NAME

       JSON::Hyper - extract links from JSON via a schema

SYNOPSIS

        my $hyper = JSON::Hyper->new($hyperschema);
        my $json  = from_json( ... );
        my @links = $hyper->find_links($json->[1]->{some}->{object});
        foreach my $link (@links)
        {
          printf("<%s> (%s)", $link->{href}, $link->{rel});
        }

DESCRIPTION

       The JSON Hyper Schema proposal defines hypertext navigation through data structures
       represented by JSON.

   Constructor
       "new($hyperschema)"
           Given a JSON (or equivalent Perl nested hashref/arrayref structure) Hyper Schema,
           returns a Perl object capable of interpreting that schema.

           If the schema is omitted, defaults to the JSON Referencing hyper schema (described at
           <http://json-schema.org/json-ref>)

   Methods
       "schema"
           Returns the original schema as a hashref/arrayref structure.

       "ua"
           Get/set the LWP::UserAgent instance used to retrieve things.

       "find_links($object, $base)"
           Given a JSON object (or equivalent Perl nested hashref/arrayref structure) and
           optionally a base URL for interpreting relative URI references, returns a list of
           links found on object node. Does not operate recursively.

           Each link is a JSON::Hyper::Link object.

       "get($uri)"
           Performs an HTTP request for the given URI and returns a list of Perl nested
           hashref/arrayref structures corresponding to the JSON response.  The URI may contain a
           fragment identifier, which will be interpreted according to the schema's fragment
           resolution method. Fragment resolution methods supported include:

           •       slash-delimited (default)

           •       dot-delimited

           •       jsonpath

           For example, assuming the hyper schema specifies slash-delimited fragments, the
           following:

            my $hyper    = JSON::Hyper->new($hyperschema);
            my ($result) = $hyper->get('http://example.com/data.json#foo/bar/0');

           Is roughly equivalent to:

            use JSON;
            use LWP::UserAgent;
            my $ua       = LWP::UserAgent->new;
            my $response = $ua->get('http://example.com/data.json');
            my $object   = from_json($response->decoded_content);
            my $result   = $object->{foo}{bar}[0];

           Note, if called multiple times on the same URL will return not just equivalent
           objects, but the same object.

           So, why does this method return a list of results instead of just a single result? In
           most cases, there will be either 0 or 1 items on the list; however, JSONPath allows a
           path to match multiple nodes, so there will occasionally be more than one result. (In
           scalar context, this method just returns the first result anyway.)

       "resolve_fragment($object, $fragment)"
           Used by "get" to resolve the fragment part of a URL against an object.

       "process_includes($object, $base, $recurse)"
           Given an JSON object (or equivalent Perl nested hashref/arrayref structure) and
           optional base URL, crawls the object finding rel="full" links, dereferences them using
           "get" and replaces the appropriate nodes with the retrieved content. $recurse is a
           boolean.

           This has the effect of rel="full" behaving like inclusion does in various programming
           languages.

           This modifies the given object rather than creating a new object.

   Utilities
       "JSON::Hyper::json_ref()"
           Returns the JSON referencing hyperschema as a hashref.

BUGS

       Please report any bugs to <http://rt.cpan.org/>.

SEE ALSO

       JSON::Hyper::Link.

       Related modules: JSON::T, JSON::Path, JSON::GRDDL, JSON::Schema.

       <http://tools.ietf.org/html/draft-zyp-json-schema>.

AUTHOR

       Toby Inkster <tobyink@cpan.org>.

COPYRIGHT AND LICENCE

       Copyright 2010-2012 Toby Inkster.

       This module is tri-licensed. It is available under the X11 (a.k.a. MIT) licence; you can
       also redistribute it and/or modify it under the same terms as Perl itself.

   a.k.a. "The MIT Licence"
       Permission is hereby granted, free of charge, to any person obtaining a copy of this
       software and associated documentation files (the "Software"), to deal in the Software
       without restriction, including without limitation the rights to use, copy, modify, merge,
       publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons
       to whom the Software is furnished to do so, subject to the following conditions:

       The above copyright notice and this permission notice shall be included in all copies or
       substantial portions of the Software.

       THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED,
       INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR
       PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE
       FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR
       OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
       DEALINGS IN THE SOFTWARE.