有没有一种方法可以在字符串中剪裁标签两侧的空白，从而实现：
<p> Lorem ipsum dolor sit amet.</p> <p>Lorem ipsum dolor sit amet.</p>
被转换成这样：
<p>Lorem ipsum dolor sit amet.</p><p>Lorem ipsum dolor sit amet.</p>
答案 0 :(得分：1)
如果您只是在寻找简单的修剪，可以使用str_replace更改所有适当的空格。
str_replace('<p> ', '<p>'); # repeat for whatever you need.
另一方面，您可以使用preg_replace接受正则表达式，这样就可以使它像单遍一样复杂。有关更多信息，请参见https://www.php.net/manual/en/function.preg-replace.php。
答案 1 :(得分：1)
我给这个人写了另一个问题（可能是一年前< on Apr 6, 2018）：PHP How to remove break line \n \r \t from string but keep intact content inside textarea
它在我的gitHub上
https://github.com/ArtisticPhoenix/MISC/blob/master/Lexers/HtmlMinifier.php
完整代码：
<?php
class Minifier{
/**
* not within an HTML tag
* @var string
*/
const MODE_CLOSED = 'closed';
/**
* withing an html tag
* @var string
*/
const MODE_OPEN = 'open';
/**
* ignore whitespace tell the next close tag
* @var string
*/
const MODE_IGNORE = 'ignore';
/**
* HTML tags to ingnore whitespace on
* @var array
*/
protected $ignoreTags = [
'script',
'style'
];
/**
* Regex tokens
* @var array
*/
protected $tokens = [
'T_EOF' => '\Z', //matches end of string
'T_COMMENT' => '<(?=!--).+(?<=--)>', //matches only <!-- comment -->
'T_OPEN_TAG' => '<(?!\/)[^>]+(?<!\/)>', //matches only <tag ... >
'T_CLOSE_TAG' => '<(?=\/)[^>]+(?<!\/)>', //matches only </tag ..>
'T_INLINE_TAG' => '<(?!\/)[^>]+(?<=\/)>', //matches only <tag ... />
'T_ENCAPSED_STRING' => '(?P<Q>\'|").*?(?<!\\\\)\k<Q>', //matches "foo\"bar" or 'foo\'bar'
'T_STRING' => '[-\w]+', //matches -0-9a-z
'T_WHITESPACE' => '\s+', //matches \s\t\r\n
'T_UNKNOWN' => '.+?' //matches everything else
];
/**
*
* @param mixed $ignoreTags
* @param mixed $removeTags
*/
public function __construct($addTags = [], $removeTags = []){
$this->unsetTag($removeTags);
$this->setTag($addTags);
}
/**
*
* @param mixed $ignoreTags
* @return bool
*/
public function issetTag($ignoreTags)
{
return in_array($ignoreTags,$this->ignoreTags);
}
/**
* Set one or more tags
*
* @param mixed $ignoreTags
*/
public function setTag($ignoreTags)
{
if(empty($ignoreTags)) return;
if(!is_array($ignoreTags)) $ignoreTags = [$ignoreTags];
$this->ignoreTags = array_unique(array_merge($this->ignoreTags, $ignoreTags));
}
/**
* Set one or more tags
*
* @param mixed $ignoreTags
*/
public function unsetTag($ignoreTags)
{
if(empty($ignoreTags)) return;
if(!is_array($ignoreTags)) $ignoreTags = [$ignoreTags];
$this->ignoreTags = array_diff($this->ignoreTags, $ignoreTags);
}
/**
*
* @param string $html
* @return string
*/
public function minify($html)
{
$token_stream = $this->lexTokens($html);
return $this->parseTokens($token_stream);
}
/**
*
* @param string $html
* @return boolean
*/
public function lexTokens($html)
{
$types = array_keys($this->tokens);
$patterns = [];
$token_stream = [];
$result = false;
foreach ($this->tokens as $k=>$v){
$patterns[] = "(?P<$k>$v)";
}
$pattern = "/".implode('|', $patterns)."/is";
if (preg_match_all($pattern, $html, $matches, PREG_OFFSET_CAPTURE)) {
//print_r($matches);
foreach ($matches[0] as $key => $value) {
$match = [];
foreach ($types as $type) {
$match = $matches[$type][$key];
if (is_array($match) && $match[1] != -1) {
break;
}
}
$tok = [
'content' => $match[0],
'type' => $type,
'offset' => $match[1]
];
$token_stream[] = $tok;
}
}
return $token_stream;
}
/**
*
* @param array $token_stream - pass by refrence
* @throws Exception
* @return string
*/
protected function parseTokens( array &$token_stream )
{
$mode = 'closed';
$string = '';
$result = '';
while($current = current($token_stream)){
$content = $current['content'];
$type = $current['type'];
next($token_stream);
switch($type){
case 'T_COMMENT':
//remove comments
break;
case 'T_OPEN_TAG':
if(strlen($string)){
//add trimmed string to result, reset string.
if($mode == 'ignore'){
$result .= $string;
}else{
$result .= trim($string);
}
$string = '';
}
//clean
$content = $this->cleanTag($content);
if($this->isIgnoredTag($content)){
//indicate ignore whitespace
$mode = 'ignore';
}else{
//indicate a tag is open
$mode = 'open';
}
$result .= $content;
break;
case 'T_INLINE_TAG':
case 'T_CLOSE_TAG':
if(strlen($string)){
//add trimmed string to result, reset string.
