Provide basic scaffolding for workboard column triggers

Summary:
Depends on D20278. Ref T5474. This change creates some new empty objects that do nothing, and some new views for looking at those objects. There's no actual useful behavior yet.

The "Edit" controller is custom instead of being driven by "EditEngine" because I expect it to be a Herald-style "add new rules" UI, and EditEngine isn't a clean match for those today (although maybe I'll try to move it over).

The general idea here is:

  - Triggers are "real" objects with a real PHID.
  - Each trigger has a name and a collection of rules, like "Change status to: X" or "Play sound: Y".
  - Each column may be bound to a trigger.
  - Multiple columns may share the same trigger.
  - Later UI refinements will make the cases around "copy trigger" vs "reference the same trigger" vs "create a new ad-hoc trigger" more clear.
  - Triggers have their own edit policy.
  - Triggers are always world-visible, like Herald rules.

Test Plan: Poked around, created some empty trigger objects, and nothing exploded. This doesn't actually do anything useful yet since triggers can't have any rule behavior and columns can't actually be bound to triggers.

Reviewers: amckinley

Reviewed By: amckinley

Subscribers: PHID-OPKG-gm6ozazyms6q6i22gyam

Maniphest Tasks: T5474

Differential Revision: https://secure.phabricator.com/D20279

resources/sql/autopatches/20190312.triggers.01.trigger.sql

@@ -0,0 +1,9 @@
+CREATE TABLE {$NAMESPACE}_project.project_trigger (
+  id INT UNSIGNED NOT NULL AUTO_INCREMENT PRIMARY KEY,
+  phid VARBINARY(64) NOT NULL,
+  name VARCHAR(255) NOT NULL COLLATE {$COLLATE_TEXT},
+  editPolicy VARBINARY(64) NOT NULL,
+  ruleset LONGTEXT NOT NULL COLLATE {$COLLATE_TEXT},
+  dateCreated INT UNSIGNED NOT NULL,
+  dateModified INT UNSIGNED NOT NULL
+) ENGINE=InnoDB, COLLATE {$COLLATE_TEXT};

resources/sql/autopatches/20190312.triggers.02.xaction.sql

@@ -0,0 +1,19 @@
+CREATE TABLE {$NAMESPACE}_project.project_triggertransaction (
+  id INT UNSIGNED NOT NULL AUTO_INCREMENT PRIMARY KEY,
+  phid VARBINARY(64) NOT NULL,
+  authorPHID VARBINARY(64) NOT NULL,
+  objectPHID VARBINARY(64) NOT NULL,
+  viewPolicy VARBINARY(64) NOT NULL,
+  editPolicy VARBINARY(64) NOT NULL,
+  commentPHID VARBINARY(64) DEFAULT NULL,
+  commentVersion INT UNSIGNED NOT NULL,
+  transactionType VARCHAR(32) NOT NULL,
+  oldValue LONGTEXT NOT NULL,
+  newValue LONGTEXT NOT NULL,
+  contentSource LONGTEXT NOT NULL,
+  metadata LONGTEXT NOT NULL,
+  dateCreated INT UNSIGNED NOT NULL,
+  dateModified INT UNSIGNED NOT NULL,
+  UNIQUE KEY `key_phid` (`phid`),
+  KEY `key_object` (`objectPHID`)
+) ENGINE=InnoDB DEFAULT CHARSET={$CHARSET} COLLATE {$COLLATE_TEXT};

resources/sql/autopatches/20190312.triggers.03.triggerphid.sql

@@ -0,0 +1,2 @@
+ALTER TABLE {$NAMESPACE}_project.project_column
+  ADD triggerPHID VARBINARY(64);

