When a Paste has a useful alternative rendering in Files, provide a hint

Summary: Ref T13528. When a file in Paste (like a Jupyter notebook) has a good/useful document engine, provide a link to Files.

Test Plan: {F7409881}

Maniphest Tasks: T13528

Differential Revision: https://secure.phabricator.com/D21196

src/applications/console/core/DarkConsoleCore.php

@@ -121,6 +121,8 @@ final class DarkConsoleCore extends Phobject {
         $data[$key] = $this->sanitizeForJSON($value);
       }
       return $data;
+    } else if (is_resource($data)) {
+      return '<resource>';
     } else {
       // Truncate huge strings. Since the data doesn't really matter much,
       // just truncate bytes to avoid PhutilUTF8StringTruncator overhead.

src/applications/files/document/PhabricatorDocumentEngine.php

@@ -281,4 +281,8 @@ abstract class PhabricatorDocumentEngine
       ));
   }
 
+  public function shouldSuggestEngine(PhabricatorDocumentRef $ref) {
+    return false;
+  }
+
 }

src/applications/files/document/PhabricatorJupyterDocumentEngine.php

@@ -748,4 +748,8 @@ final class PhabricatorJupyterDocumentEngine
     return $content;
   }
 
+  public function shouldSuggestEngine(PhabricatorDocumentRef $ref) {
+    return true;
+  }
+
 }

src/applications/files/document/render/PhabricatorDocumentRenderingEngine.php

@@ -305,6 +305,12 @@ abstract class PhabricatorDocumentRenderingEngine
     return $crumbs;
   }
 
+  public function getRefViewURI(
+    PhabricatorDocumentRef $ref,
+    PhabricatorDocumentEngine $engine) {
+    return $this->newRefViewURI($ref, $engine);
+  }
+
   abstract protected function newRefViewURI(
     PhabricatorDocumentRef $ref,
     PhabricatorDocumentEngine $engine);

src/applications/paste/controller/PhabricatorPasteViewController.php

@@ -51,16 +51,19 @@ final class PhabricatorPasteViewController extends PhabricatorPasteController {
     $timeline->setQuoteRef($monogram);
     $comment_view->setTransactionTimeline($timeline);
 
+    $recommendation_view = $this->newDocumentRecommendationView($paste);
+
     $paste_view = id(new PHUITwoColumnView())
       ->setHeader($header)
       ->setSubheader($subheader)
-      ->setMainColumn(array(
+      ->setMainColumn(
+        array(
+          $recommendation_view,
           $source_code,
           $timeline,
           $comment_view,
         ))
-      ->setCurtain($curtain)
+      ->setCurtain($curtain);
-      ->addClass('ponder-question-view');
 
     return $this->newPage()
       ->setTitle($paste->getFullName())
@@ -170,4 +173,58 @@ final class PhabricatorPasteViewController extends PhabricatorPasteController {
       ->setContent($content);
   }
 
+  private function newDocumentRecommendationView(PhabricatorPaste $paste) {
+    $viewer = $this->getViewer();
+
+    // See PHI1703. If a viewer is looking at a document in Paste which has
+    // a good rendering via a DocumentEngine, suggest they view the content
+    // in Files instead so they can see it rendered.
+
+    $ref = id(new PhabricatorDocumentRef())
+      ->setName($paste->getTitle())
+      ->setData($paste->getRawContent());
+
+    $engines = PhabricatorDocumentEngine::getEnginesForRef($viewer, $ref);
+    if (!$engines) {
+      return null;
+    }
+
+    $engine = head($engines);
+    if (!$engine->shouldSuggestEngine($ref)) {
+      return null;
+    }
+
+    $file = id(new PhabricatorFileQuery())
+      ->setViewer($viewer)
+      ->withPHIDs(array($paste->getFilePHID()))
+      ->executeOne();
+    if (!$file) {
+      return null;
+    }
+
+    $file_ref = id(new PhabricatorDocumentRef())
+      ->setFile($file);
+
+    $view_uri = id(new PhabricatorFileDocumentRenderingEngine())
+      ->getRefViewURI($file_ref, $engine);
+
+    $view_as_label = $engine->getViewAsLabel($file_ref);
+
+    $view_as_hint = pht(
+      'This content can be rendered as a document in Files.');
+
+    return id(new PHUIInfoView())
+      ->setSeverity(PHUIInfoView::SEVERITY_NOTICE)
+      ->addButton(
+        id(new PHUIButtonView())
+          ->setTag('a')
+          ->setText($view_as_label)
+          ->setHref($view_uri)
+          ->setColor('grey'))
+      ->setErrors(
+        array(
+          $view_as_hint,
+        ));
+  }
+
 }