-
Notifications
You must be signed in to change notification settings - Fork 0
Expand file tree
/
Copy pathindex.html
More file actions
915 lines (662 loc) · 54 KB
/
index.html
File metadata and controls
915 lines (662 loc) · 54 KB
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
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
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
503
504
505
506
507
508
509
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
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
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
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
832
833
834
835
836
837
838
839
840
841
842
843
844
845
846
847
848
849
850
851
852
853
854
855
856
857
858
859
860
861
862
863
864
865
866
867
868
869
870
871
872
873
874
875
876
877
878
879
880
881
882
883
884
885
886
887
888
889
890
891
892
893
894
895
896
897
898
899
900
901
902
903
904
905
906
907
908
909
910
911
912
913
914
915
<!DOCTYPE html>
<!--[if IEMobile 7 ]><html class="no-js iem7"><![endif]-->
<!--[if lt IE 9]><html class="no-js lte-ie8"><![endif]-->
<!--[if (gt IE 8)|(gt IEMobile 7)|!(IEMobile)|!(IE)]><!--><html class="no-js" lang="en"><!--<![endif]-->
<head>
<meta charset="utf-8">
<title>#akai</title>
<meta name="author" content="akai">
<meta name="description" content="Writing code that’s expressive, encapsulated & structured 1. Module Pattern Interchangeable single-parts of a larger system that can be easily re …">
<!-- http://t.co/dKP3o1e -->
<meta name="HandheldFriendly" content="True">
<meta name="MobileOptimized" content="320">
<meta name="viewport" content="width=device-width, initial-scale=1">
<link rel="canonical" href="http://akai.github.com">
<link href="/favicon.png" rel="icon">
<link href="/stylesheets/screen.css" media="screen, projection" rel="stylesheet" type="text/css">
<script src="/javascripts/modernizr-2.0.js"></script>
<script src="/javascripts/ender.js"></script>
<script src="/javascripts/octopress.js" type="text/javascript"></script>
<link href="/atom.xml" rel="alternate" title="#akai" type="application/atom+xml">
<!--Fonts from Google's Web font directory at http://google.com/webfonts -->
<link href='http://fonts.googleapis.com/css?family=PT+Serif:regular,italic,bold,bolditalic' rel='stylesheet' type='text/css'>
<link href='http://fonts.googleapis.com/css?family=PT+Sans:regular,italic,bold,bolditalic' rel='stylesheet' type='text/css'>
</head>
<body >
<header role="banner"><hgroup>
<h1><a href="/">#akai</a></h1>
<h2><span class="p">float</span><span class="v">cloud</span></h2>
</hgroup>
</header>
<nav role="navigation"><ul class="subscription" data-subscription="rss">
<li><a href="/atom.xml" rel="subscribe-rss" title="subscribe via RSS">RSS</a></li>
</ul>
<form action="http://google.com/search" method="get">
<fieldset role="search">
<input type="hidden" name="q" value="site:akai.github.com" />
<input class="search" type="text" name="q" results="0" placeholder="Search"/>
</fieldset>
</form>
<ul role=main-navigation>
<li><a href="/">Blog</a></li>
<li><a href="/blog/archives">Archives</a></li>
</ul>
</nav>
<div id="main">
<div id="content">
<div class="blog-index">
<article>
<header>
<h1 class="entry-title"><a href="/blog/js-patterns/">JavaScript Design Patterns</a></h1>
<p class="meta">
<time datetime="2011-12-01T14:16:00+08:00" pubdate data-updated="true">Dec 1<span>st</span>, 2011</time>
</p>
</header>
<div class="entry-content"><p>Writing code that’s expressive, encapsulated & structured</p>
<h2>1. Module Pattern</h2>
<p>Interchangeable single-parts of a larger system that can be easily re-used.</p>
<h3>Stepping stone: IIFE</h3>
<p>Immediately invoked function expressions (or self-executing anonymous functions)</p>
<figure class='code'> <div class="highlight"><table><tr><td class="gutter"><pre class="line-numbers"><span class='line-number'>1</span>
<span class='line-number'>2</span>
<span class='line-number'>3</span>
<span class='line-number'>4</span>
<span class='line-number'>5</span>
<span class='line-number'>6</span>
<span class='line-number'>7</span>
<span class='line-number'>8</span>
<span class='line-number'>9</span>
<span class='line-number'>10</span>
<span class='line-number'>11</span>
<span class='line-number'>12</span>
<span class='line-number'>13</span>
<span class='line-number'>14</span>
<span class='line-number'>15</span>
</pre></td><td class='code'><pre><code class='js'><span class='line'><span class="p">(</span><span class="kd">function</span><span class="p">()</span> <span class="p">{</span>
</span><span class='line'> <span class="c1">// code to be immediately invoked</span>
</span><span class='line'><span class="p">}());</span> <span class="c1">// Crockford recommends this way</span>
</span><span class='line'>
</span><span class='line'><span class="p">(</span><span class="kd">function</span><span class="p">()</span> <span class="p">{</span>
</span><span class='line'> <span class="c1">// code to be immediately invoked</span>
</span><span class='line'><span class="p">})();</span> <span class="c1">// This is just as valid</span>
</span><span class='line'>
</span><span class='line'><span class="p">(</span><span class="kd">function</span><span class="p">(</span><span class="nb">window</span><span class="p">,</span> <span class="nb">document</span><span class="p">,</span> <span class="kc">undefined</span><span class="p">)</span> <span class="p">{</span>
</span><span class='line'> <span class="c1">//code to be immediately invoked</span>
</span><span class='line'><span class="p">})(</span><span class="k">this</span><span class="p">,</span> <span class="k">this</span><span class="p">.</span><span class="nb">document</span><span class="p">);</span>
</span><span class='line'>
</span><span class='line'><span class="p">(</span><span class="kd">function</span><span class="p">(</span><span class="nx">global</span><span class="p">,</span> <span class="kc">undefined</span><span class="p">)</span> <span class="p">{</span>
</span><span class='line'> <span class="c1">//code to be immediately invoked</span>
</span><span class='line'><span class="p">})(</span><span class="k">this</span><span class="p">);</span>
</span></code></pre></td></tr></table></div></figure>
<h3>Simulate privacy</h3>
<p>The typical module pattern is where immediately invoked function expressions (IIFEs) use <strong>execution context</strong> to create ‘privacy’. Here, <strong>objects</strong> are returned instead of functions.</p>
<figure class='code'> <div class="highlight"><table><tr><td class="gutter"><pre class="line-numbers"><span class='line-number'>1</span>
