NAME¶
HTML::Microformats::Documentation::Notes - misc usage and design notes
NOTES¶
Byzantine Internals¶
The internals of HTML::Microformats are pretty complicated - best to steer clear
of them. Here are three usage patterns that mostly avoid dealing with the
internals:
- •
- Parse a page and use it as a single RDF graph.
A page can be parsed into an RDF::Trine::Model and queried using SPARQL.
use HTML::Microformats;
use LWP::Simple qw[get];
use RDF::Query;
my $page = 'http://example.net/';
my $graph = HTML::Microformats
->new_document(get($page), $page)
->assume_all_profiles
->parse_microformats
->model;
my $query = RDF::Query->new(<<SPARQL);
PREFIX foaf: <http://xmlns.com/foaf/0.1/>
SELECT DISTINCT ?friendname ?friendpage
WHERE {
<$page> ?p ?friendpage .
?person foaf:name ?friendname ;
foaf:page ?friendpage .
FILTER (
isURI(?friendpage)
&& isLiteral(?friendname)
&& regex(str(?p), "^http://vocab.sindice.com/xfn#(.+)-hyperlink")
)
}
SPARQL
my $results = $query->execute($graph);
while (my $result = $results->next)
{
printf("%s <%s>\n",
$result->{friendname}->literal_value,
$result->{friendpage}->uri,
);
}
- •
- Use the data method on each object.
The "data" method on microformat objects returns a hashref of
useful data.
use HTML::Microformats;
use LWP::Simple qw[get];
my $page = 'http://example.net/';
my @xfn_objs = HTML::Microformats
->new_document(get($page), $page)
->assume_all_profiles
->parse_microformats
->objects('XFN');
while (my $xfn = shift @xfn_objs)
{
printf("%s <%s>\n",
$xfn->data->{title},
$xfn->data->{href},
);
}
(If you're wondering why the second example's simpler it's because it
returns somewhat dumber data.)
- •
- Convert to other formats.
Various microformat objects have "to_foo" methods allowing the
data to be exported in various formats..
use HTML::Microformats;
use LWP::Simple qw[get];
my $page = 'http://example.net/';
my @hcards = HTML::Microformats
->new_document(get($page), $page)
->assume_all_profiles
->parse_microformats
->objects('hCard');
print $_->to_vcard foreach @hcards;
Methods available are:
- •
- "to_vcard" (hCard objects)
Exports as vCard 3.0.
- •
- "to_vcard4" (hCard objects)
Exports as vCard 4.0.
- •
- "to_vcard4_xml" (hCard objects)
Exports as vCard XML.
- •
- "to_icalendar" (hCalendar, hEvent, hTodo, hFreebusy, hAlarm and
hEntry objects)
Exports as iCalendar.
- •
- "to_atom" (hAtom and hEntry objects)
Exports as Atom 1.0.
- •
- "to_kml" (geo objects)
Exports as KML 2.0.
- •
- "serialialise_model(as => $format)" (all microformat objects)
Exports as RDF, serialised as $format. (Format can be 'RDFXML', 'Turtle',
'NTriples', 'RDFJSON'.)
Stuff that's b0rked¶
The "get_foo", "set_foo", "add_foo",
"clear_foo" methods defined in HTML::Microformats::Format work
unreliably and are poorly documented. You're better off using the
"data" method and inspecting the returned structure for the data you
need. This will be fixed in the future.
Here be monsters¶
There are several parts of the code which are incredibly complicated and
desperately need refactoring. This will be done at some point, so don't rely
too much on their current behaviour.
"stringify" and "_stringify_helper" in
HTML::Microformats::Utilities. The whole of HTML::Microformats::Mixin::Parser.
SEE ALSO¶
HTML::Microformats.
AUTHOR¶
Toby Inkster <tobyink@cpan.org>.
COPYRIGHT AND LICENCE¶
Copyright 2008-2012 Toby Inkster
This library is free software; you can redistribute it and/or modify it under
the same terms as Perl itself.