Move Diffusion browse rendering to DocumentEngine, breaking almost all features

Summary:
Ref T13105. This breaks about 9,000 features but moves Diffusion to DocumentEngine for rendering. See T13105 for a more complete list of all the broken stuff.

But you can't bake a software without breaking all the features every time you make a change, right?

Test Plan: Viewed various files in Diffusion, used DocumentEngine features like highlighting and rendering engine selection.

Reviewers: mydeveloperday

Reviewed By: mydeveloperday

Subscribers: mydeveloperday

Maniphest Tasks: T13105

Differential Revision: https://secure.phabricator.com/D19302

src/__phutil_library_map__.php

@@ -732,6 +732,8 @@ phutil_register_library_map(array(
     'DiffusionDiffController' => 'applications/diffusion/controller/DiffusionDiffController.php',
     'DiffusionDiffInlineCommentQuery' => 'applications/diffusion/query/DiffusionDiffInlineCommentQuery.php',
     'DiffusionDiffQueryConduitAPIMethod' => 'applications/diffusion/conduit/DiffusionDiffQueryConduitAPIMethod.php',
+    'DiffusionDocumentController' => 'applications/diffusion/controller/DiffusionDocumentController.php',
+    'DiffusionDocumentRenderingEngine' => 'applications/diffusion/document/DiffusionDocumentRenderingEngine.php',
     'DiffusionDoorkeeperCommitFeedStoryPublisher' => 'applications/diffusion/doorkeeper/DiffusionDoorkeeperCommitFeedStoryPublisher.php',
     'DiffusionEmptyResultView' => 'applications/diffusion/view/DiffusionEmptyResultView.php',
     'DiffusionExistsQueryConduitAPIMethod' => 'applications/diffusion/conduit/DiffusionExistsQueryConduitAPIMethod.php',
@@ -5987,6 +5989,8 @@ phutil_register_library_map(array(
     'DiffusionDiffController' => 'DiffusionController',
     'DiffusionDiffInlineCommentQuery' => 'PhabricatorDiffInlineCommentQuery',
     'DiffusionDiffQueryConduitAPIMethod' => 'DiffusionQueryConduitAPIMethod',
+    'DiffusionDocumentController' => 'DiffusionController',
+    'DiffusionDocumentRenderingEngine' => 'PhabricatorDocumentRenderingEngine',
     'DiffusionDoorkeeperCommitFeedStoryPublisher' => 'DoorkeeperFeedStoryPublisher',
     'DiffusionEmptyResultView' => 'DiffusionView',
     'DiffusionExistsQueryConduitAPIMethod' => 'DiffusionQueryConduitAPIMethod',

src/applications/diffusion/application/PhabricatorDiffusionApplication.php

@@ -53,6 +53,8 @@ final class PhabricatorDiffusionApplication extends PhabricatorApplication {
         'history/(?P<dblob>.*)' => 'DiffusionHistoryController',
         'graph/(?P<dblob>.*)' => 'DiffusionGraphController',
         'browse/(?P<dblob>.*)' => 'DiffusionBrowseController',
+        'document/(?P<dblob>.*)'
+          => 'DiffusionDocumentController',
         'lastmodified/(?P<dblob>.*)' => 'DiffusionLastModifiedController',
         'diff/' => 'DiffusionDiffController',
         'tags/(?P<dblob>.*)' => 'DiffusionTagListController',

src/applications/diffusion/controller/DiffusionBrowseController.php

@@ -45,13 +45,13 @@ final class DiffusionBrowseController extends DiffusionController {
 
     if ($is_file) {
       return $this->browseFile();
-    } else {
-      $paths = $results->getPaths();
-      $paths = $pager->sliceResults($paths);
-      $results->setPaths($paths);
-
-      return $this->browseDirectory($results, $pager);
     }
+
+    $paths = $results->getPaths();
+    $paths = $pager->sliceResults($paths);
+    $results->setPaths($paths);
+
+    return $this->browseDirectory($results, $pager);
   }
 
   private function browseSearch() {
@@ -187,26 +187,21 @@ final class DiffusionBrowseController extends DiffusionController {
         } else {
           $corpus = $this->buildGitLFSCorpus($lfs_ref);
         }
-      } else if (ArcanistDiffUtils::isHeuristicBinaryFile($data)) {
-        $file_uri = $file->getBestURI();
-
-        if ($file->isViewableImage()) {
-          $corpus = $this->buildImageCorpus($file_uri);
-        } else {
-          $corpus = $this->buildBinaryCorpus($file_uri, $data);
-        }
       } else {
         $this->loadLintMessages();
         $this->coverage = $drequest->loadCoverage();
         $show_editor = true;
 