<span class='line-number'>2</span>
<span class='line-number'>3</span>
<span class='line-number'>4</span>
<span class='line-number'>5</span>
<span class='line-number'>6</span>
<span class='line-number'>7</span>
<span class='line-number'>8</span>
<span class='line-number'>9</span>
<span class='line-number'>10</span>
<span class='line-number'>11</span>
<span class='line-number'>12</span>
<span class='line-number'>13</span>
<span class='line-number'>14</span>
<span class='line-number'>15</span>
<span class='line-number'>16</span>
<span class='line-number'>17</span>
<span class='line-number'>18</span>
</pre></td><td class='code'><pre><code class='js'><span class='line'><span class="kd">var</span> <span class="nx">basketModule</span> <span class="o">=</span> <span class="p">(</span><span class="kd">function</span><span class="p">()</span> <span class="p">{</span>
</span><span class='line'> <span class="kd">var</span> <span class="nx">basket</span> <span class="o">=</span> <span class="p">[];</span> <span class="c1">//private</span>
</span><span class='line'> <span class="k">return</span> <span class="p">{</span> <span class="c1">//exposed to public</span>
</span><span class='line'> <span class="nx">addItem</span><span class="o">:</span> <span class="kd">function</span><span class="p">(</span><span class="nx">values</span><span class="p">)</span> <span class="p">{</span>
</span><span class='line'> <span class="nx">basket</span><span class="p">.</span><span class="nx">push</span><span class="p">(</span><span class="nx">values</span><span class="p">);</span>
</span><span class='line'> <span class="p">},</span>
</span><span class='line'> <span class="nx">getItemCount</span><span class="o">:</span> <span class="kd">function</span><span class="p">()</span> <span class="p">{</span>
</span><span class='line'> <span class="k">return</span> <span class="nx">basket</span><span class="p">.</span><span class="nx">length</span><span class="p">;</span>
</span><span class='line'> <span class="p">},</span>
</span><span class='line'> <span class="nx">getTotal</span><span class="o">:</span> <span class="kd">function</span><span class="p">()</span> <span class="p">{</span>
</span><span class='line'> <span class="kd">var</span> <span class="nx">q</span> <span class="o">=</span> <span class="k">this</span><span class="p">.</span><span class="nx">getItemCount</span><span class="p">(),</span> <span class="nx">p</span> <span class="o">=</span> <span class="mi">0</span><span class="p">;</span>
</span><span class='line'> <span class="k">while</span> <span class="p">(</span><span class="nx">q</span><span class="o">--</span><span class="p">)</span> <span class="p">{</span>
</span><span class='line'> <span class="nx">p</span> <span class="o">+=</span> <span class="nx">basket</span><span class="p">[</span><span class="nx">q</span><span class="p">].</span><span class="nx">price</span><span class="p">;</span>
</span><span class='line'> <span class="p">}</span>
</span><span class='line'> <span class="k">return</span> <span class="nx">p</span><span class="p">;</span>
</span><span class='line'> <span class="p">}</span>
</span><span class='line'> <span class="p">}</span>
</span><span class='line'><span class="p">}());</span>
</span></code></pre></td></tr></table></div></figure>
<ul>
<li>In the pattern, variables declared are only available inside the module.</li>
<li>Variables de ned within the returning object are available to everyone</li>
<li>This allows us to simulate privacy</li>
</ul>
<h3>Sample usage</h3>
<p>Inside the module, you’ll notice we return an object. This gets automatically assigned to basketModule so that you can interact with it as follows:</p>
<figure class='code'> <div class="highlight"><table><tr><td class="gutter"><pre class="line-numbers"><span class='line-number'>1</span>
<span class='line-number'>2</span>
<span class='line-number'>3</span>
<span class='line-number'>4</span>
<span class='line-number'>5</span>
<span class='line-number'>6</span>
<span class='line-number'>7</span>
<span class='line-number'>8</span>
<span class='line-number'>9</span>
<span class='line-number'>10</span>
<span class='line-number'>11</span>
<span class='line-number'>12</span>
</pre></td><td class='code'><pre><code class='js'><span class='line'><span class="c1">//basketModule is an object with properties which can also be methodsbas</span>
</span><span class='line'><span class="nx">basketModule</span><span class="p">.</span><span class="nx">addItem</span><span class="p">({</span><span class="nx">item</span><span class="o">:</span> <span class="s1">'bread'</span><span class="p">,</span><span class="nx">price</span><span class="o">:</span> <span class="mf">0.5</span><span class="p">});</span>
</span><span class='line'><span class="nx">basketModule</span><span class="p">.</span><span class="nx">addItem</span><span class="p">({</span><span class="nx">item</span><span class="o">:</span> <span class="s1">'butter'</span><span class="p">,</span><span class="nx">price</span><span class="o">:</span> <span class="mf">0.3</span><span class="p">});</span>
</span><span class='line'>
</span><span class='line'><span class="nx">console</span><span class="p">.</span><span class="nx">log</span><span class="p">(</span><span class="nx">basketModule</span><span class="p">.</span><span class="nx">getItemCount</span><span class="p">());</span>
</span><span class='line'><span class="nx">console</span><span class="p">.</span><span class="nx">log</span><span class="p">(</span><span class="nx">basketModule</span><span class="p">.</span><span class="nx">getTotal</span><span class="p">());</span>
</span><span class='line'>
</span><span class='line'><span class="c1">//however, the following will not work:</span>
</span><span class='line'><span class="c1">// (undefined as not inside the returned object)</span>
</span><span class='line'><span class="nx">console</span><span class="p">.</span><span class="nx">log</span><span class="p">(</span><span class="nx">basketModule</span><span class="p">.</span><span class="nx">basket</span><span class="p">);</span>
</span><span class='line'><span class="c1">//(only exists within the module scope)</span>
</span><span class='line'><span class="nx">console</span><span class="p">.</span><span class="nx">log</span><span class="p">(</span><span class="nx">basket</span><span class="p">);</span>
</span></code></pre></td></tr></table></div></figure>
<h3>Module Pattern: jQuery</h3>
<p>In the following example, a <strong>library</strong> function is defined which declares a new library and automatically binds up the <strong>init</strong> function to document.ready when new libraries (ie. modules) are created.</p>
