/
using-rack-middleware-for-good-and-evil.html
150 lines (142 loc) · 7.09 KB
/
using-rack-middleware-for-good-and-evil.html
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
<!DOCTYPE html>
<html>
<head>
<meta charset="utf-8" />
<meta http-equiv="X-UA-Compatible" content="chrome=1" />
<meta name="viewport" content="width=device-width, minimum-scale=1.0" />
<link rel="stylesheet" href="/css/style-b3fa15dce221ff2373344e23bec3febe.css" type="text/css" />
<link rel="alternate" type="application/atom+xml" href="http://tomafro.net/atom.xml" />
<link rel="canonical" href="http://tomafro.net/2009/05/using-rack-middleware-for-good-and-evil"/>
<script type="text/javascript" src="http://use.typekit.com/brv6igt.js"></script>
<script type="text/javascript">try{Typekit.load();}catch(e){}</script>
<title>Using Rack Middleware for good and evil · tomafro.net</title>
<script type="text/javascript">
var _gaq = _gaq || [];
_gaq.push(['_setAccount', 'UA-1103395-2']);
_gaq.push(['_trackPageview']);
(function() {
var ga = document.createElement('script');
ga.src = ('https:' == document.location.protocol ? 'https://ssl' :
'http://www') + '.google-analytics.com/ga.js';
ga.setAttribute('async', 'true');
document.documentElement.firstChild.appendChild(ga);
})();
</script>
<!--[if lt IE 9]>
<script src="//html5shiv.googlecode.com/svn/trunk/html5.js"></script>
<![endif]-->
</head>
<body>
<nav>
<ul>
<li><a href='/'>tomafro.net</a><span class='byline'> – a blog by Tom Ward</span></li>
<li><a href='/about'>about</a></li>
<li><a href='https://github.com/tomafro'>github</a></li>
<li><a href='https://twitter.com/tomafro'>twitter</a></li>
</ul>
</nav>
<article>
<header>
<h1><a href="/2009/05/using-rack-middleware-for-good-and-evil">Using Rack Middleware for good and evil</a></h1>
</header>
<div class="content">
<p>So we all know that <a href="http://rack.rubyforge.org/">Rack</a> is awesome, and that we can use Rack::Middleware for all sorts of things: <a href="http://github.com/brynary/rack-bug/tree/master">debugging</a>, <a href="http://tomayko.com/src/rack-cache/">caching</a> and a <a href="http://github.com/rack/rack-contrib/tree/master">whole host more</a>.</p>
<p>What all these have in common (apart from maybe <a href="http://github.com/rack/rack-contrib/blob/8b6323c8eecc8279088987c52b27dda5d4cadf7b/lib/rack/contrib/evil.rb">Rack::Evil</a>) is that they’re all helpful. They all make writing Rack applications easier. Not my Middleware though.</p>
<h3>Introducing Rack::Shuffler</h3>
<div class="highlight"><pre><span class="k">module</span> <span class="nn">Rack</span>
<span class="k">class</span> <span class="nc">Shuffler</span>
<span class="k">def</span> <span class="nf">initialize</span><span class="p">(</span><span class="n">app</span><span class="p">)</span>
<span class="vi">@app</span> <span class="o">=</span> <span class="n">app</span>
<span class="vi">@responses</span> <span class="o">=</span> <span class="o">[]</span>
<span class="k">end</span>
<span class="k">def</span> <span class="nf">call</span><span class="p">(</span><span class="n">env</span><span class="p">)</span>
<span class="vi">@responses</span> <span class="o"><<</span> <span class="vi">@app</span><span class="o">.</span><span class="n">call</span><span class="p">(</span><span class="n">env</span><span class="p">)</span>
<span class="vi">@responses</span><span class="o">[</span><span class="nb">rand</span><span class="p">(</span><span class="vi">@responses</span><span class="o">.</span><span class="n">size</span><span class="p">)</span><span class="o">]</span>
