Allow Nuance source definitions to add actions to source views

Summary:
Ref T8783. If you have a source (like a "report bug" form), let it put a link (like "View Form") on the source detail page.

This also straightens out getting definitions from sources, which had a bug with the modern way we do `PhutilClassMapQuery`.

Specifically, if you called the old mechanism on two different sources, they'd return the same definition object, but they need to return different definitions.

Test Plan:
{F747093}

{F747092}

Reviewers: chad

Reviewed By: chad

Maniphest Tasks: T8783

Differential Revision: https://secure.phabricator.com/D13966

src/applications/nuance/controller/NuanceSourceActionController.php

@@ -13,7 +13,7 @@ final class NuanceSourceActionController extends NuanceController {
       return new Aphront404Response();
     }
 
-    $def = NuanceSourceDefinition::getDefinitionForSource($source);
+    $def = $source->requireDefinition();
     $def->setActor($viewer);
 
     $response = $def->handleActionRequest($request);

src/applications/nuance/controller/NuanceSourceEditController.php

@@ -41,7 +41,7 @@ final class NuanceSourceEditController extends NuanceController {
       $cancel_uri = $source->getURI();
     }
 
-    $definition = NuanceSourceDefinition::getDefinitionForSource($source);
+    $definition = $source->requireDefinition();
     $definition->setActor($viewer);
 
     $response = $definition->buildEditLayout($request);

src/applications/nuance/controller/NuanceSourceViewController.php

@@ -77,6 +77,13 @@ final class NuanceSourceViewController extends NuanceController {
         ->setDisabled(!$can_edit)
         ->setWorkflow(!$can_edit));
 
+    $request = $this->getRequest();
+    $definition = $source->requireDefinition();
+    $source_actions = $definition->getSourceViewActions($request);
+    foreach ($source_actions as $source_action) {
+      $actions->addAction($source_action);
+    }
+
     return $actions;
   }
 
@@ -90,7 +97,7 @@ final class NuanceSourceViewController extends NuanceController {
       ->setObject($source)
       ->setActionList($actions);
 
-    $definition = NuanceSourceDefinition::getDefinitionForSource($source);
+    $definition = $source->requireDefinition();
     $properties->addProperty(
       pht('Source Type'),
       $definition->getName());

src/applications/nuance/source/NuancePhabricatorFormSourceDefinition.php

@@ -15,6 +15,17 @@ final class NuancePhabricatorFormSourceDefinition
     return 'phabricator-form';
   }
 
+  public function getSourceViewActions(AphrontRequest $request) {
+    $actions = array();
+
+    $actions[] = id(new PhabricatorActionView())
+      ->setName(pht('View Form'))
+      ->setIcon('fa-align-justify')
+      ->setHref($this->getActionURI());
+
+    return $actions;
+  }
+
   public function updateItems() {
     return null;
   }

src/applications/nuance/source/NuanceSourceDefinition.php

@@ -43,18 +43,8 @@ abstract class NuanceSourceDefinition extends Phobject {
     return $source;
   }
 
-  /**
-   * Gives a @{class:NuanceSourceDefinition} object for a given
-   * @{class:NuanceSource}. Note you still need to @{method:setActor}
-   * before the @{class:NuanceSourceDefinition} object will be useful.
-   */
-  public static function getDefinitionForSource(NuanceSource $source) {
-    $definitions = self::getAllDefinitions();
-    $map = mpull($definitions, null, 'getSourceTypeConstant');
-    $definition = $map[$source->getType()];
-    $definition->setSourceObject($source);
-
-    return $definition;
+  public function getSourceViewActions(AphrontRequest $request) {
+    return array();
   }
 
   public static function getAllDefinitions() {
@@ -286,4 +276,9 @@ abstract class NuanceSourceDefinition extends Phobject {
     return new Aphront404Response();
   }
 
+  public function getActionURI($path = null) {
+    $source_id = $this->getSourceObject()->getID();
+    return '/action/'.$source_id.'/'.ltrim($path, '/');
+  }
+
 }

src/applications/nuance/storage/NuanceSource.php

@@ -12,6 +12,8 @@ final class NuanceSource extends NuanceDAO
   protected $viewPolicy;
   protected $editPolicy;
 
+  private $definition;
+
   protected function getConfiguration() {
     return array(
       self::CONFIG_AUX_PHID => true,
@@ -62,6 +64,31 @@ final class NuanceSource extends NuanceDAO
       ->setEditPolicy($edit_policy);
   }
 
+  public function getDefinition() {
+    if ($this->definition === null) {
+      $definitions = NuanceSourceDefinition::getAllDefinitions();
+      if (isset($definitions[$this->getType()])) {
+        $definition = clone $definitions[$this->getType()];
+        $definition->setSourceObject($this);
+        $this->definition = $definition;
+      }
+    }
+
+    return $this->definition;
+  }
+
+  public function requireDefinition() {
+    $definition = $this->getDefinition();
+    if (!$definition) {
+      throw new Exception(
+        pht(
+          'Unable to load source definition implementation for source '.
+          'type "%s".',
+          $this->getType()));
+    }
+    return $definition;
+  }
+
 
 /* -(  PhabricatorApplicationTransactionInterface  )------------------------- */