add nova

nova/src/ResolvesFilters.php

@@ -0,0 +1,60 @@
+<?php
+
+namespace Laravel\Nova;
+
+use Laravel\Nova\Http\Requests\NovaRequest;
+
+trait ResolvesFilters
+{
+    /**
+     * Get the filters that are available for the given request.
+     *
+     * @param  \Laravel\Nova\Http\Requests\NovaRequest  $request
+     * @return \Illuminate\Support\Collection<int, \Laravel\Nova\Filters\Filter>
+     */
+    public function availableFilters(NovaRequest $request)
+    {
+        return $this->resolveFilters($request)
+                    ->concat($this->resolveFiltersFromFields($request))
+                    ->filter->authorizedToSee($request)
+                    ->values();
+    }
+
+    /**
+     * Get the filters for the given request.
+     *
+     * @param  \Laravel\Nova\Http\Requests\NovaRequest  $request
+     * @return \Illuminate\Support\Collection<int, \Laravel\Nova\Filters\Filter>
+     */
+    public function resolveFilters(NovaRequest $request)
+    {
+        return collect(array_values($this->filter($this->filters($request))));
+    }
+
+    /**
+     * Get the filters from filterable fields for the given request.
+     *
+     * @param  \Laravel\Nova\Http\Requests\NovaRequest  $request
+     * @return \Illuminate\Support\Collection
+     */
+    public function resolveFiltersFromFields(NovaRequest $request)
+    {
+        return collect(array_values($this->filter(
+            $this->filterableFields($request)
+                ->transform(function ($field) use ($request) {
+                    return $field->resolveFilter($request);
+                })->filter()->all()
+        )));
+    }
+
+    /**
+     * Get the filters available on the entity.
+     *
+     * @param  \Laravel\Nova\Http\Requests\NovaRequest  $request
+     * @return array
+     */
+    public function filters(NovaRequest $request)
+    {
+        return [];
+    }
+}