Merge branch 'diff' of git://github.com/younes0/BookStack into younes0-diff

@@ -12,6 +12,7 @@ use BookStack\Repos\ChapterRepo;
 use BookStack\Repos\PageRepo;
 use Symfony\Component\HttpKernel\Exception\NotFoundHttpException;
 use Views;
+use GatherContent\Htmldiff\Htmldiff;
 
 class PageController extends Controller
 {
@@ -335,9 +336,18 @@ class PageController extends Controller
         $book = $this->bookRepo->getBySlug($bookSlug);
         $page = $this->pageRepo->getBySlug($pageSlug, $book->id);
         $revision = $this->pageRepo->getRevisionById($revisionId);
+        
+        $next = $revision->getNext() ?: $page;
+        $diff = (new Htmldiff)->diff($revision->html, $next->html);
+
         $page->fill($revision->toArray());
         $this->setPageTitle('Page Revision For ' . $page->getShortName());
-        return view('pages/revision', ['page' => $page, 'book' => $book]);
+        
+        return view('pages/revision', [
+            'page' => $page,
+            'book' => $book,
+            'diff' => $diff,
+        ]);
     }
 
     /**

@@ -32,4 +32,25 @@ class PageRevision extends Model
         return $this->page->getUrl() . '/revisions/' . $this->id;
     }
 
+    /**
+     * Get previous revision
+     * @return \BookStack\PageRevision
+     */
+    public function getPrevious()
+    {
+        if ($id = PageRevision::where('id', '<', $this->id)->max('id')) {
+            return PageRevision::find($id);
+        }
+    }
+
+    /**
+     * Get next revision
+     * @return \BookStack\PageRevision
+     */
+    public function getNext()
+    {
+        if ($id = PageRevision::where('id', '>', $this->id)->min('id')) {
+            return PageRevision::find($id);
+        }
+    }
 }

@@ -7,13 +7,15 @@
     "require": {
         "php": ">=5.6.4",
         "laravel/framework": "^5.3.4",
+        "ext-tidy": "*",
         "intervention/image": "^2.3",
         "laravel/socialite": "^2.0",
         "barryvdh/laravel-ide-helper": "^2.1",
         "barryvdh/laravel-debugbar": "^2.2.3",
         "league/flysystem-aws-s3-v3": "^1.0",
         "barryvdh/laravel-dompdf": "^0.7",
-        "predis/predis": "^1.1"
+        "predis/predis": "^1.1",
+        "gathercontent/htmldiff": "^0.2.1"
     },
     "require-dev": {
         "fzaninotto/faker": "~1.4",

@@ -71,6 +71,18 @@
     max-width: 100%;
     height: auto !important;
   }
+
+  // diffs
+  ins,
+  del {
+    text-decoration: none;
+  }
+  ins {
+    background: #dbffdb;
+  }
+  del {
+    background: #FFECEC;
+  }
 }
 
 // Page content pointers

@@ -24,5 +24,9 @@
 
     <div style="clear:left;"></div>
 
+    @if (isset($diff) && $diff)
+        {!! $diff !!}
+    @else
         {!! $page->html !!}
+    @endif
 </div>
\ No newline at end of file