src/__phutil_library_map__.php

@@ -4166,6 +4166,19 @@ phutil_register_library_map(array(
     'PhabricatorProjectTransactionEditor' => 'applications/project/editor/PhabricatorProjectTransactionEditor.php',
     'PhabricatorProjectTransactionQuery' => 'applications/project/query/PhabricatorProjectTransactionQuery.php',
     'PhabricatorProjectTransactionType' => 'applications/project/xaction/PhabricatorProjectTransactionType.php',
+    'PhabricatorProjectTrigger' => 'applications/project/storage/PhabricatorProjectTrigger.php',
+    'PhabricatorProjectTriggerController' => 'applications/project/controller/trigger/PhabricatorProjectTriggerController.php',
+    'PhabricatorProjectTriggerEditController' => 'applications/project/controller/trigger/PhabricatorProjectTriggerEditController.php',
+    'PhabricatorProjectTriggerEditor' => 'applications/project/editor/PhabricatorProjectTriggerEditor.php',
+    'PhabricatorProjectTriggerListController' => 'applications/project/controller/trigger/PhabricatorProjectTriggerListController.php',
+    'PhabricatorProjectTriggerNameTransaction' => 'applications/project/xaction/trigger/PhabricatorProjectTriggerNameTransaction.php',
+    'PhabricatorProjectTriggerPHIDType' => 'applications/project/phid/PhabricatorProjectTriggerPHIDType.php',
+    'PhabricatorProjectTriggerQuery' => 'applications/project/query/PhabricatorProjectTriggerQuery.php',
+    'PhabricatorProjectTriggerSearchEngine' => 'applications/project/query/PhabricatorProjectTriggerSearchEngine.php',
+    'PhabricatorProjectTriggerTransaction' => 'applications/project/storage/PhabricatorProjectTriggerTransaction.php',
+    'PhabricatorProjectTriggerTransactionQuery' => 'applications/project/query/PhabricatorProjectTriggerTransactionQuery.php',
+    'PhabricatorProjectTriggerTransactionType' => 'applications/project/xaction/trigger/PhabricatorProjectTriggerTransactionType.php',
+    'PhabricatorProjectTriggerViewController' => 'applications/project/controller/trigger/PhabricatorProjectTriggerViewController.php',
     'PhabricatorProjectTypeTransaction' => 'applications/project/xaction/PhabricatorProjectTypeTransaction.php',
     'PhabricatorProjectUIEventListener' => 'applications/project/events/PhabricatorProjectUIEventListener.php',
     'PhabricatorProjectUpdateController' => 'applications/project/controller/PhabricatorProjectUpdateController.php',
@@ -10268,6 +10281,24 @@ phutil_register_library_map(array(
     'PhabricatorProjectTransactionEditor' => 'PhabricatorApplicationTransactionEditor',
     'PhabricatorProjectTransactionQuery' => 'PhabricatorApplicationTransactionQuery',
     'PhabricatorProjectTransactionType' => 'PhabricatorModularTransactionType',
+    'PhabricatorProjectTrigger' => array(
+      'PhabricatorProjectDAO',
+      'PhabricatorApplicationTransactionInterface',
+      'PhabricatorPolicyInterface',
+      'PhabricatorDestructibleInterface',
+    ),
+    'PhabricatorProjectTriggerController' => 'PhabricatorProjectController',
+    'PhabricatorProjectTriggerEditController' => 'PhabricatorProjectTriggerController',
+    'PhabricatorProjectTriggerEditor' => 'PhabricatorApplicationTransactionEditor',
+    'PhabricatorProjectTriggerListController' => 'PhabricatorProjectTriggerController',
+    'PhabricatorProjectTriggerNameTransaction' => 'PhabricatorProjectTriggerTransactionType',
+    'PhabricatorProjectTriggerPHIDType' => 'PhabricatorPHIDType',
+    'PhabricatorProjectTriggerQuery' => 'PhabricatorCursorPagedPolicyAwareQuery',
+    'PhabricatorProjectTriggerSearchEngine' => 'PhabricatorApplicationSearchEngine',
+    'PhabricatorProjectTriggerTransaction' => 'PhabricatorModularTransaction',
+    'PhabricatorProjectTriggerTransactionQuery' => 'PhabricatorApplicationTransactionQuery',
+    'PhabricatorProjectTriggerTransactionType' => 'PhabricatorModularTransactionType',
+    'PhabricatorProjectTriggerViewController' => 'PhabricatorProjectTriggerController',
     'PhabricatorProjectTypeTransaction' => 'PhabricatorProjectTransactionType',
     'PhabricatorProjectUIEventListener' => 'PhabricatorEventListener',
     'PhabricatorProjectUpdateController' => 'PhabricatorProjectController',

src/applications/project/application/PhabricatorProjectApplication.php

@@ -89,6 +89,14 @@ final class PhabricatorProjectApplication extends PhabricatorApplication {
           'background/'
             => 'PhabricatorProjectBoardBackgroundController',
         ),
+        'trigger/' => array(
+          $this->getQueryRoutePattern() =>
+            'PhabricatorProjectTriggerListController',
+          '(?P<id>[1-9]\d*)/' =>
+            'PhabricatorProjectTriggerViewController',
+          $this->getEditRoutePattern('edit/') =>
+            'PhabricatorProjectTriggerEditController',
+        ),
         'update/(?P<id>[1-9]\d*)/(?P<action>[^/]+)/'
           => 'PhabricatorProjectUpdateController',
         'manage/(?P<id>[1-9]\d*)/' => 'PhabricatorProjectManageController',

src/applications/project/controller/PhabricatorProjectBoardViewController.php

@@ -1111,10 +1111,8 @@ final class PhabricatorProjectBoardViewController
           ));
     }
 
-    if (count($specs) > 1) {
     $column_items[] = id(new PhabricatorActionView())
       ->setType(PhabricatorActionView::TYPE_DIVIDER);
-    }
 
     $batch_edit_uri = $request->getRequestURI();
     $batch_edit_uri->replaceQueryParam('batch', $column->getID());
@@ -1174,6 +1172,40 @@ final class PhabricatorProjectBoardViewController
         ->setWorkflow(true);
     }
 
