Regular Expression

[Chetan Parekh]

I have a String that contains HTML data.

I need to achieve 2 things
(1) If <script> and </script> exist in String, remove between and including.
(2) If <script> exist but</script> doesn�t, then remove all after <script> and including.

How to do this?

[Michael Ernest]

This seems more like an intermediate topic to me.

[Keith Lynn]

This should be very easy with indexOf and substring

[Paul Sturrock]

What have you tried so far?

[Alan Moore]

str = str.replaceAll("(?i)<script\\b[^>]*>(?:[^<]++|<(?!/script>))++(?:</script>)?", "");

This assumes your tags don't have any unnecessary whitespace in them, e.g., between the "<" and the tag name. If that's a possibility, you'll need this even uglier version:

"(?i)<\\s*script\\b[^>]*>(?:[^<]++|<(?!/\\s*script\\s*>))++(?:</\\s*script\\s*>)?"

[Jim Yingst]

[Alan]: This assumes your tags don't have any unnecessary whitespace in them,

If that's a possibility, shouldn't we simply find the author of the HTML and beat them with a stick? Such so-called HTML won't fly with most browsers anyway, I think. If we're going to worry about such possibilities, why not worry about the ones that are actually legal, such as

<script foo='bar>baz'>

or

<foo bar="b>az">

or

<script>
<!--
</script>
-->
</script>

Admittedly, handling all these cases is nontrivial and quite possibly unnecessary for what Chetan needs here. But if we want to delve into special cases, there are things somewhat more important to worry about than whitespace after a <, I think.

[Alan Moore]

Yeah, now I think about it, whitespace before the tag name isn't very likely (I shouldn't post when I'm in a hurry to be elsewhere). But I do see extra space before the ">" fairly often, even in end tags. And, although it's legal to have a ">" in a (quoted) attribute value, I never see that (HTML authors just can't seem to believe it's legal). I've seen your third example (with the double end tags) once, but only because the page came up blank and I viewed the source to find out why (it may be legal, but it's almost certain to be a mistake). As you say, though, this is probably all moot anyway.

[Jim Yingst]

I should have quoted you more carefully - I meant to respond specifically to the suggestion that there might be whitespace right after the <. I disagree with that (as have you, now), but I fully agree there can be whitespace before the >.

As for < in an attribute value - I've never seen that in HTML either. But I have seen it in some XML, e.g. something like

<field name='foo' value='some arbitrary text, could be just about anything'/>

If value contains a quote, that would need to be escaped - but I think anything else is fair game there.

Anyway, sorry for the digressions Chetan - this is probably not stuff you need to worry about for HTML. Unless you need a really robust product able to handle any valid HTML.