Dancer2::Plugin::HTTP::ContentNegotiation

A Dancer2 plugin that does the right thing when it comes to Acceptable MIME-types and RFCs

Synopsis

use Dancer2;

use Dancer2::Plugin::HTTP::ContentNegotiation;

get '/greetings' => sub {
    http_choose_language (
        'en'    => sub { 'Hello World' },
        'en-GB' => sub { 'Hello London' },
        'en-US' => sub { 'Hello Washington' },
        'nl'    => sub { 'Hallo Amsterdam' },
        'de'    => sub { 'Hallo Berlin' },
        # default is first in the list
    );
};

get '/choose/:id' => sub {
    my $data = SomeResource->find(param('id'));
    http_choose_media_type (
        'application/json'  => sub { to_json $data },
        'application/xml '  => sub { to_xml $data },
        { default => undef }, # default is 406: Not Acceptable
    );
};

get '/thumbnail/:id' => sub {
    http_choose_media_type (
        [ 'image/png', 'image/gif', 'image/jpeg' ]
            => sub { Thumbnail->new( param('id') )->to(http_chosen->type) },
        { default => 'image/png' }, # must be one listed above
    );
};

dance;

Description

A web server should be capable of content negotiation. This plugin goes way beyond the Dancer2::Serializer::Mutable which picks a wrong approach on deciding what the requested type is. Also, this plugin is easy to extend with different 'serializers' for example application/pdf or image/jpg.

Dancer2::Plugin::HTTP::ContentNegotiation will produce all the correct status message described in the latest RFCs.

Dancer2 Keywords

• http_choose_media_type use the HTTP Accept header field to choose from a list of provide media-types.

• http_choose_language

• http_choose_charset

• http_choose_encoding

• http_choose name compatebility

• http_chosen_media_type holds the value of the chosen HTTP Accept header-field

• http_chosen_language

• http_chosen_charset

• http_chosen_encoding

• http_chosen

Release Note

This is only for demonstration purpose.

• It should get an option to define what the default MIME-type should be when none is given.
• Not yet implemented: Statuscode 300 "Multiple Choices" when the request is not disambigues
• There is a bug in HTTP::Headers::ActionPack that allows values to pass throug with q=0.0