楽に検証！値をチェックしてくれるfilter関数

$bool = 0;
$value = filter_var($bool, FILTER_VALIDATE_BOOLEAN, FILTER_NULL_ON_FAILURE);
var_dump($value);
 
=> boolean false

$ip = '127.0.0.1';
$value = filter_var($ip, FILTER_VALIDATE_IP, FILTER_FLAG_IPV4);
var_dump($value);
 
=> string '127.0.0.1' (length=9)

$url = 'https://php-fan.org/';
$value = filter_var($url, FILTER_VALIDATE_URL, FILTER_FLAG_PATH_REQUIRED);
 
=> string 'https://php-fan.org/' (length=23)

$url = 'وhttps://php-fan.org/فعفثز';
$value = filter_var($url, FILTER_SANITIZE_URL));
var_dump($value);
 
=> string 'https://php-fan.org/' (length=23)

$pattern = "/^([a-zA-Z0-9])+([a-zA-Z0-9\._-])*@([a-zA-Z0-9_-])+([a-zA-Z0-9\._-]+)+$/"
if (preg_match($pattern, $email) {
  echo 'ok';
}

$email = 'test@sample.com';
$value = filter_var($email, FILTER_VALIDATE_EMAIL);
var_dump($value);
 
=> string 'test@sample.com' (length=15)

if (filter_var($email, FILTER_VALIDATE_EMAIL) === false) {
 echo "emailアドレスの形式ではありません";
}

$email = '(test@sample.com)';
$value = filter_var($email, FILTER_SANITIZE_EMAIL);
var_dump($value);
 
=> string 'test@sample.com' (length=15)

$float = '3,250';
$value = filter_var($float, FILTER_VALIDATE_FLOAT, FILTER_FLAG_ALLOW_THOUSAND);
var_dump($value);
 
=> float 3250

$float = '12.3"584"';
$value = filter_var($float, FILTER_SANITIZE_NUMBER_FLOAT, FILTER_FLAG_ALLOW_FRACTION));
var_dump($value);
 
=> string '12.3584' (length=7)

$int = '012345678';
$value = filter_var($int, FILTER_VALIDATE_INT, FILTER_FLAG_ALLOW_OCTAL);
var_dump($value);
 
=> boolean false

$int = '12.3"584"';
$value = filter_var($int, FILTER_SANITIZE_NUMBER_INT);
var_dump($value);
 
=> string '123584' (length=6)

$enc = 'URLエンコードします-end';
$value = filter_var($enc, FILTER_SANITIZE_ENCODED);
var_dump($value);
 
=> string 'URL%E3%82%A8%E3%83%B3%E3%82%B3%E3%83%BC%E3%83%89%E3%81%97%E3%81%BE%E3%81%99-end' (length=79)

$char = "<script>alert('アラートです！')</script>";
$value = filter_var($char, FILTER_SANITIZE_FULL_SPECIAL_CHARS, FILTER_FLAG_NO_ENCODE_QUOTES);
 
var_dump($value);
 
=>string '&#60;script&#62;alert(&#39;アラートです！&#39;)&#60;/script&#62;' (length=71)

$char = "<script>alert('アラートです！')</script>";
$value = filter_var($char, FILTER_SANITIZE_STRING, FILTER_FLAG_NO_ENCODE_QUOTES);
var_dump($value);
 
=>string 'alert('アラートです！')' (length=30)

$reg = '03-123';
$options = array('options' => array('regexp' => '/^0\d{1,5}-?\d{0,4}-?\d{4}$/'));
$value = filter_var($reg, FILTER_VALIDATE_REGEXP, $options);
var_dump($value);
 
=> boolean false

function chars_count($str)
{
    $cnt = mb_strlen($str);
    if ($cnt > 10 ) {
        return $str;
    } else {
        return false;
    }
 
}
$callback = "文字列カウント";
$str = filter_var($callback, FILTER_CALLBACK, array('options' => 'chars_count'));
var_dump($str);
 
=> boolean false

$options = array(
    'options' => array(
        'default' => '値に収まりませんでした。', // フィルタが失敗した場合に返す値
        //その他のオプションをここに書きます
        'min_range' => 0,
        'max_range' => 100,
    ),
    'flags' => FILTER_FLAG_ALLOW_OCTAL,
);
$var = filter_var('200', FILTER_VALIDATE_INT, $options);
var_dump($var);
 
=> string '値に収まりませんでした。' (length=36)

var_dump(filter_list());
 
=>
array
  0 => string 'int' (length=3)
  1 => string 'boolean' (length=7)
  2 => string 'float' (length=5)
  3 => string 'validate_regexp' (length=15)
  4 => string 'validate_url' (length=12)
  5 => string 'validate_email' (length=14)
  6 => string 'validate_ip' (length=11)
  7 => string 'string' (length=6)
  8 => string 'stripped' (length=8)
  9 => string 'encoded' (length=7)
  10 => string 'special_chars' (length=13)
  11 => string 'full_special_chars' (length=18)
  12 => string 'unsafe_raw' (length=10)
  13 => string 'email' (length=5)
  14 => string 'url' (length=3)
  15 => string 'number_int' (length=10)
  16 => string 'number_float' (length=12)
  17 => string 'magic_quotes' (length=12)
  18 => string 'callback' (length=8)

$post = filter_input(INPUT_POST, 'text', FILTER_SANITIZE_SPECIAL_CHARS));
var_dump($post);
 
=> boolean false

$args = array(
        'url'   => array(
            'filter' =>  FILTER_VALIDATE_URL, 
            'flags' => FILTER_FLAG_PATH_REQUIRED
            ),
        'email' => FILTER_VALIDATE_EMAIL,
        'tel'   => array(
             'filter' => FILTER_VALIDATE_REGEXP,
             'options' => array('regexp' => '/^0\d{1,5}-?\d{0,4}-?\d{4}$/')
             ),
        'comment' => array(
            'filter' => FILTER_CALLBACK, 
            'options'=> 'count_vale'
            )
        );
        $error = filter_input_array(INPUT_POST, $args);
 
        if (false === $error['url']) {
            $error['url'] = '正しいURLを記入してください';
        } else {
            $error['url'] = '';
        }
        if (false === $error['email']) {
            $error['email'] = '正しいメールアドレスを記入してください';
        } else {
            $error['email'] ='';
        }
        if (false === $error['tel']) {
            $error['tel'] = '正しい電話番号を記入してください';
        } else {
            $error['tel'] = '';
        }
        if (false === $error['comment']) {
            $error['comment'] = '10文字以上1000文字以内で記入してください。';
        } else {
            $error['comment'] = '';
        }