FEATURE #1373: add history of content

This commit contains only core funcionality of displaying history. Module settings must be implemented in each module.

app/Handlers/Contracts/AppHandler.php

@@ -0,0 +1,30 @@
+<?php
+namespace App\Handlers\Contracts;
+
+use App\Models\Content;
+use App\Models\User;
+
+interface AppHandler
+{
+    /**
+     * Render given module into visitor area.
+     *
+     * @param Content $content    DB model from table contents
+     * @param array   $parameters parameters used for modifications/custom settings of given model
+     *
+     * @return mixed
+     */
+    public function render(Content $content, $parameters);
+
+    public static function getHistoryHandler();
+
+    /**
+     * Register admin menu (or multiple ones)
+     *
+     * This cannot be in ServiceProvider because Session is started at middleware. And ServiceProvider is called before
+     * starting any middleware..
+     *
+     * @param User $user model of logged user
+     */
+    public static function registerAdminMenu(User $user);
+}

app/Handlers/Contracts/HistoryHandler.php

@@ -0,0 +1,9 @@
+<?php
+namespace App\Handlers\Contracts;
+
+interface HistoryHandler
+{
+    public static function parseColumnName($name);
+
+    public static function parseChangedValue($changeset);
+}

app/Handlers/Handler.php

@@ -1,28 +1,23 @@
 <?php
 namespace App\Handlers;
 
-use App\Models\Content;
+use App\Handlers\Contracts\AppHandler;
 use App\Models\User;
-use Illuminate\Support\Facades\Auth;
 
 /**
  * Class Handler
  *
- * Handler is a class which handles module-specific behaviour which cannot be done by module itself, resp. cannot be done by some abstract magic.
+ * Handler is a class which handles module-specific behaviour which cannot be done by module itself, resp. cannot be
+ * done by some abstract magic.
  *
  * @package App\Handlers
  */
-abstract class Handler
+abstract class Handler implements AppHandler
 {
-    /**
+    public static function getHistoryHandler()
-     * Render given module into visitor area.
+    {
-     *
+        return History::class;
-     * @param Content $content    DB model from table contents
+    }
-     * @param array   $parameters parameters used for modifications/custom settings of given model
-     *
-     * @return mixed
-     */
-    abstract public function render(Content $content, $parameters);
 
     /**
      * Register admin menu (or multiple ones)
@@ -34,6 +29,6 @@ abstract class Handler
      */
     public static function registerAdminMenu(User $user)
     {
-        //
+        // core menu is registered in AdminMenuServiceProvider
     }
 }

app/Handlers/History.php

@@ -0,0 +1,45 @@
+<?php
+namespace App\Handlers;
+
+use App\Enumerations\ContentStatuses;
+use App\Handlers\Contracts\HistoryHandler;
+use App\Helpers\Differ;
+
+class History implements HistoryHandler
+{
+    public static function parseColumnName($column)
+    {
+        return trans('admin/history.column' . ucfirst($column));
+    }
+
+    public static function parseChangedValue($changeset)
+    {
+        switch ($changeset->column) {
+            case 'pageContent':
+                $route = route('history.diff', [
+                    'revision' => $changeset->edit_batch,
+                    'id'       => $changeset->id
+                ]);
+
+                return "(<a href='" . $route . "'>" . trans('admin/history.diff') . "</a>)";
+                break;
+            case 'metaDescription':
+                return Differ::htmlDiff($changeset->old_value, $changeset->new_value);
+                break;
+            case 'status':
+                $statuses = ContentStatuses::getWithTranslations();
+
+                return trans('admin/history.changedFromTo', [
+                    'from' => $statuses[$changeset->old_value],
+                    'to'   => $statuses[$changeset->new_value]
+                ]);
+                break;
+            default:
+                return trans('admin/history.changedFromTo', [
+                    'from' => $changeset->old_value,
+                    'to'   => $changeset->new_value
+                ]);
+                break;
+        }
+    }
+}

