DOMNode::insertBefore

(PHP 5, PHP 7, PHP 8)

DOMNode::insertBefore Añade un nuevo hijo antes del nodo de referencia

Descripción

public DOMNode::insertBefore(DOMNode $newnode, DOMNode $refnode = ?): DOMNode

Esta función inserta un nuevo nodo justo antes que el nodo de referencia. Si planea hacer modificaciones posteriores al hijo añadido debe usar el nodo devuelto.

Parámetros

newnode

El nuevo nodo.

refnode

El nodo de referencia. Si no se proporciona, newnode es añadido al hijo.

Valores devueltos

El nodo insertado.

Errores/Excepciones

DOM_NO_MODIFICATION_ALLOWED_ERR

Lanzado si este nodo es de sólo lectura o si el padre previo del nodo que va a ser insertado es de sólo lectura.

DOM_HIERARCHY_REQUEST_ERR

Lanzado si este nodo es de un tipo de no permite hijos del tipo del nodo newnode, o si el nodo a añadir es uno de los progenitores del nodo o si es el nodo en sí.

DOM_WRONG_DOCUMENT_ERR

Lanzado si newnode fue creado desde un documento diferente del que creó este nodo.

DOM_NOT_FOUND

Lanzado si refnode no es un hijo de este nodo.

Ver también

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User Contributed Notes 5 notes

up
7
Jerry Ellis
19 years ago
1st argument) a node to insert
2nd argument) a reference node - this is the node that the new node will be inserted before

The trick to using this method is that the OBJECT on which you actually CALL the insertBefore() method is actually the PARENT node of the reference node! 

INCORRECT:
$DOMNode_refNode->insertBefore($DOMNode_newNode, $DOMNode_refNode);

CORRECT:
$DOMNode_refNode->parentNode->insertBefore($DOMNode_newNode, $DOMNode_refNode);
up
5
jarry1250 at gmail dot com
9 years ago
Note that supplying the same node for $newnode and $refnode leads to an E_WARNING ("Couldn't add newnode as the previous sibling of refnode"). For example imagine one wanted to make $newnode the first child of its parent by doing:

<?php
$firstSibling
= $newnode->parentNode->firstChild;
// Bad:
$newnode->parentNode->insertBefore( $newnode, $firstSibling );
?>

This would generate a warning if it already was the first child of its parent, since $newnode and $firstSibling are identical. Easy to work around though:

<?php
$firstSibling
= $newnode->parentNode->firstChild;
// Better:
if( $newnode !== $firstSibling ) {
   
$newnode->parentNode->insertBefore( $newnode, $firstSibling );
}
?>
up
6
jg at handcode dot de
19 years ago
example to insert <newnode/> between <chid1/> and <child2/>

<?xml version="1.0" encoding="ISO-8859-1" ?>    
<root>
  <parent>
    <child nr="1"/>
    <child nr="2"/>
  </parent>
</root>

<?php

$xml_src
= 'test.xml';

// XPath-Querys
$parent_path = "//parent";
$next_path = "//parent/child[@nr='2']";

// Create a new DOM document
$dom = new DomDocument();
$dom->load($xml_src);

// Find the parent node
$xpath = new DomXPath($dom);

// Find parent node
$parent = $xpath->query($parent_path);

// new node will be inserted before this node
$next = $xpath->query($next_path);

// Create the new element
$element = $dom->createElement('newnode');

// Insert the new element
$parent->item(0)->insertBefore($element, $next->item(0));

echo
$dom->saveXML();

?>
up
-3
DrTebi at Yahoo
17 years ago
Sorry, my previous posting worked only for the top node. Here the corrected version, which will work for any node:

XML
----
<?xml version="1.0"?>
<contacts>
  <person>Adam</person>
  <person>Eva</person>
  <person>Thomas</person>
</contacts>

PHP
---
<?php
// load XML, create XPath object
$xml = new DomDocument();
$xml->preserveWhitespace = false;
$xml->load('contacts.xml');
$xpath = new DOMXPath($xml);

// get node eva, which we will append to
$eva = $xpath->query('/contacts/person[.="Eva"]')->item(0);

// create node john
$john = $xml->createElement('person', 'John');

// insert john after eva
//   "in eva's parent node (=contacts) insert
//   john before eva's next node"
// this also works if eva would be the last node
$eva->parentNode->insertBefore($john, $eva->nextSibling);

// show result
header('Content-Type: text/plain');
print
$xml->saveXML();
?>

Result
------
<?xml version="1.0"?>
<contacts>
  <person>Adam</person>
  <person>Eva</person><person>John</person>
  <person>Thomas</person>
</contacts>
up
-5
justin at redwiredesign dot com
17 years ago
The previous example is incorrect, and causes a DOM_NOT_FOUND error, as the child nodes are not direct descendants of the root node.

Therefore, the line:

$parent_path = "/root";

needs to change to:

$parent_path = "/root/parent";

or

$parent_path = "//parent";

for this example to work
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