php截取html字符串自动补全html标签_PHP教程-PHP-Tutorial-php.cn

php截取html字符串自动补全html标签_PHP教程

WBOY

Freigeben： 2016-07-20 11:11:08

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文章来总结一下关于利用php截取html字符串自动补全html标签，实际开发中会经常碰到，很多人直接先strip_tags过滤掉html标签，但是就只剩下纯文本了，可读性非常差，下面是一个函数

代码如下

复制代码

/**
* 截取HTML,并自动补全闭合
* @param $html
* @param $length
* @param $end
*/
function subHtml($html,$length) {
$result = '';
$tagStack = array();
$len = 0;

$contents = preg_split("~(]+?>)~si",$html, -1,PREG_SPLIT_NO_EMPTY| PREG_SPLIT_DELIM_CAPTURE);
foreach($contents as $tag)
{
if (trim($tag)=="") continue;
if(preg_match("~]*?/>~si",$tag)){
$result .= $tag;
}else if(preg_match("~([a-z0-9]+)[^/>]*?>~si",$tag,$match)){
if($tagStack[count($tagStack)-1] == $match[1]){
array_pop($tagStack);
$result .= $tag;
}
}else if(preg_match("~]*?>~si",$tag,$match)){
array_push($tagStack,$match[1]);
$result .= $tag;
}else if(preg_match("~~si",$tag)){
$result .= $tag;
}else{
if($len + mstrlen($tag) $result .= $tag;
$len += mstrlen($tag);
}else {
$str = msubstr($tag,0,$length-$len+1);
$result .= $str;
break;
}

}
}
while(!empty($tagStack)){
$result .= ''.array_pop($tagStack).'>';
}
return $result;
}

/**
* 截取中文字符串
* @param $string 字符串
* @param $start 起始位
* @param $length 长度
* @param $charset 编码
* @param $dot 附加字串
*/
function msubstr($string, $start, $length,$dot='',$charset = 'UTF-8') {
$string = str_replace(array('&', '"', '<', '>',' '), array('&', '"', '',' '), $string);
if(strlen($string) return $string;
}

if(strtolower($charset) == 'utf-8') {
$n = $tn = $noc = 0;
while($n $t = ord($string[$n]);
if($t == 9 || $t == 10 || (32 $tn = 1; $n++;
} elseif(194 $tn = 2; $n += 2;
} elseif(224 $tn = 3; $n += 3;
} elseif(240 $tn = 4; $n += 4;
} elseif(248 $tn = 5; $n += 5;
} elseif($t == 252 || $t == 253) {
$tn = 6; $n += 6;
} else {
$n++;
}
$noc++;
if($noc >= $length) {
break;
}
}
if($noc > $length) {
$n -= $tn;
}
$strcut = substr($string, 0, $n);
} else {
for($i = 0; $i $strcut .= ord($string[$i]) > 127 ? $string[$i].$string[++$i] : $string[$i];
}
}

return $strcut.$dot;
}

/**
* 取得字符串的长度，包括中英文。
*/
function mstrlen($str,$charset = 'UTF-8'){
if (function_exists('mb_substr')) {
$length=mb_strlen($str,$charset);
} elseif (function_exists('iconv_substr')) {
$length=iconv_strlen($str,$charset);
} else {
preg_match_all("/[x01-x7f]|[xc2-xdf][x80-xbf]|xe0[xa0-xbf][x80-xbf]|[xe1-xef][x80-xbf][x80-xbf]|xf0[x90-xbf][x80-xbf][x80-xbf]|[xf1-xf7][x80-xbf][x80-xbf][x80-xbf]/", $text, $ar);
$length=count($ar[0]);
}
return $length;
}

实例

代码如下

复制代码

* @param 要截取的HTML $str
* @param 截取的数量 $num
* @param 是否需要加上更多 $more
* @return 截取串
*/
function phpos_chsubstr_ahtml($str,$num,$more=false)
{
    $leng=strlen($str);
      if($num>=$leng)      return $str;
    $word=0;
    $i=0;                        /** 字符串指针 **/
    $stag=array(array());        /** 存放开始HTML的标志 **/
    $etag=array(array());        /** 存放结束HTML的标志 **/
    $sp = 0;
    $ep = 0;
      while($word!=$num)
      {

          if(ord($str[$i])>128)
          {
            //$re.=substr($str,$i,3);
            $i+=3;
            $word++;
          }
          else if ($str[$i]=='          {
              if ($str[$i+1] == '!')
              {
                $i++;
                  continue;
              }

              if ($str[$i+1]=='/')
              {
                $ptag=&$etag ;
                $k=&$ep;
                $i+=2;
              }
              else
              {
                $ptag=&$stag;
                $i+=1;
                $k=&$sp;
              }

              for(;$i              {
                  if ($str[$i] == ' ')
                  {
                    $ptag[$k] = implode('',$ptag[$k]);
                    $k++;
                      break;
                  }
                  if ($str[$i] != '>')
                  {
                    $ptag[$k][]=$str[$i];
                      continue;
                  }
                  else
                  {
                    $ptag[$k] = implode('',$ptag[$k]);
                    $k++;
                      break;
                  }
              }
            $i++;
              continue;
          }
          else
          {
            //$re.=substr($str,$i,1);
            $word++;
            $i++;
          }
      }
      foreach ($etag as $val)
      {
        $key1=array_search($val,$stag);
          if ($key1 !== false)          unset($stag[$key]);
      }
      foreach ($stag as $key => $val)
      {
          if (in_array($val,array('br','img'))) unset($stag[$key1]);
      }
    array_reverse($stag);
    $ends = ''.implode('>',$stag).'>';
    $re = substr($str,0,$i).$ends;
      if($more)    $re.='...';
      return $re;
}

PHP截取字符串,生成文章摘要
我们在写BLOG时经常需要显示文章前一部分，但是又怕不恰当截断破坏封闭标签以造成整个文档结构破坏

代码如下

复制代码

function text_zhaiyao($text,$length){ //文章摘要生成函数 $test:内容 $length:摘要长度
    global $Briefing_Length;
    mb_regex_encoding("UTF-8");
    if(mb_strlen($text)     $Foremost = mb_substr($text, 0, $length);
    $re = "    (P|DIV|H1|H2|H3|H4|H5|H6|ADDRESS|PRE|TABLE|TR|TD|TH|INPUT|SELECT|TEXTAREA|OBJECT|A|UL|OL|LI|
    BASE|META|LINK|HR|BR|PARAM|IMG|AREA|INPUT|SPAN)[^>]*(>?)";
    $Single = "/BASE|META|LINK|HR|BR|PARAM|IMG|AREA|INPUT|BR/i";

    $Stack = array(); $posStack = array();

    mb_ereg_search_init($Foremost, $re, 'i');

    while($pos = mb_ereg_search_pos()){
    $match = mb_ereg_search_getregs();
    /* [Child-matching Formulation]:

    $matche[1] : A "/" charactor indicating whether current "<...>" Friction is
    Closing Part
    $matche[2] : Element Name.
    $matche[3] : Right > of a "<...>" Friction
    */
    if($match[1]==""){
    $Elem = $match[2];
    if(mb_eregi($Single, $Elem) && $match[3] !=""){
    continue;
    }