Class: Gin::Controller

Inherits:
Object
  • Object
show all
Extended by:
GinClass
Includes:
Constants, Errorable, Filterable
Defined in:
lib/gin/controller.rb

Overview

Gin controllers follow only a few rules:

* ALL instance methods are actions (put your helper methods in a module or
  parent class not mounted to the app).
* Filters are defined by blocks passed to special class methods.
* Controller-level error handlers are defined by blocks passed to the 'error'
  class method.

Gin controller actions are any instance method defined on the controller
class. The HTTP response body takes the value of the method's return value.

If the instance method takes arguments, matching params will be assigned to
them. A required argument with a missing param triggers a Gin::BadRequest
error, resulting in a 400 response.

  class UserController < Gin::Controller
    # Get params id and email
    def show id, email=nil
      ...
    end
  end

Gin actions also support Ruby 2.0 keyed arguments, which are more flexible
for assigning default values when dealing with missing params.

  class UserController < Gin::Controller
    def show(id, email: nil, full: false)
      ...
    end
  end

Views are rendered by calling the 'view' method from a controller instance.
Views don't halt the action but return a String of the rendered view.
If a layout was set, the rendered view will include the layout.

  class UserController < Gin::Controller
    layout :user

    def show id
      # Renders <app.views_dir>/show_user.* with the layout <app.layouts_dir>/user.*
      view :show_user
    end

    def tos
      # Renders <app.views_dir>/tos.* with no layout
      view :tos, :layout => false
    end
  end

Constant Summary

Constants included from Constants

Gin::Constants::ASYNC_CALLBACK, Gin::Constants::CACHE_CTRL, Gin::Constants::CNT_DISPOSITION, Gin::Constants::CNT_LENGTH, Gin::Constants::CNT_TYPE, Gin::Constants::ENV_DEV, Gin::Constants::ENV_PROD, Gin::Constants::ENV_STAGE, Gin::Constants::ENV_TEST, Gin::Constants::EPOCH, Gin::Constants::ETAG, Gin::Constants::EXPIRES, Gin::Constants::FWD_FOR, Gin::Constants::FWD_HOST, Gin::Constants::GIN_ACTION, Gin::Constants::GIN_CTRL, Gin::Constants::GIN_ERRORS, Gin::Constants::GIN_PATH_PARAMS, Gin::Constants::GIN_RELOADED, Gin::Constants::GIN_ROUTE, Gin::Constants::GIN_STACK, Gin::Constants::GIN_STATIC, Gin::Constants::GIN_TEMPLATES, Gin::Constants::GIN_TIMESTAMP, Gin::Constants::HTTP_VERSION, Gin::Constants::IF_MATCH, Gin::Constants::IF_MOD_SINCE, Gin::Constants::IF_NONE_MATCH, Gin::Constants::IF_UNMOD_SINCE, Gin::Constants::LAST_MOD, Gin::Constants::LOCATION, Gin::Constants::PATH_INFO, Gin::Constants::PRAGMA, Gin::Constants::QUERY_STRING, Gin::Constants::REMOTE_ADDR, Gin::Constants::REMOTE_USER, Gin::Constants::REQ_METHOD, Gin::Constants::SESSION_SECRET

Instance Attribute Summary collapse

Class Method Summary collapse

Instance Method Summary collapse

Methods included from Errorable

#handle_error, #handle_status, included

Methods included from Filterable

#filter, included

Constructor Details

#initialize(app, env) ⇒ Controller

Returns a new instance of Controller.



158
159
160
161
162
163
164
 
# File 'lib/gin/controller.rb', line 158

def initialize app, env
  @app      = app
  @action   = nil
  @env      = env
  @request  = Gin::Request.new env
  @response = Gin::Response.new
end

Instance Attribute Details

#action ⇒ Object (readonly)

The action that the HTTP request resolved to, based on the App’s router.



152
153
154
 
# File 'lib/gin/controller.rb', line 152

def action
  @action
end

#app ⇒ Object (readonly)

The Gin::App instance used by the controller. The App instance is meant for read-only use. Writes are not thread-safe and at your own risk.



143
144
145
 
# File 'lib/gin/controller.rb', line 143

def app
  @app
end

#env ⇒ Object (readonly)

The Rack env hash.