-        // Build the content of the file.
+        $ref = id(new PhabricatorDocumentRef())
-        $corpus = $this->buildCorpus(
+          ->setFile($file);
-          $data,
+
-          $needs_blame,
+        $engine = id(new DiffusionDocumentRenderingEngine())
-          $drequest,
+          ->setRequest($request)
-          $path,
+          ->setDiffusionRequest($drequest);
-          $data);
+
+        $corpus = $engine->newDocumentView($ref);
+
+        $this->corpusButtons[] = $this->renderFileButton();
       }
     }
 
@@ -514,164 +509,6 @@ final class DiffusionBrowseController extends DiffusionController {
       '/'.$drequest->getPath());
   }
 
-  private function buildCorpus(
-    $file_corpus,
-    $needs_blame,
-    DiffusionRequest $drequest,
-    $path,
-    $data) {
-
-    $viewer = $this->getViewer();
-    $blame_timeout = 15;
-    $blame_failed = false;
-
-    $highlight_limit = DifferentialChangesetParser::HIGHLIGHT_BYTE_LIMIT;
-    $blame_limit = DifferentialChangesetParser::HIGHLIGHT_BYTE_LIMIT;
-    $can_highlight = (strlen($file_corpus) <= $highlight_limit);
-    $can_blame = (strlen($file_corpus) <= $blame_limit);
-
-    if ($needs_blame && $can_blame) {
-      $blame = $this->loadBlame($path, $drequest->getCommit(), $blame_timeout);
-      list($blame_list, $blame_commits) = $blame;
-      if ($blame_list === null) {
-        $blame_failed = true;
-        $blame_list = array();
-      }
-    } else {
-      $blame_list = array();
-      $blame_commits = array();
-    }
-
-    require_celerity_resource('syntax-highlighting-css');
-    if ($can_highlight) {
-      $highlighted = PhabricatorSyntaxHighlighter::highlightWithFilename(
-        $path,
-        $file_corpus);
-    } else {
-      // Highlight as plain text to escape the content properly.
-      $highlighted = PhabricatorSyntaxHighlighter::highlightWithLanguage(
-        'txt',
-        $file_corpus);
-    }
-
-    $lines = phutil_split_lines($highlighted);
-
-    $rows = $this->buildDisplayRows(
-      $lines,
-      $blame_list,
-      $blame_commits);
-
-    $corpus_table = javelin_tag(
-      'table',
-      array(
-        'class' => 'diffusion-source remarkup-code PhabricatorMonospaced',
-        'sigil' => 'phabricator-source',
-        'meta' => array(
-          'uri' => $this->getLineNumberBaseURI(),
-        ),
-      ),
-      $rows);
-
-    $corpus_table = phutil_tag_div('diffusion-source-wrap', $corpus_table);
-
-    if ($this->getRequest()->isAjax()) {
-      return $corpus_table;
-    }
-
-    $id = celerity_generate_unique_node_id();
-
-    $repo = $drequest->getRepository();
-    $symbol_repos = nonempty($repo->getSymbolSources(), array());
-    $symbol_repos[] = $repo->getPHID();
-
-    $lang = last(explode('.', $drequest->getPath()));
-    $repo_languages = $repo->getSymbolLanguages();
-    $repo_languages = nonempty($repo_languages, array());
-    $repo_languages = array_fill_keys($repo_languages, true);
-
-    $needs_symbols = true;
-    if ($repo_languages && $symbol_repos) {
-      $have_symbols = id(new DiffusionSymbolQuery())
-          ->existsSymbolsInRepository($repo->getPHID());
-      if (!$have_symbols) {
-        $needs_symbols = false;
-      }
-    }
-
-    if ($needs_symbols && $repo_languages) {
-      $needs_symbols = isset($repo_languages[$lang]);
-    }
-
-    if ($needs_symbols) {
-      Javelin::initBehavior(
-        'repository-crossreference',
-        array(
-          'container' => $id,
-          'lang' => $lang,
-          'repositories' => $symbol_repos,
-        ));
-    }
-
-    $corpus = phutil_tag(
-      'div',
-      array(
-        'id' => $id,
-      ),
-      $corpus_table);
-
-    Javelin::initBehavior('load-blame', array('id' => $id));
-
-    $this->corpusButtons[] = $this->renderFileButton();
-    $title = basename($this->getDiffusionRequest()->getPath());
-    $icon = 'fa-file-code-o';
-    $drequest = $this->getDiffusionRequest();
-    $this->buildActionButtons($drequest);
-
-    $header = $this->buildPanelHeaderView($title, $icon);
-
-    $corpus = id(new PHUIObjectBoxView())
-      ->setHeader($header)
-      ->setBackground(PHUIObjectBoxView::BLUE_PROPERTY)
-      ->appendChild($corpus)
-      ->addClass('diffusion-mobile-view')
-      ->addSigil('diffusion-file-content-view')
-      ->setMetadata(
-        array(
-          'path' => $this->getDiffusionRequest()->getPath(),
-        ))
-      ->setCollapsed(true);
-
-    $messages = array();
-
-    if (!$can_highlight) {
-      $messages[] = pht(
-        'This file is larger than %s, so syntax highlighting is disabled '.
-        'by default.',
-        phutil_format_bytes($highlight_limit));
-    }
-
-    if (!$can_blame) {
-      $messages[] = pht(
-        'This file is larger than %s, so blame is disabled.',
-        phutil_format_bytes($blame_limit));
-    }
-
-    if ($blame_failed) {
-      $messages[] = pht(
-        'Failed to load blame information for this file in %s second(s).',
-        new PhutilNumber($blame_timeout));
-    }
-
-    if ($messages) {
-      $corpus->setInfoView(
-        id(new PHUIInfoView())
-          ->setSeverity(PHUIInfoView::SEVERITY_WARNING)
-          ->setErrors($messages));
-    }
-
-    return $corpus;
-  }
-
   private function buildButtonBar(
     DiffusionRequest $drequest,
     $show_editor) {
@@ -868,389 +705,6 @@ final class DiffusionBrowseController extends DiffusionController {
       ->setColor(PHUIButtonView::GREY);
   }
 
