From d4114b3dce73ffaf786af7ce76f2e1c6f1483d47 Mon Sep 17 00:00:00 2001
From: Jonathon Menz <jonomenz@gmail.com>
Date: Thu, 11 Aug 2016 10:19:32 -0700
Subject: [PATCH] FIX include related fields on canFilter() check

closes #5576
---
 model/DataList.php           | 16 ++++++++++++++--
 tests/model/DataListTest.php | 32 ++++++++++++++++++++++++++++++++
 2 files changed, 46 insertions(+), 2 deletions(-)

diff --git a/model/DataList.php b/model/DataList.php
index ce92b048f..d50f20e13 100644
--- a/model/DataList.php
+++ b/model/DataList.php
@@ -233,12 +233,24 @@ class DataList extends ViewableData implements SS_List, SS_Filterable, SS_Sortab
 	}
 
 	/**
+	 * Returns true if this DataList can be filtered by the given field.
 	 *
-	 * @param string $fieldName
+	 * @param string $fieldName (May be a related field in dot notation like Member.FirstName)
 	 * @return boolean
 	 */
 	public function canFilterBy($fieldName) {
-		if($t = singleton($this->dataClass)->hasDatabaseField($fieldName)){
+		$model = singleton($this->dataClass);
+		$relations = explode(".", $fieldName);
+		// First validate the relationships
+		$fieldName = array_pop($relations);
+		foreach ($relations as $r) {
+			$relationClass = $model->getRelationClass($r);
+			if (!$relationClass) return false;
+			$model = singleton($relationClass);
+			if (!$model) return false;
+		}
+		// Then check field
+		if ($model->hasDatabaseField($fieldName)){
 			return true;
 		}
 		return false;
diff --git a/tests/model/DataListTest.php b/tests/model/DataListTest.php
index 828805502..1a4353127 100755
--- a/tests/model/DataListTest.php
+++ b/tests/model/DataListTest.php
@@ -533,6 +533,38 @@ class DataListTest extends SapphireTest {
 		$this->assertEquals('Phil', $list->last()->Name, 'Last comment should be from Phil');
 	}
 
+	/**
+	 * Test DataList->canFilterBy()
+	 */
+	public function testCanFilterBy() {
+		// Basic check
+		$team = DataObjectTest_Team::get();
+		$this->assertTrue($team->canFilterBy("Title"));
+		$this->assertFalse($team->canFilterBy("SomethingElse"));
+
+		// Has one
+		$this->assertTrue($team->canFilterBy("CaptainID"));
+		$this->assertTrue($team->canFilterBy("Captain.ShirtNumber"));
+		$this->assertFalse($team->canFilterBy("SomethingElse.ShirtNumber"));
+		$this->assertFalse($team->canFilterBy("Captain.SomethingElse"));
+		$this->assertTrue($team->canFilterBy("Captain.FavouriteTeam.Captain.ShirtNumber"));
+
+		// Has many
+		$this->assertTrue($team->canFilterBy("Fans.Name"));
+		$this->assertFalse($team->canFilterBy("SomethingElse.Name"));
+		$this->assertFalse($team->canFilterBy("Fans.SomethingElse"));
+
+		// Many many
+		$this->assertTrue($team->canFilterBy("Players.FirstName"));
+		$this->assertFalse($team->canFilterBy("SomethingElse.FirstName"));
+		$this->assertFalse($team->canFilterBy("Players.SomethingElse"));
+
+		// Subclasses
+		$subteam = DataObjectTest_SubTeam::get();
+		$this->assertTrue($subteam->canFilterBy("Title"));
+		$this->assertTrue($subteam->canFilterBy("SubclassDatabaseField"));
+	}
+
 	/**
 	 * $list->filter('Name', 'bob'); // only bob in the list
 	 */