The document discusses Rack middleware and how it allows for modular web application development in Ruby. Some key points: - Rack provides a modular interface between web servers and Ruby frameworks, allowing frameworks and middleware to be composed together. - Middleware can add functionality like caching, authentication, logging, etc. Middleware are run before the application code. - Popular middleware include Rack::Cache for caching and Rack::Auth for authentication. CloudKit is a middleware for building web services. - Middleware can cooperate by delegating to each other in a defined order and URI space. This allows middleware to work together to provide features to applications.

1. Rack
Middleware
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2. m/
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3. NEED
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4. CHOICE
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5. Jon Crosby
http://joncrosby.me
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6. CloudKit
http://getcloudkit.com
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7. rack-contrib
http://github.com/rack/rack-contrib
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8. Tuesday, March 17, 2009

9. Engine Yard Solo
“The platform for
on-demand management of your
Ruby on Rails application
in the cloud.”
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10. Free during HackFest
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11. Discount for Sign Up
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12. CGI
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13. app.cgi
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14. WARNING
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15. Contains Perl
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16. old skool perl cgi
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17. if ($cgi->param(‘action’) eq ‘all’) {
my $sql = “select * from customer”;
my $rows =
$dbh->selectall_arrayref($sql);
if (@$rows) {
print “<table border=1>” .
“<th>name</th>” .
...
Tuesday, March 17, 2009

18. if ($cgi->param(‘action’) eq ‘all’) {
my $sql = “select * from customer”;
my $rows =
$dbh->selectall_arrayref($sql);
if (@$rows) {
print “<table border=1>” .
“<th>name</th>” .
...
Tuesday, March 17, 2009

19. if ($cgi->param(‘action’) eq ‘all’) {
my $sql = “select * from customer”;
my $rows =
$dbh->selectall_arrayref($sql);
if (@$rows) {
print “<table border=1>” .
“<th>name</th>” .
...
Tuesday, March 17, 2009

20. if ($cgi->param(‘action’) eq ‘all’) {
my $sql = “select * from customer”;
my $rows =
$dbh->selectall_arrayref($sql);
if (@$rows) {
print “<table border=1>” .
“<th>name</th>” .
...
Tuesday, March 17, 2009

21. if ($cgi->param(‘action’) eq ‘all’) {
my $sql = “select * from customer”;
my $rows =
$dbh->selectall_arrayref($sql);
if (@$rows) {
print “<table border=1>” .
“<th>name</th>” .
...
Tuesday, March 17, 2009

22. if ($cgi->param(‘action’) eq ‘all’) {
my $sql = “select * from customer”;
my $rows =
$dbh->selectall_arrayref($sql);
if (@$rows) {
print “<table border=1>” .
“<th>name</th>” .
...
Tuesday, March 17, 2009

23. Monolith
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24. :-(
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25. Rails
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26. Merb
Sinatra
Mack
Ramaze
Waves
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27. Authentication
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28. Single Sign-On
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29. Caching
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30. Authentication Example:
OpenID + OAuth
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31. Install Auth Plugin(s)
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32. Install Auth Plugin(s)
Generate Controllers
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33. Install Auth Plugin(s)
Generate Controllers
Generate Models
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34. Install Auth Plugin(s)
Generate Controllers
Generate Models
Generate Migrations
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35. Install Auth Plugin(s)
Generate Controllers
Generate Models
Generate Migrations
Modify Existing Controllers
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36. Install Auth Plugin(s)
Generate Controllers
Generate Models
Generate Migrations
Modify Existing Controllers
Monkey Patch Rails
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37. :-(
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38. The Web
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39. Tuesday, March 17, 2009

40. HTTP
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41. Intermediaries
HTTP
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42. Intermediaries App
HTTP
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43. Intermediaries App
HTTP
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44. Rack
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45. Tuesday, March 17, 2009

