tags:

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774

answers:

5

Hi folks! Current code only replace the spaces to dash (-)

$url = str_replace(' ','-',$url);

I want only letters, numbers and dash (-) allowed on the URL.

Let me know the tricks.

A: 

Is there a reason you only want a subset of what's allowed in a URL?

Have you thought about just using urlencode()?

acrosman
+2  A: 

Your code is replacing all spaces with a dash, have a look at the documentation of str_replace().

I would use a regular expression for the actual task:

preg_replace('/[^a-z0-9-]/i', '', $url);
soulmerge
Doesn't the dash '-' need escaping, ie, '\-' ?
karim79
yeah that I wanted.. but how to keep the spaces to dash? example on url http://domain.com/how about younow the preg_replace('/[^a-z0-9-]/i', '', $url); will made the link to be http://domain.com/howaboutyouI need it to be http://domain.com/how-about-youLet me know :)
bob
@bob - see the function i posted below.
benlumley
No, you don't need to escape the dash if it is the first or the last character in brackets
soulmerge
+2  A: 

Do you want this for generating slug?

Then you can do something like this:

$slugified = preg_replace('/[^-a-z0-9]+/i', '-', strtolower(trim($url)));

It will strip leading and trailing whitespace first, convert the string to lowercase, then replace all non-word characters (not a-z, 0-9 or -) with a single -

A    Beautiful *# Day will become a-beautiful-day

Remove strtolower() if you don't mind uppercase letters in the slug.

Imran
beautiful! thanks imran.
bob
I replaced [^\w] with [^-a-z0-9], as the previous would also allow _ along with a-z, 0-9 and -
Imran
how about only allowed the dash if has a word before and after? now it's allowed /-beautiful and /beautiful-
bob
Nice one-liner! However this doesn't account for special UTF-8 characters such as é, è, á etc. To enable this, you'll need iconv, or a more advanced script like http://stackoverflow.com/questions/868163/strreplace/868275#868275
Mathias Bynens
@bob: the easiest solution would be to use trim() to strip leading and trailing - from $slugified
Imran
The best answer is the one posted by Mathias Bynens. This will not work with accents and other special characters.
Keyne
A: 

Sounds like you want to generate "slugs" for use in urls?

EG:

lala.com/user/12/user-name

You want to generate the user-name bit from something like "Ben Lumley" ?

I've been using this:

static public function slugify($text)
{ 
// replace non letter or digits by -
$text = preg_replace('~[^\\pL\d]+~u', '-', $text);

// trim
$text = trim($text, '-');

// transliterate
$text = iconv('utf-8', 'us-ascii//TRANSLIT', $text);

// lowercase
$text = strtolower($text);

// remove unwanted characters
$text = preg_replace('~[^-\w]+~', '', $text);

if (empty($text))
{
  return 'n-a';
}

return $text;

}

Its from the symfony jobeet tutorial - but its just php.

http://www.symfony-project.org/jobeet/1_2/Propel/en/

Here's the unit tests that go with it, they show what it converts:

$t->is(Jobeet::slugify('Sensio'), 'sensio', '::slugify() converts all characters to lower case');
$t->is(Jobeet::slugify('sensio labs'), 'sensio-labs', '::slugify() replaces a white space by a -');
$t->is(Jobeet::slugify('sensio   labs'), 'sensio-labs', '::slugify() replaces several white spaces by a single -');
$t->is(Jobeet::slugify('  sensio'), 'sensio', '::slugify() removes - at the beginning of a string');
$t->is(Jobeet::slugify('sensio  '), 'sensio', '::slugify() removes - at the end of a string');
$t->is(Jobeet::slugify('paris,france'), 'paris-france', '::slugify() replaces non-ASCII characters by a -');
benlumley
nice mate.. I'll keep this one. thanks
bob
+2  A: 

To generate slugs from any string (including strings with crazy UTF-8 characters), I use the following (taken from the WordPress source code). I realise it requires a little more code than the other answers posted here, but this is by far the most robust and complete solution to generating slugs automatically.

First, we need a remove_accents() function to convert all accent characters to ASCII characters, e.g. turn á into a.

