James.Q.L wrote:
> --- Rob Dixon <[EMAIL PROTECTED]> wrote:
>
> > James.Q.L wrote:
> > >
> > > I am trying to add html tag to an existing html file using HTML::TreeBuiler.
> > >
> > > the problem is that the added tags isn't encoded after the output. everything
> > > els is fine.
> > >
> > > ###########
> > > my $tree = HTML::TreeBuilder->new;
> > > $tree->no_space_compacting(1);
> > > $tree->store_comments(1);
> > > $tree->parse_file("f.html");
> > >
> > > my $ele;
> > > my $tag = '<tr><td>TEST</td></tr>';
> > >
> > > for (@{ $tree->extract_links('a', 'href') }) {
> > > my($link, $element, $attr, $tag) = @$_;
> > > if ($link=~ m{/mylink\.htm}) {
> > > $ele = $element;
> > > last;
> > > }
> > > }
> > > $ele = $ele->parent(); # td
> > > $ele = $ele->parent(); # tr
> > > my $r = $ele->postinsert($tag);
> > >
> > > open F,">f.html";
> > > print F $tree->as_HTML('<>&',' ',{});
> > > close F;
> > > $tree->delete;
> > >
> > > the output in html turn out to be
> > >
> > > <tr><td><b>TEST</b></td></tr>
> > >
> > >
> >
> > The 'postinsert' method expects an HTML::Element object to add
> > into the tree, not simple HTML text. The easiest way to build
> > what you want here is probably with the 'new_from_lol' method
> > like this.
> >
> > my $tag = HTML::Element->new_from_lol (['tr', ['td', 'TEST']])
> >
> > HTH,
> >
> > Rob
> >
>
>
> From HTML::Element doc,
> $h->postinsert($element_or_text...)
> i suppose it means postinsert accept $element or text. and the insertion didn't
> yield any error
> with text as parameter.and it looks much simpler/easier than the new_from_lol.
>
> using HTML::Element->new_from_lol (['tr', ['td', 'TEST']]) did lead to the correct
> html output.
> but when i am not using 'TEST' directly in new_from_lol
>
> $insert= <<TEST;
> <tr><td>some more tags here</td></tr>
> TEST
> $h = HTML::Element->new_from_lol (['tr', ['td', $insert]]);
> then do postinsert($h);
>
> the tags in $insert still don't get decoded after output.
If you want to insert a new piece of HTML then you have to supply
'post_insert' with an HTML::Element object. If you supply plain text
then that text will be inserted literally. That's why the < and >
brackets have been translated to < and >, which is great if
you want to display HTML in the browser, but not for much else.
The 'new_from_lol' method lets you build HTML elements from lists
of lists ('lols') but if you need to create an element directly
from HTML then you have a problem as HTML::Treebuilder::new_from_content
will wrap whatever you give it in <html>, <head>, <body>, <table> etc.
tags to make it into a valid HTML page.
As Sean says you can search the resulting tree for the part you
really want, but there is a better way. Treebuilder is kind enough
to set an attribute called '_implicit' on those elements that weren't
present in the original HTML, so you can just search for the first
element with '_implicit' undefined like this:
#!perl
use strict;
use warnings;
use HTML::TreeBuilder;
my $insert= <<TEST;
<tr>
<td>
some more tags here
</td>
</tr>
TEST
my $element = HTML::TreeBuilder->new_from_content($insert);
$element = $element->look_down('_implicit', undef);
print $element->as_HTML;
__END__
OUTPUT
<tr><td>some more tags here</td></tr>
So you can then go ahead and 'post_insert' your new $element.
If you have a fixed piece of HTML that you want to add then
you would still be better off coding it up using 'new_from_lol',
but if the content varies then you could package the lines
above as a subroutine:
sub html_element {
my $html = shift;
my $element = HTML::TreeBuilder->new_from_content($html);
$element->look_down('_implicit', undef);
}
and then call it like this
my $r = $ele->postinsert(html_element($tag));
HTH,
Rob
