silverstripe-framework/model/PolymorphicHasManyList.php
2014-03-18 09:18:04 +13:00

130 lines
3.7 KiB
PHP

<?php
/**
* Represents a has_many list linked against a polymorphic relationship
*
* @package framework
* @subpackage model
*/
class PolymorphicHasManyList extends HasManyList {
/**
* Name of foreign key field that references the class name of the relation
*
* @var string
*/
protected $classForeignKey;
/**
* Retrieve the name of the class this relation is filtered by
*
* @return string
*/
public function getForeignClass() {
return $this->dataQuery->getQueryParam('Foreign.Class');
}
/**
* Create a new PolymorphicHasManyList relation list.
*
* @param string $dataClass The class of the DataObjects that this will list.
* @param string $foreignField The name of the composite foreign relation field. Used
* to generate the ID and Class foreign keys.
* @param string $foreignClass Name of the class filter this relation is filtered against
*/
function __construct($dataClass, $foreignField, $foreignClass) {
// Set both id foreign key (as in HasManyList) and the class foreign key
parent::__construct($dataClass, "{$foreignField}ID");
$this->classForeignKey = "{$foreignField}Class";
// Ensure underlying DataQuery globally references the class filter
$this->dataQuery->setQueryParam('Foreign.Class', $foreignClass);
// For queries with multiple foreign IDs (such as that generated by
// DataList::relation) the filter must be generalised to filter by subclasses
$classNames = Convert::raw2sql(ClassInfo::subclassesFor($foreignClass));
$this->dataQuery->where(sprintf(
"\"{$this->classForeignKey}\" IN ('%s')",
implode("', '", $classNames)
));
}
/**
* Adds the item to this relation.
*
* It does so by setting the relationFilters.
*
* @param $item The DataObject to be added, or its ID
*/
public function add($item) {
if(is_numeric($item)) {
$item = DataObject::get_by_id($this->dataClass, $item);
} else if(!($item instanceof $this->dataClass)) {
user_error(
"PolymorphicHasManyList::add() expecting a $this->dataClass object, or ID value",
E_USER_ERROR
);
}
$foreignID = $this->getForeignID();
// Validate foreignID
if(!$foreignID) {
user_error(
"PolymorphicHasManyList::add() can't be called until a foreign ID is set",
E_USER_WARNING
);
return;
}
if(is_array($foreignID)) {
user_error(
"PolymorphicHasManyList::add() can't be called on a list linked to mulitple foreign IDs",
E_USER_WARNING
);
return;
}
$foreignKey = $this->foreignKey;
$classForeignKey = $this->classForeignKey;
$item->$foreignKey = $foreignID;
$item->$classForeignKey = $this->getForeignClass();
$item->write();
}
/**
* Remove an item from this relation.
* Doesn't actually remove the item, it just clears the foreign key value.
*
* @param $item The DataObject to be removed
* @todo Maybe we should delete the object instead?
*/
public function remove($item) {
if(!($item instanceof $this->dataClass)) {
throw new InvalidArgumentException("HasManyList::remove() expecting a $this->dataClass object, or ID",
E_USER_ERROR);
}
// Don't remove item with unrelated class key
$foreignClass = $this->getForeignClass();
$classNames = ClassInfo::subclassesFor($foreignClass);
$classForeignKey = $this->classForeignKey;
if(!in_array($item->$classForeignKey, $classNames)) return;
// Don't remove item which doesn't belong to this list
$foreignID = $this->getForeignID();
$foreignKey = $this->foreignKey;
if( empty($foreignID)
|| (is_array($foreignID) && in_array($item->$foreignKey, $foreignID))
|| $foreignID == $item->$foreignKey
) {
$item->$foreignKey = null;
$item->$classForeignKey = null;
$item->write();
}
}
}