'Create Document' pre-fills with current slug

Summary:
Fixes T2667

The 'Create Document' link up in the application crumbs now prefills with the slug of the current document - if available, that is

Test Plan: verified that nothing crashed, that the correct slug was pre-filled, and that pages could be created

Reviewers: alexshtuk, epriestley

CC: aran, Korvin

Maniphest Tasks: T2667

Differential Revision: https://secure.phabricator.com/D5273

src/applications/phriction/controller/PhrictionController.php

@@ -52,7 +52,7 @@ abstract class PhrictionController extends PhabricatorController {
     $crumbs->addAction(
       id(new PhabricatorMenuItemView())
         ->setName(pht('Create Document'))
-        ->setHref('/phriction/new/')
+        ->setHref('/phriction/new/?slug='.$this->getDocumentSlug())
         ->setWorkflow(true)
         ->setIcon('create'));
 
@@ -98,4 +98,8 @@ abstract class PhrictionController extends PhabricatorController {
     return $breadcrumbs;
   }
 
+  protected function getDocumentSlug() {
+    return '';
+  }
+
 }

src/applications/phriction/controller/PhrictionDocumentController.php

@@ -403,4 +403,8 @@ final class PhrictionDocumentController
     return $item;
   }
 
+  protected function getDocumentSlug() {
+    return $this->slug;
+  }
+
 }

src/applications/phriction/controller/PhrictionNewController.php

@@ -9,25 +9,31 @@ final class PhrictionNewController extends PhrictionController {
 
     $request = $this->getRequest();
     $user    = $request->getUser();
+    $slug    = PhabricatorSlug::normalize($request->getStr('slug'));
 
     if ($request->isFormPost()) {
-      $slug = PhabricatorSlug::normalize($request->getStr('slug'));
       $uri  = '/phriction/edit/?slug='.$slug;
       return id(new AphrontRedirectResponse())
         ->setURI($uri);
     }
 
+    if ($slug == '/') {
+      $slug = '';
+    }
+
     $view = id(new AphrontFormLayoutView())
       ->appendChild(id(new AphrontFormTextControl())
                        ->setLabel('/w/')
+                       ->setValue($slug)
                        ->setName('slug'));
 
     $dialog = id(new AphrontDialogView())
       ->setUser($user)
       ->setTitle(pht('New Document'))
+      ->setSubmitURI('/phriction/new/')
       ->appendChild(phutil_tag('p',
         array(),
-      pht('Create a new document at')))
+        pht('Create a new document at')))
       ->appendChild($view)
       ->addSubmitButton(pht('Create'))
       ->addCancelButton('/w/');