Class: FaradayMiddleware::RackCompatible

Inherits:
Object
  • Object
show all
Defined in:
lib/faraday_middleware/rack_compatible.rb

Overview

Wraps a handler originally written for Rack for Faraday compatibility.

Experimental. Only handles changes in request headers.

Constant Summary collapse

NON_PREFIXED_HEADERS = 
%w[CONTENT_LENGTH CONTENT_TYPE].freeze

Instance Method Summary collapse

Constructor Details

#initialize(app, rack_handler, *args) ⇒ RackCompatible

Returns a new instance of RackCompatible.



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# File 'lib/faraday_middleware/rack_compatible.rb', line 10

def initialize(app, rack_handler, *args)
  # tiny middleware that decomposes a Faraday::Response to standard Rack
  # array: [status, headers, body]
  compatible_app = lambda do |rack_env|
    env = restore_env(rack_env)
    response = app.call(env)
    [response.status, response.headers, Array(response.body)]
  end
  @rack = rack_handler.new(compatible_app, *args)
end

Instance Method Details

#call(env) ⇒ Object 



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# File 'lib/faraday_middleware/rack_compatible.rb', line 21

def call(env)
  rack_env = prepare_env(env)
  rack_response = @rack.call(rack_env)
  finalize_response(env, rack_response)
end

#finalize_response(env, rack_response) ⇒ Object 



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# File 'lib/faraday_middleware/rack_compatible.rb', line 80

def finalize_response(env, rack_response)
  status, headers, body = rack_response
  body = body.inject { |str, part| str << part }
  headers = Faraday::Utils::Headers.new(headers) unless headers.is_a?(Faraday::Utils::Headers)

  env.update status: status.to_i,
             body: body,
             response_headers: headers

  env[:response] ||= Faraday::Response.new(env)
  env[:response]
end

#headers_to_rack(env) ⇒ Object 



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# File 'lib/faraday_middleware/rack_compatible.rb', line 50

def headers_to_rack(env)
  rack_env = {}
  env[:request_headers].each do |name, value|
    name = name.upcase.tr('-', '_')
    name = "HTTP_#{name}" unless NON_PREFIXED_HEADERS.include? name
    rack_env[name] = value
  end
  rack_env
end

#prepare_env(faraday_env) ⇒ Object

faraday to rack-compatible



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# File 'lib/faraday_middleware/rack_compatible.rb', line 30

def prepare_env(faraday_env)
  env = headers_to_rack(faraday_env)

  url = faraday_env[:url]
  env['rack.url_scheme'] = url.scheme
  env['PATH_INFO'] = url.path
  env['SERVER_PORT'] = if url.respond_to?(:inferred_port)
                         url.inferred_port
                       else
                         url.port
                       end
  env['QUERY_STRING'] = url.query
  env['REQUEST_METHOD'] = faraday_env[:method].to_s.upcase

  env['rack.errors'] ||= StringIO.new
  env['faraday'] = faraday_env

  env
end

#restore_env(rack_env) ⇒ Object

rack to faraday-compatible



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# File 'lib/faraday_middleware/rack_compatible.rb', line 61

def restore_env(rack_env)
  env = rack_env.fetch('faraday')
  headers = env[:request_headers]
  headers.clear

  rack_env.each do |name, value|
    next unless name.is_a?(String) && value.is_a?(String)

    if NON_PREFIXED_HEADERS.include?(name) || name.start_with?('HTTP_')
      name = name.sub(/^HTTP_/, '').downcase.tr('_', '-')
      headers[name] = value
    end
  end

  env[:method] = rack_env['REQUEST_METHOD'].downcase.to_sym
  env[:rack_errors] = rack_env['rack.errors']
  env
end