diff --git a/src/applications/phriction/controller/PhrictionEditController.php b/src/applications/phriction/controller/PhrictionEditController.php
index 850e5f47fc..e85b7bc788 100644
--- a/src/applications/phriction/controller/PhrictionEditController.php
+++ b/src/applications/phriction/controller/PhrictionEditController.php
@@ -1,302 +1,266 @@
 <?php
 
 final class PhrictionEditController
   extends PhrictionController {
 
   private $id;
 
   public function willProcessRequest(array $data) {
     $this->id = idx($data, 'id');
   }
 
   public function processRequest() {
 
     $request = $this->getRequest();
     $user = $request->getUser();
 
     $current_version = null;
     if ($this->id) {
       $document = id(new PhrictionDocumentQuery())
         ->setViewer($user)
         ->withIDs(array($this->id))
         ->needContent(true)
         ->requireCapabilities(
           array(
             PhabricatorPolicyCapability::CAN_VIEW,
             PhabricatorPolicyCapability::CAN_EDIT,
           ))
         ->executeOne();
       if (!$document) {
         return new Aphront404Response();
       }
 
       $current_version = $document->getContent()->getVersion();
 
       $revert = $request->getInt('revert');
       if ($revert) {
         $content = id(new PhrictionContent())->loadOneWhere(
           'documentID = %d AND version = %d',
           $document->getID(),
           $revert);
         if (!$content) {
           return new Aphront404Response();
         }
       } else {
         $content = $document->getContent();
       }
 
     } else {
       $slug = $request->getStr('slug');
       $slug = PhabricatorSlug::normalize($slug);
       if (!$slug) {
         return new Aphront404Response();
       }
 
       $document = id(new PhrictionDocumentQuery())
         ->setViewer($user)
         ->withSlugs(array($slug))
         ->needContent(true)
         ->executeOne();
 
       if ($document) {
         $content = $document->getContent();
         $current_version = $content->getVersion();
       } else {
         if (PhrictionDocument::isProjectSlug($slug)) {
           $project = id(new PhabricatorProjectQuery())
             ->setViewer($user)
             ->withPhrictionSlugs(array(
               PhrictionDocument::getProjectSlugIdentifier($slug),
             ))
             ->executeOne();
           if (!$project) {
             return new Aphront404Response();
           }
         }
         $document = PhrictionDocument::initializeNewDocument($user, $slug);
         $content = $document->getContent();
       }
     }
 
     if ($request->getBool('nodraft')) {
       $draft = null;
       $draft_key = null;
     } else {
       if ($document->getPHID()) {
         $draft_key = $document->getPHID().':'.$content->getVersion();
       } else {
         $draft_key = 'phriction:'.$content->getSlug();
       }
       $draft = id(new PhabricatorDraft())->loadOneWhere(
         'authorPHID = %s AND draftKey = %s',
         $user->getPHID(),
         $draft_key);
     }
 
+    if ($draft &&
+      strlen($draft->getDraft()) &&
+      ($draft->getDraft() != $content->getContent())) {
+      $content_text = $draft->getDraft();
+
+      $discard = phutil_tag(
+        'a',
+        array(
+          'href' => $request->getRequestURI()->alter('nodraft', true),
+        ),
+        pht('discard this draft'));
+
+      $draft_note = new AphrontErrorView();
+      $draft_note->setSeverity(AphrontErrorView::SEVERITY_NOTICE);
+      $draft_note->setTitle('Recovered Draft');
+      $draft_note->appendChild(hsprintf(
+        '<p>Showing a saved draft of your edits, you can %s.</p>',
+        $discard));
+    } else {
+      $content_text = $content->getContent();
+      $draft_note = null;
+    }
+
     require_celerity_resource('phriction-document-css');
 