+    if ($column->canHaveTrigger()) {
+      $column_items[] = id(new PhabricatorActionView())
+        ->setType(PhabricatorActionView::TYPE_DIVIDER);
+
+      $trigger = $column->getTrigger();
+      if (!$trigger) {
+        $set_uri = $this->getApplicationURI(
+          new PhutilURI(
+            'trigger/edit/',
+            array(
+              'columnPHID' => $column->getPHID(),
+            )));
+
+        $column_items[] = id(new PhabricatorActionView())
+          ->setIcon('fa-cogs')
+          ->setName(pht('New Trigger...'))
+          ->setHref($set_uri)
+          ->setDisabled(!$can_edit);
+      } else {
+        $column_items[] = id(new PhabricatorActionView())
+          ->setIcon('fa-cogs')
+          ->setName(pht('View Trigger'))
+          ->setHref($trigger->getURI())
+          ->setDisabled(!$can_edit);
+      }
+
+      $column_items[] = id(new PhabricatorActionView())
+        ->setIcon('fa-times')
+        ->setName(pht('Remove Trigger'))
+        ->setHref('#')
+        ->setWorkflow(true)
+        ->setDisabled(!$can_edit || !$trigger);
+    }
+
     $column_menu = id(new PhabricatorActionListView())
       ->setUser($viewer);
     foreach ($column_items as $item) {

src/applications/project/controller/trigger/PhabricatorProjectTriggerController.php

@@ -0,0 +1,16 @@
+<?php
+
+abstract class PhabricatorProjectTriggerController
+  extends PhabricatorProjectController {
+
+  protected function buildApplicationCrumbs() {
+    $crumbs = parent::buildApplicationCrumbs();
+
+    $crumbs->addTextCrumb(
+      pht('Triggers'),
+      $this->getApplicationURI('trigger/'));
+
+    return $crumbs;
+  }
+
+}

src/applications/project/controller/trigger/PhabricatorProjectTriggerEditController.php

@@ -0,0 +1,197 @@
+<?php
+
+final class PhabricatorProjectTriggerEditController
+  extends PhabricatorProjectTriggerController {
+
+  public function handleRequest(AphrontRequest $request) {
+    $request = $this->getRequest();
+    $viewer = $request->getViewer();
+
+    $id = $request->getURIData('id');
+    if ($id) {
+      $trigger = id(new PhabricatorProjectTriggerQuery())
+        ->setViewer($viewer)
+        ->withIDs(array($id))
+        ->requireCapabilities(
+          array(
+            PhabricatorPolicyCapability::CAN_VIEW,
+            PhabricatorPolicyCapability::CAN_EDIT,
+          ))
+        ->executeOne();
+      if (!$trigger) {
+        return new Aphront404Response();
+      }
+    } else {
+      $trigger = PhabricatorProjectTrigger::initializeNewTrigger();
+    }
+
+    $column_phid = $request->getStr('columnPHID');
+    if ($column_phid) {
+      $column = id(new PhabricatorProjectColumnQuery())
+        ->setViewer($viewer)
+        ->withPHIDs(array($column_phid))
+        ->requireCapabilities(
+          array(
+            PhabricatorPolicyCapability::CAN_VIEW,
+            PhabricatorPolicyCapability::CAN_EDIT,
+          ))
+        ->executeOne();
+      if (!$column) {
+        return new Aphront404Response();
+      }
+      $board_uri = $column->getBoardURI();
+    } else {
+      $column = null;
+      $board_uri = null;
+    }
+
+    if ($board_uri) {
+      $cancel_uri = $board_uri;
+    } else if ($trigger->getID()) {
+      $cancel_uri = $trigger->getURI();
+    } else {
+      $cancel_uri = $this->getApplicationURI('trigger/');
+    }
+
+    $v_name = $trigger->getName();
+    $v_edit = $trigger->getEditPolicy();
+
+    $e_name = null;
+    $e_edit = null;
+
+    $validation_exception = null;
+    if ($request->isFormPost()) {
+      try {
+        $v_name = $request->getStr('name');
+        $v_edit = $request->getStr('editPolicy');
+
+        $xactions = array();
+        if (!$trigger->getID()) {
+          $xactions[] = $trigger->getApplicationTransactionTemplate()
