# NAME

Web::Microformats2 - Read Microformats2 metadata from HTML or JSON

# SYNOPSIS

    use Web::Microformats2;
    use v5.10;

    my $mf2_parser = Web::Microformats2::Parser->new;
    my $mf2_doc    = $mf2_parser->parse( $string_full_of_tasty_html );

    for my $item ( $mf2_doc->all_top_level_items ) {
       # Each $item is a Web::Microformats2::Item object.
       my $types_ref = $item->types;
       say "I see an MF2 item with these types set: @$types_ref";

       my $name = $item->get_property( 'name' );
       say "The value of the item's 'name' property is: '$name'";
    }

    my $serialized_mf2_doc = $mf2_doc->as_json;

    my $other_mf2_doc = Web::Microformats2::Document->new_from_json(
       $serialized_mf2_doc_from_somewhere_else
    );

# DESCRIPTION

The Web::Microformats2 modules provide Perl programs with a way to parse
and analyze HTML documents containing Microformats2 metadata. They can
pull Microformats2 information from a given HTML document, representing
it as a queryable in-memory object. They can also serialize this object
as JSON (using the Microformats2 rules for this), or read an already
JSON-serialized Microformats2 structure for further analysis.

See ["ABOUT MICROFORMATS"](#about-microformats), below, for arguments about why this might
be interesting to you.

# CLASSES

- [Web::Microformats2::Parser](https://metacpan.org/pod/Web::Microformats2::Parser)

    Parses HTML for Microformats2 metadata. Returns what it finds as a
    Web::Microformats2::Document object.

- [Web::Microformats2::Document](https://metacpan.org/pod/Web::Microformats2::Document)

    Objects are queryable structures of parsed Microformats2 metadata. Each
    came either fresh from HTML, or re-inflated from its JSON serialization
    format.

- [Web::Microformats2::Item](https://metacpan.org/pod/Web::Microformats2::Item)

    Each document object contains one or more objects of this class. Each
    item represents a single, "h-"prefixed microformat substructure,
    defining what we in the Perl world might call some _thingy_: an
    article, a person, an invitation, and so on. Each item has some number
    of properties, and possibly a parent item and a list of child items.

# STATUS

These modules are **alpha**. Their developer is still figuring out how
they want to be used, and their interface may change dramatically. It's
not ready for CPAN just yet. This software is currently being
"dogfooded" on an experimental branch of the author's own essay blog.

Further, the parser implementation is incomplete. The HTML and JSON
documents found in t/microformats-v2 include the full Microformats2
parser test suite found at [https://github.com/microformats/tests](https://github.com/microformats/tests), as
of early April, 2018. The parser-test program in t/parser.pl marks a
great deal of these tests as TODO. (But fewer than half of them, for all
that, so hey.)

# ABOUT MICROFORMATS2

Microformats2 allows the attachment of semantic metadata to arbitrary
HTML elements, in a way that neither hinders the human readability of
the underlying HTML document nor strictly prescribes any set vocabulary
to this metadata.

For example, an HTML page containing several recent blog entries might
use Microformats2 to identify the title, date, and content of each
entry, as well as its author. It could furthermore define not just the
author's name, but also their contact information, homepage URL, and
avatar-graphic. It might even identify some entries as public responses
to other articles found elsewhere on the web. Since all this metadata
exists quietly within the "class" attributes found within the HTML
page's ordinary markup, its presence does not affect or interfere with
the web page's rendering or readability to humans.

A Microfomats2 parser can read these special attribute values --
identifiable by their conspicuous use of prefixes, such as "h-entry" and
"p-name" -- and turn them into data structures that use this metadata to
give additional order, structure, and semantic labeling to the content
found within. These data structures can then be passed (usually as JSON
strings) to other processors, which can make all sorts of interesting
things happen.

Microformats2 is the successor to Microformats. While similar in intent
and execution, their implementations are very different. Rather than
using the pre-defined vocabularies of its predecessor, Microformats2
uses a relatively simple set of rules that allow for limitless
user-definable labels for metadata items and their constituent
properties.

For more information about Microformats2, please see
[http://microformats.org/wiki/microformats2](http://microformats.org/wiki/microformats2).

# SUPPORT

To file issues or submit pull requests, please see [this module's
repository on GitHub](https://github.com/jmacdotorg/microformats2-perl).

The author also welcomes any direct questions about this module via email.

# AUTHOR

Jason McIntosh (jmac@jmac.org)

# COPYRIGHT AND LICENSE

This software is Copyright (c) 2018 by Jason McIntosh.

This is free software, licensed under:

    The MIT (X11) License
