4 * Extends ArrayObject and does two things:
6 * Allows for deriving classes to easily intercept additions
7 * and deletions for purposes such as additional indexing.
9 * Enforces the objects to be of a certain type, so this
10 * can be replied upon, much like if this had true support
11 * for generics, which sadly enough is not possible in PHP.
13 * This program is free software; you can redistribute it and/or modify
14 * it under the terms of the GNU General Public License as published by
15 * the Free Software Foundation; either version 2 of the License, or
16 * (at your option) any later version.
18 * This program is distributed in the hope that it will be useful,
19 * but WITHOUT ANY WARRANTY; without even the implied warranty of
20 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
21 * GNU General Public License for more details.
23 * You should have received a copy of the GNU General Public License along
24 * with this program; if not, write to the Free Software Foundation, Inc.,
25 * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
26 * http://www.gnu.org/copyleft/gpl.html
32 * @license GNU GPL v2+
33 * @author Jeroen De Dauw < jeroendedauw@gmail.com >
35 abstract class GenericArrayObject
extends ArrayObject
{
37 * Returns the name of an interface/class that the element should implement/extend.
43 abstract public function getObjectType();
46 * @see SiteList::getNewOffset()
50 protected $indexOffset = 0;
53 * Finds a new offset for when appending an element.
54 * The base class does this, so it would be better to integrate,
55 * but there does not appear to be any way to do this...
61 protected function getNewOffset() {
62 while ( $this->offsetExists( $this->indexOffset
) ) {
66 return $this->indexOffset
;
70 * @see ArrayObject::__construct
74 * @param null|array $input
76 * @param string $iterator_class
78 public function __construct( $input = null, $flags = 0, $iterator_class = 'ArrayIterator' ) {
79 parent
::__construct( [], $flags, $iterator_class );
81 if ( !is_null( $input ) ) {
82 foreach ( $input as $offset => $value ) {
83 $this->offsetSet( $offset, $value );
89 * @see ArrayObject::append
95 public function append( $value ) {
96 $this->setElement( null, $value );
100 * @see ArrayObject::offsetSet()
104 * @param mixed $index
105 * @param mixed $value
107 public function offsetSet( $index, $value ) {
108 $this->setElement( $index, $value );
112 * Returns if the provided value has the same type as the elements
113 * that can be added to this ArrayObject.
117 * @param mixed $value
121 protected function hasValidType( $value ) {
122 $class = $this->getObjectType();
123 return $value instanceof $class;
127 * Method that actually sets the element and holds
128 * all common code needed for set operations, including
129 * type checking and offset resolving.
131 * If you want to do additional indexing or have code that
132 * otherwise needs to be executed whenever an element is added,
133 * you can overload @see preSetElement.
137 * @param mixed $index
138 * @param mixed $value
140 * @throws InvalidArgumentException
142 protected function setElement( $index, $value ) {
143 if ( !$this->hasValidType( $value ) ) {
144 throw new InvalidArgumentException(
145 'Can only add ' . $this->getObjectType() . ' implementing objects to '
146 . static::class . '.'
150 if ( is_null( $index ) ) {
151 $index = $this->getNewOffset();
154 if ( $this->preSetElement( $index, $value ) ) {
155 parent
::offsetSet( $index, $value );
160 * Gets called before a new element is added to the ArrayObject.
162 * At this point the index is always set (ie not null) and the
163 * value is always of the type returned by @see getObjectType.
165 * Should return a boolean. When false is returned the element
166 * does not get added to the ArrayObject.
170 * @param int|string $index
171 * @param mixed $value
175 protected function preSetElement( $index, $value ) {
180 * @see Serializable::serialize
186 public function serialize() {
187 return serialize( $this->getSerializationData() );
191 * Returns an array holding all the data that should go into serialization calls.
192 * This is intended to allow overloading without having to reimplement the
193 * behavior of this base class.
199 protected function getSerializationData() {
201 'data' => $this->getArrayCopy(),
202 'index' => $this->indexOffset
,
207 * @see Serializable::unserialize
211 * @param string $serialization
215 public function unserialize( $serialization ) {
216 $serializationData = unserialize( $serialization );
218 foreach ( $serializationData['data'] as $offset => $value ) {
219 // Just set the element, bypassing checks and offset resolving,
220 // as these elements have already gone through this.
221 parent
::offsetSet( $offset, $value );
224 $this->indexOffset
= $serializationData['index'];
226 return $serializationData;
230 * Returns if the ArrayObject has no elements.
236 public function isEmpty() {
237 return $this->count() === 0;