libxml_set_external_entity_loader
Description
The libxml_set_external_entity_loader of libxml for PHP changes the default external entity loader.
Syntax
libxml_set_external_entity_loader(
?callable $resolver_function
): boolParameters
resolver_function
A callable with the following signature:
resolver(
?string $public_id,
string $system_id,
array $context
): resource|string|nullpublic_id
The public ID.
system_id
The system ID.
context
An array with the four elements "directory", "intSubName", "extSubURI" and "extSubSystem".
This callable should return a resource, a string from which a resource can be opened. If null is returned, the entity reference resolution will fail.
Return
Returns true on success or false on failure.
Examples
1 · resolver_function
<?
function resolver($public_id, $system_id, $context)
{
return "mystring";
}
$resolver_function = "resolver";
$return = libxml_set_external_entity_loader($resolver_function);
var_export($return);
?>true
2 · DOMDocument
<?
function resolver($public_id, $system_id, $context)
{
var_dump($public_id, $system_id, $context);
return "mystring";
}
$resolver_function = "resolver";
libxml_set_external_entity_loader($resolver_function);
$source =
<<<XML
<!DOCTYPE mytopelement PUBLIC "myregistration//myorganization//mytype mylabel mydefinition//mylanguage" "https://mydomain.com/mypath">
<my-element></my-element>
XML;
$dom = new DOMDocument;
$dom->loadXML($source);
$dom->validate();
?>string(71) "myregistration//myorganization//mytype mylabel mydefinition//mylanguage"
string(27) "https://mydomain.com/mypath"
array(4) {
["directory"]=>
NULL
["intSubName"]=>
NULL
["extSubURI"]=>
NULL
["extSubSystem"]=>
NULL
}
