Objects pfilter

src/Objects.php

@@ -607,7 +607,7 @@ public static function psort(array $list, $property)
 
   public static function mfilter(array $list, $method, $negate = false)
   {
-    if(!is_string($method))
+    if(!is_string($method) || empty($method))
     {
       throw new InvalidArgumentException('Argument method is not a string.');
     }
@@ -626,6 +626,51 @@ public static function mfilter(array $list, $method, $negate = false)
     return $result;
   }
 
+  /**
+   * Filter a list of objects by matching the property against the match value (===)
+   *
+   * @param  $list          array        List of objects to filter.
+   * @param  $property      string       A property name.
+   * @param  $match         mixed       A value to match the property against, or a closure
+   * @param  $negate        bool         Optionally, pass true to drop objects
+   *                        which pass the filter instead of keeping them.
+   *
+   * @return array   List of objects which pass the filter.
+   * @throws InvalidArgumentException
+   */
+
+  public static function pfilter(array $list, $property, $match, $negate = false)
+  {
+    if(!is_string($property) || empty($property))
+    {
+      throw new InvalidArgumentException('Argument property is not a string.');
+    }
+
+    $result = [];
+    if(is_callable($match))
+    {
+      foreach($list as $key => $object)
+      {
+        if($match(Objects::property($object, $property)) != $negate)
+        {
+          $result[$key] = $object;
+        }
+      }
+    }
+    else
+    {
+      foreach($list as $key => $object)
+      {
+        if((Objects::property($object, $property) === $match) != $negate)
+        {
+          $result[$key] = $object;
+        }
+      }
+    }
+
+    return $result;
+  }
+
   /**
    * Perform a callback against an object, and return the object
    *

tests/ObjectsTest.php

@@ -432,4 +432,43 @@ public function testTreeM()
     $this->assertContainsOnlyInstancesOf(Branch::class, $tree->getChildren());
     $this->assertCount(1, $tree->getChildren());
   }
+
+  public function testPFilterNullPropertyThrowException()
+  {
+    $caught = null;
+    try
+    {
+      Objects::pfilter([], null, 'abc');
+    }
+    catch(InvalidArgumentException $ex)
+    {
+      $caught = $ex;
+    }
+
+    $this->assertEquals(true, ($caught instanceof InvalidArgumentException));
+  }
+
+  public function testPFilter()
+  {
+    $a = new Pancake("apple", "toffee");
+    $b = new Pancake("apple", "strawberry");
+    $c = new Pancake("orange", "toffee");
+    $d = new Pancake("orange", "gravy");
+
+    $list = ['a' => $a, 'b' => $b, 'c' => $c, 'd' => $d];
+
+    $actual = Objects::pfilter($list, 'fruit', 'apple');
+    $this->assertEquals(['a' => $a, 'b' => $b,], $actual);
+
+    $actual = Objects::pfilter($list, 'fruit', 'apple', true);
+    $this->assertEquals(['c' => $c, 'd' => $d,], $actual);
+
+    $matchApple = function ($prop) { return $prop == 'apple'; };
+
+    $actual = Objects::pfilter($list, 'fruit', $matchApple);
+    $this->assertEquals(['a' => $a, 'b' => $b,], $actual);
+
+    $actual = Objects::pfilter($list, 'fruit', $matchApple, true);
+    $this->assertEquals(['c' => $c, 'd' => $d,], $actual);
+  }
 }