155
156
157
 
# File 'lib/gin/controller.rb', line 155

def env
  @env
end

#request ⇒ Object (readonly)

Gin::Request instance representing the HTTP request.



146
147
148
 
# File 'lib/gin/controller.rb', line 146

def request
  @request
end

#response ⇒ Object (readonly)

Gin::Response instance representing the HTTP response.



149
150
151
 
# File 'lib/gin/controller.rb', line 149

def response
  @response
end

Class Method Details

.actions ⇒ Object

Array of action names for this controller.



86
87
88
 
# File 'lib/gin/controller.rb', line 86

def self.actions
  instance_methods(false)
end

.content_type(new_type = nil) ⇒ Object

Set or get the default content type for this Gin::Controller. Default value is “text/html”. This attribute is inherited.



107
108
109
110
111
112
 
# File 'lib/gin/controller.rb', line 107

def self.content_type new_type=nil
  @content_type = new_type if new_type
  return @content_type if defined?(@content_type) && @content_type
  self.superclass.respond_to?(:content_type) &&
    self.superclass.content_type || "text/html"
end

.controller_name(new_name = nil) ⇒ Object

String representing the controller name. Underscores the class name and removes mentions of ‘controller’.

MyApp::FooController.controller_name
#=> "my_app/foo"



97
98
99
100
 
# File 'lib/gin/controller.rb', line 97

def self.controller_name new_name=nil
  @ctrl_name = new_name if new_name
  @ctrl_name
end

.exec(app, env, &block) ⇒ Object

Execute arbitrary code in the context of a Gin::Controller instance. Returns a Rack response Array.



119
120
121
122
123
 
# File 'lib/gin/controller.rb', line 119

def self.exec app, env, &block
  inst = new(app, env)
  inst.invoke{ inst.instance_exec(&block) }
  inst.response.finish
end

.inherited(subclass) ⇒ Object 



69
70
71
72
 
# File 'lib/gin/controller.rb', line 69

def self.inherited subclass
  subclass.setup
  super
end

.layout(name = nil) ⇒ Object

Get or set a layout for a given controller. Value can be a symbol or filepath. Layout file is expected to be in the Gin::App.layout_dir directory Defaults to the parent class layout, or Gin::App.layout.



132
133
134
135
136
 
# File 'lib/gin/controller.rb', line 132

def self.layout name=nil
  @layout = name if name
  return @layout if @layout
  return self.superclass.layout if self.superclass.respond_to?(:layout)
end

.setup ⇒ Object

:nodoc:



75
76
77
78
 
# File 'lib/gin/controller.rb', line 75

def self.setup   # :nodoc:
  @layout = nil
  @ctrl_name = Gin.underscore(self.to_s).gsub(/_?controller_?/,'')
end

Instance Method Details

#asset(path) ⇒ Object

Check if an asset exists. Returns the full system path to the asset if found, otherwise nil.



617
618
619
 
# File 'lib/gin/controller.rb', line 617

def asset path
  @app.asset path
end

#asset_url(name) ⇒ Object

Returns the url to an asset, including predefined asset cdn hosts if set.



606
607
608
609
610
 
# File 'lib/gin/controller.rb', line 606

def asset_url name
  url = File.join(@app.asset_host_for(name).to_s, name)
  url = [url, *@app.asset_version(url)].join("?") if url !~ %r{^https?://}
  url
end

#body(body = nil) ⇒ Object

Get or set the HTTP response body.



187
188
189
190
 
# File 'lib/gin/controller.rb', line 187

def body body=nil
  @response.body = body if body
  @response.body
end

#cache_control(*values) ⇒ Object

Specify response freshness policy for HTTP caches (Cache-Control header). Any number of non-value directives (:public, :private, :no_cache, :no_store, :must_revalidate, :proxy_revalidate) may be passed along with a Hash of value directives (:max_age, :min_stale, :s_max_age).

cache_control :public, :must_revalidate, :max_age => 60
#=> Cache-Control: public, must-revalidate, max-age=60



546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
 
# File 'lib/gin/controller.rb', line 546

def cache_control *values
  if Hash === values.last
    hash = values.pop
    hash.reject!{|k,v| v == false || v == true && values << k }
  else
    hash = {}
  end

  values.map! { |value| value.to_s.tr('_','-') }
  hash.each do |key, value|
    key = key.to_s.tr('_', '-')
    value = value.to_i if key == "max-age"
    values << [key, value].join('=')
  end

  @response[CACHE_CTRL] = values.join(', ') if values.any?
end

#call_action(action) ⇒ Object

:nodoc:



167
168
169
170
171
172
 
# File 'lib/gin/controller.rb', line 167

def call_action action #:nodoc:
  invoke{ dispatch action }
  invoke{ handle_status(@response.status) }
  content_type self.class.content_type unless @response[CNT_TYPE]
  @response.finish
end

#config ⇒ Object

Accessor for @app.config.