+            ->setTransactionType(PhabricatorTransactions::TYPE_CREATE)
+            ->setNewValue(true);
+        }
+
+        $xactions[] = $trigger->getApplicationTransactionTemplate()
+          ->setTransactionType(
+            PhabricatorProjectTriggerNameTransaction::TRANSACTIONTYPE)
+          ->setNewValue($v_name);
+
+        $xactions[] = $trigger->getApplicationTransactionTemplate()
+          ->setTransactionType(PhabricatorTransactions::TYPE_EDIT_POLICY)
+          ->setNewValue($v_edit);
+
+        $editor = $trigger->getApplicationTransactionEditor()
+          ->setActor($viewer)
+          ->setContentSourceFromRequest($request)
+          ->setContinueOnNoEffect(true);
+
+        $editor->applyTransactions($trigger, $xactions);
+
+        $next_uri = $trigger->getURI();
+
+        if ($column) {
+          $column_xactions = array();
+
+          // TODO: Modularize column transactions so we can change the column
+          // trigger here. For now, this does nothing.
+
+          $column_editor = $column->getApplicationTransactionEditor()
+            ->setActor($viewer)
+            ->setContentSourceFromRequest($request)
+            ->setContinueOnNoEffect(true);
+
+          $column_editor->applyTransactions($column, $column_xactions);
+
+          $next_uri = $column->getBoardURI();
+        }
+
+        return id(new AphrontRedirectResponse())->setURI($next_uri);
+      } catch (PhabricatorApplicationTransactionValidationException $ex) {
+        $validation_exception = $ex;
+
+        $e_name = $ex->getShortMessage(
+          PhabricatorProjectTriggerNameTransaction::TRANSACTIONTYPE);
+
+        $e_edit = $ex->getShortMessage(
+          PhabricatorTransactions::TYPE_EDIT_POLICY);
+
+        $trigger->setEditPolicy($v_edit);
+      }
+    }
+
+    if ($trigger->getID()) {
+      $title = $trigger->getObjectName();
+      $submit = pht('Save Trigger');
+      $header = pht('Edit Trigger: %s', $trigger->getObjectName());
+    } else {
+      $title = pht('New Trigger');
+      $submit = pht('Create Trigger');
+      $header = pht('New Trigger');
+    }
+
+    $form = id(new AphrontFormView())
+      ->setViewer($viewer);
+
+    if ($column) {
+      $form->addHiddenInput('columnPHID', $column->getPHID());
+    }
+
+    $form->appendControl(
+      id(new AphrontFormTextControl())
+        ->setLabel(pht('Name'))
+        ->setName('name')
+        ->setValue($v_name)
+        ->setError($e_name)
+        ->setPlaceholder($trigger->getDefaultName()));
+
+    $policies = id(new PhabricatorPolicyQuery())
+      ->setViewer($viewer)
+      ->setObject($trigger)
+      ->execute();
+
+    $form->appendControl(
+      id(new AphrontFormPolicyControl())
+        ->setName('editPolicy')
+        ->setPolicyObject($trigger)
+        ->setCapability(PhabricatorPolicyCapability::CAN_EDIT)
+        ->setPolicies($policies)
+        ->setError($e_edit));
+
+    $form->appendControl(
+      id(new AphrontFormSubmitControl())
+        ->setValue($submit)
+        ->addCancelButton($cancel_uri));
+
+    $header = id(new PHUIHeaderView())
+      ->setHeader($header);
+
+    $box_view = id(new PHUIObjectBoxView())
+      ->setHeader($header)
+      ->setValidationException($validation_exception)
+      ->appendChild($form);
+
+    $column_view = id(new PHUITwoColumnView())
+      ->setFooter($box_view);
+
+    $crumbs = $this->buildApplicationCrumbs()
+      ->setBorder(true);
+
+    if ($column) {
+      $crumbs->addTextCrumb(
+        pht(
+          '%s: %s',
+          $column->getProject()->getDisplayName(),
+          $column->getName()),
+        $board_uri);
+    }
+
+    $crumbs->addTextCrumb($title);
+
+    return $this->newPage()
+      ->setTitle($title)
+      ->setCrumbs($crumbs)
+      ->appendChild($column_view);
+  }
+
+}