     $e_title = true;
+    $e_content = true;
+    $validation_exception = null;
     $notes = null;
-    $errors = array();
+    $title = $content->getTitle();
+    $overwrite = false;
 
     if ($request->isFormPost()) {
 
-      $overwrite = $request->getBool('overwrite');
-      if (!$overwrite) {
-        $edit_version = $request->getStr('contentVersion');
-        if ($edit_version != $current_version) {
-          $dialog = $this->newDialog()
-            ->setTitle(pht('Edit Conflict!'))
-            ->appendParagraph(
-              pht(
-                'Another user made changes to this document after you began '.
-                'editing it. Do you want to overwrite their changes?'))
-            ->appendParagraph(
-              pht(
-                'If you choose to overwrite their changes, you should review '.
-                'the document edit history to see what you overwrote, and '.
-                'then make another edit to merge the changes if necessary.'))
-            ->addSubmitButton(pht('Overwrite Changes'))
-            ->addCancelButton($request->getRequestURI());
-
-          $dialog->addHiddenInput('overwrite', 'true');
-          foreach ($request->getPassthroughRequestData() as $key => $value) {
-            $dialog->addHiddenInput($key, $value);
-          }
-
-          return $dialog;
-        }
-      }
-
-
       $title = $request->getStr('title');
+      $content_text = $request->getStr('content');
       $notes = $request->getStr('description');
-
-      if (!strlen($title)) {
-        $e_title = pht('Required');
-        $errors[] = pht('Document title is required.');
-      } else {
-        $e_title = null;
-      }
-
-      if ($document->getID()) {
-        if ($content->getTitle() == $title &&
-            $content->getContent() == $request->getStr('content')) {
-
-          $dialog = new AphrontDialogView();
-          $dialog->setUser($user);
-          $dialog->setTitle(pht('No Edits'));
-          $dialog->appendChild(phutil_tag('p', array(), pht(
-            'You did not make any changes to the document.')));
-          $dialog->addCancelButton($request->getRequestURI());
-
-          return id(new AphrontDialogResponse())->setDialog($dialog);
-        }
-      } else if (!strlen($request->getStr('content'))) {
-
-        // We trigger this only for new pages. For existing pages, deleting
-        // all the content counts as deleting the page.
-
-        $dialog = new AphrontDialogView();
-        $dialog->setUser($user);
-        $dialog->setTitle(pht('Empty Page'));
-        $dialog->appendChild(phutil_tag('p', array(), pht(
-          'You can not create an empty document.')));
-        $dialog->addCancelButton($request->getRequestURI());
-
-        return id(new AphrontDialogResponse())->setDialog($dialog);
-      }
-
-      if (!count($errors)) {
-
-        $xactions = array();
-        $xactions[] = id(new PhrictionTransaction())
-          ->setTransactionType(PhrictionTransaction::TYPE_TITLE)
-          ->setNewValue($title);
-        $xactions[] = id(new PhrictionTransaction())
-          ->setTransactionType(PhrictionTransaction::TYPE_CONTENT)
-          ->setNewValue($request->getStr('content'));
-
-        $editor = id(new PhrictionTransactionEditor())
-          ->setActor($user)
-          ->setContentSourceFromRequest($request)
-          ->setContinueOnNoEffect(true)
-          ->setDescription($notes)
-          ->applyTransactions($document, $xactions);
+      $current_version = $request->getInt('contentVersion');
+
+      $xactions = array();
+      $xactions[] = id(new PhrictionTransaction())
+        ->setTransactionType(PhrictionTransaction::TYPE_TITLE)
+        ->setNewValue($title);
+      $xactions[] = id(new PhrictionTransaction())
+        ->setTransactionType(PhrictionTransaction::TYPE_CONTENT)
+        ->setNewValue($content_text);
+
+      $editor = id(new PhrictionTransactionEditor())
+        ->setActor($user)
+        ->setContentSourceFromRequest($request)
+        ->setContinueOnNoEffect(true)
+        ->setDescription($notes)
+        ->setProcessContentVersionError(!$request->getBool('overwrite'))
+        ->setContentVersion($current_version);
+
+      try {
+        $editor->applyTransactions($document, $xactions);
 
         if ($draft) {
           $draft->delete();
         }
 
         $uri = PhrictionDocument::getSlugURI($document->getSlug());
         return id(new AphrontRedirectResponse())->setURI($uri);
+      } catch (PhabricatorApplicationTransactionValidationException $ex) {
+        $validation_exception = $ex;
+        $e_title = $ex->getShortMessage(
+          PhrictionTransaction::TYPE_TITLE);
+        $e_content = $ex->getShortMessage(
+          PhrictionTransaction::TYPE_CONTENT);
+
+        // if we're not supposed to process the content version error, then
+        // overwrite that content...!
+        if (!$editor->getProcessContentVersionError()) {
+          $overwrite = true;
+        }
+
+        // TODO - remember to set policy to what the user tried to set it to
       }
     }
 
     if ($document->getID()) {
       $panel_header = pht('Edit Phriction Document');
-      $submit_button = pht('Save Changes');
+      $page_title = pht('Edit Document');
+      if ($overwrite) {
+        $submit_button = pht('Overwrite Changes');
+      } else {
+        $submit_button = pht('Save Changes');
+      }
     } else {
       $panel_header = pht('Create New Phriction Document');
       $submit_button = pht('Create Document');
+      $page_title = pht('Create Document');
     }
 
