silverstripe-framework/ORM/Map.php
2016-09-09 18:43:05 +12:00

271 lines
5.1 KiB
PHP

<?php
namespace SilverStripe\ORM;
use ArrayAccess;
use Countable;
use IteratorAggregate;
/**
* Creates a map from an SS_List by defining a key column and a value column.
*/
class Map implements ArrayAccess, Countable, IteratorAggregate {
protected $list, $keyField, $valueField;
/**
* @see Map::unshift()
*
* @var array $firstItems
*/
protected $firstItems = array();
/**
* @see Map::push()
*
* @var array $lastItems
*/
protected $lastItems = array();
/**
* Construct a new map around an SS_list.
*
* @param SS_List $list The list to build a map from
* @param string $keyField The field to use as the key of each map entry
* @param string $valueField The field to use as the value of each map entry
*/
public function __construct(SS_List $list, $keyField = "ID", $valueField = "Title") {
$this->list = $list;
$this->keyField = $keyField;
$this->valueField = $valueField;
}
/**
* Set the key field for this map.
*
* @var string $keyField
*/
public function setKeyField($keyField) {
$this->keyField = $keyField;
}
/**
* Set the value field for this map.
*
* @var string $valueField
*/
public function setValueField($valueField) {
$this->valueField = $valueField;
}
/**
* Return an array equivalent to this map.
*
* @return array
*/
public function toArray() {
$array = array();
foreach($this as $k => $v) {
$array[$k] = $v;
}
return $array;
}
/**
* Return all the keys of this map.
*
* @return array
*/
public function keys() {
return array_keys($this->toArray());
}
/**
* Return all the values of this map.
*
* @return array
*/
public function values() {
return array_values($this->toArray());
}
/**
* Unshift an item onto the start of the map.
*
* Stores the value in addition to the {@link DataQuery} for the map.
*
* @var string $key
* @var mixed $value
* @return $this
*/
public function unshift($key, $value) {
$oldItems = $this->firstItems;
$this->firstItems = array(
$key => $value
);
if($oldItems) {
$this->firstItems = $this->firstItems + $oldItems;
}
return $this;
}
/**
* Pushes an item onto the end of the map.
*
* @var string $key
* @var mixed $value
* @return $this
*/
public function push($key, $value) {
$oldItems = $this->lastItems;
$this->lastItems = array(
$key => $value
);
if($oldItems) {
$this->lastItems = $this->lastItems + $oldItems;
}
return $this;
}
// ArrayAccess
/**
* @var string $key
*
* @return boolean
*/
public function offsetExists($key) {
if(isset($this->firstItems[$key])) {
return true;
}
if(isset($this->lastItems[$key])) {
return true;
}
$record = $this->list->find($this->keyField, $key);
return $record != null;
}
/**
* @var string $key
*
* @return mixed
*/
public function offsetGet($key) {
if(isset($this->firstItems[$key])) {
return $this->firstItems[$key];
}
if(isset($this->lastItems[$key])) {
return $this->lastItems[$key];
}
$record = $this->list->find($this->keyField, $key);
if($record) {
$col = $this->valueField;
return $record->$col;
}
return null;
}
/**
* Sets a value in the map by a given key that has been set via
* {@link Map::push()} or {@link Map::unshift()}
*
* Keys in the map cannot be set since these values are derived from a
* {@link DataQuery} instance. In this case, use {@link Map::toArray()}
* and manipulate the resulting array.
*
* @var string $key
* @var mixed $value
*/
public function offsetSet($key, $value) {
if(isset($this->firstItems[$key])) {
$this->firstItems[$key] = $value;
}
if(isset($this->lastItems[$key])) {
$this->lastItems[$key] = $value;
}
user_error(
'Map is read-only. Please use $map->push($key, $value) to append values',
E_USER_ERROR
);
}
/**
* Removes a value in the map by a given key which has been added to the map
* via {@link Map::push()} or {@link Map::unshift()}
*
* Keys in the map cannot be unset since these values are derived from a
* {@link DataQuery} instance. In this case, use {@link Map::toArray()}
* and manipulate the resulting array.
*
* @var string $key
* @var mixed $value
*/
public function offsetUnset($key) {
if(isset($this->firstItems[$key])) {
unset($this->firstItems[$key]);
return;
}
if(isset($this->lastItems[$key])) {
unset($this->lastItems[$key]);
return;
}
user_error(
"Map is read-only. Unset cannot be called on keys derived from the DataQuery",
E_USER_ERROR
);
}
/**
* Returns an Map_Iterator instance for iterating over the complete set
* of items in the map.
*
* Satisfies the IteratorAggreagte interface.
*
* @return Map_Iterator
*/
public function getIterator() {
return new Map_Iterator(
$this->list->getIterator(),
$this->keyField,
$this->valueField,
$this->firstItems,
$this->lastItems
);
}
/**
* Returns the count of items in the list including the additional items set
* through {@link Map::push()} and {@link Map::unshift}.
*
* @return int
*/
public function count() {
return $this->list->count() +
count($this->firstItems) +
count($this->lastItems);
}
}