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:
<?php
/**
* 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) == "") & nbsp;
continue;
if (preg_match("~<([a-z0-9]+)[^/>]*?/>~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("~<([a-z0-9]+)[^/>]*?>~si", $tag, $match)) {
array_push($tagStack, $match[1]);
$result.= $tag;
} else if (preg_match("~<!--.*?-->~si", $tag)) {
$result.= $tag;
} else {
if ($len + mstrlen($tag) < $length) {
$result.= $tag;
$len+= mstrlen($tag);
} else {
$str = msubstr($tag, 0, $length - $len + 1);
$result.= $str;
break;
}
}
}
while (!emptyempty($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) <= $length) {
return $string;
}
if (strtolower($charset) == 'utf-8') {
$n = $tn = $noc = 0;
while ($n < strlen($string)) {
$t = ord($string[$n]);
if ($t == 9 || $t == 10 || (32 <= $t && $t <= 126)) {
$tn = 1;
$n++;
} elseif (194 <= $t && $t <= 223) {
$tn = 2;
$n+= 2;
} elseif (224 <= $t && $t <= 239) {
$tn = 3;
$n+= 3;
} elseif (240 <= $t && $t <= 247) {
$tn = 4;
$n+= 4;
} elseif (248 <= $t && $t <= 251) {
$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 < $length; $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); & nbsp;
$length = count($ar[0]);
}
return $length;
}
?>实例,代码如下:
<?php
/*
* @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
*/
$leng = strlen($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 < $leng; $i++) {
if ($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 $re;
}
?>PHP截取字符串,生成文章摘要,我们在写BLOG时经常需要显示文章前一部分,但是又怕不恰当截断破坏封闭标签以造成整个文档结构破坏,代码如下:
<?php
function text_zhaiyao($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) <= $length) return $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;
}
?>本文地址：
转载随意，但请附上文章地址:-)