app/Helpers/Differ.php

@@ -0,0 +1,64 @@
+<?php
+namespace App\Helpers;
+
+/*
+    Paul's Simple Differ Algorithm v 0.1
+    (C) Paul Butler 2007 <http://www.paulbutler.org/>
+    May be used and distributed under the zlib/libpng license.
+
+    This code is intended for learning purposes; it was written with short
+    code taking priority over performance. It could be used in a practical
+    application, but there are a few ways it could be optimized.
+
+    Given two arrays, the function diff will return an array of the changes.
+    I won't describe the format of the array, but it will be obvious
+    if you use print_r() on the result of a diff on some test data.
+
+    htmlDiff is a wrapper for the diff command, it takes two strings and
+    returns the differences in HTML. The tags used are <ins> and <del>,
+    which can easily be styled with CSS.
+
+    @url https://github.com/paulgb/simplediff/blob/master/php/simplediff.php
+
+    Sorry for this kind of magic, I have no idea how this works.. :(
+*/
+
+class Differ
+{
+    public static function diff($old, $new)
+    {
+        $matrix = [];
+        $maxlen = 0;
+        foreach ($old as $oindex => $ovalue) {
+            $nkeys = array_keys($new, $ovalue);
+            foreach ($nkeys as $nindex) {
+                $matrix[$oindex][$nindex] = isset($matrix[$oindex - 1][$nindex - 1]) ? $matrix[$oindex - 1][$nindex - 1] + 1 : 1;
+                if ($matrix[$oindex][$nindex] > $maxlen) {
+                    $maxlen = $matrix[$oindex][$nindex];
+                    $omax = $oindex + 1 - $maxlen;
+                    $nmax = $nindex + 1 - $maxlen;
+                }
+            }
+        }
+        if ($maxlen == 0) {
+            return [['d' => $old, 'i' => $new]];
+        }
+
+        return array_merge(self::diff(array_slice($old, 0, $omax), array_slice($new, 0, $nmax)), array_slice($new, $nmax, $maxlen), self::diff(array_slice($old, $omax + $maxlen), array_slice($new, $nmax + $maxlen)));
+    }
+
+    public static function htmlDiff($old, $new)
+    {
+        $ret = '';
+        $diff = self::diff(preg_split("/[\s]+/", $old), preg_split("/[\s]+/", $new));
+        foreach ($diff as $k) {
+            if (is_array($k)) {
+                $ret .= (!empty($k['d']) ? "<del>" . implode(' ', $k['d']) . "</del> " : '') . (!empty($k['i']) ? "<ins>" . implode(' ', $k['i']) . "</ins> " : '');
+            } else {
+                $ret .= $k . ' ';
+            }
+        }
+
+        return $ret;
+    }
+}

app/Http/Controllers/Admin/History.php

@@ -0,0 +1,49 @@
+<?php
+namespace App\Http\Controllers\Admin;
+
+use App\Models\Content;
+use App\Models\ContentHistory;
+
+class History extends Controller
+{
+    /**
+     * @var ContentHistory
+     */
+    private $history;
+
+    public function __construct(ContentHistory $history)
+    {
+        parent::__construct();
+        $this->history = $history;
+    }
+
+    /**
+     * @param $id
+     *
+     * @return \Illuminate\Contracts\View\Factory|\Illuminate\View\View
+     */
+    public function getOverview($id)
+    {
+        // test if given content id is static page and if exists
+        $content = Content::findOrFail($id);
+
+        $history = $this->history->getStructuredHistoryOf($content);
+
+        return view('admin/history.overview', [
+            'history' => $history,
+            'page'    => $content
+        ]);
+    }
+
+    public function getDiff($revision, $id)
+    {
+        $change = $this->history->findOrFail($id);
+        $diff = $this->history->getDiff($change);
+
+        return view('admin/history.diff', [
+            'change'     => $change,
+            'columnName' => 'Page content',
+            'diff'       => $diff
+        ]);
+    }
+}

app/Http/routes.php

@@ -81,6 +81,14 @@ Route::group([
     Route::get('users/overview/{state?}/{perPage?}', 'UsersOverview@getOverview')
          ->name('users.overview');
 
+    // history of changes for specified page
+    Route::get('history/{id}', 'History@getOverview')
+         ->name('content.history');
+
+    // history of changes for specified page
+    Route::get('history/{revision}/{id}', 'History@getDiff')
+         ->name('history.diff');
+
     // custom fields
     // ------------------------------
 

app/Models/ContentHistory.php

@@ -2,6 +2,10 @@
 
 namespace App\Models;
 
+use App\Handlers\Contracts\AppHandler;
+use App\Handlers\Contracts\HistoryHandler;
+use App\Handlers\Handler;
+use App\Helpers\Differ;
 use Illuminate\Database\Eloquent\Model;
 
 /**
@@ -10,10 +14,8 @@ use Illuminate\Database\Eloquent\Model;
 class ContentHistory extends Model
 {
     protected $table = 'content_history';
-
     // this table does not have created_at and updated_at fields
     public $timestamps = false;
-
     protected $fillable = [
         'user_id',
         'content_id',
@@ -22,8 +24,81 @@ class ContentHistory extends Model
         'new_value',
         'old_value'
     ];
-
     protected $guarded = [];
 