/**
 * Converts all accent characters to ASCII characters.
 *
 * If there are no accent characters, then the string given is just returned.
 *
 * @param string $string Text that might have accent characters
 * @return string Filtered string with replaced "nice" characters.
 */
function remove_accents($string) {
 if (!preg_match('/[\x80-\xff]/', $string))
  return $string;
 if (seems_utf8($string)) {
  $chars = array(
  // Decompositions for Latin-1 Supplement
  chr(195).chr(128) => 'A', chr(195).chr(129) => 'A',
  chr(195).chr(130) => 'A', chr(195).chr(131) => 'A',
  chr(195).chr(132) => 'A', chr(195).chr(133) => 'A',
  chr(195).chr(135) => 'C', chr(195).chr(136) => 'E',
  chr(195).chr(137) => 'E', chr(195).chr(138) => 'E',
  chr(195).chr(139) => 'E', chr(195).chr(140) => 'I',
  chr(195).chr(141) => 'I', chr(195).chr(142) => 'I',
  chr(195).chr(143) => 'I', chr(195).chr(145) => 'N',
  chr(195).chr(146) => 'O', chr(195).chr(147) => 'O',
  chr(195).chr(148) => 'O', chr(195).chr(149) => 'O',
  chr(195).chr(150) => 'O', chr(195).chr(153) => 'U',
  chr(195).chr(154) => 'U', chr(195).chr(155) => 'U',
  chr(195).chr(156) => 'U', chr(195).chr(157) => 'Y',
  chr(195).chr(159) => 's', chr(195).chr(160) => 'a',
  chr(195).chr(161) => 'a', chr(195).chr(162) => 'a',
  chr(195).chr(163) => 'a', chr(195).chr(164) => 'a',
  chr(195).chr(165) => 'a', chr(195).chr(167) => 'c',
  chr(195).chr(168) => 'e', chr(195).chr(169) => 'e',
  chr(195).chr(170) => 'e', chr(195).chr(171) => 'e',
  chr(195).chr(172) => 'i', chr(195).chr(173) => 'i',
  chr(195).chr(174) => 'i', chr(195).chr(175) => 'i',
  chr(195).chr(177) => 'n', chr(195).chr(178) => 'o',
  chr(195).chr(179) => 'o', chr(195).chr(180) => 'o',
  chr(195).chr(181) => 'o', chr(195).chr(182) => 'o',
  chr(195).chr(182) => 'o', chr(195).chr(185) => 'u',
  chr(195).chr(186) => 'u', chr(195).chr(187) => 'u',
  chr(195).chr(188) => 'u', chr(195).chr(189) => 'y',
  chr(195).chr(191) => 'y',
  // Decompositions for Latin Extended-A
  chr(196).chr(128) => 'A', chr(196).chr(129) => 'a',
  chr(196).chr(130) => 'A', chr(196).chr(131) => 'a',
  chr(196).chr(132) => 'A', chr(196).chr(133) => 'a',
  chr(196).chr(134) => 'C', chr(196).chr(135) => 'c',
  chr(196).chr(136) => 'C', chr(196).chr(137) => 'c',
  chr(196).chr(138) => 'C', chr(196).chr(139) => 'c',
  chr(196).chr(140) => 'C', chr(196).chr(141) => 'c',
  chr(196).chr(142) => 'D', chr(196).chr(143) => 'd',
  chr(196).chr(144) => 'D', chr(196).chr(145) => 'd',
  chr(196).chr(146) => 'E', chr(196).chr(147) => 'e',
  chr(196).chr(148) => 'E', chr(196).chr(149) => 'e',
  chr(196).chr(150) => 'E', chr(196).chr(151) => 'e',
  chr(196).chr(152) => 'E', chr(196).chr(153) => 'e',
  chr(196).chr(154) => 'E', chr(196).chr(155) => 'e',
  chr(196).chr(156) => 'G', chr(196).chr(157) => 'g',
  chr(196).chr(158) => 'G', chr(196).chr(159) => 'g',
  chr(196).chr(160) => 'G', chr(196).chr(161) => 'g',
  chr(196).chr(162) => 'G', chr(196).chr(163) => 'g',
  chr(196).chr(164) => 'H', chr(196).chr(165) => 'h',
  chr(196).chr(166) => 'H', chr(196).chr(167) => 'h',
  chr(196).chr(168) => 'I', chr(196).chr(169) => 'i',
  chr(196).chr(170) => 'I', chr(196).chr(171) => 'i',
  chr(196).chr(172) => 'I', chr(196).chr(173) => 'i',
  chr(196).chr(174) => 'I', chr(196).chr(175) => 'i',
  chr(196).chr(176) => 'I', chr(196).chr(177) => 'i',