<span class="k">ensure</span>
<span class="vi">@responses</span><span class="o">.</span><span class="n">delete_at</span><span class="p">(</span><span class="nb">rand</span><span class="p">(</span><span class="vi">@responses</span><span class="o">.</span><span class="n">size</span><span class="p">))</span> <span class="k">if</span> <span class="vi">@responses</span><span class="o">.</span><span class="n">size</span> <span class="o">></span> <span class="mi">100</span>
<span class="k">end</span>
<span class="k">end</span>
<span class="k">end</span>
</pre>
</div>
<p>I suggest you add it to a colleague’s app late on a Friday afternoon, and see how long it takes to drive them to insanity.</p>
</div>
<footer>
<span class='author'><a rel='author' href='http://tomafro.net'>Tom Ward</a></span>
<span class='date'><a href="/2009/05">22nd May 2009</a></span>
<ul>
<li><a href="/tags/ruby" rel="tag">ruby</a></li>
<li><a href="/tags/rack" rel="tag">rack</a></li>
<li><a href="/tags/middleware" rel="tag">middleware</a></li>
<li><a href="/tags/evil" rel="tag">evil</a></li>
<li><a href="/tags/fun" rel="tag">fun</a></li>
</ul>
</footer>
</article>
<section class="related-links">
<h1>Related posts:</h1>
<ul>
<li>
<a class='title' href="/2009/05/adam-sandersons-open-gem">Adam Sanderson's open_gem</a>
<div class='meta'>
<span class='date'><a href="/2009/05"> 6th May 2009</a></span>
<ul class='tags'>
<li><a href="/tags/ruby" rel="tag">ruby</a></li>
<li><a href="/tags/gem" rel="tag">gem</a></li>
<li><a href="/tags/tip" rel="tag">tip</a></li>
<li><a href="/tags/gem-open" rel="tag">gem-open</a></li>
</ul>
</div>
</li>
<li>
<a class='title' href="/2009/05/automatching-rails-paths-in-cucumber">Automatching rails paths in cucumber</a>
<div class='meta'>
<span class='date'><a href="/2009/05">13th May 2009</a></span>
<ul class='tags'>
<li><a href="/tags/cucumber" rel="tag">cucumber</a></li>
<li><a href="/tags/rails" rel="tag">rails</a></li>
<li><a href="/tags/ruby" rel="tag">ruby</a></li>
<li><a href="/tags/testing" rel="tag">testing</a></li>
<li><a href="/tags/tip" rel="tag">tip</a></li>
</ul>
</div>
</li>
<li>
<a class='title' href="/2009/05/read-active-record-columns-directly-from-the-class">Read ActiveRecord columns directly from the class</a>
<div class='meta'>
<span class='date'><a href="/2009/05">29th May 2009</a></span>
<ul class='tags'>
<li><a href="/tags/ruby" rel="tag">ruby</a></li>
<li><a href="/tags/rails" rel="tag">rails</a></li>
<li><a href="/tags/active-record" rel="tag">active-record</a></li>
<li><a href="/tags/column-reader" rel="tag">column-reader</a></li>
</ul>
</div>
</li>
<li>
<a class='title' href="/2009/06/pimp-my-script-console">Pimp my script/console</a>
<div class='meta'>
<span class='date'><a href="/2009/06">22nd June 2009</a></span>
<ul class='tags'>
<li><a href="/tags/ruby" rel="tag">ruby</a></li>
<li><a href="/tags/rails" rel="tag">rails</a></li>
<li><a href="/tags/irb" rel="tag">irb</a></li>
<li><a href="/tags/tip" rel="tag">tip</a></li>
</ul>
</div>
</li>
<li>
<a class='title' href="/2009/08/the-cost-of-explicit-returns-in-ruby">The cost of explicit returns in ruby</a>
<div class='meta'>
<span class='date'><a href="/2009/08"> 4th August 2009</a></span>
<ul class='tags'>
<li><a href="/tags/ruby" rel="tag">ruby</a></li>
<li><a href="/tags/micro-benchmark" rel="tag">micro-benchmark</a></li>
<li><a href="/tags/return" rel="tag">return</a></li>
</ul>
</div>
</li>
</ul>
</section>
</body>
</html>