<figure class='code'> <div class="highlight"><table><tr><td class="gutter"><pre class="line-numbers"><span class='line-number'>1</span>
<span class='line-number'>2</span>
<span class='line-number'>3</span>
<span class='line-number'>4</span>
<span class='line-number'>5</span>
<span class='line-number'>6</span>
<span class='line-number'>7</span>
<span class='line-number'>8</span>
<span class='line-number'>9</span>
<span class='line-number'>10</span>
<span class='line-number'>11</span>
<span class='line-number'>12</span>
<span class='line-number'>13</span>
<span class='line-number'>14</span>
<span class='line-number'>15</span>
<span class='line-number'>16</span>
</pre></td><td class='code'><pre><code class='js'><span class='line'><span class="kd">function</span> <span class="nx">library</span><span class="p">(</span><span class="nx">module</span><span class="p">)</span> <span class="p">{</span>
</span><span class='line'> <span class="nx">$</span><span class="p">(</span><span class="kd">function</span><span class="p">()</span> <span class="p">{</span>
</span><span class='line'> <span class="k">if</span> <span class="p">(</span><span class="nx">module</span><span class="p">.</span><span class="nx">init</span><span class="p">)</span> <span class="p">{</span>
</span><span class='line'> <span class="nx">module</span><span class="p">.</span><span class="nx">init</span><span class="p">();</span>
</span><span class='line'> <span class="p">}</span>
</span><span class='line'> <span class="p">});</span>
</span><span class='line'> <span class="k">return</span> <span class="nx">module</span><span class="p">;</span>
</span><span class='line'><span class="p">}</span>
</span><span class='line'>
</span><span class='line'><span class="kd">var</span> <span class="nx">myLibrary</span> <span class="o">=</span> <span class="nx">library</span><span class="p">(</span><span class="kd">function</span><span class="p">()</span> <span class="p">{</span>
</span><span class='line'> <span class="k">return</span> <span class="p">{</span>
</span><span class='line'> <span class="nx">init</span><span class="o">:</span> <span class="kd">function</span><span class="p">()</span> <span class="p">{</span>
</span><span class='line'> <span class="cm">/*implementation*/</span>
</span><span class='line'> <span class="p">}</span>
</span><span class='line'> <span class="p">};</span>
</span><span class='line'><span class="p">}());</span>
</span></code></pre></td></tr></table></div></figure>
<h3>AMD + jQuery</h3>
<p>A very simple AMD module using jQuery and the color plugin</p>
<figure class='code'> <div class="highlight"><table><tr><td class="gutter"><pre class="line-numbers"><span class='line-number'>1</span>
<span class='line-number'>2</span>
<span class='line-number'>3</span>
<span class='line-number'>4</span>
<span class='line-number'>5</span>
<span class='line-number'>6</span>
<span class='line-number'>7</span>
<span class='line-number'>8</span>
<span class='line-number'>9</span>
<span class='line-number'>10</span>
<span class='line-number'>11</span>
<span class='line-number'>12</span>
<span class='line-number'>13</span>
</pre></td><td class='code'><pre><code class='js'><span class='line'><span class="nx">define</span><span class="p">([</span><span class="s2">"jquery"</span><span class="p">,</span> <span class="s2">"jquery.color"</span><span class="p">,</span> <span class="s2">"jquery.bounce"</span><span class="p">],</span> <span class="kd">function</span><span class="p">(</span><span class="nx">$</span><span class="p">)</span> <span class="p">{</span>
</span><span class='line'> <span class="c1">//the jquery.color and jquery.bounce plugins have been loaded</span>
</span><span class='line'> <span class="c1">// not exposed to other modules</span>
</span><span class='line'> <span class="nx">$</span><span class="p">(</span><span class="kd">function</span><span class="p">()</span> <span class="p">{</span>
</span><span class='line'> <span class="nx">$</span><span class="p">(</span><span class="s1">'#container'</span><span class="p">)</span>
</span><span class='line'> <span class="p">.</span><span class="nx">animate</span><span class="p">({</span><span class="s1">'backgroundColor'</span><span class="o">:</span> <span class="s1">'#ccc'</span><span class="p">},</span> <span class="mi">500</span><span class="p">)</span>
</span><span class='line'> <span class="p">.</span><span class="nx">bounce</span><span class="p">();</span>
</span><span class='line'> <span class="p">});</span>
</span><span class='line'> <span class="c1">// exposed to other modules</span>
</span><span class='line'> <span class="k">return</span> <span class="kd">function</span> <span class="p">()</span> <span class="p">{</span>
</span><span class='line'> <span class="c1">// your modules functionality</span>
</span><span class='line'> <span class="p">};</span>
</span><span class='line'><span class="p">});</span>
</span></code></pre></td></tr></table></div></figure>
<h3>AMD/UMD jQuery Plugin</h3>
<p><strong>Recommended</strong> by Require.js author James Burke</p>
<figure class='code'> <div class="highlight"><table><tr><td class="gutter"><pre class="line-numbers"><span class='line-number'>1</span>
<span class='line-number'>2</span>
<span class='line-number'>3</span>
<span class='line-number'>4</span>
<span class='line-number'>5</span>
<span class='line-number'>6</span>
<span class='line-number'>7</span>
<span class='line-number'>8</span>
<span class='line-number'>9</span>
<span class='line-number'>10</span>
<span class='line-number'>11</span>
<span class='line-number'>12</span>
<span class='line-number'>13</span>
<span class='line-number'>14</span>
<span class='line-number'>15</span>
<span class='line-number'>16</span>
<span class='line-number'>17</span>
</pre></td><td class='code'><pre><code class='js'><span class='line'><span class="p">(</span><span class="kd">function</span><span class="p">(</span><span class="nx">root</span><span class="p">,</span> <span class="nx">factory</span><span class="p">)</span> <span class="p">{</span>
</span><span class='line'> <span class="k">if</span> <span class="p">(</span><span class="k">typeof</span> <span class="nx">exports</span> <span class="o">===</span> <span class="s1">'object'</span><span class="p">)</span> <span class="p">{</span>
</span><span class='line'> <span class="c1">// Node/CommonJS</span>
</span><span class='line'> <span class="nx">factory</span><span class="p">(</span><span class="nx">require</span><span class="p">(</span><span class="s1">'jquery'</span><span class="p">));</span>
