Re^2: Cleaning up HTML

I've been trying some things with this module, and it's a bit hard going.

Now, how do you recommend combining two span tags? For example, I have this crufty html:

<span style="font-family:Arial"><span style="font-size:10pt; color:#00
+0080;">text</span></span>
[download]

I'd like to combine the two span tags, merging their style attributes:

<span style="font-family:Arial; font-size:10pt; color:#000080;">text</
+span></span>
[download]

Well, I know HTML::StripScripts has built in handling of style tags...

Now, if I do a callback for the span like

my $p = HTML::StripScripts::Parser->new({
  Rules => {
    span => sub { my ($filter,$element) = @_;
                    print Dumper $element if $element->{content} =~ /^
+<span\W/;
                    1;
                },
    }
  }
);
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then I get this result for the outer span:

$VAR1 = {
          'content' => '<span style="font-size:10pt; color:#000080;">t
+ext</span>',
          'tag' => 'span',
          'attr' => {
                      'style' => 'font-family:Arial'
                    }
        };
[download]

How do you recommend to proceed from here? Should I parse the "content" again, and how?

Also... how do you remove tags but not its content? If I return '0' from this callback sub, then both the tags and the inner HTML are gone.

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Re^3: Cleaning up HTML by clinton (Priest) on Apr 22, 2008 at 09:51 UTC
I've been trying some things with this module, and it's a bit hard going. Agreed - it makes certain things very easy, but other bits (like adding allowed attributes) are nasty and crust. As we've discussed privately, this module could do with a major API overhaul. And a new name! Stripping scripts is just a part of what this does. It's actually a very powerful HTML tidier I'd like to combine the two span tags, merging their style attributes: Merging adjacent tags wasn't a use that I envisaged, but that was my own lack of imagination - the next version will have some nice way of querying the parent and sibling elements. I've been trying to think about how you could do this with the current module (using private methods and properties), but it's nasty, and would probably result in having to reparse content, because to merge two `span`s, you need to know: that the child `span` HAS content the the parent `span` has NO content but you don't know that until you're finished with the parent `span` because it's a stream parser by which time, the child `span` has been converted to text As per the private message you've just sent me, maintaining the nodes as a DOM-tree seems like the only reasonable way to handle this. UPDATE So if we're planning on building DOM-trees, this starts sounding like a job for XML::LibXML, or HTML::TreeBuilder. But HTML::StripScripts does three things that neither of these modules does (AFAIK): it understands the meaning and context of tags, so that it can figure out that lone `<li>` elements cannot exist outside `<ul>` or `<ol>` it provides a mechanism for parsing / allowing / disallowing attribute and CSS style declarations it cleans up XSS attacks Ideas for the new glamorous DOM-tree based version gladly accepted	[reply] [d/l] [select]

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Re^3: Cleaning up HTML
by clinton (Priest) on Apr 22, 2008 at 09:51 UTC

I've been trying some things with this module, and it's a bit hard going.

Agreed - it makes certain things very easy, but other bits (like adding allowed attributes) are nasty and crust. As we've discussed privately, this module could do with a major API overhaul. And a new name! Stripping scripts is just a part of what this does. It's actually a very powerful HTML tidier

I'd like to combine the two span tags, merging their style attributes:

Merging adjacent tags wasn't a use that I envisaged, but that was my own lack of imagination - the next version will have some nice way of querying the parent and sibling elements.

I've been trying to think about how you could do this with the current module (using private methods and properties), but it's nasty, and would probably result in having to reparse content, because to merge two spans, you need to know:

that the child span HAS content
the the parent span has NO content
but you don't know that until you're finished with the parent span because it's a stream parser
by which time, the child span has been converted to text

As per the private message you've just sent me, maintaining the nodes as a DOM-tree seems like the only reasonable way to handle this.

UPDATE So if we're planning on building DOM-trees, this starts sounding like a job for XML::LibXML, or HTML::TreeBuilder. But HTML::StripScripts does three things that neither of these modules does (AFAIK):

it understands the meaning and context of tags, so that it can figure out that lone <li> elements cannot exist outside <ul> or <ol>
it provides a mechanism for parsing / allowing / disallowing attribute and CSS style declarations
it cleans up XSS attacks

Ideas for the new glamorous DOM-tree based version gladly accepted

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