code: public function update(Request $request, $id)
      {
          $stripped_tags_body = ['body' => strip_tags($request->body)];
          $validator = Validator::make($stripped_tags_body, [
              'body' => 'required|min:10',
          ],[
  			'body.required' => trans('chatter::alert.danger.reason.content_required'),
  			'body.min' => trans('chatter::alert.danger.reason.content_min'),
  		]);
  
          if ($validator->fails()) {
              return back()->withErrors($validator)->withInput();
          }
  
          $post = Models::post()->find($id);
          if (!Auth::guest() && (Auth::user()->id == $post->user_id)) {
              if ($post->markdown) {
                  $post->body = $request->body;
              } else {
   	        $post->body = Purifier::clean($request->body);
              }
              $post->save();
  
              $discussion = Models::discussion()->find($post->chatter_discussion_id);
  
              $category = Models::category()->find($discussion->chatter_category_id);
              if (!isset($category->slug)) {
                  $category = Models::category()->first();
              }
  
              $chatter_alert = [
                  'chatter_alert_type' => 'success',
                  'chatter_alert'      => trans('chatter::alert.success.reason.updated_post'),
                  ];
  
              return redirect('/'.config('chatter.routes.home').'/'.config('chatter.routes.discussion').'/'.$category->slug.'/'.$discussion->slug)->with($chatter_alert);
          } else {
              $chatter_alert = [
                  'chatter_alert_type' => 'danger',
                  'chatter_alert'      => trans('chatter::alert.danger.reason.update_post'),
                  ];
  
              return redirect('/'.config('chatter.routes.home'))->with($chatter_alert);
          }
      }
docs: Update the specified resource in storage.
  
  @param \Illuminate\Http\Request $request
  @param int                      $id
  
  @return \Illuminate\Http\Response