How to remove html special chars?
PhpHtml EncodePhp Problem Overview
I am creating a RSS feed file for my application in which I want to remove HTML tags, which is done by strip_tags. But strip_tags is not removing HTML special code chars:
& ©
etc.
Please tell me any function which I can use to remove these special code chars from my string.
Php Solutions
Solution 1 - Php
Either decode them using html_entity_decode or remove them using preg_replace:
$Content = preg_replace("/&#?[a-z0-9]+;/i","",$Content);
(From here)
EDIT: Alternative according to Jacco's comment
> might be nice to replace the '+' with > {2,8} or something. This will limit > the chance of replacing entire > sentences when an unencoded '&' is > present.
$Content = preg_replace("/&#?[a-z0-9]{2,8};/i","",$Content);
Solution 2 - Php
Use html_entity_decode to convert HTML entities.
You'll need to set charset to make it work correctly.
Solution 3 - Php
In addition to the good answers above, PHP also has a built-in filter function that is quite useful: filter-var.
To remove HMTL characters, use:
$cleanString = filter_var($dirtyString, FILTER_SANITIZE_STRING);
More info:
Solution 4 - Php
You may want take a look at htmlentities() and html_entity_decode() here
$orig = "I'll \"walk\" the <b>dog</b> now";
$a = htmlentities($orig);
$b = html_entity_decode($a);
echo $a; // I'll "walk" the <b>dog</b> now
echo $b; // I'll "walk" the <b>dog</b> now
Solution 5 - Php
This might work well to remove special characters.
$modifiedString = preg_replace("/[^a-zA-Z0-9_.-\s]/", "", $content);
Solution 6 - Php
If you want to convert the HTML special characters and not just remove them as well as strip things down and prepare for plain text this was the solution that worked for me...
function htmlToPlainText($str){
$str = str_replace(' ', ' ', $str);
$str = html_entity_decode($str, ENT_QUOTES | ENT_COMPAT , 'UTF-8');
$str = html_entity_decode($str, ENT_HTML5, 'UTF-8');
$str = html_entity_decode($str);
$str = htmlspecialchars_decode($str);
$str = strip_tags($str);
return $str;
}
$string = '<p>this is ( ) a test</p>
<div>Yes this is! & does it get "processed"? </div>'
htmlToPlainText($string);
// "this is ( ) a test. Yes this is! & does it get processed?"`
html_entity_decode w/ ENT_QUOTES | ENT_XML1 converts things like '
htmlspecialchars_decode converts things like &
html_entity_decode converts things like '<
and strip_tags removes any HTML tags left over.
EDIT - Added str_replace(' ', ' ', $str); and several other html_entity_decode() as continued testing has shown a need for them.
Solution 7 - Php
A plain vanilla strings way to do it without engaging the preg regex engine:
function remEntities($str) {
if(substr_count($str, '&') && substr_count($str, ';')) {
// Find amper
$amp_pos = strpos($str, '&');
//Find the ;
$semi_pos = strpos($str, ';');
// Only if the ; is after the &
if($semi_pos > $amp_pos) {
//is a HTML entity, try to remove
$tmp = substr($str, 0, $amp_pos);
$tmp = $tmp. substr($str, $semi_pos + 1, strlen($str));
$str = $tmp;
//Has another entity in it?
if(substr_count($str, '&') && substr_count($str, ';'))
$str = remEntities($tmp);
}
}
return $str;
}
Solution 8 - Php
What I have done was to use: html_entity_decode, then use strip_tags to removed them.
Solution 9 - Php
try this
<?php
$str = "\x8F!!!";
// Outputs an empty string
echo htmlentities($str, ENT_QUOTES, "UTF-8");
// Outputs "!!!"
echo htmlentities($str, ENT_QUOTES | ENT_IGNORE, "UTF-8");
?>
Solution 10 - Php
It looks like what you really want is:
function xmlEntities($string) {
$translationTable = get_html_translation_table(HTML_ENTITIES, ENT_QUOTES);
foreach ($translationTable as $char => $entity) {
$from[] = $entity;
$to[] = '&#'.ord($char).';';
}
return str_replace($from, $to, $string);
}
It replaces the named-entities with their number-equivalent.