46. HTTP
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47. Intermediaries
HTTP
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48. Middleware
HTTP
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49. Middleware App
HTTP
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50. Rack is the Web
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51. The Web is Rack
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52. WSGI
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53. SPEC
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54. lambda { |env|
[
200,
{
‘Content-Type’ => ‘text/plain’,
‘Content-Length’ => ‘5’
},
[‘Hello’]
]
}
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55. lambda { |env|
[
200,
{
‘Content-Type’ => ‘text/plain’,
‘Content-Length’ => ‘5’
},
[‘Hello’]
]
}
Tuesday, March 17, 2009

56. lambda { |env|
[
200,
{
‘Content-Type’ => ‘text/plain’,
‘Content-Length’ => ‘5’
},
[‘Hello’]
]
}
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57. lambda { |env|
[
200,
{
‘Content-Type’ => ‘text/plain’,
‘Content-Length’ => ‘5’
},
[‘Hello’]
]
}
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58. lambda { |env|
[
200,
{
‘Content-Type’ => ‘text/plain’,
‘Content-Length’ => ‘5’
},
[‘Hello’]
]
}
Tuesday, March 17, 2009

59. lambda { |env|
[
200,
{
‘Content-Type’ => ‘text/plain’,
‘Content-Length’ => ‘5’
},
[‘Hello’]
]
}
Tuesday, March 17, 2009

60. lambda { |env|
[
200,
{
‘Content-Type’ => ‘text/plain’,
‘Content-Length’ => ‘5’
},
[‘Hello’]
]
}
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61. run lambda { |env|
[
200,
{
‘Content-Type’ => ‘text/plain’,
‘Content-Length’ => ‘5’
},
[‘Hello’]
]
}
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62. config.ru
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63. $ rackup config.ru
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64. $ curl http://localhost:9292
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65. Hello
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66. class App
def call(env)
[200, {...}, [...]]
end
end
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67. SPEC
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68. $ rake SPEC
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69. Rack::Lint
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70. lambda { |env|
[
200,
{
‘Content-Type’ => ‘text/plain’,
‘Content-Length’ => ‘5’
},
[‘Hello’]
]
}
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71. env
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72. REQUEST_METHOD
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73. env[‘REQUEST_METHOD’]
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74. GET
PUT
POST
DELETE
HEAD
OPTIONS
TRACE
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75. PATH_INFO
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76. /items/123
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77. HTTP_*
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78. HTTP_ACCEPT
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79. application/json
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80. rack.*
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81. rack.input
(the input stream)
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82. #gets
#each
#read
#rewind
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83. yournamespace.*
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84. request = Rack::Request.new(env)
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85. request.post?
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86. request.params[‘id’]
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87. request[‘HTTP_IF_MATCH’]
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88. m/
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89. Middleware App
HTTP
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90. use MiddlewareA
use MiddlewareB
use MiddlewareC
run app
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91. class GoSlower
def initialize(app)
@app = app
end
def call(env)
sleep(1)
@app.call(env)
end
end
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92. class GoSlower
def initialize(app)
@app = app
end
def call(env)
sleep(1)
@app.call(env)
end
end
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93. class GoSlower
def initialize(app)
@app = app
end
def call(env)
sleep(1)
@app.call(env)
end
end
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94. class GoSlower
def initialize(app)
@app = app
end
def call(env)
sleep(1)
@app.call(env)
end
end
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95. class GoSlower
def initialize(app)
@app = app
end
def call(env)
sleep(1)
@app.call(env)
end
end
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96. rack-contrib
http://github.com/rack/rack-contrib
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97. Rack::Profiler
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98. Rack::MailExceptions
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99. Rack::JSONP
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100. Rack::CSSHTTPRequest
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101. Rack::Cache
http://github.com/rtomayko/rack-cache
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102. Rack::NotFound
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103. 404
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104. Middleware App
HTTP
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105. use MiddlewareA
use MiddlewareB
use MiddlewareC
run app
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106. class App
def call(env)
[200, {...}, [...]]
end
end
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107. class GoSlower
def initialize(app)
@app = app
end
def call(env)
sleep(1)
@app.call(env)
end
end
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108. class GoSlower
def initialize(app)
@app = app
end
def call(env)
sleep(1)
@app.call(env)
end
end
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109. use MiddlewareA
use MiddlewareB
use MiddlewareC
run app
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110. Middleware App
HTTP
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111. Middleware App
HTTP
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112. Cooperative Middleware
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113. URI Space
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114. /*
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115. /just-what-it-needs
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116. CloudKit
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117. Open Web
JSON
Appliance
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118. expose :notes, :todos
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119. expose :notes, :todos
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120. contain :notes, :todos
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121. use Rack::Pool::Session
use CloudKit::OAuthFilter
use CloudKit::OpenIDFilter
use CloudKit::Service, :collections => [:notes, :todos]
(run DefaultApp)
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122. CloudKit::OAuthFilter
/oauth/*
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123. CloudKit::OpenIDFilter
/login
/logout
/openid_complete
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124. CloudKit::Service
/notes/*
/todos/*
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125. ?
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126. Browser
OAuth OpenID Service
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127. Browser
OAuth OpenID Service
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128. Browser
{...}
OAuth OpenID Service
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129. Browser
OAuth OpenID Service
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130. Browser
OAuth OpenID Service
{...}
Login
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131. Browser
OAuth OpenID Service
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132. Browser
OAuth OpenID Service
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133. Browser
OAuth OpenID Service
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134. Service or Desktop App
OAuth OpenID Service
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135. Service or Desktop App
OAuth OpenID Service
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136. Service or Desktop App
{...}
OAuth OpenID Service
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137. Service or Desktop App
OAuth OpenID Service
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138. Service or Desktop App
OAuth OpenID Service
{...}
Login
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139. Service or Desktop App
OAuth OpenID Service
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140. Service or Desktop App
OAuth OpenID Service
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141. Service or Desktop App
OAuth OpenID Service
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142. Service or Desktop App
OAuth OpenID Service
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143. Announcing
Middleware
Presence
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144. HTTP
Via
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145. Via: 1.0 ricky, 1.1 ethel, 1.1 fred
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146. Via: 1.0 ricky, 1.1 ethel, 1.1 fred
Tuesday, March 17, 2009

