用一个单独的<br />替换<br />的多个连接实例

Question

I am stripping HTML and replacing all <div> and <p> tags with <br /> tags. Problem is that I am left with random <br /> tags like

<br /><br /><br />
<br /><br />
<br /><br /><br /><br />

I am taking the body of an email and stripping tags like

$comment = strip_tags($comment,'<div><p>');
$comment = preg_replace("/<p[^>]*?>/", "", $comment);
$comment = str_replace("</p>", "<br />", $comment);
$comment = preg_replace("/<div[^>]*?>/", "", $comment);
$comment = str_replace("</div>", "<br />", $comment);

I want to be able to replace any instance of at least 2 <br /> tags next to each other with one single <br /> tag. At this point every <br /> will match exactly as I have shown, but...there is a possibility that they can vary like <br>, <br /> so just need to make sure that I can replace any type of br tag (when there are at least 2 of them) with one single one when they are sequentially repeated next to each other.

The "possibility" of a br tag looking like <br> is based on if it was already in the original HTML that I did not catch. I know I can do a str_replace("<br>", "<br />", $comment) but I was hoping to shorten my code and not add more lines.

Any idea how to do this? Im sure there is regex involved and preg_replace but not sure where to start.

Answer 1

When you run $comment = strip_tags($comment, '<div><p>'), there will be no <br> left as it is not an allowed tag. So the only <br /> would be from your four replacements below. You only need to care about the form "<br />" in the other words. But handling just <br /> vs. all other <br> form aren't much different in difficulty.

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Anyway, you could use:

$comment = preg_replace('/(\s*<br[^>]*>){2,}/', '\1', $comment);

• <br[^>]*> — match any kind of <br> tag
• \s*<br[^>]*> — match zero or more whitespaces before the <br> tag
• (\s*<br[^>]*>) — group this regex and capture into \1
• (…){2,} — match two or more such groups.

The replacement will keep the last <br> found.