问题
I'm trying to remove all empty <p> tags CKEditor is inserting in to a description box but they all seem to vary. The possibilities seem to be:
<p></p>
<p>(WHITESPACE)</p>
<p> </p>
<p><br /></p>
<p>(NEWLINE) </p>
<p>(NEWLINE)<br /><br />(NEWLINE) </p>
With these possibilities, there could be any amount of whitespace, and <br /> tags in between the paragraphs, and there could be some of each kind in one paragraph.
I'm also not sure about the <br /> tag, from what I've seen it could be <br />, <br/> or <br>.
I've searched SO for a similar answer but of all the answers I've seen they all seem to cater for just one of these cases, not all at once. I guess in simple terms what I'm asking is, Is there a regular expression I can use to remove all <p> tags from some HTML that don't have any alphanumeric text or symbols/punctuation in them?
回答1:
Well, in conflict with my suggestion not to parse HTML with regexes, I wrote up a regex to do just that:
"#<p>(\s| |</?\s?br\s?/?>)*</?p>#"
This will match properly for:
<p></p>
<p> </p> <!-- ([space]) -->
<p> </p> <!-- (That's a [tab] character in there -->
<p> </p>
<p><br /></p>
<p>
</p>
<p>
<br /><br />
</p>
What it does:
# / --> Regex start
# <p> --> match the opening <p> tag
# ( --> group open.
# \s --> match any whitespace character (newline, space, tab)
# | --> or
# --> match
# | --> or
# </?\s?br\s?/?> --> match the <br> tag
# )* --> group close, match any number of any of the elements in the group
# </?p> --> match the closing </p> tag ("/" optional)
# / --> regex end.
回答2:
The selected answer is great, but it doesn't work if <p> tag has inline style attributes defined, like <p style="font-weight:bold">.
A regex to match this, would be:
#<p[^>]*>(\s| |</?\s?br\s?/?>)*</?p>#
来源：https://stackoverflow.com/questions/14260670/php-regex-remove-empty-paragraph-tags