HTML::Microformats::Documentation::Notes - misc usage and design notes

       Toby Inkster <tobyink@cpan.org>.

       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                                       2021-09-12             HTML::Microform...entation::Notes(3pm)

       HTML::Microformats::Documentation::Notes - misc usage and design notes

ByzantineInternals
       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:

       •   ParseapageanduseitasasingleRDFgraph.

           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,
                                   );
                   }

       •   Usethedatamethodoneachobject.

           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.)

       •   Converttootherformats.

           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'.)

   Stuffthat'sb0rked
       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.

   Herebemonsters
       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.

       HTML::Microformats.