     $uri = $document->getSlug();
     $uri = PhrictionDocument::getSlugURI($uri);
     $uri = PhabricatorEnv::getProductionURI($uri);
 
     $cancel_uri = PhrictionDocument::getSlugURI($document->getSlug());
 
-    if ($draft &&
-        strlen($draft->getDraft()) &&
-        ($draft->getDraft() != $content->getContent())) {
-      $content_text = $draft->getDraft();
-
-      $discard = phutil_tag(
-        'a',
-        array(
-          'href' => $request->getRequestURI()->alter('nodraft', true),
-        ),
-        pht('discard this draft'));
-
-      $draft_note = new AphrontErrorView();
-      $draft_note->setSeverity(AphrontErrorView::SEVERITY_NOTICE);
-      $draft_note->setTitle('Recovered Draft');
-      $draft_note->appendChild(hsprintf(
-        '<p>Showing a saved draft of your edits, you can %s.</p>',
-        $discard));
-    } else {
-      $content_text = $content->getContent();
-      $draft_note = null;
-    }
-
     $form = id(new AphrontFormView())
       ->setUser($user)
-      ->setWorkflow(true)
-      ->setAction($request->getRequestURI()->getPath())
       ->addHiddenInput('slug', $document->getSlug())
       ->addHiddenInput('nodraft', $request->getBool('nodraft'))
       ->addHiddenInput('contentVersion', $current_version)
+      ->addHiddenInput('overwrite', $overwrite)
       ->appendChild(
         id(new AphrontFormTextControl())
           ->setLabel(pht('Title'))
-          ->setValue($content->getTitle())
+          ->setValue($title)
           ->setError($e_title)
           ->setName('title'))
       ->appendChild(
         id(new AphrontFormStaticControl())
           ->setLabel(pht('URI'))
           ->setValue($uri))
       ->appendChild(
         id(new PhabricatorRemarkupControl())
           ->setLabel(pht('Content'))
           ->setValue($content_text)
+          ->setError($e_content)
           ->setHeight(AphrontFormTextAreaControl::HEIGHT_VERY_TALL)
           ->setName('content')
           ->setID('document-textarea')
           ->setUser($user))
       ->appendChild(
         id(new AphrontFormTextControl())
           ->setLabel(pht('Edit Notes'))
           ->setValue($notes)
           ->setError(null)
           ->setName('description'))
       ->appendChild(
         id(new AphrontFormSubmitControl())
           ->addCancelButton($cancel_uri)
           ->setValue($submit_button));
 
     $form_box = id(new PHUIObjectBoxView())
-      ->setHeaderText(pht('Edit Document'))
-      ->setFormErrors($errors)
+      ->setHeaderText($panel_header)
+      ->setValidationException($validation_exception)
       ->setForm($form);
 
     $preview = id(new PHUIRemarkupPreviewPanel())
       ->setHeader(pht('Document Preview'))
       ->setPreviewURI('/phriction/preview/')
       ->setControlID('document-textarea')
       ->setSkin('document');
 
     $crumbs = $this->buildApplicationCrumbs();
     if ($document->getID()) {
       $crumbs->addTextCrumb(
         $content->getTitle(),
         PhrictionDocument::getSlugURI($document->getSlug()));
       $crumbs->addTextCrumb(pht('Edit'));
     } else {
       $crumbs->addTextCrumb(pht('Create'));
     }
 
     return $this->buildApplicationPage(
       array(
         $crumbs,
         $draft_note,
         $form_box,
         $preview,
       ),
       array(
-        'title'   => pht('Edit Document'),
+        'title'   => $page_title,
       ));
   }
 
