libxml_set_external_entity_loader

(PHP 5 >= 5.4.0)

libxml_set_external_entity_loader — Changes the default external entity loader

说明

void libxml_set_external_entity_loader ( callable $resolver_function )

Changes the default external entity loader.

参数

resolver_function: A callable 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 .

返回值

没有返回值。

范例

Example #1 libxml_set_external_entity_loader() example

  <?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 ());
 ?>

以上例程会输出：

string(10) "-//FOO/BAR"
string(25) "http://example.com/foobar"
array(4) {
    ["directory"]    => NULL
    ["intSubName"]   => NULL
    ["extSubURI"]    => NULL
    ["extSubSystem"] => NULL
}
bool(true)

参见

libxml_disable_entity_loader() - Disable the ability to load external entities