from.
    * @param string          Key to read in the request.
    * @param list<const>     Optional, list of permitted PHID types.
    * @return list<phid>     List of object PHIDs.
    *
    * @task read
    */
   protected function readPHIDsFromRequest(
     AphrontRequest $request,
     $key,
     array $allow_types = array()) {
 
     $list = $this->readListFromRequest($request, $key);
 
     $objects = id(new PhabricatorObjectQuery())
       ->setViewer($this->requireViewer())
       ->withNames($list)
       ->execute();
     $list = mpull($objects, 'getPHID');
 
     if (!$list) {
       return array();
     }
 
     // If only certain PHID types are allowed, filter out all the others.
     if ($allow_types) {
       $allow_types = array_fuse($allow_types);
       foreach ($list as $key => $phid) {
         if (empty($allow_types[phid_get_type($phid)])) {
           unset($list[$key]);
         }
       }
     }
 
     return $list;
   }
 
 
   /**
    * Read a list of items from the request, in either array format or string
    * format:
    *
    *   list[]=item1&list[]=item2
    *   list=item1,item2
    *
    * This provides flexibility when constructing URIs, especially from external
    * sources.
    *
    * @param AphrontRequest  Request to read strings from.
    * @param string          Key to read in the request.
    * @return list<string>   List of values.
    */
   protected function readListFromRequest(
     AphrontRequest $request,
     $key) {
     $list = $request->getArr($key, null);
     if ($list === null) {
       $list = $request->getStrList($key);
     }
 
     if (!$list) {
       return array();
     }
 
     return $list;
   }
 
   protected function readDateFromRequest(
     AphrontRequest $request,
     $key) {
 
     return id(new AphrontFormDateControl())
       ->setUser($this->requireViewer())
       ->setName($key)
       ->setAllowNull(true)
       ->readValueFromRequest($request);
   }
 
   protected function readBoolFromRequest(
     AphrontRequest $request,
     $key) {
     if (!strlen($request->getStr($key))) {
       return null;
     }
     return $request->getBool($key);
   }
 
 
   protected function getBoolFromQuery(PhabricatorSavedQuery $query, $key) {
     $value = $query->getParameter($key);
     if ($value === null) {
       return $value;
     }
     return $value ? 'true' : 'false';
   }
 
 
 /* -(  Dates  )-------------------------------------------------------------- */
 
 
   /**
    * @task dates
    */
   protected function parseDateTime($date_time) {
     if (!strlen($date_time)) {
       return null;
     }
 
     return PhabricatorTime::parseLocalTime($date_time, $this->requireViewer());
   }
 
 
   /**
    * @task dates
    */
   protected function buildDateRange(
     AphrontFormView $form,
     PhabricatorSavedQuery $saved_query,
     $start_key,
     $start_name,
     $end_key,
     $end_name) {
 
     $start_str = $saved_query->getParameter($start_key);
     $start = null;
     if (strlen($start_str)) {
       $start = $this->parseDateTime($start_str);
       if (!$start) {
         $this->addError(
           pht(
             '"%s" date can not be parsed.',
             $start_name));
       }
     }
 
 
     $end_str = $saved_query->getParameter($end_key);
     $end = null;
     if (strlen($end_str)) {
       $end = $this->parseDateTime($end_str);
       if (!$end) {
         $this->addError(
           pht(
             '"%s" date can not be parsed.',
             $end_name));
       }
     }
 
     if ($start && $end && ($start >= $end)) {
       $this->addError(
         pht(
           '"%s" must be a date before "%s".',
           $start_name,
           $end_name));
     }
 
     $form
       ->appendChild(
         id(new PHUIFormFreeformDateControl())
           ->setName($start_key)
           ->setLabel($start_name)
           ->setValue($start_str))
       ->appendChild(
         id(new AphrontFormTextControl())
           ->setName($end_key)
           ->setLabel($end_name)
           ->setValue($end_str));
   }
 
 
 /* -(  Paging and Executing Queries  )--------------------------------------- */
 
 
   public function getPageSize(PhabricatorSavedQuery $saved) {
     return $saved->getParameter('limit', 100);
   }
 
 
   public function shouldUseOffsetPaging() {
     return false;
   }
 
 
   public function newPagerForSavedQuery(PhabricatorSavedQuery $saved) {
     if ($this->shouldUseOffsetPaging()) {
       $pager = new AphrontPagerView();
     } else {
       $pager = new AphrontCursorPagerView();
     }
 
     $page_size = $this->getPageSize($saved);
     if (is_finite($page_size)) {
       $pager->setPageSize($page_size);
     } else {
       // Consider an INF pagesize to mean a large finite pagesize.
 