-  private function buildDisplayRows(
-    array $lines,
-    array $blame_list,
-    array $blame_commits) {
-
-    $request = $this->getRequest();
-    $viewer = $this->getViewer();
-    $drequest = $this->getDiffusionRequest();
-    $repository = $drequest->getRepository();
-
-    $revision_map = array();
-    $revisions = array();
-    if ($blame_commits) {
-      $commit_map = mpull($blame_commits, 'getCommitIdentifier', 'getPHID');
-
-      $revision_ids = id(new DifferentialRevision())
-        ->loadIDsByCommitPHIDs(array_keys($commit_map));
-      if ($revision_ids) {
-        $revisions = id(new DifferentialRevisionQuery())
-          ->setViewer($viewer)
-          ->withIDs($revision_ids)
-          ->execute();
-        $revisions = mpull($revisions, null, 'getID');
-      }
-
-      foreach ($revision_ids as $commit_phid => $revision_id) {
-        // If the viewer can't actually see this revision, skip it.
-        if (!isset($revisions[$revision_id])) {
-          continue;
-        }
-        $revision_map[$commit_map[$commit_phid]] = $revision_id;
-      }
-    }
-
-    $phids = array();
-    foreach ($blame_commits as $commit) {
-      $author_phid = $commit->getAuthorPHID();
-      if ($author_phid === null) {
-        continue;
-      }
-      $phids[$author_phid] = $author_phid;
-    }
-
-    foreach ($revisions as $revision) {
-      $author_phid = $revision->getAuthorPHID();
-      if ($author_phid === null) {
-        continue;
-      }
-      $phids[$author_phid] = $author_phid;
-    }
-
-    $handles = $viewer->loadHandles($phids);
-
-    $author_phids = array();
-    $author_map = array();
-    foreach ($blame_commits as $commit) {
-      $commit_identifier = $commit->getCommitIdentifier();
-
-      $author_phid = '';
-      if (isset($revision_map[$commit_identifier])) {
-        $revision_id = $revision_map[$commit_identifier];
-        $revision = $revisions[$revision_id];
-        $author_phid = $revision->getAuthorPHID();
-      } else {
-        $author_phid = $commit->getAuthorPHID();
-      }
-
-      $author_map[$commit_identifier] = $author_phid;
-      $author_phids[$author_phid] = $author_phid;
-    }
-
-    $colors = array();
-    if ($blame_commits) {
-      $epochs = array();
-
-      foreach ($blame_commits as $identifier => $commit) {
-        $epochs[$identifier] = $commit->getEpoch();
-      }
-
-      $epoch_list = array_filter($epochs);
-      $epoch_list = array_unique($epoch_list);
-      $epoch_list = array_values($epoch_list);
-
-      $epoch_min   = min($epoch_list);
-      $epoch_max   = max($epoch_list);
-      $epoch_range = ($epoch_max - $epoch_min) + 1;
-
-      foreach ($blame_commits as $identifier => $commit) {
-        $epoch = $epochs[$identifier];
-        if (!$epoch) {
-          $color = '#ffffdd'; // Warning color, missing data.
-        } else {
-          $color_ratio = ($epoch - $epoch_min) / $epoch_range;
-          $color_value = 0xE6 * (1.0 - $color_ratio);
-          $color = sprintf(
-            '#%02x%02x%02x',
-            $color_value,
-            0xF6,
-            $color_value);
-        }
-
-        $colors[$identifier] = $color;
-      }
-    }
-
-    $display = array();
-    $last_identifier = null;
-    $last_color = null;
-    foreach ($lines as $line_index => $line) {
-      $color = '#f6f6f6';
-      $duplicate = false;
-      if (isset($blame_list[$line_index])) {
-        $identifier = $blame_list[$line_index];
-        if (isset($colors[$identifier])) {
-          $color = $colors[$identifier];
-        }
-
-        if ($identifier === $last_identifier) {
-          $duplicate = true;
-        } else {
-          $last_identifier = $identifier;
-        }
-      }
-
-      $display[$line_index] = array(
-        'data' => $line,
-        'target' => false,
-        'highlighted' => false,
-        'color' => $color,
-        'duplicate' => $duplicate,
-      );
-    }
-
-    $line_arr = array();
-    $line_str = $drequest->getLine();
-    $ranges = explode(',', $line_str);
-    foreach ($ranges as $range) {
-      if (strpos($range, '-') !== false) {
-        list($min, $max) = explode('-', $range, 2);
-        $line_arr[] = array(
-          'min' => min($min, $max),
-          'max' => max($min, $max),
-        );
-      } else if (strlen($range)) {
-        $line_arr[] = array(
-          'min' => $range,
-          'max' => $range,
-        );
-      }
-    }
-
-    // Mark the first highlighted line as the target line.
-    if ($line_arr) {
-      $target_line = $line_arr[0]['min'];
-      if (isset($display[$target_line - 1])) {
-        $display[$target_line - 1]['target'] = true;
-      }
-    }
-
-    // Mark all other highlighted lines as highlighted.
-    foreach ($line_arr as $range) {
-      for ($ii = $range['min']; $ii <= $range['max']; $ii++) {
-        if (isset($display[$ii - 1])) {
-          $display[$ii - 1]['highlighted'] = true;
-        }
-      }
-    }
-
-    $engine = null;
-    $inlines = array();
-    if ($this->getRequest()->getStr('lint') !== null && $this->lintMessages) {
-      $engine = new PhabricatorMarkupEngine();
-      $engine->setViewer($viewer);
-
-      foreach ($this->lintMessages as $message) {
-        $inline = id(new PhabricatorAuditInlineComment())
-          ->setSyntheticAuthor(
-            ArcanistLintSeverity::getStringForSeverity($message['severity']).
-            ' '.$message['code'].' ('.$message['name'].')')
-          ->setLineNumber($message['line'])
-          ->setContent($message['description']);
-        $inlines[$message['line']][] = $inline;
