fix issue #58 add formatDate to query helper

library/Solarium/Query/Helper.php

@@ -123,6 +123,36 @@ class Solarium_Query_Helper
         return '"' . preg_replace('/("|\\\)/', '\\\$1', $input) . '"';
     }
 
+    public function formatDate($input)
+    {
+        $isTimestamp = function($input) {
+            return checkdate(date('m', $input), date('d', $input), date('Y', $input));
+        };
+
+        switch(true) {
+            case is_numeric($input) && $isTimestamp($input):
+                $dateTime = new DateTime($input);
+                break;
+
+            case is_string($input) && $isTimestamp(strtotime($input)):
+                $dateTime = new DateTime(strtotime($input));
+                break;
+
+            case !is_string($input) && !is_numeric($input) && $input instanceof DateTime:
+                $dateTime = $input;
+                break;
+
+            //if input does not match any of these requirements then fail
+            default:
+                return false;
+        }
+
+        $iso8601 = $dateTime->format(DateTime::ISO8601);
+        $iso8601 = strstr($iso8601, '+', true); //strip timezone
+        $iso8601 .= 'Z';
+        return $iso8601;
+    }
+
     /**
      * Render a range query
      *
@@ -346,4 +376,4 @@ class Solarium_Query_Helper
         return $this->qparser('join', array('from' => $from, 'to' => $to), $dereferenced);
     }
 
-}
\ No newline at end of file
+}

tests/Solarium/Query/HelperTest.php

@@ -185,6 +185,35 @@ class Solarium_Query_HelperTest extends PHPUnit_Framework_TestCase
         );
     }
 
+    public function testFormatDate()
+    {
+        //accepts a time
+        $this->assertNotEquals(
+            false,
+            $this->_helper->formatDate(strtotime('2011-10-01')),
+            'Expects timestamp input to be accpted'
+        );
+
+        //accepts a date
+        $this->assertNotEquals(
+            false,
+            $this->_helper->formatDate(date('Y-m-d', strtotime('2011-10-01'))),
+            'Expects date string inputs to be accepted'
+        );
+
+        //accepts a DateTime object
+        $this->assertNotEquals(
+            false,
+            $this->_helper->formatDate(new DateTime(strtotime('2011-10-01'))),
+            'Expects DateTime object to be accepted'
+        );
+
+        //check if timezone is stripped
+        $expected = strtoupper('Z');
+        $actual = substr($this->_helper->formatDate(time()), 19, 20);
+        $this->assertEquals($expected, $actual, 'Expects last charachter to be uppercased Z');
+    }
+
     public function testAssemble()
     {
         // test single basic placeholder