module Roda::RodaPlugins::TypeRouting

  1. lib/roda/plugins/type_routing.rb

Allows to respond to specific request data types. User agents can request specific data types by either supplying an appropriate Accept header or by appending it as file extension to the path.

Example:

plugin :type_routing

route do |r|
  r.get 'a' do
    r.html{ "<h1>This is the HTML response</h1>" }
    r.json{ '{"json": "ok"}' }
    r.xml{ "<root>This is the XML response</root>" }
    "Unsupported data type"
  end
end

This application will handle the following paths:

/a.html

HTML response

/a.json

JSON response

/a.xml

XML response

/a

HTML, JSON, or XML response, depending on the Accept header

The response Content-Type header will be set to a suitable value when the block is matched.

Note that if no match is found, code will continue to execute, which can result in unexpected behaviour. This should only happen if you do not handle all supported/configured types. If you want to simplify handling, you can just place the html handling after the other types, without using a separate block:

route do |r|
  r.get 'a' do
    r.json{ '{"json": "ok"}' }
    r.xml{ "<root>This is the XML response</root>" }

    "<h1>This is the HTML response</h1>"
  end
end

This works correctly because Roda assumes the html type by default.

To match custom extensions, use the :types option:

plugin :type_routing, :types => {
  :yaml => 'application/x-yaml',
  :js => 'application/javascript; charset=utf-8',
}

route do |r|
  r.get 'a' do
    r.yaml{ YAML.dump "YAML data" }
    r.js{ "JavaScript code" }
    # or:
    r.on_type(:js){ "JavaScript code" }
    "Unsupported data type"
  end
end

Plugin options

The following plugin options are supported:

:default_type

The default data type to assume if the client did not provide one. Defaults to :html.

:exclude

Exclude one or more types from the default set (default set is :html, :xml, :json).

:types

Mapping from a data type to its MIME-Type. Used both to match incoming requests and to provide Content-Type values. If the value is nil, no Content-Type will be set. The type may contain media type parameters, which will be sent to the client but ignored for request matching.

:use_extension

Whether to take the path extension into account. Default is true.

:use_header

Whether to take the Accept header into account. Default is true.

Methods

Public Class

  1. configure

Constants

ACCEPT_HEADER = 'HTTP_ACCEPT'.freeze  
CONFIGURATION = { :mimes => { 'text/json' => :json, 'application/json' => :json, 'text/xml' => :xml, 'application/xml' => :xml, 'text/html' => :html, }.freeze, :types => { :json => 'application/json'.freeze, :xml => 'application/xml'.freeze, :html => 'text/html'.freeze, }.freeze, :use_extension => true, :use_header => true, :default_type => :html }.freeze  
CONTENT_TYPE_HEADER = 'Content-Type'.freeze  

Public Class methods

configure (app, opts = {})
[show source]
# File lib/roda/plugins/type_routing.rb, line 104
def self.configure(app, opts = {})
  config = (app.opts[:type_routing] || CONFIGURATION).dup
  [:use_extension, :use_header, :default_type].each do |key|
    config[key] = opts[key] if opts.has_key?(key)
  end

  types = config[:types] = config[:types].dup
  mimes = config[:mimes] = config[:mimes].dup

  Array(opts[:exclude]).each do |type|
    types.delete(type)
    mimes.reject!{|_, v| v == type}
  end

  if mapping = opts[:types]
    types.merge!(mapping)

    mapping.each do |k, v|
      if v
        mimes[v.split(';', 2).first] = k
      end
    end
  end

  types.freeze
  mimes.freeze

  type_keys = config[:types].keys
  config[:extension_regexp] = /(.+)\.(#{Regexp.union(type_keys.map(&:to_s))})\z/

  type_keys.each do |type|
    app::RodaRequest.send(:define_method, type) do |&block|
      on_type(type, &block)
    end
  end

  app.opts[:type_routing] = config.freeze
end