I needed to merge SplObjectStorages.
<?php
// As an object set
$SplObjectStorage_1 = new SplObjectStorage();
$object1 = new StdClass;
$object1->attr = 'obj 1';
$object2 = new StdClass;
$object2->attr = 'obj 2';
$object3 = new StdClass;
$object3->attr = 'obj 3';
$SplObjectStorage_1->attach($object1);
$SplObjectStorage_1->attach($object2);
$SplObjectStorage_1->attach($object3);
// Another one object set
$SplObjectStorage_2 = new SplObjectStorage();
$object4 = new StdClass;
$object4->attr = 'obj 4';
$object5 = new StdClass;
$object5->attr = 'obj 5';
$object6 = new StdClass;
$object6->attr = 'obj 6';
$SplObjectStorage_2->attach($object4);
$SplObjectStorage_2->attach($object5);
$SplObjectStorage_2->attach($object6);
/**
* Merge SplObjectStorage
*
* @param how many SplObjectStorage params as you want
* @return SplObjectStorage
*/
function mergeSplObjectStorage() {
$buffer = new SplObjectStorage();
if( func_num_args() > 0 ) {
$args = func_get_args();
foreach ($args as $objectStorage) {
foreach($objectStorage as $object) {
if(is_object( $object ) ) {
$buffer->attach($object);
}
}
}
}
else{
return FALSE;
}
return $buffer;
}
$merge = mergeSplObjectStorage($SplObjectStorage_1, $SplObjectStorage_2);
?>
<?php
echo $merge->count();
?>
Will output :
6
<?php
$merge->rewind();
while($merge->valid()) {
$object = $merge->current();
var_dump($object);
$merge->next();
}
?>
Will ouput :
object(stdClass)#2 (1) {
["attr"]=>
string(5) "obj 1"
}
object(stdClass)#3 (1) {
["attr"]=>
string(5) "obj 2"
}
object(stdClass)#4 (1) {
["attr"]=>
string(5) "obj 3"
}
object(stdClass)#6 (1) {
["attr"]=>
string(5) "obj 4"
}
object(stdClass)#7 (1) {
["attr"]=>
string(5) "obj 5"
}
object(stdClass)#8 (1) {
["attr"]=>
string(5) "obj 6"
}
My two cents.
The SplObjectStorage class
(PHP 5 >= 5.3.0)
Introduzione
The SplObjectStorage class provides a map from objects to data or, by ignoring data, an object set. This dual purpose can be useful in many cases involving the need to uniquely identify objects.
Sommario dellla classe
/* Metodi */
}Esempi
Example #1 SplObjectStorage as a set
<?php
// As an object set
$s = new SplObjectStorage();
$o1 = new StdClass;
$o2 = new StdClass;
$o3 = new StdClass;
$s->attach($o1);
$s->attach($o2);
var_dump($s->contains($o1));
var_dump($s->contains($o2));
var_dump($s->contains($o3));
$s->detach($o2);
var_dump($s->contains($o1));
var_dump($s->contains($o2));
var_dump($s->contains($o3));
?>
Il precedente esempio visualizzerà:
bool(true) bool(true) bool(false) bool(true) bool(false) bool(false)
Example #2 SplObjectStorage as a map
<?php
// As a map from objects to data
$s = new SplObjectStorage();
$o1 = new StdClass;
$o2 = new StdClass;
$o3 = new StdClass;
$s[$o1] = "data for object 1";
$s[$o2] = array(1,2,3);
if (isset($s[$o2])) {
var_dump($s[$o2]);
}
?>
Il precedente esempio visualizzerà:
array(3) {
[0]=>
int(1)
[1]=>
int(2)
[2]=>
int(3)
}
Indice dei contenuti
- SplObjectStorage::addAll — Adds all objects from another storage
- SplObjectStorage::attach — Adds an object in the storage
- SplObjectStorage::contains — Checks if the storage contains a specific object
- SplObjectStorage::count — Returns the number of objects in the storage
- SplObjectStorage::current — Returns the current storage entry
- SplObjectStorage::detach — Removes an object from the storage
- SplObjectStorage::getHash — Calculate a unique identifier for the contained objects
- SplObjectStorage::getInfo — Returns the data associated with the current iterator entry
- SplObjectStorage::key — Returns the index at which the iterator currently is
- SplObjectStorage::next — Move to the next entry
- SplObjectStorage::offsetExists — Checks whether an object exists in the storage
- SplObjectStorage::offsetGet — Returns the data associated with an object