src/applications/project/controller/trigger/PhabricatorProjectTriggerListController.php

@@ -0,0 +1,16 @@
+<?php
+
+final class PhabricatorProjectTriggerListController
+  extends PhabricatorProjectTriggerController {
+
+  public function shouldAllowPublic() {
+    return true;
+  }
+
+  public function handleRequest(AphrontRequest $request) {
+    return id(new PhabricatorProjectTriggerSearchEngine())
+      ->setController($this)
+      ->buildResponse();
+  }
+
+}

src/applications/project/controller/trigger/PhabricatorProjectTriggerViewController.php

@@ -0,0 +1,168 @@
+<?php
+
+final class PhabricatorProjectTriggerViewController
+  extends PhabricatorProjectTriggerController {
+
+  public function shouldAllowPublic() {
+    return true;
+  }
+
+  public function handleRequest(AphrontRequest $request) {
+    $request = $this->getRequest();
+    $viewer = $request->getViewer();
+
+    $id = $request->getURIData('id');
+
+    $trigger = id(new PhabricatorProjectTriggerQuery())
+      ->setViewer($viewer)
+      ->withIDs(array($id))
+      ->executeOne();
+    if (!$trigger) {
+      return new Aphront404Response();
+    }
+
+    $columns_view = $this->newColumnsView($trigger);
+
+    $title = $trigger->getObjectName();
+
+    $header = id(new PHUIHeaderView())
+      ->setHeader($trigger->getDisplayName());
+
+    $timeline = $this->buildTransactionTimeline(
+      $trigger,
+      new PhabricatorProjectTriggerTransactionQuery());
+    $timeline->setShouldTerminate(true);
+
+    $curtain = $this->newCurtain($trigger);
+
+    $column_view = id(new PHUITwoColumnView())
+      ->setHeader($header)
+      ->setCurtain($curtain)
+      ->setMainColumn(
+        array(
+          $columns_view,
+          $timeline,
+        ));
+
+    $crumbs = $this->buildApplicationCrumbs()
+      ->addTextCrumb($trigger->getObjectName())
+      ->setBorder(true);
+
+    return $this->newPage()
+      ->setTitle($title)
+      ->setCrumbs($crumbs)
+      ->appendChild($column_view);
+  }
+
+  private function newColumnsView(PhabricatorProjectTrigger $trigger) {
+    $viewer = $this->getViewer();
+
+    // NOTE: When showing columns which use this trigger, we want to represent
+    // all columns the trigger is used by: even columns the user can't see.
+
+    // If we hide columns the viewer can't see, they might think that the
+    // trigger isn't widely used and is safe to edit, when it may actually
+    // be in use on workboards they don't have access to.
+
+    // Query the columns with the omnipotent viewer first, then pull out their
+    // PHIDs and throw the actual objects away. Re-query with the real viewer
+    // so we load only the columns they can actually see, but have a list of
+    // all the impacted column PHIDs.
+
+    $omnipotent_viewer = PhabricatorUser::getOmnipotentUser();
+    $all_columns = id(new PhabricatorProjectColumnQuery())
+      ->setViewer($omnipotent_viewer)
+      ->withTriggerPHIDs(array($trigger->getPHID()))
+      ->execute();
+    $column_phids = mpull($all_columns, 'getPHID');
+
+    if ($column_phids) {
+      $visible_columns = id(new PhabricatorProjectColumnQuery())
+        ->setViewer($viewer)
+        ->withPHIDs($column_phids)
+        ->execute();
+      $visible_columns = mpull($visible_columns, null, 'getPHID');
+    } else {
+      $visible_columns = array();
+    }
+
+    $rows = array();
+    foreach ($column_phids as $column_phid) {
+      $column = idx($visible_columns, $column_phid);
+
+      if ($column) {
+        $project = $column->getProject();
+
+        $project_name = phutil_tag(
+          'a',
+          array(
+            'href' => $project->getURI(),
+          ),
+          $project->getDisplayName());
+
+        $column_name = phutil_tag(
+          'a',
+          array(
+            'href' => $column->getBoardURI(),
+          ),
+          $column->getDisplayName());
+      } else {
+        $project_name = null;
+        $column_name = phutil_tag('em', array(), pht('Restricted Column'));
+      }
+
+      $rows[] = array(
+        $project_name,
+        $column_name,
+      );
+    }
+
+    $table_view = id(new AphrontTableView($rows))
+      ->setNoDataString(pht('This trigger is not used by any columns.'))
+      ->setHeaders(
+        array(
+          pht('Project'),
+          pht('Column'),
+        ))
+      ->setColumnClasses(
+        array(
+          null,
+          'wide pri',
+        ));
+
+    $header_view = id(new PHUIHeaderView())
+      ->setHeader(pht('Used by Columns'));
+
+    return id(new PHUIObjectBoxView())
+      ->setBackground(PHUIObjectBoxView::BLUE_PROPERTY)
+      ->setHeader($header_view)
+      ->setTable($table_view);
+  }
+
+  private function newCurtain(PhabricatorProjectTrigger $trigger) {
+    $viewer = $this->getViewer();
+
+    $can_edit = PhabricatorPolicyFilter::hasCapability(
+      $viewer,
+      $trigger,
+      PhabricatorPolicyCapability::CAN_EDIT);
+
+    $curtain = $this->newCurtainView($trigger);
+
+    $edit_uri = $this->getApplicationURI(
+      urisprintf(
+        'trigger/edit/%d/',
+        $trigger->getID()));
+
+    $curtain->addAction(
+      id(new PhabricatorActionView())
+        ->setName(pht('Edit Trigger'))
+        ->setIcon('fa-pencil')
+        ->setHref($edit_uri)
+        ->setDisabled(!$can_edit)
+        ->setWorkflow(!$can_edit));
+
+    return $curtain;
+  }
+
+}

src/applications/project/editor/PhabricatorProjectTriggerEditor.php

@@ -0,0 +1,30 @@
+<?php
+
+final class PhabricatorProjectTriggerEditor
+  extends PhabricatorApplicationTransactionEditor {
+
+  public function getEditorApplicationClass() {
+    return 'PhabricatorProjectApplication';
+  }
+
+  public function getEditorObjectsDescription() {
+    return pht('Triggers');
+  }
+
+  public function getCreateObjectTitle($author, $object) {
+    return pht('%s created this trigger.', $author);
+  }
+
+  public function getCreateObjectTitleForFeed($author, $object) {
+    return pht('%s created %s.', $author, $object);
+  }
+
+  public function getTransactionTypes() {
+    $types = parent::getTransactionTypes();
+
+    $types[] = PhabricatorTransactions::TYPE_EDIT_POLICY;
+
+    return $types;
+  }
+
+}

src/applications/project/engine/PhabricatorBoardLayoutEngine.php

@@ -336,6 +336,7 @@ final class PhabricatorBoardLayoutEngine extends Phobject {
     $columns = id(new PhabricatorProjectColumnQuery())
       ->setViewer($viewer)
       ->withProjectPHIDs(array_keys($boards))
+      ->needTriggers(true)
       ->execute();
     $columns = msort($columns, 'getOrderingKey');
     $columns = mpull($columns, null, 'getPHID');