196
197
198
 
# File 'lib/gin/controller.rb', line 196

def config
  @app.config
end

#content_type(type = nil, params = {}) ⇒ Object

Get or set the HTTP response Content-Type header.

content_type :json
content_type 'application/json;charset=us-ascii'
content_type :json, charset: 'us-ascii'



215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
 
# File 'lib/gin/controller.rb', line 215

def content_type type=nil, params={}
  return @response[CNT_TYPE] unless type

  default   = params.delete(:default)
  mime_type = mime_type(type) || default
  raise "Unknown media type: %p" % type if mime_type.nil?

  mime_type = mime_type.dup
  unless params.include? :charset
    params[:charset] = params.delete('charset') || 'UTF-8'
  end

  params.delete :charset if mime_type.include? 'charset'
  unless params.empty?
    mime_type << (mime_type.include?(';') ? ', ' : ';')
    mime_type << params.map do |key, val|
      val = val.inspect if val =~ /[";,]/
      "#{key}=#{val}"
    end.join(', ')
  end

  @response[CNT_TYPE] = mime_type
end

#cookies ⇒ Object

Access the request cookies.



357
358
359
 
# File 'lib/gin/controller.rb', line 357

def cookies
  @request.cookies
end

#delete_cookie(name) ⇒ Object

Delete the response cookie with the given name. Does not affect request cookies.



383
384
385
 
# File 'lib/gin/controller.rb', line 383

def delete_cookie name
  @response.delete_cookie name
end

#dispatch(action) ⇒ Object

Dispatch the call to the action, calling before and after filers, and including error handling.



742
743
744
745
746
747
748
749
750
751
752
753
754
755
 
# File 'lib/gin/controller.rb', line 742

def dispatch action
  @action = action

  invoke do
    filter(*before_filters_for(action))
    args = action_arguments action
    __send__(action, *args)
  end

rescue => err
  invoke{ handle_error err }
ensure
  filter(*after_filters_for(action))
end

#error(code, body = nil) ⇒ Object

Halt processing and return the error status provided.



261
262
263
264
265
 
# File 'lib/gin/controller.rb', line 261

def error code, body=nil
  code, body     = 500, code if code.respond_to? :to_str
  @response.body = body unless body.nil?
  halt code
end

#etag(value, opts = {}) ⇒ Object

Set the ETag header. If the ETag was set in a previous request and matches the current one, halts the action and returns a 304 on GET and HEAD requests.



273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
 
# File 'lib/gin/controller.rb', line 273

def etag value, opts={}
  opts         = {:kind => opts} unless Hash === opts
  kind         = opts[:kind] || :strong
  new_resource = opts.fetch(:new_resource) { @request.post? }

  unless [:strong, :weak].include?(kind)
    raise ArgumentError, ":strong or :weak expected"
  end

  value = '"%s"' % value
  value = 'W/' + value if kind == :weak
  @response[ETAG] = value

  if (200..299).include?(status) || status == 304
    if etag_matches? @env[IF_NONE_MATCH], new_resource
      halt(@request.safe? ? 304 : 412)
    end

    if @env[IF_MATCH]
      halt 412 unless etag_matches? @env[IF_MATCH], new_resource
    end
  end
end

#etag_matches?(list, new_resource = @request.post?) ⇒ Boolean

:nodoc:

Returns:

  • (Boolean) 


298
299
300
301
 
# File 'lib/gin/controller.rb', line 298

def etag_matches? list, new_resource=@request.post? #:nodoc:
  return !new_resource if list == '*'
  list.to_s.split(/\s*,\s*/).include? response[ETAG]
end

#expire_cache_control ⇒ Object

Sets Cache-Control, Expires, and Pragma headers to tell the browser not to cache the response.