</span><span class='line'> <span class="p">}</span> <span class="k">else</span> <span class="k">if</span> <span class="p">(</span><span class="k">typeof</span> <span class="nx">define</span> <span class="o">===</span> <span class="s1">'function'</span> <span class="o">&&</span> <span class="nx">define</span><span class="p">.</span><span class="nx">amd</span><span class="p">)</span> <span class="p">{</span>
</span><span class='line'> <span class="c1">// AMD. Use a named plugin in case this</span>
</span><span class='line'> <span class="c1">// file is loaded outside an AMD loader,</span>
</span><span class='line'> <span class="c1">// but an AMD loader lives on the page.</span>
</span><span class='line'> <span class="nx">define</span><span class="p">(</span><span class="s1">'myPlugin'</span><span class="p">,</span> <span class="p">[</span><span class="s1">'jquery'</span><span class="p">],</span> <span class="nx">factory</span><span class="p">);</span>
</span><span class='line'> <span class="p">}</span> <span class="k">else</span> <span class="p">{</span>
</span><span class='line'> <span class="c1">// Browser globals</span>
</span><span class='line'> <span class="nx">factory</span><span class="p">(</span><span class="nx">root</span><span class="p">.</span><span class="nx">jQuery</span><span class="p">);</span>
</span><span class='line'> <span class="p">}</span>
</span><span class='line'><span class="p">}(</span><span class="k">this</span><span class="p">,</span> <span class="kd">function</span><span class="p">(</span><span class="nx">$</span><span class="p">)</span> <span class="p">{</span>
</span><span class='line'> <span class="nx">$</span><span class="p">.</span><span class="nx">fn</span><span class="p">.</span><span class="nx">myPlugin</span> <span class="o">=</span> <span class="kd">function</span><span class="p">()</span> <span class="p">{</span>
</span><span class='line'> <span class="p">};</span>
</span><span class='line'><span class="p">}));</span>
</span></code></pre></td></tr></table></div></figure>
<h3>CommonJS Modules</h3>
<p>They basically contain two parts: an <strong>exports</strong> object that contains the objects a module wishes to expose and a <strong>require</strong> function that modules can use to import the exports of other modules</p>
<figure class='code'> <div class="highlight"><table><tr><td class="gutter"><pre class="line-numbers"><span class='line-number'>1</span>
<span class='line-number'>2</span>
<span class='line-number'>3</span>
<span class='line-number'>4</span>
<span class='line-number'>5</span>
<span class='line-number'>6</span>
<span class='line-number'>7</span>
<span class='line-number'>8</span>
<span class='line-number'>9</span>
<span class='line-number'>10</span>
<span class='line-number'>11</span>
</pre></td><td class='code'><pre><code class='js'><span class='line'><span class="cm">/* here we achieve compatibility with AMD and CommonJS</span>
</span><span class='line'><span class="cm">using some boilerplate around the CommonJS module format*/</span>
</span><span class='line'><span class="p">(</span><span class="kd">function</span><span class="p">(</span><span class="nx">define</span><span class="p">){</span>
</span><span class='line'> <span class="nx">define</span><span class="p">(</span><span class="kd">function</span><span class="p">(</span><span class="nx">require</span><span class="p">,</span><span class="nx">exports</span><span class="p">){</span>
</span><span class='line'> <span class="cm">/*module contents*/</span>
</span><span class='line'> <span class="kd">var</span> <span class="nx">dep1</span> <span class="o">=</span> <span class="nx">require</span><span class="p">(</span><span class="s2">"foo"</span><span class="p">);</span>
</span><span class='line'> <span class="kd">var</span> <span class="nx">dep2</span> <span class="o">=</span> <span class="nx">require</span><span class="p">(</span><span class="s2">"bar"</span><span class="p">);</span>
</span><span class='line'> <span class="nx">exports</span><span class="p">.</span><span class="nx">hello</span> <span class="o">=</span> <span class="kd">function</span><span class="p">(){...};</span>
</span><span class='line'> <span class="nx">exports</span><span class="p">.</span><span class="nx">world</span> <span class="o">=</span> <span class="kd">function</span><span class="p">(){...};</span>
</span><span class='line'> <span class="p">});</span>
</span><span class='line'><span class="p">})(</span><span class="k">typeof</span> <span class="nx">define</span> <span class="o">==</span> <span class="s2">"function"</span> <span class="o">?</span> <span class="nx">define</span> <span class="o">:</span> <span class="kd">function</span><span class="p">(</span><span class="nx">factory</span><span class="p">)</span> <span class="p">{</span> <span class="nx">factory</span><span class="p">(</span><span class="nx">require</span><span class="p">,</span> <span class="nx">exports</span><span class="p">)</span> <span class="p">});</span>
</span></code></pre></td></tr></table></div></figure>
<h2>2. Facade Pattern</h2>
<p>Convenient, high-level interfaces to larger bodies of code that hide underlying complexity</p>
<h3>Facade Implementation</h3>
<p>A higher-level facade is provided to our underlying module, without directly exposing methods.</p>
<figure class='code'> <div class="highlight"><table><tr><td class="gutter"><pre class="line-numbers"><span class='line-number'>1</span>
<span class='line-number'>2</span>
<span class='line-number'>3</span>
<span class='line-number'>4</span>
<span class='line-number'>5</span>
<span class='line-number'>6</span>
<span class='line-number'>7</span>
<span class='line-number'>8</span>
<span class='line-number'>9</span>
<span class='line-number'>10</span>
<span class='line-number'>11</span>
<span class='line-number'>12</span>
<span class='line-number'>13</span>
<span class='line-number'>14</span>
<span class='line-number'>15</span>
<span class='line-number'>16</span>
<span class='line-number'>17</span>
<span class='line-number'>18</span>
<span class='line-number'>19</span>
<span class='line-number'>20</span>
<span class='line-number'>21</span>
<span class='line-number'>22</span>
<span class='line-number'>23</span>
<span class='line-number'>24</span>
<span class='line-number'>25</span>
</pre></td><td class='code'><pre><code class='js'><span class='line'><span class="kd">var</span> <span class="nx">module</span> <span class="o">=</span> <span class="p">(</span><span class="kd">function</span><span class="p">()</span> <span class="p">{</span>
</span><span class='line'> <span class="kd">var</span> <span class="nx">_private</span> <span class="o">=</span> <span class="p">{</span>
