/**
* Returns a many-to-many component, as a ManyManyList.
* @param string $componentName Name of the many-many component
* @return ManyManyList The set of components
*/
public function getManyManyComponents($componentName)
{
$manyManyComponent = $this->manyManyComponent($componentName);
if (!$manyManyComponent) {
throw new InvalidArgumentException(sprintf("DataObject::getComponents(): Unknown many-to-many component '%s' on class '%s'", $componentName, $this->class));
}
list($parentClass, $componentClass, $parentField, $componentField, $table) = $manyManyComponent;
// If we haven't been written yet, we can't save these relations, so use a list that handles this case
if (!$this->ID) {
if (!isset($this->unsavedRelations[$componentName])) {
$this->unsavedRelations[$componentName] = new UnsavedRelationList($parentClass, $componentName, $componentClass);
}
return $this->unsavedRelations[$componentName];
}
$extraFields = $this->manyManyExtraFieldsForComponent($componentName) ?: array();
/** @var ManyManyList $result */
$result = ManyManyList::create($componentClass, $table, $componentField, $parentField, $extraFields);
// Store component data in query meta-data
$result = $result->alterDataQuery(function ($query) use($extraFields) {
$query->setQueryParam('Component.ExtraFields', $extraFields);
});
if ($this->model) {
$result->setDataModel($this->model);
}
$this->extend('updateManyManyComponents', $result);
// If this is called on a singleton, then we return an 'orphaned relation' that can have the
// foreignID set elsewhere.
return $result->setDataQueryParam($this->getInheritableQueryParams())->forForeignID($this->ID);
}
public function testSubtractOnAManyManyList()
{
$allList = ManyManyList::create('DataObjectTest_Player', 'DataObjectTest_Team_Players', 'DataObjectTest_PlayerID', 'DataObjectTest_TeamID');
$this->assertEquals(3, $allList->count(), 'Precondition; we have all 3 players connected to a team in the list');
$teamOneID = $this->idFromFixture('DataObjectTest_Team', 'team1');
$teamTwoID = $this->idFromFixture('DataObjectTest_Team', 'team2');
// Captain 1 belongs to one team; team1
$captain1 = $this->objFromFixture('DataObjectTest_Player', 'captain1');
$this->assertEquals(array($teamOneID), $captain1->Teams()->column("ID"), 'Precondition; player2 belongs to team1');
// Player 2 belongs to both teams: team1, team2
$player2 = $this->objFromFixture('DataObjectTest_Player', 'player2');
$this->assertEquals(array($teamOneID, $teamTwoID), $player2->Teams()->sort('Title')->column('ID'), 'Precondition; player2 belongs to team1 and team2');
// We want to find the teams for player2 where the captain does not belong to
$teamsWithoutTheCaptain = $player2->Teams()->subtract($captain1->Teams());
// Assertions
$this->assertEquals(1, $teamsWithoutTheCaptain->count(), 'The ManyManyList should onlu contain one team');
$this->assertEquals($teamTwoID, $teamsWithoutTheCaptain->first()->ID, 'The ManyManyList contains the wrong team');
}
