xml_parser_free

(PHP 4, PHP 5, PHP 7, PHP 8)

xml_parser_freeLibera um analisador XML

Descrição

xml_parser_free(XMLParser $parser): bool

Nota:

Esta função não tem efeito. Antes do PHP 8.0.0, esta função era usada para fechar o recurso.

Libera o analisador XML informado em parser.

Cuidado

Além de chamar xml_parser_free() quando a análise está terminada, antes do PHP 8.0.0, era necessário também explicitamente remover a definição da referência ao analisador informado em parser para evitar vazamentos de memória, se o recurso do analisador fosse referenciado de um objeto, e este objeto referenciasse o recurso do analisador.

Parâmetros

parser
Uma referência para o analisador XML a ser liberado.

Valor Retornado

Retorna true em caso de sucesso ou false em caso de falha.

Registro de Alterações

Versão Descrição
8.0.0 O parâmetro parser agora espera uma instância de XMLParser; anteriormente, um resource xml válido era esperado.
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User Contributed Notes 3 notes

up
-1
nidzho
7 years ago
Unset the parser after calling xml_parser_free() to prevent memory leaks:

<?php
xml_parser_free
($parser);
unset(
$parser);
?>
up
-2
dio at edu dot uni-klu dot ac dot at
18 years ago
If you try to free an XML parser while it is still parsing, strange things will happen - your script will "hang" and no output will be sent to the browser. Consider this pseudo-code example:

-------

...
if (!xml_parse($parser)) echo 'XML error';

xml_parser_free($parser);

...

function SomeCallbackWhichWasSetBefore(...)
{
global $parser;

...

if (some_error_happened) xml_parser_free($parser);  //problem!

...

}

------

It would be logical that xml_parse would return false if the parser was freed while parsing, right? Wrong! Instead, everything hangs and no output will be sent out (no matter whether output buffering is on or not). It took me more than an hour to figure out why: you cannot free a parser handle that is currently parsing. A simple solution:

-------

$xml_error = false;
if (!xml_parse($parser))
echo 'XML error (directly from parser)';
else if ($xml_error)
echo 'XML error (from some callback function);

xml_parser_free($parser);

...

function SomeCallbackWhichWasSetBefore(...)
{
global $parser;
global $xml_error;

if ($xml_error)
return;

...

if (some_error_occured)
{
$xml_error = false;
return;
}

...

}

-------

If you use this solution you will have to check for $xml_error in every callback function. Essentially what you're doing is that, in case you want to stop parsing because of an error, you continue until xml_parse() is finished (without actually doing anything) and then free the parser and act on the error.

Of course the underlying problem is that you cannot stop a parser while it is parsing. There should be some function like xml_throw_error() or xml_parser_stop() or whatever, but unfortunately there isn't.
up
-3
php dot net at gwprogramming dot com (George Webb)
20 years ago
I found that with PHP 4.3.4RC1, if you don't call xml_parser_free() before your script ends, some sort of ugliness occurs with the webserver; i.e. the HTTP connection is closed.  (The apache error_log says "exit signal Segmentation fault (11)".)

Usually PHP tends to clean up connections you don't explicitly close (e.g. database connections), but in this case apparently it doesn't.

Some web browsers (MSIE for one) do not actually show this problem, so you may not actually notice it.  Opera 7.11 does show it, which is how I discovered it.

So don't forget to call xml_parser_free() ... always!
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