-
-        $engine->addObject(
-          $inline,
-          PhabricatorInlineCommentInterface::MARKUP_FIELD_BODY);
-      }
-
-      $engine->process();
-      require_celerity_resource('differential-changeset-view-css');
-    }
-
-    $rows = $this->renderInlines(
-      idx($inlines, 0, array()),
-      (bool)$this->coverage,
-      $engine);
-
-    // NOTE: We're doing this manually because rendering is otherwise
-    // dominated by URI generation for very large files.
-    $line_base = $this->getLineNumberBaseURI();
-
-    require_celerity_resource('aphront-tooltip-css');
-    Javelin::initBehavior('phabricator-oncopy');
-    Javelin::initBehavior('phabricator-tooltips');
-    Javelin::initBehavior('phabricator-line-linker');
-
-    // Render these once, since they tend to get repeated many times in large
-    // blame outputs.
-    $commit_links = $this->renderCommitLinks($blame_commits, $handles);
-    $revision_links = $this->renderRevisionLinks($revisions, $handles);
-    $author_links = $this->renderAuthorLinks($author_map, $handles);
-
-    if ($this->coverage) {
-      require_celerity_resource('differential-changeset-view-css');
-      Javelin::initBehavior(
-        'diffusion-browse-file',
-        array(
-          'labels' => array(
-            'cov-C' => pht('Covered'),
-            'cov-N' => pht('Not Covered'),
-            'cov-U' => pht('Not Executable'),
-          ),
-        ));
-    }
-
-    $skip_text = pht('Skip Past This Commit');
-    $skip_icon = id(new PHUIIconView())
-      ->setIcon('fa-backward');
-
-    foreach ($display as $line_index => $line) {
-      $row = array();
-
-      $line_number = $line_index + 1;
-      $line_href = $line_base.'$'.$line_number;
-
-      if (isset($blame_list[$line_index])) {
-        $identifier = $blame_list[$line_index];
-      } else {
-        $identifier = null;
-      }
-
-      $revision_link = null;
-      $commit_link = null;
-      $author_link = null;
-      $before_link = null;
-
-      $style = 'background: '.$line['color'].';';
-
-      if ($identifier && !$line['duplicate']) {
-        if (isset($commit_links[$identifier])) {
-          $commit_link = $commit_links[$identifier];
-          $author_link = $author_links[$author_map[$identifier]];
-        }
-
-        if (isset($revision_map[$identifier])) {
-          $revision_id = $revision_map[$identifier];
-          if (isset($revision_links[$revision_id])) {
-            $revision_link = $revision_links[$revision_id];
-          }
-        }
-
-        $skip_href = $line_href.'?before='.$identifier;
-        $before_link = javelin_tag(
-          'a',
-          array(
-            'href'  => $skip_href,
-            'sigil' => 'has-tooltip',
-            'meta'  => array(
-              'tip'     => $skip_text,
-              'align'   => 'E',
-              'size'    => 300,
-            ),
-          ),
-          $skip_icon);
-      }
-
-      $row[] = phutil_tag(
-        'th',
-        array(
-          'class' => 'diffusion-blame-link',
-        ),
-        $before_link);
-
-      $object_links = array();
-      $object_links[] = $author_link;
-      $object_links[] = $commit_link;
-      if ($revision_link) {
-        $object_links[] = phutil_tag('span', array(), '/');
-        $object_links[] = $revision_link;
-      }
-
-      $row[] = phutil_tag(
-        'th',
-        array(
-          'class' => 'diffusion-rev-link',
-        ),
-        $object_links);
-
-      $line_link = phutil_tag(
-        'a',
-        array(
-          'href' => $line_href,
-          'style' => $style,
-        ),
-        $line_number);
-
-      $row[] = javelin_tag(
-        'th',
-        array(
-          'class' => 'diffusion-line-link',
-          'sigil' => 'phabricator-source-line',
-          'style' => $style,
-        ),
-        $line_link);
-
-      if ($line['target']) {
-        Javelin::initBehavior(
-          'diffusion-jump-to',
-          array(
-            'target' => 'scroll_target',
-          ));
-        $anchor_text = phutil_tag(
-          'a',
-          array(
-            'id' => 'scroll_target',
-          ),
-          '');
-      } else {
-        $anchor_text = null;
-      }
-
-      $row[] = phutil_tag(
-        'td',
-        array(
-        ),
-        array(
-          $anchor_text,
-
-          // NOTE: See phabricator-oncopy behavior.
-          "\xE2\x80\x8B",
-
-          // TODO: [HTML] Not ideal.
-          phutil_safe_html(str_replace("\t", '  ', $line['data'])),
-        ));
-
-      if ($this->coverage) {
-        $cov_index = $line_index;
-
-        if (isset($this->coverage[$cov_index])) {
-          $cov_class = $this->coverage[$cov_index];
-        } else {
-          $cov_class = 'N';
-        }
-
-        $row[] = phutil_tag(
-          'td',
-          array(
-            'class' => 'cov cov-'.$cov_class,
-          ),
-          '');
-      }
-
-      $rows[] = phutil_tag(
-        'tr',
-        array(
-          'class' => ($line['highlighted'] ?
-                      'phabricator-source-highlight' :
-                      null),
-        ),
-        $row);
-
-      $cur_inlines = $this->renderInlines(
-        idx($inlines, $line_number, array()),
-        $this->coverage,
-        $engine);
-      foreach ($cur_inlines as $cur_inline) {
-        $rows[] = $cur_inline;
-      }
-    }
-
-    return $rows;
-  }
-
   private function renderInlines(
     array $inlines,
     $has_coverage,
@@ -1285,53 +739,6 @@ final class DiffusionBrowseController extends DiffusionController {
     return $rows;
   }
 
