This plugin makes it easier to to respond to specific request data types. User agents can request specific data types by either supplying an appropriate Accept
request 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 r.html
, r.json
, or r.xml
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’s default Content-Type is text/html. Note that if you use this approach, the type_routing plugin’s :html content type will not be used for html responses, since you aren’t using an r.html
block. Instead, the Content-Type header will be set to Roda’s default (which you can override via the default_headers plugin).
If the type routing is based on the Accept
request header and not the file extension, then an appropriate Vary
header will be set or appended to, so that HTTP caches do not serve the same result for requests with different Accept
headers.
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 |
: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 |
:use_extension |
Whether to take the path extension into account. Default is |
:use_header |
Whether to take the |
Classes and Modules
Constants
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 |
Public Class methods
# File lib/roda/plugins/type_routing.rb 110 def self.configure(app, opts = {}) 111 config = (app.opts[:type_routing] || CONFIGURATION).dup 112 [:use_extension, :use_header, :default_type].each do |key| 113 config[key] = opts[key] if opts.has_key?(key) 114 end 115 116 types = config[:types] = config[:types].dup 117 mimes = config[:mimes] = config[:mimes].dup 118 119 Array(opts[:exclude]).each do |type| 120 types.delete(type) 121 mimes.reject!{|_, v| v == type} 122 end 123 124 if mapping = opts[:types] 125 types.merge!(mapping) 126 127 mapping.each do |k, v| 128 if v 129 mimes[v.split(';', 2).first] = k 130 end 131 end 132 end 133 134 types.freeze 135 mimes.freeze 136 137 type_keys = config[:types].keys 138 config[:extension_regexp] = /(.*?)\.(#{Regexp.union(type_keys.map(&:to_s))})\z/ 139 140 type_keys.each do |type| 141 app::RodaRequest.send(:define_method, type) do |&block| 142 on_type(type, &block) 143 end 144 app::RodaRequest.send(:alias_method, type, type) 145 end 146 147 app.opts[:type_routing] = config.freeze 148 end