</span><span class='line'> <span class="nx">i</span><span class="o">:</span> <span class="mi">5</span><span class="p">,</span>
</span><span class='line'> <span class="nx">get</span><span class="o">:</span> <span class="kd">function</span><span class="p">()</span> <span class="p">{</span>
</span><span class='line'> <span class="nx">console</span><span class="p">.</span><span class="nx">log</span><span class="p">(</span><span class="s1">'current value:'</span> <span class="o">+</span> <span class="k">this</span><span class="p">.</span><span class="nx">i</span><span class="p">);</span>
</span><span class='line'> <span class="p">},</span>
</span><span class='line'> <span class="nx">set</span><span class="o">:</span> <span class="kd">function</span><span class="p">(</span><span class="nx">val</span><span class="p">)</span> <span class="p">{</span>
</span><span class='line'> <span class="k">this</span><span class="p">.</span><span class="nx">i</span> <span class="o">=</span> <span class="nx">val</span><span class="p">;</span>
</span><span class='line'> <span class="p">},</span>
</span><span class='line'> <span class="nx">run</span><span class="o">:</span> <span class="kd">function</span><span class="p">()</span> <span class="p">{</span>
</span><span class='line'> <span class="nx">console</span><span class="p">.</span><span class="nx">log</span><span class="p">(</span><span class="s1">'running'</span><span class="p">);</span>
</span><span class='line'> <span class="p">},</span>
</span><span class='line'> <span class="nx">jump</span><span class="o">:</span> <span class="kd">function</span><span class="p">()</span> <span class="p">{</span>
</span><span class='line'> <span class="nx">console</span><span class="p">.</span><span class="nx">log</span><span class="p">(</span><span class="s1">'jumping'</span><span class="p">);</span>
</span><span class='line'> <span class="p">}};</span>
</span><span class='line'> <span class="k">return</span> <span class="p">{</span>
</span><span class='line'> <span class="nx">facade</span><span class="o">:</span> <span class="kd">function</span><span class="p">(</span><span class="nx">args</span><span class="p">)</span> <span class="p">{</span>
</span><span class='line'> <span class="nx">_private</span><span class="p">.</span><span class="nx">set</span><span class="p">(</span><span class="nx">args</span><span class="p">.</span><span class="nx">val</span><span class="p">);</span>
</span><span class='line'> <span class="nx">_private</span><span class="p">.</span><span class="nx">get</span><span class="p">();</span>
</span><span class='line'> <span class="k">if</span> <span class="p">(</span><span class="nx">args</span><span class="p">.</span><span class="nx">run</span><span class="p">)</span> <span class="p">{</span>
</span><span class='line'> <span class="nx">_private</span><span class="p">.</span><span class="nx">run</span><span class="p">();</span>
</span><span class='line'> <span class="p">}</span>
</span><span class='line'> <span class="p">}}</span>
</span><span class='line'><span class="p">}());</span>
</span><span class='line'><span class="nx">module</span><span class="p">.</span><span class="nx">facade</span><span class="p">({</span><span class="nx">run</span><span class="o">:</span> <span class="kc">true</span><span class="p">,</span><span class="nx">val</span><span class="o">:</span> <span class="mi">10</span><span class="p">});</span> <span class="c1">//outputs current value: 10, running</span>
</span></code></pre></td></tr></table></div></figure>
<h2>3. Mediator Pattern</h2>
<p>Encapsulates how disparate modules interact with each other by acting as an intermediary</p>
<h3>Mediator Implementation</h3>
<p>One possible implementation, exposing publish and subscribe capabilities.</p>
<figure class='code'> <div class="highlight"><table><tr><td class="gutter"><pre class="line-numbers"><span class='line-number'>1</span>
<span class='line-number'>2</span>
<span class='line-number'>3</span>
<span class='line-number'>4</span>
<span class='line-number'>5</span>
<span class='line-number'>6</span>
<span class='line-number'>7</span>
<span class='line-number'>8</span>
<span class='line-number'>9</span>
<span class='line-number'>10</span>
<span class='line-number'>11</span>
<span class='line-number'>12</span>
<span class='line-number'>13</span>
<span class='line-number'>14</span>
<span class='line-number'>15</span>
<span class='line-number'>16</span>
<span class='line-number'>17</span>
<span class='line-number'>18</span>
<span class='line-number'>19</span>
<span class='line-number'>20</span>
<span class='line-number'>21</span>
<span class='line-number'>22</span>
<span class='line-number'>23</span>
<span class='line-number'>24</span>
<span class='line-number'>25</span>
<span class='line-number'>26</span>
<span class='line-number'>27</span>
</pre></td><td class='code'><pre><code class='js'><span class='line'><span class="kd">var</span> <span class="nx">mediator</span> <span class="o">=</span> <span class="p">(</span><span class="kd">function</span><span class="p">()</span> <span class="p">{</span>
</span><span class='line'> <span class="kd">var</span> <span class="nx">subscribe</span> <span class="o">=</span> <span class="kd">function</span><span class="p">(</span><span class="nx">channel</span><span class="p">,</span> <span class="nx">fn</span><span class="p">)</span> <span class="p">{</span>
</span><span class='line'> <span class="k">if</span> <span class="p">(</span><span class="o">!</span><span class="nx">mediator</span><span class="p">.</span><span class="nx">channels</span><span class="p">[</span><span class="nx">channel</span><span class="p">])</span> <span class="nx">mediator</span><span class="p">.</span><span class="nx">channels</span><span class="p">[</span><span class="nx">channel</span><span class="p">]</span> <span class="o">=</span> <span class="p">[];</span>
</span><span class='line'> <span class="nx">mediator</span><span class="p">.</span><span class="nx">channels</span><span class="p">[</span><span class="nx">channel</span><span class="p">].</span><span class="nx">push</span><span class="p">({</span> <span class="nx">context</span><span class="o">:</span> <span class="k">this</span><span class="p">,</span> <span class="nx">callback</span><span class="o">:</span> <span class="nx">fn</span> <span class="p">});</span>
</span><span class='line'> <span class="k">return</span> <span class="k">this</span><span class="p">;</span>
</span><span class='line'> <span class="p">},</span>
</span><span class='line'>