-  private function buildImageCorpus($file_uri) {
-    $properties = new PHUIPropertyListView();
-
-    $properties->addImageContent(
-      phutil_tag(
-        'img',
-        array(
-          'src' => $file_uri,
-        )));
-
-    $this->corpusButtons[] = $this->renderFileButton($file_uri);
-    $title = basename($this->getDiffusionRequest()->getPath());
-    $icon = 'fa-file-image-o';
-    $drequest = $this->getDiffusionRequest();
-    $this->buildActionButtons($drequest);
-    $header = $this->buildPanelHeaderView($title, $icon);
-
-    return id(new PHUIObjectBoxView())
-      ->setHeader($header)
-      ->setBackground(PHUIObjectBoxView::BLUE_PROPERTY)
-      ->addClass('diffusion-mobile-view')
-      ->addPropertyList($properties);
-  }
-
-  private function buildBinaryCorpus($file_uri, $data) {
-    $size = new PhutilNumber(strlen($data));
-    $text = pht('This is a binary file. It is %s byte(s) in length.', $size);
-    $text = id(new PHUIBoxView())
-      ->addPadding(PHUI::PADDING_LARGE)
-      ->appendChild($text);
-
-    $this->corpusButtons[] = $this->renderFileButton($file_uri);
-    $title = basename($this->getDiffusionRequest()->getPath());
-    $icon = 'fa-file';
-    $drequest = $this->getDiffusionRequest();
-    $this->buildActionButtons($drequest);
-    $header = $this->buildPanelHeaderView($title, $icon);
-
-    $box = id(new PHUIObjectBoxView())
-      ->setHeader($header)
-      ->setBackground(PHUIObjectBoxView::BLUE_PROPERTY)
-      ->addClass('diffusion-mobile-view')
-      ->appendChild($text);
-
-    return $box;
-  }
-
   private function buildErrorCorpus($message) {
     $text = id(new PHUIBoxView())
       ->addPadding(PHUI::PADDING_LARGE)

