Removing html tags in a php string

Visto en http://php.net/manual/en/function.strip-tags.php 

strip_tags

(PHP 4, PHP 5)

strip_tags — Strip HTML and PHP tags from a string

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Description

string strip_tags ( string $str [, string $allowable_tags ] )

This function tries to return a string with all NUL bytes, HTML and PHP tags stripped from a given str. It uses the same tag stripping state machine as the fgetss() function.

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Parameters

str

The input string.

allowable_tags

You can use the optional second parameter to specify tags which should not be stripped.

Note:

HTML comments and PHP tags are also stripped. This is hardcoded and can not be changed with allowable_tags.

Note:

This parameter should not contain whitespace. strip_tags() sees a tag as a case-insensitive string between < and the first whitespace or >. It means that strip_tags(" ", " ") returns an empty string.

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Return Values

Returns the stripped string.

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Changelog

Version	Description
5.0.0	strip_tags() is now binary safe
4.3.0	HTML comments are now always stripped

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Examples

Example #1 strip_tags() example

$text = 'Test paragraph.
 Other text';
echo strip_tags($text);
echo "\n";
// Allow  and 
echo strip_tags($text, '');?>

The above example will output:

Test paragraph. Other textTest paragraph.
 Other text

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Notes

Warning

Because strip_tags() does not actually validate the HTML, partial or broken tags can result in the removal of more text/data than expected.

Warning

This function does not modify any attributes on the tags that you allow using allowable_tags, including the style and onmouseover attributes that a mischievous user may abuse when posting text that will be shown to other users.

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See Also

• htmlspecialchars() - Convert special characters to HTML entities

stripcslashes strcspn

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[edit] Last updated: Fri, 14 Oct 2011

 

add a note User Contributed Notes strip_tags

dhgouveia at hotmail dot com 10-Oct-2011 11:09

this is just for strip the inside tags

$allow = '

• ';
  
  $str = '
  Paragraph
  Bold
  Red

  Header

  ';
  
  $result = strip_tags($str,$allow);
  $result = clean_inside_tags($result,$allow);
  
  echo ''</span><span class="keyword">.</span><span class="default">$result</span><span class="keyword">.</span><span class="string">'';
  
  //Clean the inside of the tags
  function clean_inside_tags($txt,$tags){
     
      preg_match_all("/<([^>]+)>/i",$tags,$allTags,PREG_PATTERN_ORDER);
  
      foreach ($allTags[1] as $tag){
          $txt = preg_replace("/<".$tag."[^>]*>/i","<".$tag.">",$txt);
      }
  
      return $txt;
  }
  
  ?>