Funções da Filter

Índice

filter_has_var — Verifica se uma variável de um especificado tipo existe
filter_id — Retorna o ID de filtro pertencente a um filtro nomeado
filter_input — Obtém uma variável externa específica por nome e filtra-a opcionalmente
filter_input_array — Obtem variáveis externas e opcionalmente as filtra
filter_list — Retorna a lista de todos os filtros suportados
filter_var — Filtra uma variável com um filtro especificado
filter_var_array — Obtêm múltiplas variáveis e opcionalmente as filtra

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Notas Enviadas por Usuários (em inglês) 4 notes

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vojtech at x dot cz ¶

17 years ago

Also notice that filter functions are using only the original variable values passed to the script even if you change the value in super global variable ($_GET, $_POST, ...) later in the script.

<?php
echo filter_input(INPUT_GET, 'var'); // print 'something'
echo $_GET['var']; // print 'something'
$_GET['var'] = 'changed';
echo filter_input(INPUT_GET, 'var'); // print 'something'
echo $_GET['var']; // print 'changed'
?>

In fact, external data are duplicated in SAPI before the script is processed and filter functions don't use super globals anymore (as explained in Filter tutorial bellow, section 'How does it work?').

down

fumble1 at web dot de ¶

17 years ago

I recommend you to use the FILTER_REQUIRE_SCALAR (or FILTER_REQUIRE_ARRAY) flags, since you can use array-brackets both to access string offsets and array-element -- however, not only this can lead to unexpected behaviour. Look at this example:

<?php
$image = basename(filter_input(INPUT_GET, 'src', FILTER_UNSAFE_RAW, FILTER_FLAG_STRIP_LOW));
// further checks
?>

/script.php?src[0]=foobar will cause a warning. :-(
Hence my recommendation:

<?php
$image = basename(filter_input(INPUT_GET, 'src', FILTER_UNSAFE_RAW, FILTER_REQUIRE_SCALAR | FILTER_FLAG_STRIP_LOW));
// further checks
?>

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-1

vojtech at x dot cz ¶

17 years ago

Just to note that "server and env support may not work in all sapi, for filter 0.11.0 or php 5.2.0" as mentioned in Filter tutorial bellow.

The workaround is obvious:
Instead of 
<?php
$var = filter_input(INPUT_SERVER, 'SERVER_NAME', FILTER_DEFAULT);
?>
use
<?php
$var = filter_var(isset($_SERVER['SERVER_NAME']) ? $_SERVER['SERVER_NAME'] : NULL, FILTER_DEFAULT);
?>

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-5

Richard Davey rich at corephp dot co dot uk ¶

17 years ago

There is an undocumented filter flag for FILTER_VALIDATE_BOOLEAN. The documentation implies that it will return NULL if the value doesn't match the allowed true/false values. However this doesn't happen unless you give it the FILTER_NULL_ON_FAILURE flag like this:

<?php
$value = 'car';
$result = filter_var($value, FILTER_VALIDATE_BOOLEAN, FILTER_NULL_ON_FAILURE);
?>

In the above $result will equal NULL. Without the extra flag it would equal FALSE, which isn't usually a desired result for this specific filter.

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