</span><span class='line'> <span class="nx">publish</span> <span class="o">=</span> <span class="kd">function</span><span class="p">(</span><span class="nx">channel</span><span class="p">)</span> <span class="p">{</span>
</span><span class='line'> <span class="k">if</span> <span class="p">(</span><span class="o">!</span><span class="nx">mediator</span><span class="p">.</span><span class="nx">channels</span><span class="p">[</span><span class="nx">channel</span><span class="p">])</span> <span class="k">return</span> <span class="kc">false</span><span class="p">;</span>
</span><span class='line'> <span class="kd">var</span> <span class="nx">args</span> <span class="o">=</span> <span class="nb">Array</span><span class="p">.</span><span class="nx">prototype</span><span class="p">.</span><span class="nx">slice</span><span class="p">.</span><span class="nx">call</span><span class="p">(</span><span class="nx">arguments</span><span class="p">,</span> <span class="mi">1</span><span class="p">);</span>
</span><span class='line'> <span class="k">for</span> <span class="p">(</span><span class="kd">var</span> <span class="nx">i</span> <span class="o">=</span> <span class="mi">0</span><span class="p">,</span> <span class="nx">l</span> <span class="o">=</span> <span class="nx">mediator</span><span class="p">.</span><span class="nx">channels</span><span class="p">[</span><span class="nx">channel</span><span class="p">].</span><span class="nx">length</span><span class="p">;</span> <span class="nx">i</span> <span class="o"><</span> <span class="nx">l</span><span class="p">;</span> <span class="nx">i</span><span class="o">++</span><span class="p">)</span> <span class="p">{</span>
</span><span class='line'> <span class="kd">var</span> <span class="nx">subscription</span> <span class="o">=</span> <span class="nx">mediator</span><span class="p">.</span><span class="nx">channels</span><span class="p">[</span><span class="nx">channel</span><span class="p">][</span><span class="nx">i</span><span class="p">];</span>
</span><span class='line'> <span class="nx">subscription</span><span class="p">.</span><span class="nx">callback</span><span class="p">.</span><span class="nx">apply</span><span class="p">(</span><span class="nx">subscription</span><span class="p">.</span><span class="nx">context</span><span class="p">,</span> <span class="nx">args</span><span class="p">);</span>
</span><span class='line'> <span class="p">}</span>
</span><span class='line'> <span class="k">return</span> <span class="k">this</span><span class="p">;</span>
</span><span class='line'> <span class="p">};</span>
</span><span class='line'>
</span><span class='line'> <span class="k">return</span> <span class="p">{</span>
</span><span class='line'> <span class="nx">channels</span><span class="o">:</span> <span class="p">{},</span>
</span><span class='line'> <span class="nx">publish</span><span class="o">:</span> <span class="nx">publish</span><span class="p">,</span>
</span><span class='line'> <span class="nx">subscribe</span><span class="o">:</span> <span class="nx">subscribe</span><span class="p">,</span>
</span><span class='line'> <span class="nx">installTo</span><span class="o">:</span> <span class="kd">function</span><span class="p">(</span><span class="nx">obj</span><span class="p">)</span> <span class="p">{</span>
</span><span class='line'> <span class="nx">obj</span><span class="p">.</span><span class="nx">subscribe</span> <span class="o">=</span> <span class="nx">subscribe</span><span class="p">;</span>
</span><span class='line'> <span class="nx">obj</span><span class="p">.</span><span class="nx">publish</span> <span class="o">=</span> <span class="nx">publish</span><span class="p">;</span>
</span><span class='line'> <span class="p">}</span>
</span><span class='line'> <span class="p">};</span>
</span><span class='line'><span class="p">}());</span>
</span></code></pre></td></tr></table></div></figure>
<h3>Example</h3>
<p>Usage of the implementation from the last slide.</p>
<figure class='code'> <div class="highlight"><table><tr><td class="gutter"><pre class="line-numbers"><span class='line-number'>1</span>
<span class='line-number'>2</span>
<span class='line-number'>3</span>
<span class='line-number'>4</span>
<span class='line-number'>5</span>
<span class='line-number'>6</span>
<span class='line-number'>7</span>
<span class='line-number'>8</span>
<span class='line-number'>9</span>
<span class='line-number'>10</span>
<span class='line-number'>11</span>
<span class='line-number'>12</span>
<span class='line-number'>13</span>
<span class='line-number'>14</span>
<span class='line-number'>15</span>
<span class='line-number'>16</span>
<span class='line-number'>17</span>
<span class='line-number'>18</span>
<span class='line-number'>19</span>
<span class='line-number'>20</span>
<span class='line-number'>21</span>
<span class='line-number'>22</span>
</pre></td><td class='code'><pre><code class='js'><span class='line'><span class="c1">//Pub/sub on a centralized mediator</span>
</span><span class='line'>
</span><span class='line'><span class="nx">mediator</span><span class="p">.</span><span class="nx">name</span> <span class="o">=</span> <span class="s2">"tim"</span><span class="p">;</span>
</span><span class='line'><span class="nx">mediator</span><span class="p">.</span><span class="nx">subscribe</span><span class="p">(</span><span class="s1">'nameChange'</span><span class="p">,</span> <span class="kd">function</span><span class="p">(</span><span class="nx">arg</span><span class="p">)</span> <span class="p">{</span>
</span><span class='line'> <span class="nx">console</span><span class="p">.</span><span class="nx">log</span><span class="p">(</span><span class="k">this</span><span class="p">.</span><span class="nx">name</span><span class="p">);</span>
</span><span class='line'> <span class="k">this</span><span class="p">.</span><span class="nx">name</span> <span class="o">=</span> <span class="nx">arg</span><span class="p">;</span>
</span><span class='line'> <span class="nx">console</span><span class="p">.</span><span class="nx">log</span><span class="p">(</span><span class="k">this</span><span class="p">.</span><span class="nx">name</span><span class="p">);</span>
</span><span class='line'><span class="p">});</span>
</span><span class='line'>
</span><span class='line'><span class="nx">mediator</span><span class="p">.</span><span class="nx">publish</span><span class="p">(</span><span class="s1">'nameChange'</span><span class="p">,</span> <span class="s1">'david'</span><span class="p">);</span> <span class="c1">//tim, david</span>
</span><span class='line'>
</span><span class='line'><span class="c1">//Pub/sub via third party mediator</span>