Solution 11 - Php
<?php
function strip_only($str, $tags, $stripContent = false) {
$content = '';
if(!is_array($tags)) {
$tags = (strpos($str, '>') !== false
? explode('>', str_replace('<', '', $tags))
: array($tags));
if(end($tags) == '') array_pop($tags);
}
foreach($tags as $tag) {
if ($stripContent)
$content = '(.+</'.$tag.'[^>]*>|)';
$str = preg_replace('#</?'.$tag.'[^>]*>'.$content.'#is', '', $str);
}
return $str;
}
$str = '<font color="red">red</font> text';
$tags = 'font';
$a = strip_only($str, $tags); // red text
$b = strip_only($str, $tags, true); // text
?>
Solution 12 - Php
The function I used to perform the task, joining the upgrade made by schnaader is:
mysql_real_escape_string(
preg_replace_callback("/&#?[a-z0-9]+;/i", function($m) {
return mb_convert_encoding($m[1], "UTF-8", "HTML-ENTITIES");
}, strip_tags($row['cuerpo'])))
This function removes every html tag and html symbol, converted in UTF-8 ready to save in MySQL
Solution 13 - Php
You can try htmlspecialchars_decode($string). It works for me.
http://www.w3schools.com/php/func_string_htmlspecialchars_decode.asp
Solution 14 - Php
If you are working in WordPress and are like me and simply need to check for an empty field (and there are a copious amount of random html entities in what seems like a blank string) then take a look at:
sanitize_title_with_dashes( string $title, string $raw_title = '', string $context = 'display' )
Link to wordpress function page
For people not working on WordPress, I found this function REALLY useful to create my own sanitizer, take a look at the full code and it's really in depth!
Solution 15 - Php
$string = "äáčé";
$convert = Array(
'ä'=>'a',
'Ä'=>'A',
'á'=>'a',
'Á'=>'A',
'à'=>'a',
'À'=>'A',
'ã'=>'a',
'Ã'=>'A',
'â'=>'a',
'Â'=>'A',
'č'=>'c',
'Č'=>'C',
'ć'=>'c',
'Ć'=>'C',
'ď'=>'d',
'Ď'=>'D',
'ě'=>'e',
'Ě'=>'E',
'é'=>'e',
'É'=>'E',
'ë'=>'e',
);
$string = strtr($string , $convert );
echo $string; //aace
Solution 16 - Php
What If By "Remove HTML Special Chars" You Meant "Replace Appropriately"?
After all, just look at your example...
& ©
If you're stripping this for an RSS feed, shouldn't you want the equivalents?
" ", &, ©
Or maybe you don't exactly want the equivalents. Maybe you'd want to have just be ignored (to prevent too much space), but then have © actually get replaced. Let's work out a solution that solves anyone's version of this problem...
How to SELECTIVELY-REPLACE HTML Special Chars
The logic is simple: preg_match_all('/(&#[0-9]+;)/' grabs all of the matches, and then we simply build a list of matchables and replaceables, such as str_replace([searchlist], [replacelist], $term). Before we do this, we also need to convert named entities to their numeric counterparts, i.e., " " is unacceptable, but "�A0;" is fine. (Thanks to it-alien's solution to this part of the problem.)
Working Demo
In this demo, I replace { with "HTML Entity #123". Of course, you can fine-tune this to any kind of find-replace you want for your case.
Why did I make this? I use it with generating Rich Text Format from UTF8-character-encoded HTML.
See full working demo:
function FixUTF8($args) {
$output = $args['input'];
$output = convertNamedHTMLEntitiesToNumeric(['input'=>$output]);
preg_match_all('/(&#[0-9]+;)/', $output, $matches, PREG_OFFSET_CAPTURE);
$full_matches = $matches[0];
$found = [];
$search = [];
$replace = [];
for($i = 0; $i < count($full_matches); $i++) {
$match = $full_matches[$i];
$word = $match[0];
if(!$found[$word]) {
$found[$word] = TRUE;
$search[] = $word;
$replacement = str_replace(['&#', ';'], ['HTML Entity #', ''], $word);
$replace[] = $replacement;
}
}
$new_output = str_replace($search, $replace, $output);
return $new_output;
}
function convertNamedHTMLEntitiesToNumeric($args) {
$input = $args['input'];
return preg_replace_callback("/(&[a-zA-Z][a-zA-Z0-9]*;)/",function($m){
$c = html_entity_decode($m[0],ENT_HTML5,"UTF-8");
# return htmlentities($c,ENT_XML1,"UTF-8"); -- see update below
$convmap = array(0x80, 0xffff, 0, 0xffff);
return mb_encode_numericentity($c, $convmap, 'UTF-8');
}, $input);
}
print(FixUTF8(['input'=>"Oggi è un bel giorno"]));
Input:
>"Oggi è un bel giorno"
Output:
>Oggi HTML Entity #232 un belHTML Entity #160giorno