PHP Conference Japan 2024

La classe DOMDocumentFragment

(PHP 5, PHP 7, PHP 8)

Synopsis de la classe

class DOMDocumentFragment extends DOMNode implements DOMParentNode {
/* Constantes héritées */
/* Propriétés */
public readonly ?DOMElement $firstElementChild;
public readonly ?DOMElement $lastElementChild;
public readonly int $childElementCount;
/* Propriétés héritées */
public readonly string $nodeName;
public readonly int $nodeType;
public readonly ?DOMNode $parentNode;
public readonly ?DOMElement $parentElement;
public readonly DOMNodeList $childNodes;
public readonly ?DOMNode $firstChild;
public readonly ?DOMNode $lastChild;
public readonly ?DOMNode $previousSibling;
public readonly ?DOMNode $nextSibling;
public readonly ?DOMNamedNodeMap $attributes;
public readonly bool $isConnected;
public readonly ?DOMDocument $ownerDocument;
public readonly ?string $namespaceURI;
public string $prefix;
public readonly ?string $localName;
public readonly ?string $baseURI;
/* Méthodes */
public __construct()
public append(DOMNode|string ...$nodes): void
public appendXML(string $data): bool
public prepend(DOMNode|string ...$nodes): void
public replaceChildren(DOMNode|string ...$nodes): void
/* Méthodes héritées */
public DOMNode::C14N(
    bool $exclusive = false,
    bool $withComments = false,
    ?array $xpath = null,
    ?array $nsPrefixes = null
): string|false
public DOMNode::C14NFile(
    string $uri,
    bool $exclusive = false,
    bool $withComments = false,
    ?array $xpath = null,
    ?array $nsPrefixes = null
): int|false
public DOMNode::isEqualNode(?DOMNode $otherNode): bool
public DOMNode::isSameNode(DOMNode $otherNode): bool
public DOMNode::isSupported(string $feature, string $version): bool
}

Propriétés

childElementCount

Le nombre d'éléments enfants.

firstElementChild

Premier élément enfant ou null.

lastElementChild

Dernier élément enfant ou null.

Historique

Version Description
8.0.0 Les propriétés firstElementChild, lastElementChild et childElementCount ont été ajoutées.
8.0.0 DOMDocumentFragment implémente désormais DOMParentNode.

Sommaire

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User Contributed Notes 3 notes

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17
Ricki
13 years ago
DOMDocumentFragment only appears useful if created from a parent DOMDocument eg.

1. $dom = new DOMDocument("1.0","UTF-8");
2. $docFrag = $dom->createDocumentFragment();
3. Now append items to $docFrag
4. Graft $docFrag contents back onto $dom at the desired location

Conversely taking this approach:
1. $dom = new DOMDocument("1.0","UTF-8");
2. $docFrag = new DOMDocumentFragment();
3. Now append items to $docFrag

...will fail on step 3 with a "read only" error as $docFrag is not created as a child of DOMDocument.

I'm not sure of the reason for this: on the web people have cited security, and others have cited poor design however whatever the reason, it is really limiting when wanting to encapsulating generic independent DocumentFragments into classes for easy grafting to the desired tree. The only workarounds i have seen look expensive from a performance perspective and cumbersome from a coding perspective ie. create a dummy $dom for temporary use.

(This is valid as of PHP 5.3) I've put this here as i've wasted a lot of time finding it out - I hope this saves others some heartache.

Using new DOMDocumentFramt
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11
matthijs at stdin dot nl
13 years ago
Note that DOMDocumentFragment is a bit special when it's added to another node. When that happens, not the fragment itself is added as a child, but all of the children of the fragment are moved over to the new parent node.

For example, consider this script:

<?php

/* Create a document and a fragment containing a single node */
$doc = new DOMDocument();
$fragment = $doc->createDocumentFragment();
$fragment->appendChild($doc->createElement('foo'));

/* Now, the foo node is a child of the fragment */
var_dump($fragment->firstChild);

/* After appending the fragment to another node, the children of the
* fragment will have been transfered to that node (and the fragment is
* not present in the children list!) */
$doc->appendChild($fragment);
/* So the fragment has no children anymore */
var_dump($fragment->firstChild);
/* But $doc has a single child, which is the foo element, not the
* fragment */
var_dump($doc->childNodes->length);
var_dump($doc->firstChild);

?>

This produces the following output:

object(DOMElement)#3 (0) {
}
NULL
int(1)
object(DOMElement)#3 (0) {
}
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1
peter at softcoded dot com
7 years ago
DOMDocumentFragment makes it easy to add (or replace)
nodes. Individually creating nodes using DOM methods can
be tedious. Instead, do something like this:

/**
* Create fragment of colgroup
* @param DOMDocument $doc The DOMDocument
* @return DOMDocumentFragment
*/
function makeFragment($d){
$chunk = <<<HTML
<colgroup>
<col class="c1"/>
<col class="c2"/>
<col class="c3"/>
<col class="c4"/>
</colgroup>
HTML;
$fragment = $d->createDocumentFragment();
$fragment->appendXML($chunk);
return $fragment;
}
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