</span><span class='line'>
</span><span class='line'><span class="kd">var</span> <span class="nx">obj</span> <span class="o">=</span> <span class="p">{</span><span class="nx">name</span><span class="o">:</span> <span class="s1">'sam'</span><span class="p">};</span>
</span><span class='line'><span class="nx">mediator</span><span class="p">.</span><span class="nx">installTo</span><span class="p">(</span><span class="nx">obj</span><span class="p">);</span>
</span><span class='line'><span class="nx">obj</span><span class="p">.</span><span class="nx">subscribe</span><span class="p">(</span><span class="s1">'nameChange'</span><span class="p">,</span> <span class="kd">function</span><span class="p">(</span><span class="nx">arg</span><span class="p">)</span> <span class="p">{</span>
</span><span class='line'> <span class="nx">console</span><span class="p">.</span><span class="nx">log</span><span class="p">(</span><span class="k">this</span><span class="p">.</span><span class="nx">name</span><span class="p">);</span>
</span><span class='line'> <span class="k">this</span><span class="p">.</span><span class="nx">name</span> <span class="o">=</span> <span class="nx">arg</span><span class="p">;</span>
</span><span class='line'> <span class="nx">console</span><span class="p">.</span><span class="nx">log</span><span class="p">(</span><span class="k">this</span><span class="p">.</span><span class="nx">name</span><span class="p">);</span>
</span><span class='line'><span class="p">});</span>
</span><span class='line'>
</span><span class='line'><span class="nx">obj</span><span class="p">.</span><span class="nx">publish</span><span class="p">(</span><span class="s1">'nameChange'</span><span class="p">,</span> <span class="s1">'john'</span><span class="p">);</span> <span class="c1">//sam, john</span>
</span></code></pre></td></tr></table></div></figure>
<p><em>Form http://www.slideshare.net/AddyOsmani/futureproofing-your-javascript-apps-compact-edition</em></p>
</div>
</article>
<article>
<header>
<h1 class="entry-title"><a href="/blog/bootstrap/">Installing Rails on Mac OS X</a></h1>
<p class="meta">
<time datetime="2011-09-10T14:47:00+08:00" pubdate data-updated="true">Sep 10<span>th</span>, 2011</time>
</p>
</header>
<div class="entry-content"><ol>
<li>
<p>Run software update</p>
</li>
<li>
<p>Form Mac App Store download & install <a href="http://itunes.apple.com/us/app/xcode/id448457090?mt=12">XCode</a></p>
</li>
<li>
<p>Install Homebrew</p>
<figure class='code'> <div class="highlight"><table><tr><td class="gutter"><pre class="line-numbers"><span class='line-number'>1</span>
</pre></td><td class='code'><pre><code class='bash'><span class='line'>/usr/bin/ruby -e <span class="s2">"$(curl -fsSL https://raw.github.com/gist/323731)"</span>
</span></code></pre></td></tr></table></div></figure>
</li>
<li>
<p>Install Git</p>
<figure class='code'> <div class="highlight"><table><tr><td class="gutter"><pre class="line-numbers"><span class='line-number'>1</span>
</pre></td><td class='code'><pre><code class='bash'><span class='line'>brew install git
</span></code></pre></td></tr></table></div></figure>
</li>
<li>
<p>Install rbenv & ruby-build</p>
<figure class='code'> <div class="highlight"><table><tr><td class="gutter"><pre class="line-numbers"><span class='line-number'>1</span>
<span class='line-number'>2</span>
</pre></td><td class='code'><pre><code class='bash'><span class='line'>brew install rbenv
</span><span class='line'>brew install ruby-build
</span></code></pre></td></tr></table></div></figure>
</li>
<li>
<p>Install Ruby</p>
<figure class='code'> <div class="highlight"><table><tr><td class="gutter"><pre class="line-numbers"><span class='line-number'>1</span>
<span class='line-number'>2</span>
</pre></td><td class='code'><pre><code class='bash'><span class='line'>rbenv install 1.9.2-p290
</span><span class='line'>rbenv global 1.9.2-p290
</span></code></pre></td></tr></table></div></figure>
</li>
<li>
<p>Install MySQL</p>
<figure class='code'> <div class="highlight"><table><tr><td class="gutter"><pre class="line-numbers"><span class='line-number'>1</span>
</pre></td><td class='code'><pre><code class='bash'><span class='line'>brew install mysql
</span></code></pre></td></tr></table></div></figure>
</li>
<li>
<p>Install Rails</p>
<figure class='code'> <div class="highlight"><table><tr><td class="gutter"><pre class="line-numbers"><span class='line-number'>1</span>
</pre></td><td class='code'><pre><code class='bash'><span class='line'>gem install rails --no-rdoc --no-ri
</span></code></pre></td></tr></table></div></figure>
</li>
<li>
<p>Enjoy!</p>
</li>
</ol>
</div>
</article>
<article>
<header>
<h1 class="entry-title"><a href="/blog/rbenv/">用 Rbenv 来管理 Ruby 的安装</a></h1>
<p class="meta">
<time datetime="2011-08-22T10:43:00+08:00" pubdate data-updated="true">Aug 22<span>nd</span>, 2011</time>
</p>
</header>
<div class="entry-content"><p>如果你 Ruby 开发者，应该知道用 <a href="http://beginrescueend.com/">RVM</a> 来安装/管理 Ruby 版本，同时也能用它的 gemset 功能来管理各个工程的 gems。</p>
<p>最近，<a href="http://37signals.com">37Signals</a> 的 <a href="http://sstephenson.us/">Sam Stephenson</a> 也创建了一个类似的软件，叫做 <a href="https://github.com/sstephenson/rbenv">rbenv</a>。不过它功能非常简单，简单到只是用来管理 Ruby 版本，连安装的功能也没提供。</p>
<p><em>注意：rbenv 和 RVM 是不兼容的，所以安装 rbenv 之前要先把 RVM 卸载了。</em></p>
<h2>1 安装</h2>
<h3>1.1 安装 rbenv</h3>
<p>rbenv 的源代码托管在 <a href="http://github.com">GitHub</a> 下，安装只需要简单的 <code>clone</code> 下来就可以来。</p>
<p>把 rbenv clone 到 <code>~/.rbenv</code> 下：</p>
<figure class='code'><figcaption><span></span></figcaption><div class="highlight"><table><tr><td class="gutter"><pre class="line-numbers"><span class='line-number'>1</span>
</pre></td><td class='code'><pre><code class='bash'><span class='line'>git clone https://github.com/sstephenson/rbenv ~/.rbenv
</span></code></pre></td></tr></table></div></figure>
<p>然后让 shell 加载 rbenv：</p>
<figure class='code'><figcaption><span></span></figcaption><div class="highlight"><table><tr><td class="gutter"><pre class="line-numbers"><span class='line-number'>1</span>
<span class='line-number'>2</span>
</pre></td><td class='code'><pre><code class='bash'><span class='line'><span class="nb">echo</span> <span class="s1">'export PATH="$HOME/.rbenv/bin:$PATH"'</span> >> ~/.bash_profile
</span><span class='line'><span class="nb">echo</span> <span class="s1">'eval "$(rbenv init -)"'</span> >> ~/.bash_profile
</span></code></pre></td></tr></table></div></figure>
<p><em>如果用 Zsh，就用 <code>~/.zshrc</code> 替换 <code>~/.bash_profile</code>。</em></p>
<p>重启 shell， 或者运行 <code>exec $SHELL</code>，就可以开始用 rbenv 了。</p>
<h3>1.2 安装 ruby-build</h3>
