PHP libxml_set_external_entity_loader() Function

Example

Change the default external entity loader:

<?php
$xml = <<<XML
<!DOCTYPE foo PUBLIC "-//FOO/BAR" "http://example.com/foobar">
<foo>bar</foo>
XML;

$dtd = <<<DTD
<!ELEMENT foo (#PCDATA)>
DTD;

libxml_set_external_entity_loader(
function ($public, $system, $context) use($dtd) {
    var_dump($public);
    var_dump($system);
    var_dump($context);
    $f = fopen("php://temp", "r+");
    fwrite($f, $dtd);
    rewind($f);
    return $f;
}
);

$dd = new DOMDocument;
$r = $dd->loadXML($xml);

var_dump($dd->validate());
?>

Definition and Usage

The libxml_set_external_entity_loader() function changes the default external entity loader.

Syntax

libxml_set_external_entity_loader(function)

Parameter Values

Parameter	Description
function	Required. A function that takes three arguments. Two strings, a public id and system id, and a context (an array with four keys) as the third argument. This callback should return a resource, a string from which a resource can be opened, or NULL.

Technical Details

Return Value:	Returns TRUE on success, FALSE on failure
PHP Version:	5.4+

❮ PHP libxml Reference