-        
+    /**
+     * Returns history grouped by revisions (edit_batches)
+     *
+     * @param Content $content
+     *
+     * @return array
+     */
+    public function getStructuredHistoryOf(Content $content)
+    {
+        $data = $content->history()
+                        ->select('content_history.*', 'contents.module_handler', 'users.email AS user_email', 'users.name AS user_name')
+                        ->join('users', 'users.id', '=', 'content_history.user_id')
+                        ->join('contents', 'contents.id', '=', 'content_history.content_id')
+                        ->orderBy('changed_at', 'DESC')
+                        ->get();
+
+        $info = [];
+        $history = [];
+        foreach ($data as $change) {
+            $info[$change->edit_batch] = [
+                'changed_at' => $change->changed_at,
+                'user'       => [
+                    'id'    => $change->user_id,
+                    'name'  => $change->user_name,
+                    'email' => $change->user_email
+                ]
+            ];
+
+            $change = $this->handleChangeset($change);
+
+            $history[$change->edit_batch][] = $change;
+        }
+
+        return [
+            'changesets' => $history,
+            'info'       => $info
+        ];
+    }
+
+    /**
+     * @param $change
+     *
+     * @return HistoryHandler
+     */
+    protected function getHistoryHandler($change)
+    {
+        /**
+         * @var $handler        AppHandler
+         * @var $historyHandler HistoryHandler
+         */
+
+        // get handler of given content page
+        if ($change->column == 'module_settings') {
+            $handler = $handler = $change->module_handler;
+        } else {
+            $handler = Handler::class;
+        }
+
+        return $handler::getHistoryHandler();
+    }
+
+    public function handleChangeset($change)
+    {
+        $historyHandler = $this->getHistoryHandler($change);
+
+        $change->column_trans = $historyHandler::parseColumnName($change->column);
+        $change->diff = $historyHandler::parseChangedValue($change);
+
+        return $change;
+    }
+
+    public function getDiff($change)
+    {
+        return Differ::htmlDiff($change->old_value, $change->new_value);
+    }
 }

resources/assets/css/admin.css

@@ -1,4 +1,13 @@
 
+del {
+	text-decoration: line-through;
+	color: red;
+}
+ins {
+	text-decoration: none;
+	color: green;
+}
+
 .columns:last-child:not(:first-child), .column:last-child:not(:first-child) {
 	float: left;
 }

resources/lang/en/admin/history.php

@@ -0,0 +1,16 @@
+<?php
+return [
+    'pageName'              => 'History of :name',
+    'columnPageContent'     => 'Page content',
+    'columnUrl'             => 'URL',
+    'columnTitle'           => 'Title',
+    'columnMetaKeywords'    => 'Meta keywords',
+    'columnMetaDescription' => 'Description',
+    'columnStatus'          => 'Page visibility',
+    'changedFromTo'         => 'Changed from <del>:from</del> to <ins>:to</ins>',
+    'numOfChanges'          => 'One change|:count changes',
+    'diff'                  => 'Difference',
+    'diffPageName'          => 'Difference of :column',
+    'backToOverview'        => 'Back to history overview'
+
+];

resources/views/admin/history/diff.blade.php

@@ -0,0 +1,21 @@
+@extends('admin.layout')
+
+@section('pageName', @trans('admin/history.diffPageName', ['column' => $columnName]))
+
+@section('content')
+
+    <div class="row">
+        <h2>@lang('admin/history.diffPageName', ['column' => $columnName])</h2>
+
+    </div>
+
+    <div class="row callout">
+        {!! $diff !!}
+    </div>
+
+    <div class="row">
+        <a href="{{route('content.history', ['id' => $change->content_id])}}" class="button success">
+            @lang('admin/history.backToOverview')
+        </a>
+    </div>
+@stop

resources/views/admin/history/overview.blade.php

@@ -0,0 +1,31 @@
+@extends('admin.layout')
+
+@section('pageName', @trans('admin/history.pageName', ['name' => $page->title]))
+
+@section('content')
+
+    <div class="row">
+        <h2>@lang('admin/history.pageName', ['name' => $page->title])</h2>
+
+    </div>
+
+    <div class="row">
+        <ul class="accordion" data-accordion>
+            @foreach($history['changesets'] as $revision => $changes)
+            <li class="accordion-item" data-accordion-item>
+                <a class="accordion-title">
+                    <strong>{{$history['info'][$revision]['user']['name']}}</strong> |
+                    {{$history['info'][$revision]['changed_at']}} |
+                    {{trans_choice('admin/history.numOfChanges', count($changes))}}
+                </a>
+
+                @foreach($changes as $change)
+                <div class="accordion-content" data-tab-content>
+                    <strong>{{$change->column_trans}}</strong>: {!! $change->diff !!}
+                </div>
+                    @endforeach
+            </li>
+            @endforeach
+        </ul>
+    </div>
+@stop