 }
diff --git a/src/applications/phriction/editor/PhrictionTransactionEditor.php b/src/applications/phriction/editor/PhrictionTransactionEditor.php
index d97b9e0844..c8bd4096de 100644
--- a/src/applications/phriction/editor/PhrictionTransactionEditor.php
+++ b/src/applications/phriction/editor/PhrictionTransactionEditor.php
@@ -1,396 +1,532 @@
 <?php
 
 final class PhrictionTransactionEditor
   extends PhabricatorApplicationTransactionEditor {
 
   private $description;
   private $oldContent;
   private $newContent;
   private $moveAwayDocument;
   private $skipAncestorCheck;
+  private $contentVersion;
+  private $processContentVersionError = true;
 
   public function setDescription($description) {
     $this->description = $description;
     return $this;
   }
 
   private function getDescription() {
     return $this->description;
   }
 
   private function setOldContent(PhrictionContent $content) {
     $this->oldContent = $content;
     return $this;
   }
 
   private function getOldContent() {
     return $this->oldContent;
   }
 
   private function setNewContent(PhrictionContent $content) {
     $this->newContent = $content;
     return $this;
   }
 
   private function getNewContent() {
     return $this->newContent;
   }
 
   public function setSkipAncestorCheck($bool) {
     $this->skipAncestorCheck = $bool;
     return $this;
   }
 
   public function getSkipAncestorCheck() {
     return $this->skipAncestorCheck;
   }
 
+  public function setContentVersion($version) {
+    $this->contentVersion = $version;
+    return $this;
+  }
+
+  public function getContentVersion() {
+    return $this->contentVersion;
+  }
+
+  public function setProcessContentVersionError($process) {
+    $this->processContentVersionError = $process;
+    return $this;
+  }
+
+  public function getProcessContentVersionError() {
+    return $this->processContentVersionError;
+  }
+
   public function getEditorApplicationClass() {
     return 'PhabricatorPhrictionApplication';
   }
 
   public function getEditorObjectsDescription() {
     return pht('Phriction Documents');
   }
 
   public function getTransactionTypes() {
     $types = parent::getTransactionTypes();
 
     $types[] = PhabricatorTransactions::TYPE_COMMENT;
     $types[] = PhrictionTransaction::TYPE_TITLE;
     $types[] = PhrictionTransaction::TYPE_CONTENT;
     $types[] = PhrictionTransaction::TYPE_DELETE;
     $types[] = PhrictionTransaction::TYPE_MOVE_TO;
     $types[] = PhrictionTransaction::TYPE_MOVE_AWAY;
 
     /* TODO
     $types[] = PhabricatorTransactions::TYPE_VIEW_POLICY;
     $types[] = PhabricatorTransactions::TYPE_EDIT_POLICY;
      */
 
     return $types;
   }
 
   protected function getCustomTransactionOldValue(
     PhabricatorLiskDAO $object,
     PhabricatorApplicationTransaction $xaction) {
 
     switch ($xaction->getTransactionType()) {
       case PhrictionTransaction::TYPE_TITLE:
         if ($this->getIsNewObject()) {
           return null;
         }
         return $this->getOldContent()->getTitle();
       case PhrictionTransaction::TYPE_CONTENT:
         if ($this->getIsNewObject()) {
           return null;
         }
         return $this->getOldContent()->getContent();
       case PhrictionTransaction::TYPE_DELETE:
       case PhrictionTransaction::TYPE_MOVE_TO:
       case PhrictionTransaction::TYPE_MOVE_AWAY:
         return null;
     }
   }
 
   protected function getCustomTransactionNewValue(
     PhabricatorLiskDAO $object,
     PhabricatorApplicationTransaction $xaction) {
 
     switch ($xaction->getTransactionType()) {
       case PhrictionTransaction::TYPE_TITLE:
       case PhrictionTransaction::TYPE_CONTENT:
       case PhrictionTransaction::TYPE_DELETE:
         return $xaction->getNewValue();
       case PhrictionTransaction::TYPE_MOVE_TO:
         $document = $xaction->getNewValue();
         // grab the real object now for the sub-editor to come
         $this->moveAwayDocument = $document;
         $dict = array(
           'id' => $document->getID(),
           'phid' => $document->getPHID(),
           'content' => $document->getContent()->getContent(),);
         return $dict;
       case PhrictionTransaction::TYPE_MOVE_AWAY:
         $document = $xaction->getNewValue();
         $dict = array(
           'id' => $document->getID(),
           'phid' => $document->getPHID(),
           'content' => $document->getContent()->getContent(),);
         return $dict;
     }
   }
 
   protected function shouldApplyInitialEffects(
     PhabricatorLiskDAO $object,
     array $xactions) {
 
     foreach ($xactions as $xaction) {
       switch ($xaction->getTransactionType()) {
       case PhrictionTransaction::TYPE_TITLE:
       case PhrictionTransaction::TYPE_CONTENT:
       case PhrictionTransaction::TYPE_DELETE:
       case PhrictionTransaction::TYPE_MOVE_TO:
       case PhrictionTransaction::TYPE_MOVE_AWAY:
         return true;
       }
     }
     return parent::shouldApplyInitialEffects($object, $xactions);
   }
 
   protected function applyInitialEffects(
     PhabricatorLiskDAO $object,
     array $xactions) {
 
