Add new filter for empty fields

docs/reference/filter_field_definition.rst

@@ -44,6 +44,7 @@ For now, only `Doctrine ORM` filters are available:
 * ``Sonata\DoctrineORMAdminBundle\Filter\DateTimeFilter``: depends on the ``Sonata\AdminBundle\Form\Type\Filter\DateTimeType`` Form Type, renders a datetime field,
 * ``Sonata\DoctrineORMAdminBundle\Filter\DateTimeRangeFilter``: depends on the ``Sonata\AdminBundle\Form\Type\Filter\DateTimeRangeType`` Form Type, renders a 2 datetime fields,
 * ``Sonata\DoctrineORMAdminBundle\Filter\ClassFilter``: depends on the ``Sonata\AdminBundle\Form\Type\Filter\DefaultType`` Form type, renders a choice list field.
+* ``Sonata\DoctrineORMAdminBundle\Filter\EmptyFieldFilter``: depends on the ``Sonata\AdminBundle\Form\Type\Filter\DefaultType`` Form type, renders a choice list field.
 
 Example
 -------
@@ -162,6 +163,26 @@ ClassFilter
         }
     }
 
+Empty
+-----
+
+``Sonata\DoctrineORMAdminBundle\Filter\EmptyFieldFilter`` supports filtering for empty (null) entity fields::
+
+    namespace Sonata\NewsBundle\Admin;
+
+    use Sonata\AdminBundle\Admin\AbstractAdmin;
+    use Sonata\AdminBundle\Datagrid\DatagridMapper;
+    use Sonata\AdminBundle\Filter\EmptyFieldFilter;
+
+    final class PostAdmin extends AbstractAdmin
+    {
+        protected function configureDatagridFilters(DatagridMapper $datagridMapper)
+        {
+            $datagridMapper
+                ->add('deleted', EmptyFieldFilter::class, ['field_name' => 'deletedAt']);
+        }
+    }
+
 Advanced usage
 --------------
 

src/Filter/EmptyFieldFilter.php

@@ -0,0 +1,97 @@
+<?php
+
+declare(strict_types=1);
+
+/*
+ * This file is part of the Sonata Project package.
+ *
+ * (c) Thomas Rabaix <thomas.rabaix@sonata-project.org>
+ *
+ * For the full copyright and license information, please view the LICENSE
+ * file that was distributed with this source code.
+ */
+
+namespace Sonata\DoctrineORMAdminBundle\Filter;
+
+use Sonata\AdminBundle\Datagrid\ProxyQueryInterface;
+use Sonata\AdminBundle\Form\Type\Filter\DefaultType;
+use Sonata\Form\Type\BooleanType;
+use Symfony\Component\Form\Extension\Core\Type\HiddenType;
+
+final class EmptyFieldFilter extends Filter
+{
+    /**
+     * @param string       $alias
+     * @param string       $field
+     * @param mixed[]|null $data
+     */
+    public function filter(ProxyQueryInterface $queryBuilder, $alias, $field, $data): void
+    {
+        if (null === $data || !\is_array($data) || !\array_key_exists('value', $data)) {
+            return;
+        }
+
+        if (BooleanType::TYPE_NO === (int) $data['value']) {
+            $this->applyWhere(
+                $queryBuilder,
+                $queryBuilder
+                ->expr()
+                ->isNull(sprintf('%s.%s', $alias, $field))
+            );
+        } elseif (BooleanType::TYPE_YES === (int) $data['value']) {
+            $this->applyWhere(
+                $queryBuilder,
+                $queryBuilder
+                ->expr()
+                ->isNotNull(sprintf('%s.%s', $alias, $field))
+            );
+        }
+    }
+
+    public function getDefaultOptions()
+    {
+        return [
+            'field_type' => BooleanType::class,
+            'operator_type' => HiddenType::class,
+            'operator_options' => [],
+        ];
+    }
+
+    public function getRenderSettings()
+    {
+        return [DefaultType::class, [
+            'field_type' => $this->getFieldType(),
+            'field_options' => $this->getFieldOptions(),
+            'operator_type' => $this->getOption('operator_type'),
+            'operator_options' => $this->getOption('operator_options'),
+            'label' => $this->getLabel(),
+        ]];
+    }
+
+    public function getParentAssociationMappings()
+    {
+        $mappings = $this->getOption('parent_association_mappings', []);
+
+        $fields = explode('.', $this->getFieldName(), -1);
+
+        foreach ($fields as $field) {
+            $mappings[] = ['fieldName' => $field];
+        }
+
+        return $mappings;
+    }
+
+    /**
+     * @param mixed|null $data
+     *
+     * @return string[]
+     */
+    protected function association(ProxyQueryInterface $queryBuilder, $data): array
+    {
+        $alias = $queryBuilder->entityJoin($this->getParentAssociationMappings());
+        $part = strrchr('.'.$this->getFieldName(), '.');
+        $fieldName = substr(false === $part ? $this->getFieldType() : $part, 1);
+
+        return [$alias, $fieldName];
+    }
+}

src/Resources/config/doctrine_orm_filter_types.xml

@@ -40,5 +40,8 @@
         <service id="sonata.admin.orm.filter.type.class" class="Sonata\DoctrineORMAdminBundle\Filter\ClassFilter">
             <tag name="sonata.admin.filter.type" alias="doctrine_orm_class"/>
         </service>
+        <service id="Sonata\DoctrineORMAdminBundle\Filter\EmptyFieldFilter">
+            <tag name="sonata.admin.filter.type" alias="doctrine_orm_empty"/>
+        </service>
     </services>
 </container>

tests/Filter/EmptyFieldFilterTest.php

@@ -0,0 +1,33 @@
+<?php
+
+declare(strict_types=1);
+
+/*
+ * This file is part of the Sonata Project package.
+ *
+ * (c) Thomas Rabaix <thomas.rabaix@sonata-project.org>
+ *
+ * For the full copyright and license information, please view the LICENSE
+ * file that was distributed with this source code.
+ */
+
+namespace Sonata\DoctrineORMAdminBundle\Tests\Filter;
+
+use PHPUnit\Framework\TestCase;
+use Sonata\DoctrineORMAdminBundle\Filter\EmptyFieldFilter;
+use Sonata\Form\Type\BooleanType;
+use Symfony\Component\Form\Extension\Core\Type\ChoiceType;
+
+final class EmptyFieldFilterTest extends TestCase
+{
+    public function testRenderSettings(): void
+    {
+        $filter = new EmptyFieldFilter();
+        $filter->initialize('field_name', [
+            'field_options' => ['class' => 'FooBar'],
+        ]);
+        $options = $filter->getRenderSettings()[1];
+
+        $this->assertSame(BooleanType::class, $options['field_type']);
+    }
+}