597
598
599
600
 
# File 'lib/gin/controller.rb', line 597

def expire_cache_control
  @response[PRAGMA] = 'no-cache'
  expires EPOCH, :no_cache, :no_store, :must_revalidate, max_age: 0
end

#expires(amount, *values) ⇒ Object

Set the Expires header and Cache-Control/max-age directive. Amount can be an integer number of seconds in the future or a Time object indicating when the response should be considered “stale”. The remaining “values” arguments are passed to the #cache_control helper:

expires 500, :public, :must_revalidate
=> Cache-Control: public, must-revalidate, max-age=60
=> Expires: Mon, 08 Jun 2009 08:50:17 GMT



575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
 
# File 'lib/gin/controller.rb', line 575

def expires amount, *values
  values << {} unless Hash === values.last

  if Integer === amount
    time    = Time.now + amount.to_i
    max_age = amount
  else
    time    = String === amount ? Time.parse(amount) : amount
    max_age = time - Time.now
  end

  values.last.merge!(:max_age => max_age) unless values.last[:max_age]
  cache_control(*values)

  @response[EXPIRES] = time.httpdate
end

#h(obj) ⇒ Object

HTML-escape the given String.



794
795
796
 
# File 'lib/gin/controller.rb', line 794

def h obj
  CGI.escapeHTML obj.to_s
end

#halt(*resp) ⇒ Object

Stop the execution of an action and return the response. May be given a status code, string, header Hash, or a combination:

halt 400, "Badly formed request"
halt "Done early! WOOO!"
halt 302, {'Location' => 'http://example.com'}, "You are being redirected"



247
248
249
250
251
252
253
254
255
 
# File 'lib/gin/controller.rb', line 247

def halt *resp
  if @app.development?
    line = caller.find{|l| !l.start_with?(Gin::LIB_DIR) && !l.include?("/ruby/gems/")}
    logger << "[HALT] #{line}\n" if line
  end

  resp = resp.first if resp.length == 1
  throw :halt, resp
end

#headers(hash = nil) ⇒ Object

Set multiple response headers with Hash.



309
310
311
312
 
# File 'lib/gin/controller.rb', line 309

def headers hash=nil
  @response.headers.merge! hash if hash
  @response.headers
end

#html_error_page(err, code = nil) ⇒ Object

In development mode, returns an HTML page displaying the full error and backtrace, otherwise shows a generic error page.

Production error pages are first looked for in the public directory as <status>.html or 500.html. If none is found, falls back on Gin’s internal error html pages.



766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
 
# File 'lib/gin/controller.rb', line 766

def html_error_page err, code=nil
  if @app.development?
    fulltrace = err.backtrace.join("\n")
    fulltrace = "<pre>#{h(fulltrace)}</pre>"

    apptrace  = Gin.app_trace(err.backtrace).join("\n")
    apptrace  = "<pre>#{h(apptrace)}</pre>" unless apptrace.empty?

    DEV_ERROR_HTML %
      [h(err.class), h(err.class), h(err.message), apptrace, fulltrace]

  else
    code ||= status
    filepath = asset("#{code}.html") || asset("500.html")

    unless filepath
      filepath = File.join(Gin::PUBLIC_DIR, "#{code}.html")
      filepath = File.join(Gin::PUBLIC_DIR, "500.html") if !File.file?(filepath)
    end

    File.open(filepath, "rb")
  end
end

#invoke ⇒ Object

Taken from Sinatra.

Run the block with ‘throw :halt’ support and apply result to the response.



723
724
725
726
727
728
729
730
731
732
733
734
735
 
# File 'lib/gin/controller.rb', line 723

def invoke
  res = catch(:halt) { yield }
  res = [res] if Fixnum === res || String === res
  if Array === res && Fixnum === res.first
    res = res.dup
    status(res.shift)
    body(res.pop)
    headers(*res)
  elsif res.respond_to? :each
    body res
  end
  nil # avoid double setting the same response tuple twice
end

#last_modified(time) ⇒ Object

Set the last modified time of the resource (HTTP ‘Last-Modified’ header) and halt if conditional GET matches. The time argument is a Time, DateTime, or other object that responds to to_time or httpdate.



