silverstripe-framework/model/RelationList.php
Hamish Friedlander 27113f82c3 API Make DataList and ArrayList immutable
In 3.0 there was some confusion about whether DataLists and ArrayLists
were mutable or not. If DataLists were immutable, they'd return the result, and your code
would look like

  $list = $list->filter(....);

If DataLists were mutable, they'd operate on themselves, returning nothing, and your code
would look like

 $list->filter(....);

This makes all DataLists and ArrayList immutable for all _searching_ operations.
Operations on DataList that modify the underlying SQL data store remain mutating.

- These functions no longer mutate the existing object, and if you do not capture the value
returned by them will have no effect:

  ArrayList#reverse
  ArrayList#sort
  ArrayList#filter
  ArrayList#exclude

  DataList#dataQuery (use DataList#alterDataQuery to modify dataQuery in a safe manner)
  DataList#where
  DataList#limit
  DataList#sort
  DataList#addFilter
  DataList#applyFilterContext
  DataList#innerJoin
  DataList#leftJoin
  DataList#find
  DataList#byIDs
  DataList#reverse

- DataList#setDataQueryParam has been added as syntactic sugar around the most common
cause of accessing the dataQuery directly - setting query parameters

- RelationList#setForeignID has been removed. Always use RelationList#forForeignID
when querying, and overload RelationList#foreignIDList when subclassing.

- Relatedly,the protected variable RelationList->foreignID has been removed, as the ID is
now stored on a query parameter. Use RelationList#getForeignID to read it.
2012-12-14 13:30:35 +13:00

51 lines
1.4 KiB
PHP

<?php
/**
* A DataList that represents a relation.
* Adds the notion of a foreign ID that can be optionally set.
*
* @todo Is this additional class really necessary?
*/
abstract class RelationList extends DataList {
public function getForeignID() {
return $this->dataQuery->getQueryParam('Foreign.ID');
}
/**
* Returns a copy of this list with the ManyMany relationship linked to the given foreign ID.
* @param $id An ID or an array of IDs.
*/
public function forForeignID($id) {
// Turn a 1-element array into a simple value
if(is_array($id) && sizeof($id) == 1) $id = reset($id);
// Calculate the new filter
$filter = $this->foreignIDFilter($id);
$list = $this->alterDataQuery(function($query, $list) use ($id, $filter){
// Check if there is an existing filter, remove if there is
$currentFilter = $query->getQueryParam('Foreign.Filter');
if($currentFilter) {
try {
$query->removeFilterOn($currentFilter);
}
catch (Exception $e) { /* NOP */ }
}
// Add the new filter
$query->setQueryParam('Foreign.ID', $id);
$query->setQueryParam('Foreign.Filter', $filter);
$query->where($filter);
});
return $list;
}
/**
* Returns a where clause that filters the members of this relationship to just the related items
* @param $id (optional) An ID or an array of IDs - if not provided, will use the current ids as per getForeignID
*/
abstract protected function foreignIDFilter($id = null);
}