147. Via: 1.0 ricky, 1.1 ethel, 1.1 fred
Tuesday, March 17, 2009

148. Via: 1.0 ricky, 1.1 ethel, 1.1 fred
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149. env[‘cloudkit.auth’] = 1
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150. env[‘cloudkit.via’] << ‘cloudkit.filter.oauth’
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151. env[‘cloudkit.via’] << ‘cloudkit.filter.openid’
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152. env[‘cloudkit.user’] = ‘http://joncrosby.me’
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153. Alternative Stacks
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154. Rack::Map
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155. map “/” do
run Blog::Public
end
map “/db” do
run Blog::DBAdmin
end
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156. Rack::Map + Sinatra
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157. require ‘sinatra/base’
module Blog
class Public < Sinatra::Base
get ‘/’ do
erb :index
end
end
end
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158. require ‘sinatra/base’
module Blog
class Public < Sinatra::Base
get ‘/’ do
erb :index
end
end
end
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159. require ‘sinatra/base’
module Blog
class Public < Sinatra::Base
get ‘/’ do
erb :index
end
end
end
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160. require ‘sinatra’
for “apps”
/* URI space
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161. require ‘sinatra/base’
MyClass < Sinatra::Base
Minimal Sinatra (routing, rendering, etc.)
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162. m/
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163. use MySinatraApp
run SomeOtherApp
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164. Rack::Cascade
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165. app1 = lambda { ... }
app2 = lambda { ... }
run Rack::Cascade.new([app1, app2])
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166. Sinatra as Middleware
in Rails
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167. class X < Sinatra::Base
get ‘/what’ do
‘what’
end
end
Rails::Initializer.run do |config|
config.use.middleware ‘X’
end
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168. CloudKit in Rails
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169. Rails::Initializer.run do |config|
config.use.middleware ‘CloudKit::Service’, :collections => [:notes, :todos]
end
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170. Middleware App
HTTP
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171. Middleware App
Rails
HTTP
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172. Middleware App
Rails Merb
HTTP
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173. Middleware App
Rails Merb *
HTTP
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174. New Unit of Composition
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175. m/
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