       // TODO: It would be nice to handle this more gracefully, but math
       // with INF seems to vary across PHP versions, systems, and runtimes.
       $pager->setPageSize(0xFFFF);
     }
 
     return $pager;
   }
 
 
   public function executeQuery(
     PhabricatorPolicyAwareQuery $query,
     AphrontView $pager) {
 
     $query->setViewer($this->requireViewer());
 
     if ($this->shouldUseOffsetPaging()) {
       $objects = $query->executeWithOffsetPager($pager);
     } else {
       $objects = $query->executeWithCursorPager($pager);
     }
 
     return $objects;
   }
 
 
 /* -(  Rendering  )---------------------------------------------------------- */
 
 
   public function setRequest(AphrontRequest $request) {
     $this->request = $request;
     return $this;
   }
 
   public function getRequest() {
     return $this->request;
   }
 
   public function renderResults(
     array $objects,
     PhabricatorSavedQuery $query) {
 
     $phids = $this->getRequiredHandlePHIDsForResultList($objects, $query);
 
     if ($phids) {
       $handles = id(new PhabricatorHandleQuery())
         ->setViewer($this->requireViewer())
         ->witHPHIDs($phids)
         ->execute();
     } else {
       $handles = array();
     }
 
     return $this->renderResultList($objects, $query, $handles);
   }
 
   protected function getRequiredHandlePHIDsForResultList(
     array $objects,
     PhabricatorSavedQuery $query) {
     return array();
   }
 
   protected function renderResultList(
     array $objects,
     PhabricatorSavedQuery $query,
     array $handles) {
     throw new Exception(pht('Not supported here yet!'));
   }
 
 
 /* -(  Application Search  )------------------------------------------------- */
 
 
   /**
    * Retrieve an object to use to define custom fields for this search.
    *
    * To integrate with custom fields, subclasses should override this method
    * and return an instance of the application object which implements
    * @{interface:PhabricatorCustomFieldInterface}.
    *
    * @return PhabricatorCustomFieldInterface|null Object with custom fields.
    * @task appsearch
    */
   public function getCustomFieldObject() {
     return null;
   }
 
 
   /**
    * Get the custom fields for this search.
    *
    * @return PhabricatorCustomFieldList|null Custom fields, if this search
    *   supports custom fields.
    * @task appsearch
    */
   public function getCustomFieldList() {
     if ($this->customFields === false) {
       $object = $this->getCustomFieldObject();
       if ($object) {
         $fields = PhabricatorCustomField::getObjectFields(
           $object,
           PhabricatorCustomField::ROLE_APPLICATIONSEARCH);
         $fields->setViewer($this->requireViewer());
       } else {
         $fields = null;
       }
       $this->customFields = $fields;
     }
     return $this->customFields;
   }
 
 
   /**
    * Moves data from the request into a saved query.
    *
    * @param AphrontRequest Request to read.
    * @param PhabricatorSavedQuery Query to write to.
    * @return void
    * @task appsearch
    */
   protected function readCustomFieldsFromRequest(
     AphrontRequest $request,
     PhabricatorSavedQuery $saved) {
 
     $list = $this->getCustomFieldList();
     if (!$list) {
       return;
     }
 
     foreach ($list->getFields() as $field) {
       $key = $this->getKeyForCustomField($field);
       $value = $field->readApplicationSearchValueFromRequest(
         $this,
         $request);
       $saved->setParameter($key, $value);
     }
   }
 
 
   /**
    * Applies data from a saved query to an executable query.
    *
    * @param PhabricatorCursorPagedPolicyAwareQuery Query to constrain.
    * @param PhabricatorSavedQuery Saved query to read.
    * @return void
    */
   protected function applyCustomFieldsToQuery(
     PhabricatorCursorPagedPolicyAwareQuery $query,
     PhabricatorSavedQuery $saved) {
 
     $list = $this->getCustomFieldList();
     if (!$list) {
       return;
     }
 
     foreach ($list->getFields() as $field) {
       $key = $this->getKeyForCustomField($field);
       $value = $field->applyApplicationSearchConstraintToQuery(
         $this,
         $query,
         $saved->getParameter($key));
     }
   }
 
 
   /**
    * Get a unique key identifying a field.
    *
    * @param PhabricatorCustomField Field to identify.
    * @return string Unique identifier, suitable for use as an input name.
    */
   public function getKeyForCustomField(PhabricatorCustomField $field) {
     return 'custom:'.$field->getFieldIndex();
   }
 
 
   /**
    * Add inputs to an application search form so the user can query on custom
    * fields.
    *
    * @param AphrontFormView Form to update.
    * @param PhabricatorSavedQuery Values to prefill.
    * @return void
    */
   protected function appendCustomFieldsToForm(
     AphrontFormView $form,
     PhabricatorSavedQuery $saved) {
 
     $list = $this->getCustomFieldList();
     if (!$list) {
       return;
     }
 
     $phids = array();
     foreach ($list->getFields() as $field) {
       $key = $this->getKeyForCustomField($field);
       $value = $saved->getParameter($key);
       $phids[$key] = $field->getRequiredHandlePHIDsForApplicationSearch($value);
     }
     $all_phids = array_mergev($phids);
 
     $handles = array();
     if ($all_phids) {
       $handles = id(new PhabricatorHandleQuery())
         ->setViewer($this->requireViewer())
         ->withPHIDs($all_phids)
         ->execute();
     }
 
     foreach ($list->getFields() as $field) {
       $key = $this->getKeyForCustomField($field);
       $value = $saved->getParameter($key);
       $field->appendToApplicationSearchForm(
         $this,
         $form,
         $value,
         array_select_keys($handles, $phids[$key]));
     }
   }
 
 }