     $this->setOldContent($object->getContent());
     $this->setNewContent($this->buildNewContentTemplate($object));
   }
 
   protected function applyCustomInternalTransaction(
     PhabricatorLiskDAO $object,
     PhabricatorApplicationTransaction $xaction) {
 
     switch ($xaction->getTransactionType()) {
       case PhrictionTransaction::TYPE_TITLE:
       case PhrictionTransaction::TYPE_CONTENT:
       case PhrictionTransaction::TYPE_MOVE_TO:
         $object->setStatus(PhrictionDocumentStatus::STATUS_EXISTS);
         return;
       case PhrictionTransaction::TYPE_MOVE_AWAY:
         $object->setStatus(PhrictionDocumentStatus::STATUS_MOVED);
         return;
     }
   }
 
+  protected function expandTransaction(
+    PhabricatorLiskDAO $object,
+    PhabricatorApplicationTransaction $xaction) {
+
+    $xactions = parent::expandTransaction($object, $xaction);
+    switch ($xaction->getTransactionType()) {
+      case PhrictionTransaction::TYPE_CONTENT:
+        if ($this->getIsNewObject()) {
+          break;
+        }
+        $content = $xaction->getNewValue();
+        if ($content === '') {
+          $xactions[] = id(new PhrictionTransaction())
+            ->setTransactionType(PhrictionTransaction::TYPE_DELETE)
+            ->setNewValue(true);
+        }
+        break;
+      default:
+        break;
+    }
+
+    return $xactions;
+  }
+
   protected function applyCustomExternalTransaction(
     PhabricatorLiskDAO $object,
     PhabricatorApplicationTransaction $xaction) {
 
     switch ($xaction->getTransactionType()) {
       case PhrictionTransaction::TYPE_TITLE:
         $this->getNewContent()->setTitle($xaction->getNewValue());
         break;
       case PhrictionTransaction::TYPE_CONTENT:
         $this->getNewContent()->setContent($xaction->getNewValue());
         break;
       case PhrictionTransaction::TYPE_DELETE:
         $this->getNewContent()->setContent('');
         $this->getNewContent()->setChangeType(
           PhrictionChangeType::CHANGE_DELETE);
         break;
       case PhrictionTransaction::TYPE_MOVE_TO:
         $dict = $xaction->getNewValue();
         $this->getNewContent()->setContent($dict['content']);
         $this->getNewContent()->setChangeType(
           PhrictionChangeType::CHANGE_MOVE_HERE);
         $this->getNewContent()->setChangeRef($dict['id']);
         break;
       case PhrictionTransaction::TYPE_MOVE_AWAY:
         $dict = $xaction->getNewValue();
         $this->getNewContent()->setContent('');
         $this->getNewContent()->setChangeType(
           PhrictionChangeType::CHANGE_MOVE_AWAY);
         $this->getNewContent()->setChangeRef($dict['id']);
         break;
       default:
         break;
     }
   }
 
   protected function applyFinalEffects(
     PhabricatorLiskDAO $object,
     array $xactions) {
 
     $save_content = false;
     foreach ($xactions as $xaction) {
       switch ($xaction->getTransactionType()) {
         case PhrictionTransaction::TYPE_TITLE:
         case PhrictionTransaction::TYPE_CONTENT:
         case PhrictionTransaction::TYPE_DELETE:
         case PhrictionTransaction::TYPE_MOVE_AWAY:
         case PhrictionTransaction::TYPE_MOVE_TO:
           $save_content = true;
           break;
         default:
           break;
       }
     }
 
     if ($save_content) {
       $content = $this->getNewContent();
       $content->setDocumentID($object->getID());
       $content->save();
 