- SplObjectStorage::offsetSet — Associates data to an object in the storage
- SplObjectStorage::offsetUnset — Removes an object from the storage
- SplObjectStorage::removeAll — Removes objects contained in another storage from the current storage
- SplObjectStorage::removeAllExcept — Removes all objects except for those contained in another storage from the current storage
- SplObjectStorage::rewind — Rewind the iterator to the first storage element
- SplObjectStorage::serialize — Serializes the storage
- SplObjectStorage::setInfo — Sets the data associated with the current iterator entry
- SplObjectStorage::unserialize — Unserializes a storage from its string representation
- SplObjectStorage::valid — Returns if the current iterator entry is valid
inwebo at gmail dot fr ¶
1 year ago
Jan Walther ¶
1 year ago
I rewrote some scripts and changed object storage with arrays to SplObjectStorage. At some point I needed support of array_rand() but I did not find a function to return a random attached object of an SplObjectStorage object.
So here is my solution for random access to SplObjectStorage:
<?php
$o1 = new StdClass;
$o2 = new StdClass;
$s = new SplObjectStorage;
$s->attach($o1);
$s->attach($o2);
$random = rand(0,$s->count()-1);
$s->rewind();
for($i=0;$i<$random;$i++) {
$s->next();
}
var_dump($s->current());
?>
Robertas at pobox com ¶
3 years ago
PHP 5.2.x and lower doesn't implement ArrayAccess in SplObjectStorage - it is only implemented starting from PHP 5.3
randallgirard at hotmail dot com ¶
3 years ago
I have two things to note about SplObjectStorage:
#1: A reference to the object itself is stored (not just a hash to compare against the object) and it must be removed before the object is destroyed and the destructor is executed.
#2: SplObjectStorage::rewind() MUST be called to initiate the iterator and before SplObjectStorage::current() will return an object (and I think the only way to retrieve an object?) rather than automatically starting at the first element as I expected it to, like an array for example. This assumption is based on SplObjectStorage::current() returning NULL until SplObjectStorage::rewind() is called once the objects are contained. As a note, always use REWIND before iterating through or fetching objects.
<?php
class foo {
public function __destruct() {
print("--- DESTRUCTOR FIRED!!<br />\r\n");
}
}
# Create object and storage
$bar = new foo();
$s = new SplObjectStorage();
# Rewind early just as a test
$s->rewind();
# attach the object
$s->attach($bar, array('test'));
# Unset the object; destructor does NOT fire
unset($bar);
print("Object has been unset<br />\r\n");
# First demonstrate that REWIND must be called to initialize the iterator
$obj = $s->current();
var_dump($obj);
print("- Note the NULL (from \$s->current())<br />\r\n");
# Initialize, and then detach the current (and only) object
$s->rewind();
$s->detach( $s->current() );
# The destructor should NOW execute
?>
Output:
Object has been unset
NULL - Note the NULL (from $s->current())
--- DESTRUCTOR FIRED!!
Hayley Watson ¶
1 year ago
As an iterator, SplObjectStorage traverses the _keys_ of the map (the $o1, $o2 of Example 2) rather than the values. To retrieve each of those in turn requires an additional lookup:
<?php
// As a map from objects to data
$s = new SplObjectStorage();
$o1 = (object)array('a'=>1);
$o2 = (object)array('b'=>2);
$o3 = (object)array('c'=>3);
$s[$o1] = "data for object 1";
$s[$o2] = array(1,2,3);
foreach($s as $i => $key)
{
echo "Entry $i:\n"; // You get a numeric index
var_dump($key, $s[$key]);
echo "\n";
}
?>
This makes sense when you use an SplObjectStorage as a set, since in that case all of the "values" are null.