src/applications/diffusion/controller/DiffusionDocumentController.php

@@ -0,0 +1,45 @@
+<?php
+
+final class DiffusionDocumentController extends DiffusionController {
+
+  public function shouldAllowPublic() {
+    return true;
+  }
+
+  public function handleRequest(AphrontRequest $request) {
+    $response = $this->loadDiffusionContext();
+    if ($response) {
+      return $response;
+    }
+
+    $drequest = $this->getDiffusionRequest();
+
+    $engine = id(new DiffusionDocumentRenderingEngine())
+      ->setRequest($request)
+      ->setDiffusionRequest($drequest)
+      ->setController($this);
+
+    $viewer = $this->getViewer();
+    $request = $this->getRequest();
+    $repository = $drequest->getRepository();
+
+    $file_phid = $request->getStr('filePHID');
+
+    $file = id(new PhabricatorFileQuery())
+      ->setViewer($viewer)
+      ->withPHIDs(array($file_phid))
+      ->executeOne();
+    if (!$file) {
+      return $engine->newErrorResponse(
+        pht(
+          'This file ("%s") does not exist or could not be loaded.',
+          $file_phid));
+    }
+
+    $ref = id(new PhabricatorDocumentRef())
+      ->setFile($file);
+
+    return $engine->newRenderResponse($ref);
+  }
+
+}