       $object->setContentID($content->getID());
       $object->save();
       $object->attachContent($content);
     }
 
     if ($this->getIsNewObject() && !$this->getSkipAncestorCheck()) {
       // Stub out empty parent documents if they don't exist
       $ancestral_slugs = PhabricatorSlug::getAncestry($object->getSlug());
       if ($ancestral_slugs) {
         $ancestors = id(new PhrictionDocumentQuery())
           ->setViewer(PhabricatorUser::getOmnipotentUser())
           ->withSlugs($ancestral_slugs)
           ->needContent(true)
           ->execute();
         $ancestors = mpull($ancestors, null, 'getSlug');
         $stub_type = PhrictionChangeType::CHANGE_STUB;
         foreach ($ancestral_slugs as $slug) {
           $ancestor_doc = idx($ancestors, $slug);
           // We check for change type to prevent near-infinite recursion
           if (!$ancestor_doc && $content->getChangeType() != $stub_type) {
             $ancestor_doc = PhrictionDocument::initializeNewDocument(
               $this->getActor(),
               $slug);
             $stub_xactions = array();
             $stub_xactions[] = id(new PhrictionTransaction())
               ->setTransactionType(PhrictionTransaction::TYPE_TITLE)
               ->setNewValue(PhabricatorSlug::getDefaultTitle($slug))
               ->setMetadataValue('stub:create:phid', $object->getPHID());
             $stub_xactions[] = id(new PhrictionTransaction())
               ->setTransactionType(PhrictionTransaction::TYPE_CONTENT)
-              ->setNewValue('');
+              ->setNewValue('')
+              ->setMetadataValue('stub:create:phid', $object->getPHID());
             $sub_editor = id(new PhrictionTransactionEditor())
               ->setActor($this->getActor())
               ->setContentSource($this->getContentSource())
               ->setContinueOnNoEffect($this->getContinueOnNoEffect())
               ->setSkipAncestorCheck(true)
               ->setDescription(pht('Empty Parent Document'))
               ->applyTransactions($ancestor_doc, $stub_xactions);
           }
         }
       }
     }
 
     if ($this->moveAwayDocument !== null) {
       $move_away_xactions = array();
       $move_away_xactions[] = id(new PhrictionTransaction())
         ->setTransactionType(PhrictionTransaction::TYPE_MOVE_AWAY)
         ->setNewValue($object);
       $sub_editor = id(new PhrictionTransactionEditor())
         ->setActor($this->getActor())
         ->setContentSource($this->getContentSource())
         ->setContinueOnNoEffect($this->getContinueOnNoEffect())
         ->setDescription($this->getDescription())
         ->applyTransactions($this->moveAwayDocument, $move_away_xactions);
     }
 
     return $xactions;
   }
 
   protected function shouldSendMail(
     PhabricatorLiskDAO $object,
     array $xactions) {
     return true;
   }
 
   protected function getMailSubjectPrefix() {
     return '[Phriction]';
   }
 
   protected function getMailTo(PhabricatorLiskDAO $object) {
     return array(
       $object->getContent()->getAuthorPHID(),
       $this->getActingAsPHID(),
     );
   }
 
   public function getMailTagsMap() {
     return array(
       PhrictionTransaction::MAILTAG_TITLE =>
         pht("A document's title changes."),
       PhrictionTransaction::MAILTAG_CONTENT =>
         pht("A document's content changes."),
       PhrictionTransaction::MAILTAG_DELETE =>
         pht('A document is deleted.'),
     );
   }
 
   protected function buildReplyHandler(PhabricatorLiskDAO $object) {
     return id(new PhrictionReplyHandler())
       ->setMailReceiver($object);
   }
 
   protected function buildMailTemplate(PhabricatorLiskDAO $object) {
     $id = $object->getID();
     $title = $object->getContent()->getTitle();
 
     return id(new PhabricatorMetaMTAMail())
       ->setSubject($title)
       ->addHeader('Thread-Topic', $object->getPHID());
   }
 
   protected function buildMailBody(
     PhabricatorLiskDAO $object,
     array $xactions) {
 
     $body = parent::buildMailBody($object, $xactions);
 
     if ($this->getIsNewObject()) {
       $body->addTextSection(
         pht('DOCUMENT CONTENT'),
         $object->getContent()->getContent());
     }
 