src/applications/project/phid/PhabricatorProjectTriggerPHIDType.php

@@ -0,0 +1,45 @@
+<?php
+
+final class PhabricatorProjectTriggerPHIDType
+  extends PhabricatorPHIDType {
+
+  const TYPECONST = 'WTRG';
+
+  public function getTypeName() {
+    return pht('Trigger');
+  }
+
+  public function getTypeIcon() {
+    return 'fa-exclamation-triangle';
+  }
+
+  public function newObject() {
+    return new PhabricatorProjectTrigger();
+  }
+
+  public function getPHIDTypeApplicationClass() {
+    return 'PhabricatorProjectApplication';
+  }
+
+  protected function buildQueryForObjects(
+    PhabricatorObjectQuery $query,
+    array $phids) {
+
+    return id(new PhabricatorProjectTriggerQuery())
+      ->withPHIDs($phids);
+  }
+
+  public function loadHandles(
+    PhabricatorHandleQuery $query,
+    array $handles,
+    array $objects) {
+
+    foreach ($handles as $phid => $handle) {
+      $trigger = $objects[$phid];
+
+      $handle->setName($trigger->getDisplayName());
+      $handle->setURI($trigger->getURI());
+    }
+  }
+
+}

src/applications/project/query/PhabricatorProjectColumnQuery.php

@@ -9,6 +9,8 @@ final class PhabricatorProjectColumnQuery
   private $proxyPHIDs;
   private $statuses;
   private $isProxyColumn;
+  private $triggerPHIDs;
+  private $needTriggers;
 
   public function withIDs(array $ids) {
     $this->ids = $ids;
@@ -40,6 +42,16 @@ final class PhabricatorProjectColumnQuery
     return $this;
   }
 
+  public function withTriggerPHIDs(array $trigger_phids) {
+    $this->triggerPHIDs = $trigger_phids;
+    return $this;
+  }
+
+  public function needTriggers($need_triggers) {
+    $this->needTriggers = true;
+    return $this;
+  }
+
   public function newResultObject() {
     return new PhabricatorProjectColumn();
   }
@@ -121,6 +133,42 @@ final class PhabricatorProjectColumnQuery
       $column->attachProxy($proxy);
     }
 
+    if ($this->needTriggers) {
+      $trigger_phids = array();
+      foreach ($page as $column) {
+        if ($column->canHaveTrigger()) {
+          $trigger_phid = $column->getTriggerPHID();
+          if ($trigger_phid) {
+            $trigger_phids[] = $trigger_phid;
+          }
+        }
+      }
+
+      if ($trigger_phids) {
+        $triggers = id(new PhabricatorProjectTriggerQuery())
+          ->setViewer($this->getViewer())
+          ->setParentQuery($this)
+          ->withPHIDs(array($this->getPHID()))
+          ->execute();
+        $triggers = mpull($triggers, null, 'getPHID');
+      } else {
+        $triggers = array();
+      }
+
+      foreach ($page as $column) {
+        $trigger = null;
+
+        if ($column->canHaveTrigger()) {
+          $trigger_phid = $column->getTriggerPHID();
+          if ($trigger_phid) {
+            $trigger = idx($triggers, $trigger_phid);
+          }
+        }
+
+        $column->attachTrigger($trigger);
+      }
+    }
+
     return $page;
   }
 
@@ -162,6 +210,13 @@ final class PhabricatorProjectColumnQuery
         $this->statuses);
     }
 
+    if ($this->triggerPHIDs !== null) {
+      $where[] = qsprintf(
+        $conn,
+        'triggerPHID IN (%Ls)',
+        $this->triggerPHIDs);
+    }
+
     if ($this->isProxyColumn !== null) {
       if ($this->isProxyColumn) {
         $where[] = qsprintf($conn, 'proxyPHID IS NOT NULL');

src/applications/project/query/PhabricatorProjectTriggerQuery.php

@@ -0,0 +1,51 @@
+<?php
+
+final class PhabricatorProjectTriggerQuery
+  extends PhabricatorCursorPagedPolicyAwareQuery {
+
+  private $ids;
+  private $phids;
+
+  public function withIDs(array $ids) {
+    $this->ids = $ids;
+    return $this;
+  }
+
+  public function withPHIDs(array $phids) {
+    $this->phids = $phids;
+    return $this;
+  }
+
+  public function newResultObject() {
+    return new PhabricatorProjectTrigger();
+  }
+
+  protected function loadPage() {
+    return $this->loadStandardPage($this->newResultObject());
+  }
+
+  protected function buildWhereClauseParts(AphrontDatabaseConnection $conn) {
+    $where = parent::buildWhereClauseParts($conn);
+
+    if ($this->ids !== null) {
+      $where[] = qsprintf(
+        $conn,
+        'id IN (%Ld)',
+        $this->ids);
+    }
+
+    if ($this->phids !== null) {
+      $where[] = qsprintf(
+        $conn,
+        'phid IN (%Ls)',
+        $this->phids);
+    }
+
+    return $where;
+  }
+
+  public function getQueryApplicationClass() {
+    return 'PhabricatorProjectApplication';
+  }
+
+}

