FEATURE: add functionality for creating new widget.

This commit adds functionality for creating widget of whatever type. Controller calls widget admin handler, which renders and handles input form.

app/Http/Controllers/Admin/CreateNewWidget.php

@@ -0,0 +1,81 @@
+<?php
+
+namespace App\Http\Controllers\Admin;
+
+use App\Http\Controllers\Controller;
+use App\Http\Requests;
+use App\Http\Requests\NewWidgetRequest;
+use App\Models\Widget;
+use App\Models\WidgetType;
+use App\Widgets\Exceptions\MissingParameterException;
+use Illuminate\Support\Facades\Auth;
+
+class CreateNewWidget extends Controller
+{
+    /**
+     * Form for new widget area
+     *
+     * @param $type
+     *
+     * @return \Illuminate\Contracts\View\Factory|\Illuminate\View\View
+     */
+    public function getNew($type)
+    {
+        $widgetType = WidgetType::findOrFail($type);
+
+        $presenter = call_user_func([$widgetType->handler, 'getPresenter']);
+
+        return call_user_func([$presenter, 'renderAddForm'], $widgetType);
+    }
+
+    /**
+     * Create new instance of given widget type
+     *
+     * @param NewWidgetRequest $request
+     * @param                  $type
+     *
+     * @return \Illuminate\Http\RedirectResponse
+     */
+    public function postNew(NewWidgetRequest $request, $type)
+    {
+        $widgetType = WidgetType::findOrFail($type);
+
+        // create new widget
+        $widget = new Widget();
+        $widget->widget_type_handler = $widgetType->handler;
+        $widget->user_id = Auth::user()->id;
+        $widget->name = $request->name;
+
+        // save description if available
+        if (isset($request->description)) {
+            $widget->description = $request->description;
+        }
+
+        // try to save this widget
+        try {
+            $widget = call_user_func([$widgetType->handler, 'save'], $widget, $request);
+        } catch (MissingParameterException $e) {
+            // user omitted some value
+            return $this->invalidWidget($type, $e->getMessage());
+        } catch (\Exception $e) {
+            // something went wrong
+            return $this->invalidWidget($type, trans('admin/widgets.cannotSave', ['exception' => $e->getMessage()]));
+        }
+
+        // save into database
+        $widget->save();
+
+        // redirect with success notification
+        return redirect()
+            ->route('widgets.new', ['type' => $type])
+            ->with('success', trans('admin/widgets.successfullyCreated'));
+    }
+
+    private function invalidWidget($widgetType, $error)
+    {
+        return redirect()
+            ->route('widgets.new', ['type' => $widgetType])
+            ->withInput()
+            ->with('error', $error);
+    }
+}

app/Http/Requests/NewWidgetRequest.php

@@ -0,0 +1,18 @@
+<?php
+
+namespace App\Http\Requests;
+
+class NewWidgetRequest extends Request
+{
+    /**
+     * Get the validation rules that apply to the request.
+     *
+     * @return array
+     */
+    public function rules()
+    {
+        return [
+            'name' => 'required'
+        ];
+    }
+}