src/applications/diffusion/document/DiffusionDocumentRenderingEngine.php

@@ -0,0 +1,67 @@
+<?php
+
+final class DiffusionDocumentRenderingEngine
+  extends PhabricatorDocumentRenderingEngine {
+
+  private $diffusionRequest;
+
+  public function setDiffusionRequest(DiffusionRequest $drequest) {
+    $this->diffusionRequest = $drequest;
+    return $this;
+  }
+
+  public function getDiffusionRequest() {
+    return $this->diffusionRequest;
+  }
+
+  protected function getSelectedDocumentEngineKey() {
+    return $this->getRequest()->getStr('as');
+  }
+
+  protected function newRefViewURI(
+    PhabricatorDocumentRef $ref,
+    PhabricatorDocumentEngine $engine) {
+
+    $file = $ref->getFile();
+    $engine_key = $engine->getDocumentEngineKey();
+    $drequest = $this->getDiffusionRequest();
+
+    return (string)$drequest->generateURI(
+      array(
+        'action' => 'browse',
+        'stable' => true,
+        'params' => array(
+          'as' => $engine_key,
+        ),
+      ));
+  }
+
+  protected function newRefRenderURI(
+    PhabricatorDocumentRef $ref,
+    PhabricatorDocumentEngine $engine) {
+
+    $engine_key = $engine->getDocumentEngineKey();
+
+    $file = $ref->getFile();
+    $file_phid = $file->getPHID();
+
+    $drequest = $this->getDiffusionRequest();
+
+    return (string)$drequest->generateURI(
+      array(
+        'action' => 'document',
+        'stable' => true,
+        'params' => array(
+          'as' => $engine_key,
+          'filePHID' => $file_phid,
+        ),
+      ));
+  }
+
+  protected function addApplicationCrumbs(
+    PHUICrumbsView $crumbs,
+    PhabricatorDocumentRef $ref = null) {
+    return;
+  }
+
+}

src/applications/files/controller/PhabricatorFileDocumentController.php

@@ -8,6 +8,10 @@ final class PhabricatorFileDocumentController
   }
 
   public function handleRequest(AphrontRequest $request) {
+    $engine = id(new PhabricatorFileDocumentRenderingEngine())
+      ->setRequest($request)
+      ->setController($this);
+
     $viewer = $request->getViewer();
 
     $file_phid = $request->getURIData('phid');
@@ -17,7 +21,7 @@ final class PhabricatorFileDocumentController
       ->withPHIDs(array($file_phid))
       ->executeOne();
     if (!$file) {
-      return $this->newErrorResponse(
+      return $engine->newErrorResponse(
         pht(
           'This file ("%s") does not exist or could not be loaded.',
           $file_phid));
@@ -26,10 +30,7 @@ final class PhabricatorFileDocumentController
     $ref = id(new PhabricatorDocumentRef())
       ->setFile($file);
 
-    return id(new PhabricatorFileDocumentRenderingEngine())
+    return $engine->newRenderResponse($ref);
-      ->setRequest($request)
-      ->setController($this)
-      ->newRenderResponse($ref);
   }
 
 }

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

@@ -6,6 +6,7 @@ abstract class PhabricatorDocumentRenderingEngine
   private $request;
   private $controller;
   private $activeEngine;
+  private $ref;
 
   final public function setRequest(AphrontRequest $request) {
     $this->request = $request;
@@ -34,13 +35,13 @@ abstract class PhabricatorDocumentRenderingEngine
   }
 
   final protected function getActiveEngine() {
-    if (!$this->activeEngine) {
-      throw new PhutilInvalidStateException('setActiveEngine');
-    }
-
     return $this->activeEngine;
   }
 
+  final protected function getRef() {
+    return $this->ref;
+  }
+
   final public function newDocumentView(PhabricatorDocumentRef $ref) {
     $request = $this->getRequest();
     $viewer = $request->getViewer();
@@ -173,10 +174,9 @@ abstract class PhabricatorDocumentRenderingEngine
     $viewer = $request->getViewer();
 
     $engines = PhabricatorDocumentEngine::getEnginesForRef($viewer, $ref);
-    $engine_key = $request->getURIData('engineKey');
+    $engine_key = $this->getSelectedDocumentEngineKey();
     if (!isset($engines[$engine_key])) {
       return $this->newErrorResponse(
-        $ref,
         pht(
           'The engine ("%s") is unknown, or unable to render this document.',
           $engine_key));
@@ -198,16 +198,13 @@ abstract class PhabricatorDocumentRenderingEngine
     try {
       $content = $engine->newDocument($ref);
     } catch (Exception $ex) {
-      return $this->newErrorResponse($ref, $ex->getMessage());
+      return $this->newErrorResponse($ex->getMessage());
     }
 
