How to truncate HTML to certain number of characters?

I have some content (some from an external source, some specially written) that is displayed in a kind of blog format. I want to cut off the text after a certai开发者_开发技巧n number of characters, so currently I'm doing this:

<?=substr( strip_tags($a['content']), 0, 400 )?>

The problem is, this loses all the formatting and I just get one massive blob of text. But if I don't strip the tags, obviously some tags will go unclosed and mess up the layout.

What would be a good way to truncate after X number of characters, but also keep some basic formatting?

http://snippets.dzone.com/posts/show/7125

That will auto-close any tags that got snipped. The versions in the comments seem to be better.

Not convinced if this is the best approach for your problem, but it is a simple one, and would work if you're only concerned about preserving 1 or 2 tags to retain some basic formatting in the html.

So, you could do something like: find the tags you want to keep and replace them with some unique combination of characters, then after truncating the string, find/replace the unique string combination you created with the tag you originally replaced them with.

$content = str_replace("<br/>", "\n", $a['content']);
$content = substr(strip_tags($content), 0, 400); 
echo str_replace("\n", "<br/>", $content);

This might not answer your question but this is one method to solve this issue.

If I was writing a blog I'd want to define where the post would be truncated. This way I'd be able to post stuff like a video and truncate the post at where the video ends and then the rest can be displayed when the post is viewed.

Try adding a specific string at where you want the post to be truncated e.g. "--" or some tag so the break location isn't visable.

Then from there you can use mb_stripos to store the location of the break string and then pass that location as the length for the substring method.

or...

<?=substr( strip_tags($a['content']), 0, mb_stripo(strip_tags($a['content']),
"break string"))?>

This might not be as accurate as you want, but if you could be sure that only text markups such as headings links and paragraphs where being used, something like:

$i = 0;
while($i < 400){
    $i = strpos($string, '</p>', $i) + 4;
  }
 echo substr( $string, 0, strpos($string, '</p>', $i)+4);

It would mean you would have variable string lengths but they would be as close as possible to the nearest paragraph.