<p>由于 rbenv 本身并不能用来安装 Ruby，为了方便我们还需要用到 <a href="https://github.com/sstephenson/ruby-build">ruby-build</a>，它的安装也非常简单：</p>
<figure class='code'><figcaption><span></span></figcaption><div class="highlight"><table><tr><td class="gutter"><pre class="line-numbers"><span class='line-number'>1</span>
<span class='line-number'>2</span>
<span class='line-number'>3</span>
</pre></td><td class='code'><pre><code class='bash'><span class='line'>git clone git://github.com/sstephenson/ruby-build.git
</span><span class='line'><span class="nb">cd </span>ruby-build
</span><span class='line'>./install.sh
</span></code></pre></td></tr></table></div></figure>
<h3>1.3 安装 Ruby</h3>
<p>安装好 ruby-build 后，就可以用简单的一条命令来安装 Ruby：</p>
<figure class='code'><figcaption><span></span></figcaption><div class="highlight"><table><tr><td class="gutter"><pre class="line-numbers"><span class='line-number'>1</span>
</pre></td><td class='code'><pre><code class='bash'><span class='line'>ruby-build 1.9.3-p0 ~/.rbenv/versions/1.9.3-p0
</span></code></pre></td></tr></table></div></figure>
<p><em>注意：Ruby 需要安装在 <code>~/.rbenv/versions/</code> 下</em></p>
<p>同时 ruby-build 还提供了一个 <code>rbenv install</code> 命令给 rbenv，所以上面的命令可以变成：</p>
<figure class='code'><figcaption><span></span></figcaption><div class="highlight"><table><tr><td class="gutter"><pre class="line-numbers"><span class='line-number'>1</span>
</pre></td><td class='code'><pre><code class='bash'><span class='line'>rbenv install 1.9.3-p0
</span></code></pre></td></tr></table></div></figure>
<h2>2 rbenv 的常用命令</h2>
<p>rbenv 提供了很多命令，这里列几个常用的：</p>
<h3>2.1 rbenv global</h3>
<p>来用设置 Ruby 的全局版本。</p>
<p>上面安装好 Ruby 后，还需要运行一下这条命令：</p>
<figure class='code'><figcaption><span></span></figcaption><div class="highlight"><table><tr><td class="gutter"><pre class="line-numbers"><span class='line-number'>1</span>
</pre></td><td class='code'><pre><code class='bash'><span class='line'>rbenv global 1.9.3-p0
</span></code></pre></td></tr></table></div></figure>
<p>这样默认就会用 1.9.3-p0 了。但如果当前目录下有 <code>.rbenv-version</code> 文件，就会用文件里显示的版本。</p>
<h3>2.2 rbenv local</h3>
<figure class='code'><figcaption><span></span></figcaption><div class="highlight"><table><tr><td class="gutter"><pre class="line-numbers"><span class='line-number'>1</span>
</pre></td><td class='code'><pre><code class='bash'><span class='line'>rbenv <span class="nb">local </span>1.9.2-p290
</span></code></pre></td></tr></table></div></figure>
<p>会在当前目录下生成 <code>.rbenv-version</code> 文件，此文件会覆盖 rbenv global 设定。</p>
<p>如果想取消的话，可以这样：</p>
<figure class='code'><figcaption><span></span></figcaption><div class="highlight"><table><tr><td class="gutter"><pre class="line-numbers"><span class='line-number'>1</span>
</pre></td><td class='code'><pre><code class='bash'><span class='line'>rbenv <span class="nb">local</span> --unset
</span></code></pre></td></tr></table></div></figure>
<h3>2.3 rbenv versions</h3>
<p>显示所有版本，前面加 * 的为当前激活的版本。</p>
<figure class='code'><figcaption><span></span></figcaption><div class="highlight"><table><tr><td class="gutter"><pre class="line-numbers"><span class='line-number'>1</span>
</pre></td><td class='code'><pre><code class='bash'><span class='line'>rbenv versions
</span></code></pre></td></tr></table></div></figure>
<h3>2.4 rbenv rehash</h3>
<p>每当安装新的 Ruby 版本，或 gem 都要运行一下，不然有可能会出现新安装的不起作用的现象：</p>
<figure class='code'><figcaption><span></span></figcaption><div class="highlight"><table><tr><td class="gutter"><pre class="line-numbers"><span class='line-number'>1</span>
</pre></td><td class='code'><pre><code class='bash'><span class='line'>rbenv rehash
</span></code></pre></td></tr></table></div></figure>
<h3>2.5 其它</h3>
<p>当然还有其它命令，具体可以用 <code>rbenv help</code> 查看。</p>
<figure class='code'><figcaption><span></span></figcaption><div class="highlight"><table><tr><td class="gutter"><pre class="line-numbers"><span class='line-number'>1</span>
</pre></td><td class='code'><pre><code class='bash'><span class='line'>rbenv <span class="nb">help</span>
</span></code></pre></td></tr></table></div></figure>
<h2>3 最后</h2>
<p>虽然 rbenv 提供的功能非常少，但对我来说者正是我需要的，less is more，其它的功能我根本不需要。</p>
<p>喜欢用 RVM gemset 的人，可以安装 <a href="https://github.com/jamis/rbenv-gemset">rbenv-gemset</a> 插件来实现同样的功能。但还是用 <a href="http://gembundler.com/">Bundler</a> 来管理应用依赖吧。</p>
<h3>更新</h3>
<p>如果你有安装 <a href="http://mxcl.github.com/homebrew/">Homebrew</a> 的话，可以用以下命令来安装 rbenv 和 ruby-build：</p>
<figure class='code'><figcaption><span></span></figcaption><div class="highlight"><table><tr><td class="gutter"><pre class="line-numbers"><span class='line-number'>1</span>
<span class='line-number'>2</span>
<span class='line-number'>3</span>
</pre></td><td class='code'><pre><code class='bash'><span class='line'>brew update
</span><span class='line'>brew install rbenv
</span><span class='line'>brew install ruby-build
</span></code></pre></td></tr></table></div></figure>
</div>
</article>
<div class="pagination">
<a href="/blog/archives">Blog Archives</a>
</div>
</div>
<aside class="sidebar">
<section>
<h1>Recent Posts</h1>
<ul id="recent_posts">
<li class="post">
<a href="/blog/js-patterns/">JavaScript Design Patterns</a>
</li>
<li class="post">
<a href="/blog/bootstrap/">Installing Rails on Mac OS X</a>
</li>
<li class="post">
<a href="/blog/rbenv/">用 rbenv 来管理 Ruby 的安装</a>
</li>
</ul>
</section>
<section>
<h1>Latest Tweets</h1>
<ul id="tweets">
<li class="loading">Status updating…</li>
</ul>
<script type="text/javascript">
$.domReady(function(){
getTwitterFeed("akai404", 4, false);
});
</script>
<script src="/javascripts/twitter.js" type="text/javascript"> </script>
<a href="http://twitter.com/akai404" class="twitter-follow-button" data-width="208px" data-show-count="false">Follow @akai404</a>
</section>
</aside>
</div>
</div>
<footer role="contentinfo"><p>
Copyright © 2011 - akai -
<span class="credit">Powered by <a href="http://octopress.org">Octopress</a></span>
</p>
</footer>
<script type="text/javascript">
var disqus_shortname = 'akai404';
var disqus_script = 'count.js';
(function () {
var dsq = document.createElement('script'); dsq.type = 'text/javascript'; dsq.async = true;
dsq.src = 'http://' + disqus_shortname + '.disqus.com/' + disqus_script;
(document.getElementsByTagName('head')[0] || document.getElementsByTagName('body')[0]).appendChild(dsq);
}());
</script>
<script type="text/javascript">
(function(){
var twitterWidgets = document.createElement('script');
twitterWidgets.type = 'text/javascript';
twitterWidgets.async = true;
twitterWidgets.src = 'http://platform.twitter.com/widgets.js';
document.getElementsByTagName('head')[0].appendChild(twitterWidgets);
})();
</script>
</body>
</html>