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.

perl v5.32.1                                2021-09-HTML::Microformats::Documentation::Notes(3pm)