lib/grape/middleware/base.rb
# frozen_string_literal: true
module Grape
module Middleware
class Base
include Helpers
attr_reader :app, :env, :options
TEXT_HTML = 'text/html'
include Grape::DSL::Headers
# @param [Rack Application] app The standard argument for a Rack middleware.
# @param [Hash] options A hash of options, simply stored for use by subclasses.
def initialize(app, *options)
@app = app
@options = options.any? ? default_options.merge(options.shift) : default_options
@app_response = nil
end
def default_options
{}
end
def call(env)
dup.call!(env).to_a
end
def call!(env)
@env = env
before
begin
@app_response = @app.call(@env)
ensure
begin
after_response = after
rescue StandardError => e
warn "caught error of type #{e.class} in after callback inside #{self.class.name} : #{e.message}"
raise e
end
end
response = after_response || @app_response
merge_headers response
response
end
# @abstract
# Called before the application is called in the middleware lifecycle.
def before; end
# @abstract
# Called after the application is called in the middleware lifecycle.
# @return [Response, nil] a Rack SPEC response or nil to call the application afterwards.
def after; end
def response
return @app_response if @app_response.is_a?(Rack::Response)
@app_response = Rack::Response.new(@app_response[2], @app_response[0], @app_response[1])
end
def content_type_for(format)
HashWithIndifferentAccess.new(content_types)[format]
end
def content_types
ContentTypes.content_types_for(options[:content_types])
end
def content_type
content_type_for(env[Grape::Env::API_FORMAT] || options[:format]) || TEXT_HTML
end
def mime_types
@mime_type ||= content_types.each_pair.with_object({}) do |(k, v), types_without_params|
types_without_params[v.split(';').first] = k
end
end
private
def merge_headers(response)
return unless headers.is_a?(Hash)
case response
when Rack::Response then response.headers.merge!(headers)
when Array then response[1].merge!(headers)
end
end
end
end
end