src/applications/project/query/PhabricatorProjectTriggerSearchEngine.php

@@ -0,0 +1,75 @@
+<?php
+
+final class PhabricatorProjectTriggerSearchEngine
+  extends PhabricatorApplicationSearchEngine {
+
+  public function getResultTypeDescription() {
+    return pht('Triggers');
+  }
+
+  public function getApplicationClassName() {
+    return 'PhabricatorProjectApplication';
+  }
+
+  public function newQuery() {
+    return new PhabricatorProjectTriggerQuery();
+  }
+
+  protected function buildCustomSearchFields() {
+    return array();
+  }
+
+  protected function buildQueryFromParameters(array $map) {
+    $query = $this->newQuery();
+
+    return $query;
+  }
+
+  protected function getURI($path) {
+    return '/project/trigger/'.$path;
+  }
+
+  protected function getBuiltinQueryNames() {
+    $names = array();
+
+    $names['all'] = pht('All');
+
+    return $names;
+  }
+
+  public function buildSavedQueryFromBuiltin($query_key) {
+    $query = $this->newSavedQuery();
+    $query->setQueryKey($query_key);
+
+    switch ($query_key) {
+      case 'all':
+        return $query;
+    }
+
+    return parent::buildSavedQueryFromBuiltin($query_key);
+  }
+
+  protected function renderResultList(
+    array $triggers,
+    PhabricatorSavedQuery $query,
+    array $handles) {
+    assert_instances_of($triggers, 'PhabricatorProjectTrigger');
+    $viewer = $this->requireViewer();
+
+    $list = id(new PHUIObjectItemListView())
+      ->setViewer($viewer);
+    foreach ($triggers as $trigger) {
+      $item = id(new PHUIObjectItemView())
+        ->setObjectName($trigger->getObjectName())
+        ->setHeader($trigger->getDisplayName())
+        ->setHref($trigger->getURI());
+
+      $list->addItem($item);
+    }
+
+    return id(new PhabricatorApplicationSearchResultView())
+      ->setObjectList($list)
+      ->setNoDataString(pht('No triggers found.'));
+  }
+
+}

src/applications/project/query/PhabricatorProjectTriggerTransactionQuery.php

@@ -0,0 +1,10 @@
+<?php
+
+final class PhabricatorProjectTriggerTransactionQuery
+  extends PhabricatorApplicationTransactionQuery {
+
+  public function getTemplateApplicationTransaction() {
+    return new PhabricatorProjectTriggerTransaction();
+  }
+
+}

src/applications/project/storage/PhabricatorProjectColumn.php

@@ -18,9 +18,11 @@ final class PhabricatorProjectColumn
   protected $proxyPHID;
   protected $sequence;
   protected $properties = array();
+  protected $triggerPHID;
 
   private $project = self::ATTACHABLE;
   private $proxy = self::ATTACHABLE;
+  private $trigger = self::ATTACHABLE;
 
   public static function initializeNewColumn(PhabricatorUser $user) {
     return id(new PhabricatorProjectColumn())
@@ -40,6 +42,7 @@ final class PhabricatorProjectColumn
         'status' => 'uint32',
         'sequence' => 'uint32',
         'proxyPHID' => 'phid?',
+        'triggerPHID' => 'phid?',
       ),
       self::CONFIG_KEY_SCHEMA => array(
         'key_status' => array(
@@ -52,6 +55,9 @@ final class PhabricatorProjectColumn
           'columns' => array('projectPHID', 'proxyPHID'),
           'unique' => true,
         ),
+        'key_trigger' => array(
+          'columns' => array('triggerPHID'),
+        ),
       ),
     ) + parent::getConfiguration();
   }
@@ -180,6 +186,39 @@ final class PhabricatorProjectColumn
     return sprintf('%s%012d', $group, $sequence);
   }
 
+  public function attachTrigger(PhabricatorProjectTrigger $trigger = null) {
+    $this->trigger = $trigger;
+    return $this;
+  }
+
+  public function getTrigger() {
+    return $this->assertAttached($this->trigger);
+  }
+
+  public function canHaveTrigger() {
+    // Backlog columns and proxy (subproject / milestone) columns can't have
+    // triggers because cards routinely end up in these columns through tag
+    // edits rather than drag-and-drop and it would likely be confusing to
+    // have these triggers act only a small fraction of the time.
+
+    if ($this->isDefaultColumn()) {
+      return false;
+    }
+
+    if ($this->getProxy()) {
+      return false;
+    }
+
+    return true;
+  }
+
+  public function getBoardURI() {
+    return urisprintf(
+      '/project/board/%d/',
+      $this->getProject()->getID());
+  }
+
+
 /* -(  PhabricatorConduitResultInterface  )---------------------------------- */
 