510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
 
# File 'lib/gin/controller.rb', line 510

def last_modified time
  return unless time

  time = Time.at(time)    if Integer === time
  time = Time.parse(time) if String === time
  time = time.to_time     if time.respond_to?(:to_time)

  @response[LAST_MOD] = time.httpdate
  return if @env[IF_NONE_MATCH]

  if status == 200 && @env[IF_MOD_SINCE]
    # compare based on seconds since epoch
    since = Time.httpdate(@env[IF_MOD_SINCE]).to_i
    halt 304 if since >= time.to_i
  end

  if @env[IF_UNMOD_SINCE] &&
    ((200..299).include?(status) || status == 412)

    # compare based on seconds since epoch
    since = Time.httpdate(@env[IF_UNMOD_SINCE]).to_i
    halt 412 if since < time.to_i
  end
rescue ArgumentError
end

#layout ⇒ Object

Value of the layout to use for rendering. See also Gin::Controller.layout and Gin::App.layout.



626
627
628
 
# File 'lib/gin/controller.rb', line 626

def layout
  self.class.layout || @app.layout
end

#logger ⇒ Object

Accessor for main application logger.



333
334
335
 
# File 'lib/gin/controller.rb', line 333

def logger
  @app.logger
end

#mime_type(type) ⇒ Object

Get the normalized mime-type matching the given input.



204
205
206
 
# File 'lib/gin/controller.rb', line 204

def mime_type type
  @app.mime_type type
end

#params ⇒ Object

Get the request params.



341
342
343
 
# File 'lib/gin/controller.rb', line 341

def params
  @request.params
end

#path_to(*args) ⇒ Object

Build a path to the given controller and action or route name, with any expected params. If no controller is specified and the current controller responds to the symbol given, uses the current controller for path lookup.

path_to FooController, :show, :id => 123
#=> "/foo/123"

# From FooController
path_to :show, :id => 123
#=> "/foo/123"

# Default named route
path_to :show_foo, :id => 123
#=> "/foo/123"



405
406
407
408
409
 
# File 'lib/gin/controller.rb', line 405

def path_to *args
  return "#{args[0]}#{"?" << Gin.build_query(args[1]) if args[1]}" if String === args[0]
  args.unshift(self.class) if Symbol === args[0] && respond_to?(args[0])
  @app.router.path_to(*args)
end

#redirect(uri, *args) ⇒ Object

Send a 301, 302, or 303 redirect and halt. Supports passing a full URI, partial path.

redirect "http://google.com"
redirect "/foo"
redirect "/foo", 301, "You are being redirected..."
redirect to(MyController, :action, :id => 123)
redirect to(:show_foo, :id => 123)



462
463
464
465
466
467
468
469
470
471
 
# File 'lib/gin/controller.rb', line 462

def redirect uri, *args
  if @env[HTTP_VERSION] == 'HTTP/1.1' && @env[REQ_METHOD] != 'GET'
    status 303
  else
    status 302
  end

  @response[LOCATION] = url_to(uri.to_s)
  halt(*args)
end

#send_file(path, opts = {}) ⇒ Object

Assigns a file to the response body and halts the execution of the action. Produces a 404 response if no file is found.



478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
 
# File 'lib/gin/controller.rb', line 478

def send_file path, opts={}
  if opts[:type] || !@response[CNT_TYPE]
    content_type opts[:type] || File.extname(path),
                  :default => 'application/octet-stream'
  end

  disposition = opts[:disposition]
  filename    = opts[:filename]
  disposition = 'attachment'        if disposition.nil? && filename
  filename    = File.basename(path) if filename.nil?

  if disposition
    @response[CNT_DISPOSITION] =
      "%s; filename=\"%s\"" % [disposition, filename]
  end

  last_modified opts[:last_modified] || File.mtime(path).httpdate
  halt 200 if @request.head?

  @response[CNT_LENGTH] = File.size?(path).to_s
  halt 200, File.open(path, "rb")

rescue Errno::ENOENT
  halt 404
end

#session ⇒ Object

Access the request session.



349
350
351
 
# File 'lib/gin/controller.rb', line 349

def session
  @request.session
end

#set_cookie(name, value = nil, opts = {}) ⇒ Object

Set a cookie on the Rack response.

set_cookie "mycookie", "FOO", :expires => 600, :path => "/"
set_cookie "mycookie", :expires => 600



368
369
370
371
372
373
374
375
376
 
# File 'lib/gin/controller.rb', line 368

def set_cookie name, value=nil, opts={}
  if Hash === value
    opts = value
  else
    opts[:value] = value
  end

  @response.set_cookie name, opts
end

#status(code = nil) ⇒ Object

Set or get the HTTP response status code.



