From 6bdb8162a808fc09e97a54f3d8e3e01ac17eff51 Mon Sep 17 00:00:00 2001
From: Xenofon Spafaridis <nohponex@gmail.com>
Date: Sat, 13 Feb 2016 13:04:05 +0200
Subject: [PATCH] Allow to filter relationships using Operator::OPERATOR_EMPTY

---
 src/Filter.php           | 53 +++++++++++++++++++++++++++-------------
 src/Model/Directives.php | 22 +++++++++++------
 tests/src/FilterTest.php | 21 ++++++++++++++++
 3 files changed, 72 insertions(+), 24 deletions(-)

diff --git a/src/Filter.php b/src/Filter.php
index bb3f212..f272932 100644
--- a/src/Filter.php
+++ b/src/Filter.php
@@ -109,10 +109,11 @@ public function __construct(
         }
 
         foreach ($relationships as $relationshipKey => $relationshipValue) {
-            if (!is_array($relationshipValue)) {
+            if (!is_array($relationshipValue) &&  $relationshipValue !== Operator::OPERATOR_EMPTY) {
                 throw new \Exception(sprintf(
-                    'Values for relationship filter "%s" MUST be an array',
-                    $relationshipKey
+                    'Values for relationship filter "%s" MUST be an array or Operator::"%s"',
+                    $relationshipKey,
+                    Operator::OPERATOR_EMPTY
                 ));
             }
         }
@@ -168,7 +169,7 @@ public function validate($modelClass)
          */
 
         if ($this->relationships !== null) {
-            foreach ($this->relationships as $relationshipKey => $value) {
+            foreach ($this->relationships as $relationshipKey => $relationshipValue) {
                 if (!$modelClass::relationshipExists($relationshipKey)) {
                     throw new RequestException(sprintf(
                         'Not a valid relationship for filter relationship "%"',
@@ -176,11 +177,15 @@ public function validate($modelClass)
                     ));
                 }
 
+                if ($relationshipValue === Operator::OPERATOR_EMPTY) {
+                    continue;
+                }
+
                 //@TODO add relationship validator
                 $relationshipValidator = [UnsignedIntegerValidator::class, 'parseStatic'];
 
                 //Run validator, if any value is incorrect IncorrectParametersException will be thrown
-                foreach ($value as $id) {
+                foreach ($relationshipValue as $id) {
                     call_user_func($relationshipValidator, $id);
                 }
             }
@@ -296,6 +301,16 @@ public function validate($modelClass)
      *     Article::class
      * );
      * ```
+     * @example
+     * ```php
+     * $filter = Filter::parseFromParameters(
+     *     (object) [
+     *         'filter' => [
+     *             'tag'       => Operator::OPERATOR_EMPTY
+     *         ]
+     *     ],
+     *     Article::class
+     * );
      * @throws RequestException
      * @throws \Exception
      * @throws IncorrectParametersException
@@ -352,18 +367,22 @@ public static function parseFromParameters($parameters, $modelClass)
                     ));
                 }
 
-                //Todo use filterValidation model
-                //$function = 'intval';
-
-                //Split multiples and trim additional spaces and force string
-                $values = array_map(
-                    'strval',
-                    //array_map(
-                    //    $function,
-                    //    array_map('trim', explode(',', trim($filterValue)))
-                    //)
-                    array_map('trim', explode(',', trim($filterValue)))
-                );
+                if ($filterValue === Operator::OPERATOR_EMPTY) {
+                    $values = Operator::OPERATOR_EMPTY;
+                } else {
+                    //Todo use filterValidation model
+                    //$function = 'intval';
+
+                    //Split multiples and trim additional spaces and force string
+                    $values = array_map(
+                        'strval',
+                        //array_map(
+                        //    $function,
+                        //    array_map('trim', explode(',', trim($filterValue)))
+                        //)
+                        array_map('trim', explode(',', trim($filterValue)))
+                    );
+                }
 
                 $filterRelationships->{$filterKey} = $values;
             } else {
diff --git a/src/Model/Directives.php b/src/Model/Directives.php
index 11b6927..6e29bab 100644
--- a/src/Model/Directives.php
+++ b/src/Model/Directives.php
@@ -250,13 +250,21 @@ protected static function handleFilter(
                 $relationship = $relationships->{$relationshipKey};
 
                 if ($relationship->type === Relationship::TYPE_TO_ONE) {
-                    $additionalQuery[] = sprintf(
-                        '%s "%s"."%s" IN (%s)',
-                        ($hasWhere ? 'AND' : 'WHERE'),
-                        static::$table,
-                        $relationship->recordDataAttribute,
-                        self::handleFilterParseIn($relationshipFilterValue)
-                    );
+                    if ($relationshipFilterValue === Operator::OPERATOR_EMPTY) {
+                        $additionalQuery[] = sprintf(
+                            '%s "%s"."%s" IS NULL',
+                            ($hasWhere ? 'AND' : 'WHERE'),
+                            $relationship->recordDataAttribute
+                        );
+                    } else {
+                        $additionalQuery[] = sprintf(
+                            '%s "%s"."%s" IN (%s)',
+                            ($hasWhere ? 'AND' : 'WHERE'),
+                            static::$table,
+                            $relationship->recordDataAttribute,
+                            self::handleFilterParseIn($relationshipFilterValue)
+                        );
+                    }
                     $hasWhere = true;
                 } else {
                     throw new NotImplementedException(
diff --git a/tests/src/FilterTest.php b/tests/src/FilterTest.php
index f2a80f1..c1a0d3f 100644
--- a/tests/src/FilterTest.php
+++ b/tests/src/FilterTest.php
@@ -123,6 +123,27 @@ public function testParseFromParametersPrimaryUsingIntval()
         $this->assertEquals([4], $filter->primary);
     }
 
+    /**
+     * @covers ::parseFromParameters
+     */
+    public function testParseFromParametersRelationshipEmpty()
+    {
+        $parameters = (object) [
+            'filter' => (object) [ //Will accept both arrays and object
+                'tag' => Operator::OPERATOR_EMPTY
+            ]
+        ];
+
+        $filter = Filter::parseFromParameters(
+            $parameters,
+            Article::class //Use article resource model's filters
+        );
+
+        $this->assertInstanceOf(Filter::class, $filter);
+
+        $this->assertEquals(Operator::OPERATOR_EMPTY, $filter->relationships->tag);
+    }
+
     /**
      * @covers ::parseFromParameters
      */