     $body->addLinkSection(
       pht('DOCUMENT DETAIL'),
       PhabricatorEnv::getProductionURI(
         PhrictionDocument::getSlugURI($object->getSlug())));
 
     return $body;
   }
 
   protected function shouldPublishFeedStory(
     PhabricatorLiskDAO $object,
     array $xactions) {
     return $this->shouldSendMail($object, $xactions);
   }
 
   protected function getFeedRelatedPHIDs(
     PhabricatorLiskDAO $object,
     array $xactions) {
 
     $phids = parent::getFeedRelatedPHIDs($object, $xactions);
 
     foreach ($xactions as $xaction) {
       switch ($xaction->getTransactionType()) {
         case PhrictionTransaction::TYPE_MOVE_TO:
           $dict = $xaction->getNewValue();
           $phids[] = $dict['phid'];
           break;
       }
     }
 
     return $phids;
   }
 
+  protected function validateTransaction(
+    PhabricatorLiskDAO $object,
+    $type,
+    array $xactions) {
+
+    $errors = parent::validateTransaction($object, $type, $xactions);
+
+    foreach ($xactions as $xaction) {
+      switch ($type) {
+        case PhrictionTransaction::TYPE_TITLE:
+          $title = $object->getContent()->getTitle();
+          $missing = $this->validateIsEmptyTextField(
+            $title,
+            $xactions);
+
+          if ($missing) {
+            $error = new PhabricatorApplicationTransactionValidationError(
+              $type,
+              pht('Required'),
+              pht('Document title is required.'),
+              nonempty(last($xactions), null));
+
+            $error->setIsMissingFieldError(true);
+            $errors[] = $error;
+          } else if ($this->getProcessContentVersionError()) {
+            $error = $this->validateContentVersion($object, $type, $xaction);
+            if ($error) {
+              $this->setProcessContentVersionError(false);
+              $errors[] = $error;
+            }
+          }
+          break;
+
+        case PhrictionTransaction::TYPE_CONTENT:
+          if ($xaction->getMetadataValue('stub:create:phid')) {
+            continue;
+          }
+
+          $missing = false;
+          if ($this->getIsNewObject()) {
+            $content = $object->getContent()->getContent();
+            $missing = $this->validateIsEmptyTextField(
+              $content,
+              $xactions);
+          }
+
+          if ($missing) {
+            $error = new PhabricatorApplicationTransactionValidationError(
+              $type,
+              pht('Required'),
+              pht('Document content is required.'),
+              nonempty(last($xactions), null));
+
+            $error->setIsMissingFieldError(true);
+            $errors[] = $error;
+          } else if ($this->getProcessContentVersionError()) {
+            $error = $this->validateContentVersion($object, $type, $xaction);
+            if ($error) {
+              $this->setProcessContentVersionError(false);
+              $errors[] = $error;
+            }
+          }
+          break;
+      }
+    }
+
+    return $errors;
+  }
+
+  private function validateContentVersion(
+    PhabricatorLiskDAO $object,
+    $type,
+    PhabricatorApplicationTransaction $xaction) {
+
+    $error = null;
+    if ($this->getContentVersion() &&
+       ($object->getContent()->getVersion() != $this->getContentVersion())) {
+      $error = new PhabricatorApplicationTransactionValidationError(
+        $type,
+        pht('Edit Conflict'),
+        pht(
+          'Another user made changes to this document after you began '.
+          'editing it. Do you want to overwrite their changes? '.
+          '(If you choose to overwrite their changes, you should review '.
+          'the document edit history to see what you overwrote, and '.
+          'then make another edit to merge the changes if necessary.)'),
+        $xaction);
+    }
+    return $error;
+  }
+
   protected function supportsSearch() {
     return true;
   }
 
   protected function shouldApplyHeraldRules(
     PhabricatorLiskDAO $object,
     array $xactions) {
     return false;
   }
 
   private function buildNewContentTemplate(
     PhrictionDocument $document) {
 
     $new_content = id(new PhrictionContent())
       ->setSlug($document->getSlug())
       ->setAuthorPHID($this->getActor()->getPHID())
       ->setChangeType(PhrictionChangeType::CHANGE_EDIT)
       ->setTitle($this->getOldContent()->getTitle())
       ->setContent($this->getOldContent()->getContent());
     if (strlen($this->getDescription())) {
       $new_content->setDescription($this->getDescription());
     }
     $new_content->setVersion($this->getOldContent()->getVersion() + 1);
 
     return $new_content;
   }
 
 }