add support for filter (#201)

Author: jkrenge

src/Liquid/StandardFilters.php

@@ -150,6 +150,19 @@ public static function raw($input)
 	}
 
 
+	/**
+	 * Converts into JSON string
+	 *
+	 * @param mixed $input
+	 *
+	 * @return string
+	 */
+	public static function json($input)
+	{
+		return json_encode($input);
+	}
+
+
 	/**
 	 * Escape a string
 	 *

tests/Liquid/StandardFiltersTest.php

@@ -174,6 +174,36 @@ public function testRaw()
 		}
 	}
 
+	public function testJson()
+	{
+		$data = array(
+			array(
+				"before" => "Anything",
+				"after" => "\"Anything\"",
+			),
+			array(
+				"before" => 3,
+				"after" => 3,
+			),
+			array(
+				"before" => array(1, 2, 3),
+				"after" => "[1,2,3]",
+			),
+			array(
+				"before" => array("one" => 1, "two" => 2, "three" => 3),
+				"after" => "{\"one\":1,\"two\":2,\"three\":3}",
+			),
+			array(
+				"before" => array("one" => 1, "two" => array(1, 2, 3), "three" => 3),
+				"after" => "{\"one\":1,\"two\":[1,2,3],\"three\":3}",
+			),
+		);
+
+		foreach ($data as $testCase) {
+			$this->assertEquals($testCase['after'], StandardFilters::json($testCase['before']));
+		}
+	}
+
 	public function testEscape()
 	{
 		$data = array(