ENHANCEMENT: DataObject and SiteTree duplicate now duplicate relations (except for has_many relations, as the object at the other end of such a relation has an existing relation to the original object and that should not be modified by the duplication)

git-svn-id: svn://svn.silverstripe.com/silverstripe/open/modules/sapphire/trunk@110845 467b73ca-7a2a-4603-9d3b-597d59a354a9

core/model/DataObject.php

@@ -379,7 +379,7 @@ class DataObject extends ViewableData implements DataObjectInterface, i18nEntity
 
 	/**
 	 * Create a duplicate of this node.
-	 * Caution: Doesn't duplicate relations.
+	 * Note: now also duplicates relations.
 	 *
 	 * @param $doWrite Perform a write() operation before returning the object.  If this is true, it will create the duplicate in the database.
 	 * @return DataObject A duplicate of this node. The exact type will be the type of this node.
@@ -388,10 +388,55 @@ class DataObject extends ViewableData implements DataObjectInterface, i18nEntity
 		$className = $this->class;
 		$clone = new $className( $this->record );
 		$clone->ID = 0;
-		if($doWrite) $clone->write();
+
+		if($doWrite) {
+			$clone->write();
+
+			$this->duplicateManyManyRelations($this, $clone);
+		}
 		return $clone;
 	}
 
+	/**
+	 * Copies the many_many and belongs_many_many relations from one object to another instance of the name of object
+	 * The destinationObject must be written to the database already and have an ID. Writing is performed automatically when adding the new relations.
+	 * @return DataObject with the new many_many relations copied in */
+	protected function duplicateManyManyRelations($sourceObject, $destinationObject) {
+		if (!$destinationObject || $destinationObject->ID < 1) user_error("Can't duplicate relations for an object that has not been written to the database", E_USER_ERROR);
+
+		//duplicate complex relations
+		// DO NOT copy has_many relations, because copying the relation would result in us changing the has_one relation
+		// on the other side of this relation to point at the copy and no longer the original (being a has_one, it can
+		// only point at one thing at a time). So, all relations except has_many can and are copied
+		if ($sourceObject::$has_one) foreach($sourceObject::$has_one as $name => $type) {
+			$this->duplicateRelations($sourceObject, $destinationObject, $name);
+		}
+		if ($sourceObject::$many_many) foreach($sourceObject::$many_many as $name => $type) {
+			$this->duplicateRelations($sourceObject, $destinationObject, $name);
+		}
+		if ($sourceObject::$belongs_many_many) foreach($sourceObject::$belongs_many_many as $name => $type) {
+			$this->duplicateRelations($sourceObject, $destinationObject, $name);
+		}
+
+		return $destinationObject;
+	}
+
+	/** Helper function to duplicate relations from one object to another */
+	private function duplicateRelations($sourceObject, $destinationObject, $name) {
+		$relations = $sourceObject->$name();
+		if ($relations) {
+			if ($relations instanceOf ComponentSet) {   //many-to-something relation
+				if ($relations->Count() > 0) {  //with more than one thing it is related to
+					foreach($relations as $relation) {
+						$destinationObject->$name()->add($relation);
+					}
+				}
+			} else {    //one-to-one relation
+				$destinationObject->$name = $relations;
+			}
+		}
+	}
+	
 	/**
 	 * Set the ClassName attribute. {@link $class} is also updated.
 	 * Warning: This will produce an inconsistent record, as the object

core/model/SiteTree.php

@@ -538,6 +538,8 @@ class SiteTree extends DataObject implements PermissionProvider,i18nEntityProvid
 		
 		if($doWrite) {
 			$page->write();
+
+			$page = $this->duplicateManyManyRelations($this, $page);
 		}
 		$this->extend('onAfterDuplicate', $page);
 		

tests/model/DataObjectDuplicationTest.php

@@ -0,0 +1,101 @@
+<?php
+
+class DataObjectDuplicationTest extends SapphireTest {
+
+	function testDuplicateManyManyClasses() {
+		//create new test classes below
+		$one = new DataObjectDuplicateTestClass1();
+		$two = new DataObjectDuplicateTestClass2();
+		$three = new DataObjectDuplicateTestClass3();
+
+		//set some simple fields
+		$text1 = "Test Text 1";
+		$text2 = "Test Text 2";
+		$text3 = "Test Text 3";
+		$one->text = $text1;
+		$two->text = $text2;
+		$three->text = $text3;
+
+		//write the to DB
+		$one->write();
+		$two->write();
+		$three->write();
+
+		//create relations
+		$one->twos()->add($two);
+		$one->threes()->add($three);
+
+		$one = DataObject::get_by_id("DataObjectDuplicateTestClass1", $one->ID);
+		$two = DataObject::get_by_id("DataObjectDuplicateTestClass2", $two->ID);
+		$three = DataObject::get_by_id("DataObjectDuplicateTestClass3", $three->ID);
+
+		//test duplication
+		$oneCopy = $one->duplicate();
+		$twoCopy = $two->duplicate();
+		$threeCopy = $three->duplicate();
+
+		$oneCopy = DataObject::get_by_id("DataObjectDuplicateTestClass1", $oneCopy->ID);
+		$twoCopy = DataObject::get_by_id("DataObjectDuplicateTestClass2", $twoCopy->ID);
+		$threeCopy = DataObject::get_by_id("DataObjectDuplicateTestClass3", $threeCopy->ID);
+
+		$this->assertNotNull($oneCopy, "Copy of 1 exists");
+		$this->assertNotNull($twoCopy, "Copy of 2 exists");
+		$this->assertNotNull($threeCopy, "Copy of 3 exists");
+
+		$this->assertEquals($text1, $oneCopy->text);
+		$this->assertEquals($text2, $twoCopy->text);
+		$this->assertEquals($text3, $threeCopy->text);
+
+		$this->assertNotEquals($one->twos()->Count(), $oneCopy->twos()->Count(), "Many-to-one relation not copied (has_many)");
+		$this->assertEquals($one->threes()->Count(), $oneCopy->threes()->Count(), "Object has the correct number of relations");
+		$this->assertEquals($three->ones()->Count(), $threeCopy->ones()->Count(), "Object has the correct number of relations");
+
+		$this->assertEquals($one->ID, $twoCopy->one()->ID, "Match between relation of copy and the original");
+		$this->assertEquals(0, $oneCopy->twos()->Count(), "Many-to-one relation not copied (has_many)");
+		$this->assertEquals($three->ID, $oneCopy->threes()->First()->ID, "Match between relation of copy and the original");
+		$this->assertEquals($one->ID, $threeCopy->ones()->First()->ID, "Match between relation of copy and the original");
+	}
+
+}
+
+
+class DataObjectDuplicateTestClass1 extends SiteTree {
+
+	static $db = array(
+		'text' => 'Varchar'
+	);
+
+	static $has_many = array(
+		'twos' => 'DataObjectDuplicateTestClass2'
+	);
+
+	static $many_many = array(
+		'threes' => 'DataObjectDuplicateTestClass3'
+	);
+}
+
+class DataObjectDuplicateTestClass2 extends SiteTree {
+
+	static $db = array(
+		'text' => 'Varchar'
+	);
+
+	static $has_one = array(
+		'one' => 'DataObjectDuplicateTestClass1'
+	);
+
+}
+
+class DataObjectDuplicateTestClass3 extends SiteTree {
+
+	static $db = array(
+		'text' => 'Varchar'
+	);
+
+	static $belongs_many_many = array(
+		'ones' => 'DataObjectDuplicateTestClass1'
+	);
+}
+
+
+?>