  chr(196).chr(178) => 'IJ',chr(196).chr(179) => 'ij',
  chr(196).chr(180) => 'J', chr(196).chr(181) => 'j',
  chr(196).chr(182) => 'K', chr(196).chr(183) => 'k',
  chr(196).chr(184) => 'k', chr(196).chr(185) => 'L',
  chr(196).chr(186) => 'l', chr(196).chr(187) => 'L',
  chr(196).chr(188) => 'l', chr(196).chr(189) => 'L',
  chr(196).chr(190) => 'l', chr(196).chr(191) => 'L',
  chr(197).chr(128) => 'l', chr(197).chr(129) => 'L',
  chr(197).chr(130) => 'l', chr(197).chr(131) => 'N',
  chr(197).chr(132) => 'n', chr(197).chr(133) => 'N',
  chr(197).chr(134) => 'n', chr(197).chr(135) => 'N',
  chr(197).chr(136) => 'n', chr(197).chr(137) => 'N',
  chr(197).chr(138) => 'n', chr(197).chr(139) => 'N',
  chr(197).chr(140) => 'O', chr(197).chr(141) => 'o',
  chr(197).chr(142) => 'O', chr(197).chr(143) => 'o',
  chr(197).chr(144) => 'O', chr(197).chr(145) => 'o',
  chr(197).chr(146) => 'OE',chr(197).chr(147) => 'oe',
  chr(197).chr(148) => 'R',chr(197).chr(149) => 'r',
  chr(197).chr(150) => 'R',chr(197).chr(151) => 'r',
  chr(197).chr(152) => 'R',chr(197).chr(153) => 'r',
  chr(197).chr(154) => 'S',chr(197).chr(155) => 's',
  chr(197).chr(156) => 'S',chr(197).chr(157) => 's',
  chr(197).chr(158) => 'S',chr(197).chr(159) => 's',
  chr(197).chr(160) => 'S', chr(197).chr(161) => 's',
  chr(197).chr(162) => 'T', chr(197).chr(163) => 't',
  chr(197).chr(164) => 'T', chr(197).chr(165) => 't',
  chr(197).chr(166) => 'T', chr(197).chr(167) => 't',
  chr(197).chr(168) => 'U', chr(197).chr(169) => 'u',
  chr(197).chr(170) => 'U', chr(197).chr(171) => 'u',
  chr(197).chr(172) => 'U', chr(197).chr(173) => 'u',
  chr(197).chr(174) => 'U', chr(197).chr(175) => 'u',
  chr(197).chr(176) => 'U', chr(197).chr(177) => 'u',
  chr(197).chr(178) => 'U', chr(197).chr(179) => 'u',
  chr(197).chr(180) => 'W', chr(197).chr(181) => 'w',
  chr(197).chr(182) => 'Y', chr(197).chr(183) => 'y',
  chr(197).chr(184) => 'Y', chr(197).chr(185) => 'Z',
  chr(197).chr(186) => 'z', chr(197).chr(187) => 'Z',
  chr(197).chr(188) => 'z', chr(197).chr(189) => 'Z',
  chr(197).chr(190) => 'z', chr(197).chr(191) => 's',
  // Euro Sign
  chr(226).chr(130).chr(172) => 'E',
  // GBP (Pound) Sign
  chr(194).chr(163) => '');
  $string = strtr($string, $chars);
 } else {
  // Assume ISO-8859-1 if not UTF-8
  $chars['in'] = chr(128).chr(131).chr(138).chr(142).chr(154).chr(158)
   .chr(159).chr(162).chr(165).chr(181).chr(192).chr(193).chr(194)
   .chr(195).chr(196).chr(197).chr(199).chr(200).chr(201).chr(202)
   .chr(203).chr(204).chr(205).chr(206).chr(207).chr(209).chr(210)
   .chr(211).chr(212).chr(213).chr(214).chr(216).chr(217).chr(218)
   .chr(219).chr(220).chr(221).chr(224).chr(225).chr(226).chr(227)
   .chr(228).chr(229).chr(231).chr(232).chr(233).chr(234).chr(235)
   .chr(236).chr(237).chr(238).chr(239).chr(241).chr(242).chr(243)
   .chr(244).chr(245).chr(246).chr(248).chr(249).chr(250).chr(251)
   .chr(252).chr(253).chr(255);
  $chars['out'] = "EfSZszYcYuAAAAAACEEEEIIIINOOOOOOUUUUYaaaaaaceeeeiiiinoooooouuuuyy";
  $string = strtr($string, $chars['in'], $chars['out']);
  $double_chars['in'] = array(chr(140), chr(156), chr(198), chr(208), chr(222), chr(223), chr(230), chr(240), chr(254));
  $double_chars['out'] = array('OE', 'oe', 'AE', 'DH', 'TH', 'ss', 'ae', 'dh', 'th');
  $string = str_replace($double_chars['in'], $double_chars['out'], $string);
 }
 return $string;
}

