Automatically apply all filters of a compound filter using reflection.

src/DataTables/Filters/CompoundFilterTrait.php

@@ -0,0 +1,44 @@
+<?php
+
+namespace App\DataTables\Filters;
+
+use Doctrine\ORM\QueryBuilder;
+
+trait CompoundFilterTrait
+{
+
+    /**
+     * Find all child filters that are contained in this filter using reflection.
+     * A map is returned to the form "property_name" => $filter_object
+     * @return FilterInterface[]
+     */
+    protected function findAllChildFilters(): array
+    {
+        $filters = [];
+        $reflection = new \ReflectionClass($this);
+
+        foreach ($reflection->getProperties() as $property) {
+            $value = $property->getValue($this);
+            //We only want filters (objects implementing FilterInterface)
+            if($value instanceof FilterInterface) {
+                $filters[$property->getName()] = $value;
+            }
+        }
+        return $filters;
+    }
+
+    /**
+     * Applies all children filters that are declared as property of this filter using reflection.
+     * @param  QueryBuilder  $queryBuilder
+     * @return void
+     */
+    protected function applyAllChildFilters(QueryBuilder $queryBuilder): void
+    {
+        //Retrieve all child filters and apply them
+        $filters = $this->findAllChildFilters();
+
+        foreach ($filters as $filter) {
+            $filter->apply($queryBuilder);
+        }
+    }
+}

src/DataTables/Filters/PartFilter.php

@@ -9,6 +9,9 @@ use Doctrine\ORM\QueryBuilder;
 
 class PartFilter implements FilterInterface
 {
+
+    use CompoundFilterTrait;
+
     /** @var TextConstraint */
     protected $name;
 
@@ -66,10 +69,6 @@ class PartFilter implements FilterInterface
 
     public function apply(QueryBuilder $queryBuilder): void
     {
-        $this->favorite->apply($queryBuilder);
-        $this->needsReview->apply($queryBuilder);
-        $this->mass->apply($queryBuilder);
-        $this->name->apply($queryBuilder);
-        $this->description->apply($queryBuilder);
+        $this->applyAllChildFilters($queryBuilder);
     }
 }