filter_input
(PHP 5 >= 5.2.0)
filter_input — Принимает переменную извне PHP и, при необходимости, фильтрует ее
Описание
Список параметров
-
type -
Один из
INPUT_GET,INPUT_POST,INPUT_COOKIE,INPUT_SERVERилиINPUT_ENV. -
variable_name -
Имя получаемой переменной.
-
filter -
Идентификатор применяемого фильтра. См.список допустимых значений в Types of filters
-
options -
Ассоциативный массив параметров либо логическое ИЛИ флагов. Если фильтр принимает параметры, флаги могут быть указаны в элементе массива "flags".
Возвращаемые значения
Значение запрашиваемой переменной в случае успеха, FALSE, если фильтрация завершилась неудачей,
или NULL, если переменная variable_name не определена.
Если установлен флаг FILTER_NULL_ON_FAILURE, функция
возвращает FALSE, если переменная не определена и NULL, если фильтрация завершилась неудачей.
Примеры
Пример #1 Пример использования filter_input()
<?php
$search_html = filter_input(INPUT_GET, 'search', FILTER_SANITIZE_SPECIAL_CHARS);
$search_url = filter_input(INPUT_GET, 'search', FILTER_SANITIZE_ENCODED);
echo "Вы искали $search_html.\n";
echo "<a href='?search=$search_url'>Искать снова.</a>";
?>
Результатом выполнения данного примера будет что-то подобное:
Вы искали Me & son. <a href='?search=Me%20%26%20son'>Искать снова.</a>
Смотрите также
- filter_var() - Фильтрует переменную с помощью определенного фильтра
- filter_input_array() - Принимает несколько переменных извне PHP и, при необходимости, фильтрует их
- filter_var_array() - Принимает несколько переменных и, при необходимости, фильтрует их
- Types of filters
Коментарии
FastCGI seems to cause strange side-effects with unexpected null values when using INPUT_SERVER and INPUT_ENV with this function. You can use this code to see if it affects your server:<?php
var_dump($_SERVER);
foreach ( array_keys($_SERVER) as $b ) {
var_dump($b, filter_input(INPUT_SERVER, $b));
}
echo '<hr>';
var_dump($_ENV);
foreach ( array_keys($_ENV) as $b ) {
var_dump($b, filter_input(INPUT_ENV, $b));
}
?>
If you want to be on the safe side, using the superglobal $_SERVER and $_ENV variables will always work. You can still use the filter_* functions for Get/Post/Cookie without a problem, which is the important part!
I wouldn't recommend people use this function to store their data in a database. It's best not to encode data when storing it, it's better to store it raw and convert in upon the time of need.
One main reason for this is because if you have a short CHAR(16) field and the text contains encoded characters (quotes, ampersand) you can easily take a 12 character entry which obviously fits, but because of encoding it no longer fits.
Also, while not as common, if you need to use this data in another place, such as a non webpage (perhaps in a desktop app, or to a cell phone SMS or to a pager) the HTML encoded data will appear raw, and now you have to decode the data.
In summary, the best way to architect your system, is to store data as raw, and encode it only the moment you need to. So this means in your PHP upon doing a SQL query, instead of merely doing an echo $row['title'] you need to run htmlentities() on your echos, or better yet, an abstract function.
Note that this function doesn't (or at least doesn't seem to) actually filter based on the current values of $_GET etc. Instead, it seems to filter based off the original values.
<?php
$_GET['search'] = 'foo'; // This has no effect on the filter_input
$search_html = filter_input(INPUT_GET, 'search', FILTER_SANITIZE_SPECIAL_CHARS);
$search_url = filter_input(INPUT_GET, 'search', FILTER_SANITIZE_ENCODED);
echo "You have searched for $search_html.\n";
echo "<a href='?search=$search_url'>Search again.</a>";
?>
If you need to set a default input value and filter that, use filter_var on your required input variable instead
To use a class method for a callback function, as usual, provide an array with an instance of the class and the method name.
Example:
<?php
class myValidator
{
public function username($value)
{
// return username or boolean false
}
}
$myValidator = new myValidator;
$options = array('options' => array($myValidator, 'username'));
$username = filter_input(INPUT_GET, 'username', FILTER_CALLBACK, $options);
var_dump($username);
?>
The beauty of using this instead of directly using filter_var( $_GET['search'] ) is that you don't need to check if( isset( $_GET['search'] ) ) as if you pass that to filter_var and the key is not set then it will result in a warning. This function simplifies this and will return the relevant result to you (as per your options set) if the key has not been set in the user input.
If the type of filter you are using also supports a 'default' argument then this function will also stuff your missing input key with that value, again saving your efforts
Here is an example how to work with the options-parameter. Notice the 'options' in the 'options'-Parameter!
<?php
$options=array('options'=>array('default'=>5, 'min_range'=>0, 'max_range'=>9));
$priority=filter_input(INPUT_GET, 'priority', FILTER_VALIDATE_INT, $options);
?>
$priority will be 5 if the priority-Parameter isn't set or out the given range.
This function provides us the extremely simple solution for type filtering.
Without this function...
<?php
if (!isset($_GET['a'])) {
$a = null;
} elseif (!is_string($_GET['a'])) {
$a = false;
} else {
$a = $_GET['a'];
}
$b = isset($_GET['b']) && is_string($_GET['b']) ? $_GET['b'] : '';
?>
With this function...
<?php
$a = filter_input(INPUT_GET, 'a');
$b = (string)filter_input(INPUT_GET, 'b');
?>
Yes, FILTER_REQUIRE_SCALAR seems to be set as a default option.
It's very helpful for eliminating E_NOTICE, E_WARNING and E_ERROR.
This fact should be documented.
If your $_POST contains an array value:<?php
$_POST = array(
'var' => array('more', 'than', 'one', 'values')
);
?>
you should use FILTER_REQUIRE_ARRAY option:
<?php
var_dump(filter_input(INPUT_POST, 'var', FILTER_DEFAULT , FILTER_REQUIRE_ARRAY));
?>
Otherwise it returns false.
In fastcgi sapi implementations, filter_input(INPUT_SERVER) can return empty results.
In my case (8.1.9 64bit php-cgi) it was caused by auto_globals_jit enabled . When disabled (in php.ini on php startup), filter_input(INPUT_SERVER) works correctly.
php-fpm sapi isn't affected.