我有一个复杂的HTML字符串,类似于:
some text <blockquote>main text<blockquote>quotation</blockquote>end of main text</blockquote> some other text
使用 PHP,我想提取第一个块引用的全部内容,即使这包括其他块引用:
main text<blockquote>quotation</blockquote>end of main text
困难的部分是我需要停止在右侧结束标签处切割字符串 - 属于第一个开始标签的那个(在本例中为最后一个 - 但这必须动态确定)。
这是我到目前为止的尝试:
<?php
$some_html = "<blockquote>main text<blockquote>quotation</blockquote>end of main text</blockquote>";
$result = get_first_element_of_HTML_tag_name($some_html,'blockquote');
function get_first_element_of_HTML_tag_name($html_string,$tag_name) {
$h = strtolower($html_string);
$tag_open = "<" . $tag_name . ">";
$tag_close = "</" . $tag_name . ">";
$element_start = strpos($h,$tag_open)+strlen($tag_open);
$element_end = strpos($h,$tag_close);
$element = substr($h,$element_start,$element_end); // cut to first closing tag
$element_s = $element;
$i = 2;
while ( strpos($element_s,"<blockquote") !== false ) { // as long as substring contains another opening tag
// include another closing tag in the result
$element = substr($h,$element_start,nth_strpos($h,$element_end,$i));
$element_s = substr( $element_s, strpos($element_s,$tag_open)+strlen($tag_open), nth_strpos($element_s,strpos($element_s,$tag_close),$i));
$i++;
}
return $hs; // return complete first element with $tag_name
}
function nth_strpos($str, $substr, $n) {
$ct = 0;
$pos = 0;
while ( ( $pos = strpos($str, $substr, $pos) ) !== false ) {
if (++$ct == $n) {
return $pos;
}
$pos++;
}
return false;
}
php?>
$result返回空白...
我认为它卡在nth_strpos函数中的某个地方。
帮助甚至更简单的替代方案非常感谢!
正如Barmar所建议的,你可能应该使用DOM解析器。碰巧的是,PHP 5 附带了一个 DOM API,可以让您非常轻松地做到这一点。下面是一个示例:
$str = "some text <blockquote>main text<blockquote>quotation</blockquote>end of main text</blockquote> some other text";
$doc = new DOMDocument();
$doc->loadHTML($str);
$element = $doc->getElementsByTagName("blockquote")->item(0);
$innerHTML= '';
foreach ($element->childNodes as $child)
$innerHTML .= $doc->saveXML($child);
echo $innerHTML;
输出:
main text<blockquote>quotation</blockquote>end of main text