The following function, seems_utf8(), will check if a string is UTF-8 encoded.

/**
 * Checks to see if a string is utf8 encoded.
 *
 * @author bmorel at ssi dot fr
 *
 * @param string $Str The string to be checked
 * @return bool True if $Str fits a UTF-8 model, false otherwise.
 */
function seems_utf8($Str) { # by bmorel at ssi dot fr
 $length = strlen($Str);
 for ($i = 0; $i < $length; $i++) {
  if (ord($Str[$i]) < 0x80) continue; # 0bbbbbbb
  elseif ((ord($Str[$i]) & 0xE0) == 0xC0) $n = 1; # 110bbbbb
  elseif ((ord($Str[$i]) & 0xF0) == 0xE0) $n = 2; # 1110bbbb
  elseif ((ord($Str[$i]) & 0xF8) == 0xF0) $n = 3; # 11110bbb
  elseif ((ord($Str[$i]) & 0xFC) == 0xF8) $n = 4; # 111110bb
  elseif ((ord($Str[$i]) & 0xFE) == 0xFC) $n = 5; # 1111110b
  else return false; # Does not match any model
  for ($j = 0; $j < $n; $j++) { # n bytes matching 10bbbbbb follow ?
   if ((++$i == $length) || ((ord($Str[$i]) & 0xC0) != 0x80))
   return false;
  }
 }
 return true;
}

The utf8_uri_encode() function encodes the Unicode values to be used in the slug.

/**
 * Encode the Unicode values to be used in the URI.
 *
 * @param string $utf8_string
 * @param int $length Max length of the string
 * @return string String with Unicode encoded for URI.
 */
function utf8_uri_encode($utf8_string, $length = 0) {
 $unicode = '';
 $values = array();
 $num_octets = 1;
 $unicode_length = 0;
 $string_length = strlen($utf8_string);
 for ($i = 0; $i < $string_length; $i++) {
  $value = ord($utf8_string[$i]);
  if ($value < 128) {
   if ($length && ($unicode_length >= $length))
    break;
   $unicode .= chr($value);
   $unicode_length++;
  } else {
   if (count($values) == 0) $num_octets = ($value < 224) ? 2 : 3;
   $values[] = $value;
   if ($length && ($unicode_length + ($num_octets * 3)) > $length)
    break;
   if (count( $values ) == $num_octets) {
    if ($num_octets == 3) {
     $unicode .= '%' . dechex($values[0]) . '%' . dechex($values[1]) . '%' . dechex($values[2]);
     $unicode_length += 9;
    } else {
     $unicode .= '%' . dechex($values[0]) . '%' . dechex($values[1]);
     $unicode_length += 6;
    }
    $values = array();
    $num_octets = 1;
   }
  }
 }
 return $unicode;
}

Finally, we can declare the slug() function, which will generate a slug from any UTF-8 string:

/**
 * Sanitizes title, replacing whitespace with dashes.
 *
 * Limits the output to alphanumeric characters, underscore (_) and dash (-).
 * Whitespace becomes a dash.
 *
 * @param string $title The title to be sanitized.
 * @return string The sanitized title.
 */
function slug($title) {
 $title = strip_tags($title);
 // Preserve escaped octets.
 $title = preg_replace('|%([a-fA-F0-9][a-fA-F0-9])|', '---$1---', $title);
 // Remove percent signs that are not part of an octet.
 $title = str_replace('%', '', $title);
 // Restore octets.
 $title = preg_replace('|---([a-fA-F0-9][a-fA-F0-9])---|', '%$1', $title);
 $title = remove_accents($title);
 if (seems_utf8($title)) {
  if (function_exists('mb_strtolower')) {
   $title = mb_strtolower($title, 'UTF-8');
  }
  $title = utf8_uri_encode($title, 200);
 }
 $title = strtolower($title);
 $title = preg_replace('/&.+?;/', '', $title); // kill entities
 $title = preg_replace('/[^%a-z0-9 _-]/', '', $title);
 $title = preg_replace('/\s+/', '-', $title);
 $title = preg_replace('|-+|', '-', $title);
 $title = trim($title, '-');
 return $title;
}

After this, you can simply use the slug() function to sluggify anything.

<?php
// The following line of code would echo 'internationalization-is-awesome'
echo slug('Iñtërnâtiônàlizætiøn is awesome');
?>
Mathias Bynens
thanks mate. noted.
bob