if($mode == 'ignore'){
$result .= $string;
}else{
$result .= trim($string);
}
$string = '';
}
//clean
$content = $this->cleanTag($content);
//add content to result
$result .= $content;
//indicate a tag is closed
$mode = 'closed';
break;
case 'T_ENCAPSED_STRING':
case 'T_STRING':
case 'T_UNKNOWN':
switch ($mode){
case 'ignore':
case 'open':
case 'closed':
//add content to string (not result)
$string .= $content;
break;
default:
print_r($result);
throw new Exception("Unknown Mode:$mode for $type value $content", 1002);
}
break;
case 'T_WHITESPACE':
switch ($mode){
case 'closed':
//remove whitespace between tags.
break;
case 'open':
//add only on space ot string no matter how many we find
$string .= ' ';
break;
case 'ignore':
$string .= $content;
break;
default:
print_r($result);
throw new Exception("Unknown Mode:$mode for $type value $content", 1002);
}
break;
case 'T_EOF': return $result;
default:
print_r($current);
print_r($result);
throw new Exception("Unknown token $type value $content", 1001);
}
}
}
/**
*
* @param string $tag
* @return string
*/
protected function cleanTag($tag)
{
return preg_replace([
'/\s{2,}/',
'/^<\s+/',
'/^<\/\s+/',
'/\s+>$/',
'/\s\/>$/'
],[
' ',
'<',
'</',
'>',
'/>',
], $tag);
}
/**
*
* should be cleand with cleanTag first.
*
* @param string $htmlTag
* @param array $ignoreTags
* @throws Exception
* @return boolean
*/
protected function isIgnoredTag($htmlTag)
{
if(!preg_match('/<\/?([a-z]+)\b/i', $htmlTag, $tagName))
throw new Exception("Cound not parse HTML tag name $htmlTag", 1000);
return in_array($tagName[1],$this->ignoreTags);
}
}
包含的示例
$html = <<<HTML
<style type="text/css" >
.body, div
{
background-color: #CCC;
}
#someid
{
color: #fff;
}
</style>
<p> Lorem ipsum dolor sit amet.</p> <p>Lorem ipsum dolor sit amet.</p>
<p>
This is
a
stupid p tag
that has
all kinds of extra space in it.
</p>
< span id="foo" >Insert title< / span ><!-- extra space in this tag, comments are removed -->
<
br
><!-- new line tag -->
<br / ><!-- spaced inline tag -->
<form class="some class other another">
<div class="title-box">
<div class="title">Questions</div>
</div>
<div class="content">
<div>
<span>Insert title</span>
<div>
<input name="question" placeholder="Insert some text here" type="text" />
</div>
</div>
<div class="margin-t-10">
<label>Insert BIO</label>
<div>
<textarea name="bio" class="textarea-content">This is first line text
This is second line text
more lines...</textarea>
</div>
</div>
<div class="description">
<label>Insert description here</label>
<div>
<textarea data-something name="description" class="textarea-content other class">
Line one
line two
have some tabulation here to keep...
another line...</textarea>
</div>
</div>
</div>
</form>
<script type="text/javascript">
(function($){
$(document).ready(function(){
var div = "<div>foobar</div>";
var span = '<span>span</span>';
$('textarea[name="bio"]').focuus();
$(form).on('submit', function(e){
e.preventDefault();
return false;
}
});
})(jQuery);
</script>
HTML;
运行它：
echo (new Minifier('textarea'))->minify($html);
这里有一个示例，您可以在这里尝试：Sandbox我实际上在其中添加了一点HTML，大声笑。但是，这种测试故意被弄乱了，超出了正常情况。
输出
<style type="text/css">
.body, div
{
background-color: #CCC;
}
#someid
{
color: #fff;
}
</style><p>Lorem ipsum dolor sit amet.</p><p>Lorem ipsum dolor sit amet.</p><p>This is a stupid p tag that has all kinds of extra space in it.</p><span id="foo">Insert title</span><form class="some class other another"><div class="title-box"><div class="title">Questions</div></div><div class="content"><div><span>Insert title</span><div><input name="question" placeholder="Insert some text here" type="text"/></div></div><div class="margin-t-10"><label>Insert BIO</label><div><textarea name="bio" class="textarea-content">This is first line text
This is second line text
more lines...</textarea></div></div><div class="description"><label>Insert description here</label><div><textarea data-something name="description" class="textarea-content other class">
Line one
line two
have some tabulation here to keep...
another line...</textarea></div></div></div></form><script type="text/javascript">
(function($){
$(document).ready(function(){
var div = "<div>foobar</div>";
var span = '<span>span</span>';
$('textarea[name="bio"]').focuus();
$(form).on('submit', function(e){
e.preventDefault();
return false;
}
});
})(jQuery);
</script>
在上面的输出中，script style和textarea并不是有意缩小的。缩小这些[script style]将需要额外的工作和规则，因为它们与HTML不同（它们本身就是语言）。这是默认的两个：
protected $ignoreTags = [
'script',
'style'
];
然后textarea在构造函数new Minifier('textarea')中传递。对于textarea，其中的内容对空白非常敏感，因为它是“值”字段的一部分，因此我们不想修改它，这就是问题所在和原因。对您来说，这只是个不错的“奖金”。
我无法授予它在每种情况下都可以在每段HTML上使用的功能
但是欢迎您对其进行修改