使用正则表达式删除HTML标记

I need to convert

我需要转换

$text = 'We had <i>fun</i>. Look at <a href="http://example.com">this photo</a> of Joe';

[Edit] There could be multiple links in the text.

[编辑]文本中可能有多个链接。

至

$text = 'We had fun. Look at this photo (http://example.com) of Joe';

All HTML tags are to be removed and the href value from <a> tags needs to be added like above.

将删除所有HTML标记，并且需要像上面一样添加来自标记的href值。

What would be an efficient way to solve this with regex? Any code snippet would be great.

用正则表达式解决这个问题的有效方法是什么？任何代码片段都会很棒。

5 个解决方案

#1

First do a preg_replace to keep the link. You could use:

首先做一个preg_replace来保持链接。你可以使用：

preg_replace('<a href="(.*?)">(.*?)</a>', '$\2 ($\1)', $str);

Then use strip_tags which will finish off the rest of the tags.

然后使用strip_tags来完成其余的标签。

#2

try an xml parser to replace any tag with it's inner html and the a tags with its href attribute.

尝试使用xml解析器将任何标记替换为内部html和带有href属性的a标记。

http://www.php.net/manual/en/book.domxml.php

#3

The DOM solution:

DOM解决方案：

$dom = new DOMDocument;
$dom->loadHTML($html);
$xpath = new DOMXPath($dom);
foreach($xpath->query('//a[@href]') as $node) {
    $textNode = new DOMText(sprintf('%s (%s)',
        $node->nodeValue, $node->getAttribute('href')));
    $node->parentNode->replaceChild($textNode, $node);
}
echo strip_tags($dom->saveHTML());

and the same without XPath:

并且没有XPath：

$dom = new DOMDocument;
$dom->loadHTML($html);
foreach($dom->getElementsByTagName('a') as $node) {
    if($node->hasAttribute('href')) {
        $textNode = new DOMText(sprintf('%s (%s)',
            $node->nodeValue, $node->getAttribute('href')));
        $node->parentNode->replaceChild($textNode, $node);
    }
}
echo strip_tags($dom->saveHTML());

All it does is load any HTML into a DomDocument instance. In the first case it uses an XPath expression, which is kinda like SQL for XML, and gets all links with an href attribute. It then creates a text node element from the innerHTML and the href attribute and replaces the link. The second version just uses the DOM API and no Xpath.

它只是将任何HTML加载到DomDocument实例中。在第一种情况下，它使用XPath表达式，有点像SQL for XML，并获得具有href属性的所有链接。然后，它从innerHTML和href属性创建一个文本节点元素，并替换该链接。第二个版本只使用DOM API而没有Xpath。

Yes, it's a few lines more than Regex but this is clean and easy to understand and it won't give you any headaches when you need to add additional logic.

是的，它比Regex多了几行，但这很干净且易于理解，当你需要添加额外的逻辑时它不会给你带来任何麻烦。

#4

I've done things like this using variations of substring and replace. ~~I'd probably use regex today~~ but you wanted an alternative so:

我使用子串和替换的变体做了这样的事情。我今天可能会使用正则表达式，但你想要一个替代方案：

For the <i> tags, I'd do something like:

对于标签，我会做类似的事情：

$text = replace($text, "<i>", "");
$text = replace($text, "</i>", "");

(My php is really rusty, so replace may not be the right function name -- but the idea is what I'm sharing.)

（我的php真的很生疏，所以替换可能不是正确的功能名称 - 但这个想法就是我所分享的。）

The <a> tag is a bit more tricky. But, it can be done. You need to find the point that <a starts and that the > ends with. Then you extract the entire length and replace the closing </a>

标签有点棘手。但这是可以完成的。您需要找到以...结尾的点。然后，您提取整个长度并替换结束

That might go something like:

这可能是这样的：

$start = strrpos( $text, "<a" );
$end = strrpos( $text, "</a>", $start );
$text = substr( $text,  $start, $end );
$text = replace($text, "</a>", "");

(I don't know if this will work, again the idea is what I want to communicate. I hope the code fragments help but they probably don't work "out of the box". There are also a lot of possible bugs in the code snippets depending on your exact implementation and environment)

（我不知道这是否会起作用，这个想法也是我想要传达的。我希望代码片段有所帮助，但它们可能无法“开箱即用”。还有很多可能的错误代码片段取决于您的确切实施和环境）

Reference:

参考：

strrpos - http://www.php.net/manual/en/function.strrpos.php
strrpos - http://www.php.net/manual/en/function.strrpos.php
replace - http://www.php.net/manual/en/function.str-replace.php
替换 - http://www.php.net/manual/en/function.str-replace.php
substr - http://php.net/manual/en/function.substr.php
substr - http://php.net/manual/en/function.substr.php

#5

It's also very easy to do with a parser:

使用解析器也很容易：

# available from http://simplehtmldom.sourceforge.net
include('simple_html_dom.php');

# parse and echo
$html = str_get_html('We had <i>fun</i>. Look at <a href="http://example.com">this photo</a> of Joe');

$a = $html->find('a');
$a[0]->outertext = "{$a[0]->innertext} ( {$a[0]->href} )";

echo strip_tags($html);

And that produces the code you want in your test case.

这会在您的测试用例中生成您想要的代码。

#1