Php 过滤html标签，只保留指定属性

湖中沉

1. function parse($m){  return call_user_func("parse{$m[1]}",$m[3]);}
   
2. 
   
3. function parsea($str,$attr=array('href')){  return '<a '.parseattr($str,$attr).'>';}
   
4. 
   
5. function parsep($str,$attr=array('align','id')){  return '<p '.parseattr($str,$attr).'>';}
   
6. 
   
7. function parseattr($str,$attr=array()){  if(empty($attr))return '';  $attrs=explode(' ', $str);  foreach ($attrs as $k=>$v)  {    foreach ($attr as $a)    {      if(strtolower(substr($v, 0,strlen($a)).'=')===strtolower($a.'='))      {        continue 2;      }    }    unset($attrs[$k]);  }  return implode(' ', $attrs);}
   
8. 
   
9. function myreplace($str){  $reg='/<(p|a)(\s+)(.*?[^>])>/is';
   
10. return (preg_replace_callback($reg,'parse',$str));}
    
11. 
    
12. $str='<p align="center" class="asd" id="qwe">adf<a href="#" class="asd" id="qwe" align="center">123</a><div id="iii" style="color:red">4<p id="ww">5</p>6</div></p>';
    
13. 
    
14. echo myreplace(strip_tags($str,'<p><a>'));
    
15. 
    
16. //<p align="center" id="qwe">adf<a href="#">123</a>4<p id="ww">5</p>6</p>
    
17. 
    
18. 
    
19. 重构版:Only for php5.3
    
20. 
    
21. function parseattr($str,$tag,$attr=array())
    
22. {
    
23. if(empty($attr))return '';
    
24. $attrs=explode(' ', $str[2]);
    
25. foreach ($attrs as $k=>$v)
    
26. {
    
27. foreach ($attr as $a)
    
28. {
    
29. if(strtolower(substr($v, 0,strlen($a)).'=')==strtolower($a.'='))
    
30. {
    
31. continue 2;
    
32. }
    
33. }
    
34. unset($attrs[$k]);
    
35. }
    
36. return '< '.$tag.' '.implode(' ', $attrs).'>';
    
37. }
    
38. function myreplace($str,$tag,$attr=array())
    
39. {
    
40. $reg='/< '.$tag.'(\s+)(.*?[^>])>/is';
    
41. return (preg_replace_callback($reg,function ($v) use ($attr,$tag){return parseattr($v,$tag,$attr);},$str));
    
42. }
    
43. 
    
44. $str='<p align="center" class="asd" id="qwe">adf<a href="#" class="asd" id="qwe" align="center" rel="nofollow">123<div id="iii" style="color:red">4<p id="ww">56';
    
45. 
    
46. $str=strip_tags($str,'<p><a>');
    
47. $str=myreplace($str,'a',array('href'));
    
48. $str=myreplace($str,'p',array('align','id'));
    
49. echo $str;

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