First name pregmatch

I am trying to only accept the following special characters into the name field:

' - ´

the first two work fine but when trying to use the third for example, josé, it fails validation.

 if (!preg_match("/^[a-zA-Z '-´]*$/",$_POST['first_name'])) {

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Black SulfurAsked:
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Ray PaseurConnect With a Mentor Commented:
Please see: https://iconoun.com/demo/temp_blacksulfur.php

This shows how to set up the regex, and how to test it with good data visualization.  Check the man page references in the top comments for more information.
<?php // demo/temp_blacksulfur.php
/**
 * https://www.experts-exchange.com/questions/28979848/First-name-pregmatch.html
 *
 * https://www.experts-exchange.com/articles/7830/A-Quick-Tour-of-Test-Driven-Development.html
 * https://www.experts-exchange.com/articles/11880/Unicode-and-Character-Collisions.html
 * http://www.regular-expressions.info/unicode.html
 */
ini_set('display_errors', TRUE);
error_reporting(E_ALL);

// SET UP PHP AND BROWSER TO USE UTF-8
mb_internal_encoding('utf-8');
mb_regex_encoding('utf-8');
mb_http_output('utf-8');
echo '<meta charset="utf-8" />';
echo '<pre>';

// SOME DATA VISUALIZATION TOOLS
Class Letter
{
    public function __construct($chr)
    {
        $this->chr = $chr;
        $this->hex = array();
        $bytes     = $this->usplit($chr);
        foreach ($bytes as $byte)
        {
            $this->hex = array_merge($this->hex, $this->gethex($byte));
        }
        return $this;
    }

    public function usplit ($chr)
    {
        $len = strlen($chr);
        while ($len) {
            $arr[] = substr($chr, 0, 1);
            $chr   = substr($chr, 1, $len);
            $len   = strlen($chr);
        }
        return $arr;
    }

    public function gethex($chr)
    {
        // GET THE HEX NIBBLE VALUES IN AN ARRAY
        $ret = str_split(implode(NULL, unpack('H*', $chr)));
        return $ret;
    }
}

Class Hexdump
{
    public function __construct($str)
    {
        $this->str = $str;
        $this->arr = $this->mb_str_split($str);
        $this->len = mb_strlen($str);
        foreach ($this->arr as $uchr)
        {
            $this->dat[] = new Letter($uchr);
        }
        return $this;
    }

    public function mb_str_split($ustr)
    {
        return preg_split('/(?<!^)(?!$)/u', $ustr);
    }

    public function render($br = PHP_EOL)
    {
        foreach ($this->dat as $poz => $chr)
        {
            echo $br;
            echo str_pad($poz, 4, ' ', STR_PAD_LEFT);
            echo ' ';
            echo $chr->chr;
            echo "\t";
            echo implode(null, $chr->hex);
        }
        echo $br;
    }
}

// A REGEX TO TEST WITH
$rgx
= '#'             // REGEX DELIMITER
. '^'             // AT START STRING
. '['             // START CHARACTER CLASS
. '\p{L}'         // ANY LETTER
. " '-"           // BLANK, APOSTROPHE, DASH
. ']'             // ENDOF CHARACTER CLASS
. '*'             // ONE OR MORE
. '$'             // AT ENDOF STRING
. '#'             // REGEX DELIMITER
. 'u'             // FLAG: ALLOW UNICODE
. 'i'             // FLAG: CASE-INSENSITIVE
;
echo PHP_EOL . htmlentities($rgx);

// ADD TEST CASES AS NEEDED HERE
$tests = array
( 'josé'
, 'Ray'
, 'R&aacute;y'
, '42'
, ' '
, 'J.R.R.'
, '----'
, 'BlackSulfur'
)
;

// MAKE THE TESTS
foreach ($tests as $test)
{
    echo PHP_EOL;
    $out = new HexDump($test);
    $out->render();
    echo $test;
    if (preg_match($rgx, $test)) echo ' MATCH';
}

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Outputs
#^[\p{L} '-]*$#ui

   0 j	6a
   1 o	6f
   2 s	73
   3 é	c3a9
josé MATCH

   0 R	52
   1 a	61
   2 y	79
Ray MATCH

   0 R	52
   1 &	26
   2 a	61
   3 a	61
   4 c	63
   5 u	75
   6 t	74
   7 e	65
   8 ;	3b
   9 y	79
Ráy

   0 4	34
   1 2	32
42

   0  	20
  MATCH

   0 J	4a
   1 .	2e
   2 R	52
   3 .	2e
   4 R	52
   5 .	2e
J.R.R.

   0 -	2d
   1 -	2d
   2 -	2d
   3 -	2d
---- MATCH

   0 B	42
   1 l	6c
   2 a	61
   3 c	63
   4 k	6b
   5 S	53
   6 u	75
   7 l	6c
   8 f	66
   9 u	75
  10 r	72
BlackSulfur MATCH

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0
 
Rgonzo1971Connect With a Mentor Commented:
Hi

If you want accented chars then try
if (!preg_match("/^[a-zA-ZÀ-ÿ '-]*$/",$_POST['first_name'])) {

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Regards
0
 
Rgonzo1971Commented:
or maybe

if (!preg_match("/^[\p{L} '-]*$/",$_POST['first_name'])) {

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0
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Ray PaseurCommented:
The correct answer to this question depends on the character set encoding.  What character set are you using?
0
 
Black SulfurAuthor Commented:
utf-8
0
 
Black SulfurAuthor Commented:
Hmm, Ray is right. I have my database set as utf-8 general and when I inserted josé into the database I get josé
0
 
Black SulfurAuthor Commented:
Thanks, Ray

This is a hectic answer for my level of knowledge! Does one of these:

= '#'             // REGEX DELIMITER
. '^'             // AT START STRING
. '['             // START CHARACTER CLASS
. '\p{L}'         // ANY LETTER
. " '-"           // BLANK, APOSTROPHE, DASH
. ']'             // ENDOF CHARACTER CLASS
. '*'             // ONE OR MORE
. '$'             // AT ENDOF STRING
. '#'             // REGEX DELIMITER
. 'u'             // FLAG: ALLOW UNICODE
. 'i'             // FLAG: CASE-INSENSITIVE

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allow for the ´being inserted into the database correctly or is it the below? It's a bit over my head...

mb_internal_encoding('utf-8');
mb_regex_encoding('utf-8');
mb_http_output('utf-8');

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0
 
Ray PaseurConnect With a Mentor Commented:
The character encoding for the database is independent and separate from the character encoding for PHP or HTML.  Have a look at this article, and check the part about Character Sets in MySQL.
https://www.experts-exchange.com/articles/11880/Unicode-and-Character-Collisions.html
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Black SulfurAuthor Commented:
Aha, I get it now.

I used :

if (!preg_match("#^[\p{L} '-]*$#ui",$_POST['first_name'])) {

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And for my database connection I used:

$link = new mysqli($server_name, $db_username, $db_password, $db_dbname);
$link->set_charset("utf8mb4");

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All seems to work now!  :)
1
 
Ray PaseurCommented:
Bingo!

The way I wrote the REGEX used PHP string concatenation to build up the REGEX string one piece at a time.  I like to write REGEX and other complicated strings that way because it lets me add comments, and it's easy to change when testing.

Best of luck with your project, ~Ray
0
 
Black SulfurAuthor Commented:
Makes sense to do that, I think I should try it!
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