   public function getFieldSpecificationsForConduit() {

src/applications/project/storage/PhabricatorProjectTrigger.php

@@ -0,0 +1,108 @@
+<?php
+
+final class PhabricatorProjectTrigger
+  extends PhabricatorProjectDAO
+  implements
+    PhabricatorApplicationTransactionInterface,
+    PhabricatorPolicyInterface,
+    PhabricatorDestructibleInterface {
+
+  protected $name;
+  protected $ruleset = array();
+  protected $editPolicy;
+
+  public static function initializeNewTrigger() {
+    $default_edit = PhabricatorPolicies::POLICY_USER;
+
+    return id(new self())
+      ->setName('')
+      ->setEditPolicy($default_edit);
+  }
+
+  protected function getConfiguration() {
+    return array(
+      self::CONFIG_AUX_PHID => true,
+      self::CONFIG_SERIALIZATION => array(
+        'ruleset' => self::SERIALIZATION_JSON,
+      ),
+      self::CONFIG_COLUMN_SCHEMA => array(
+        'name' => 'text255',
+      ),
+      self::CONFIG_KEY_SCHEMA => array(
+      ),
+    ) + parent::getConfiguration();
+  }
+
+  public function getPHIDType() {
+    return PhabricatorProjectTriggerPHIDType::TYPECONST;
+  }
+
+  public function getDisplayName() {
+    $name = $this->getName();
+    if (strlen($name)) {
+      return $name;
+    }
+
+    return $this->getDefaultName();
+  }
+
+  public function getDefaultName() {
+    return pht('Custom Trigger');
+  }
+
+  public function getURI() {
+    return urisprintf(
+      '/project/trigger/%d/',
+      $this->getID());
+  }
+
+  public function getObjectName() {
+    return pht('Trigger %d', $this->getID());
+  }
+
+
+/* -(  PhabricatorApplicationTransactionInterface  )------------------------- */
+
+
+  public function getApplicationTransactionEditor() {
+    return new PhabricatorProjectTriggerEditor();
+  }
+
+  public function getApplicationTransactionTemplate() {
+    return new PhabricatorProjectTriggerTransaction();
+  }
+
+
+/* -(  PhabricatorPolicyInterface  )----------------------------------------- */
+
+
+  public function getCapabilities() {
+    return array(
+      PhabricatorPolicyCapability::CAN_VIEW,
+      PhabricatorPolicyCapability::CAN_EDIT,
+    );
+  }
+
+  public function getPolicy($capability) {
+    switch ($capability) {
+      case PhabricatorPolicyCapability::CAN_VIEW:
+        return PhabricatorPolicies::getMostOpenPolicy();
+      case PhabricatorPolicyCapability::CAN_EDIT:
+        return $this->getEditPolicy();
+    }
+  }
+
+  public function hasAutomaticCapability($capability, PhabricatorUser $viewer) {
+    return false;
+  }
+
+
+/* -(  PhabricatorDestructibleInterface  )----------------------------------- */
+
+
+  public function destroyObjectPermanently(
+    PhabricatorDestructionEngine $engine) {
+    $this->delete();
+  }
+
+}

src/applications/project/storage/PhabricatorProjectTriggerTransaction.php

@@ -0,0 +1,18 @@
+<?php
+
+final class PhabricatorProjectTriggerTransaction
+  extends PhabricatorModularTransaction {
+
+  public function getApplicationName() {
+    return 'project';
+  }
+
+  public function getApplicationTransactionType() {
+    return PhabricatorProjectTriggerPHIDType::TYPECONST;
+  }
+
+  public function getBaseTransactionClass() {
+    return 'PhabricatorProjectTriggerTransactionType';
+  }
+
+}

src/applications/project/xaction/trigger/PhabricatorProjectTriggerNameTransaction.php

@@ -0,0 +1,58 @@
+<?php
+
+final class PhabricatorProjectTriggerNameTransaction
+  extends PhabricatorProjectTriggerTransactionType {
+
+  const TRANSACTIONTYPE = 'name';
+
+  public function generateOldValue($object) {
+    return $object->getName();
+  }
+
+  public function applyInternalEffects($object, $value) {
+    $object->setName($value);
+  }
+
+  public function getTitle() {
+    $old = $this->getOldValue();
+    $new = $this->getNewValue();
+
+    if (strlen($old) && strlen($new)) {
+      return pht(
+        '%s renamed this trigger from %s to %s.',
+        $this->renderAuthor(),
+        $this->renderOldValue(),
+        $this->renderNewValue());
+    } else if (strlen($new)) {
+      return pht(
+        '%s named this trigger %s.',
+        $this->renderAuthor(),
+        $this->renderNewValue());
+    } else {
+      return pht(
+        '%s stripped the name %s from this trigger.',
+        $this->renderAuthor(),
+        $this->renderOldValue());
+    }
+  }
+
+  public function validateTransactions($object, array $xactions) {
+    $errors = array();
+
+    $max_length = $object->getColumnMaximumByteLength('name');
+    foreach ($xactions as $xaction) {
+      $new_value = $xaction->getNewValue();
+      $new_length = strlen($new_value);
+      if ($new_length > $max_length) {
+        $errors[] = $this->newInvalidError(
+          pht(
+            'Trigger names must not be longer than %s characters.',
+            new PhutilNumber($max_length)),
+          $xaction);
+      }
+    }
+
+    return $errors;
+  }
+
+}

src/applications/project/xaction/trigger/PhabricatorProjectTriggerTransactionType.php

@@ -0,0 +1,4 @@
+<?php
+
+abstract class PhabricatorProjectTriggerTransactionType
+  extends PhabricatorModularTransactionType {}

src/applications/search/controller/PhabricatorApplicationSearchController.php

@@ -276,9 +276,10 @@ final class PhabricatorApplicationSearchController
             throw new Exception(
               pht(
                 'SearchEngines must render a "%s" object, but this engine '.
-                '(of class "%s") rendered something else.',
+                '(of class "%s") rendered something else ("%s").',
                 'PhabricatorApplicationSearchResultView',
-                get_class($engine)));
+                get_class($engine),
+                phutil_describe_type($list)));
           }
 
           if ($list->getObjectList()) {