-    return $this->newContentResponse($ref, $content);
+    return $this->newContentResponse($content);
   }
 
-  private function newErrorResponse(
+  public function newErrorResponse($message) {
-    PhabricatorDocumentRef $ref,
-    $message) {
-
     $container = phutil_tag(
       'div',
       array(
@@ -220,13 +217,10 @@ abstract class PhabricatorDocumentRenderingEngine
         $message,
       ));
 
-    return $this->newContentResponse($ref, $container);
+    return $this->newContentResponse($container);
   }
 
-  private function newContentResponse(
+  private function newContentResponse($content) {
-    PhabricatorDocumentRef $ref,
-    $content) {
-
     $request = $this->getRequest();
     $viewer = $request->getViewer();
     $controller = $this->getController();
@@ -239,10 +233,8 @@ abstract class PhabricatorDocumentRenderingEngine
           ));
     }
 
-    $crumbs = $this->newCrumbs($ref);
+    $crumbs = $this->newCrumbs();
-    if ($crumbs) {
+    $crumbs->setBorder(true);
-      $crumbs->setBorder(true);
-    }
 
     $content_frame = id(new PHUIObjectBoxView())
       ->setBackground(PHUIObjectBoxView::BLUE_PROPERTY)
@@ -251,34 +243,46 @@ abstract class PhabricatorDocumentRenderingEngine
     $page_frame = id(new PHUITwoColumnView())
       ->setFooter($content_frame);
 
+    $title = array();
+    $ref = $this->getRef();
+    if ($ref) {
+      $title = array(
+        $ref->getName(),
+        pht('Standalone'),
+      );
+    } else {
+      $title = pht('Document');
+    }
+
     return $controller->newPage()
       ->setCrumbs($crumbs)
-      ->setTitle(
+      ->setTitle($title)
-        array(
-          $ref->getName(),
-          pht('Standalone'),
-        ))
       ->appendChild($page_frame);
   }
 
-  protected function newCrumbs(PhabricatorDocumentRef $ref) {
+  protected function newCrumbs() {
+    $engine = $this->getActiveEngine();
     $controller = $this->getController();
+
     $crumbs = $controller->buildApplicationCrumbsForEditEngine();
 
-    $this->addApplicationCrumbs($ref, $crumbs);
+    $ref = $this->getRef();
 
-    $engine = $this->getActiveEngine();
+    $this->addApplicationCrumbs($crumbs, $ref);
-    $label = $engine->getViewAsLabel($ref);
+
-    if ($label) {
+    if ($ref) {
-      $crumbs->addTextCrumb($label);
+      $label = $engine->getViewAsLabel($ref);
+      if ($label) {
+        $crumbs->addTextCrumb($label);
+      }
     }
 
     return $crumbs;
   }
 
   protected function addApplicationCrumbs(
-    PhabricatorDocumentRef $ref,
+    PHUICrumbsView $crumbs,
-    PHUICrumbsView $crumbs) {
+    PhabricatorDocumentRef $ref = null) {
     return;
   }
 

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

@@ -34,12 +34,14 @@ final class PhabricatorFileDocumentRenderingEngine
   }
 
   protected function addApplicationCrumbs(
-    PhabricatorDocumentRef $ref,
+    PHUICrumbsView $crumbs,
-    PHUICrumbsView $crumbs) {
+    PhabricatorDocumentRef $ref = null) {
 
-    $file = $ref->getFile();
+    if ($ref) {
-    if ($file) {
+      $file = $ref->getFile();
-      $crumbs->addTextCrumb($file->getMonogram(), $file->getInfoURI());
+      if ($file) {
+        $crumbs->addTextCrumb($file->getMonogram(), $file->getInfoURI());
+      }
     }
 
   }

src/applications/repository/storage/PhabricatorRepository.php

@@ -704,6 +704,7 @@ final class PhabricatorRepository extends PhabricatorRepositoryDAO
       case 'graph':
       case 'clone':
       case 'browse':
+      case 'document':
       case 'change':
       case 'lastmodified':
       case 'tags':
@@ -782,6 +783,7 @@ final class PhabricatorRepository extends PhabricatorRepositoryDAO
       case 'history':
       case 'graph':
       case 'browse':
+      case 'document':
       case 'lastmodified':
       case 'tags':
       case 'branches':