178
179
180
181
 
# File 'lib/gin/controller.rb', line 178

def status code=nil
  @response.status = code if code
  @response.status
end

#stream(keep_open = false, &block) ⇒ Object

Assigns a Gin::Stream to the response body, which is yielded to the block. The block execution is delayed until the action returns.

stream do |io|
  file = File.open "somefile", "rb"
  io << file.read(1024) until file.eof?
  file.close
end



324
325
326
327
 
# File 'lib/gin/controller.rb', line 324

def stream keep_open=false, &block
  scheduler = env[ASYNC_CALLBACK] ? EventMachine : Gin::Stream
  body Gin::Stream.new(scheduler, keep_open){ |out| yield(out) }
end

#template_path(template, is_layout = false) ⇒ Object

Returns the path to where the template is expected to be.

template_path :foo
#=> "<views_dir>/foo"

template_path "sub/foo"
#=> "<views_dir>/sub/foo"

template_path "sub/foo", :layout
#=> "<layouts_dir>/sub/foo"

template_path "/other/foo"
#=> "<root_dir>/other/foo"



645
646
647
648
649
650
651
652
653
654
655
656
657
 
# File 'lib/gin/controller.rb', line 645

def template_path template, is_layout=false
  dir = if template[0] == ?/
          @app.root_dir
        elsif is_layout
          @app.layouts_dir
        else
          @app.views_dir
        end

  path = File.join(dir, template.to_s)
  path.gsub!('*', controller_name)
  File.expand_path(path)
end

#url_to(*args) ⇒ Object Also known as: to 



431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
 
# File 'lib/gin/controller.rb', line 431

def url_to *args
  path = path_to(*args)

  return path if path =~ /\A[A-z][A-z0-9\+\.\-]*:/

  uri  = [host = ""]
  host << "http#{'s' if @request.ssl?}://"

  if @request.forwarded? || @request.port != (@request.ssl? ? 443 : 80)
    host << @request.host_with_port
  else
    host << @request.host
  end

  uri << @request.script_name.to_s
  uri << path
  File.join uri
end

#view(template, opts = {}, &block) ⇒ Object

Render a template with the given view template. Options supported:

:locals

Hash - local variables used in template

:layout

Symbol/String - a custom layout to use

:scope

Object - The scope in which to render the template: default self

:content_type

Symbol/String - Content-Type header to set

:engine

String - Tilt rendering engine to use

:layout_engine

String - Tilt layout rendering engine to use

The template argument may be a String or a Symbol. By default the template location will be looked for under Gin::App.views_dir, but the directory may be specified as any directory under Gin::App.root_dir by using the ‘/’ prefix:

view 'foo/template'
#=> Renders file "<views_dir>/foo/template"

view '/foo/template'
#=> Renders file "<root_dir>/foo/template"

# Render without layout
view 'foo/template', layout: false

Raises:



684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
 
# File 'lib/gin/controller.rb', line 684

def view template, opts={}, &block
  content_type(opts.delete(:content_type)) if opts[:content_type]

  scope  = opts[:scope]  || self
  locals = opts[:locals] || {}

  template   = template_path(template)
  v_template = @app.template_for template, opts[:engine]
  raise Gin::TemplateMissing, "No such template `#{template}'" unless v_template

  if opts[:layout] != false
    r_layout   = template_path((opts[:layout] || layout), true)
    r_template = @app.template_for r_layout, opts[:layout_engine] if r_layout
  end

  if !@response[CNT_TYPE]
    mime_type = v_template.class.default_mime_type ||
      r_template && r_template.class.default_mime_type
    content_type(mime_type) if mime_type
  end

  @env[GIN_TEMPLATES] ||= []

  if r_template
    @env[GIN_TEMPLATES] << r_template.file << v_template.file
    r_template.render(scope, locals){
      v_template.render(scope, locals, &block) }
  else
    @env[GIN_TEMPLATES] << v_template.file
    v_template.render(scope, locals, &block)
  end
end