module Roda::RodaPlugins::JsonParser

  1. lib/roda/plugins/json_parser.rb

The json_parser plugin parses request bodies in JSON format if the request’s content type specifies json. This is mostly designed for use with JSON API sites.

This only parses the request body as JSON if the Content-Type header for the request includes “json”.

The parsed JSON body will be available in r.POST, just as a parsed HTML form body would be. It will also be available in r.params (which merges r.GET with r.POST).


Public Class

  1. configure


DEFAULT_ERROR_HANDLER = proc{|r| r.halt [400, {}, []]}  

Public Class methods

configure(app, opts=OPTS)

Handle options for the json_parser plugin:


A proc to call if an exception is raised when parsing a JSON request body. The proc is called with the request object, and should probably call halt on the request or raise an exception.


The parser to use for parsing incoming json. Should be an object that responds to +call(str)+ and returns the parsed data. The default is to call JSON.parse.


If true, the parser will be called with the request object as the second argument, so the parser needs to respond to +call(str, request)+.


Whether to wrap uploaded JSON data in a hash with a “_json” key. Without this, calls to r.params will fail if a non-Hash (such as an array) is uploaded in JSON format. A value of :always will wrap all values, and a value of :unless_hash will only wrap values that are not already hashes.

[show source]
   # File lib/roda/plugins/json_parser.rb
36 def self.configure(app, opts=OPTS)
37   app.opts[:json_parser_error_handler] = opts[:error_handler] || app.opts[:json_parser_error_handler] || DEFAULT_ERROR_HANDLER
38   app.opts[:json_parser_parser] = opts[:parser] || app.opts[:json_parser_parser] || app.opts[:json_parser] || JSON.method(:parse)
39   app.opts[:json_parser_include_request] = opts[:include_request] if opts.has_key?(:include_request)
41   case opts[:wrap]
42   when :unless_hash, :always
43     app.opts[:json_parser_wrap] = opts[:wrap]
44   when nil
45     # Nothing
46   else
47     raise RodaError, "unsupported option value for json_parser plugin :wrap option: #{opts[:wrap].inspect} (should be :unless_hash or :always)"
48   end
49 end