-
Notifications
You must be signed in to change notification settings - Fork 1
Expand file tree
/
Copy pathslides_node_vs_rails.html
More file actions
324 lines (303 loc) · 19.4 KB
/
slides_node_vs_rails.html
File metadata and controls
324 lines (303 loc) · 19.4 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
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="utf-8">
<title>Slides for
Node.js vs Rails — Ruby on Rails Guides
</title>
<link rel="stylesheet" type="text/css" href="stylesheets/style.css" data-turbo-track="reload">
<link rel="stylesheet" type="text/css" href="stylesheets/print.css" media="print">
<link rel="stylesheet" type="text/css" href="stylesheets/highlight.css" data-turbo-track="reload">
<meta name="apple-mobile-web-app-capable" content="yes">
<meta name="apple-mobile-web-app-status-bar-style" content="black-translucent">
<meta name="viewport" content="width=device-width, initial-scale=1.0">
<link rel="stylesheet" href="stylesheets/reset.css">
<link rel="stylesheet" href="stylesheets/reveal.css">
<link rel="stylesheet" href="stylesheets/myslide.css" id="theme">
<link rel="stylesheet" href="stylesheets/code.css">
<script src="javascripts/clipboard.js" data-turbo-track="reload"></script>
<script src="javascripts/slides.js" data-turbo-track="reload"></script>
</head>
<body>
<div class="reveal">
<!-- Any section element inside of this container is displayed as a slide -->
<div class="slides">
<section>
<h1>Node.js vs Rails</h1><p>After working through this guide you should</p>
<ul>
<li>understand the differences and similarities of JavaScript and Ruby</li>
<li>understand the different roles node.js and Rails have</li>
</ul>
<p><small>Slides - use arrow keys to navigate, esc to return to page view, f for fullscreen</small></p>
</section>
<section><a class='slide_break' href='node_vs_rails.html#slide-0'>▻</a>
<h2 id="javascript-vs-ruby"><a class="anchorlink" href="#javascript-vs-ruby"><span>1</span> JavaScript vs. Ruby</a></h2></section>
<section><a class='slide_break' href='node_vs_rails.html#slide-1'>▻</a>
<h3 id="background"><a class="anchorlink" href="#background"><span>1.1</span> Background</a></h3><p>Both JavaScript and Ruby are interpreted languages with more than
20 years of history. The both were influenced by object orientation
and functional programming.</p></section>
<section><a class='slide_break' href='node_vs_rails.html#slide-2'>▻</a>
<h3 id="syntax"><a class="anchorlink" href="#syntax"><span>1.2</span> Syntax</a></h3><p>JavaScript Syntax is inspired by the C family of languages:
curly braces and semicolons. But it adds it's own idiosyncrasies
(e.g. you can leave out the semicolons).</p><div class="interstitial code">
<pre><code class="highlight js"><span class="c1">// Javascript</span>
<span class="k">if </span><span class="p">(</span><span class="k">this</span><span class="p">)</span> <span class="p">{</span>
<span class="nx">console</span><span class="p">.</span><span class="nf">log</span><span class="p">(</span><span class="dl">'</span><span class="s1">Hello World</span><span class="dl">'</span><span class="p">);</span>
<span class="p">}</span>
</code></pre>
<button class="clipboard-button" data-clipboard-text="// Javascript
if (this) {
console.log('Hello World');
}
">Copy</button>
</div>
<p>Ruby mostly uses words instead of curly braces, and no Semicolons</p><div class="interstitial code">
<pre><code class="highlight ruby"><span class="c1"># Ruby</span>
<span class="k">if</span> <span class="n">this</span>
<span class="nb">puts</span> <span class="s1">'Hello World'</span>
<span class="k">end</span>
</code></pre>
<button class="clipboard-button" data-clipboard-text="# Ruby
if this
puts 'Hello World'
end
">Copy</button>
</div>
</section>
<section><a class='slide_break' href='node_vs_rails.html#slide-3'>▻</a>
<h3 id="variables-and-types"><a class="anchorlink" href="#variables-and-types"><span>1.3</span> Variables and Types</a></h3><p>Both Interpreter will check if your variables were initialized before
you start using them. In both languages values are typed,
but variables are not: you can store values of different type in the same variable:</p><div class="interstitial code">
<pre><code class="highlight plaintext">a = 5
a = "not a problem"
a = 3.141
</code></pre>
<button class="clipboard-button" data-clipboard-text="a = 5
a = "not a problem"
a = 3.141
">Copy</button>
</div>
<p>Ruby is strongly typed:</p><div class="interstitial code">
<pre><code class="highlight ruby"><span class="n">irb</span><span class="o">></span> <span class="s2">"3"</span> <span class="o">+</span> <span class="mi">5</span>
<span class="no">TypeError</span><span class="p">:</span> <span class="n">no</span> <span class="n">implicit</span> <span class="n">conversion</span> <span class="n">of</span> <span class="no">Fixnum</span> <span class="n">into</span> <span class="no">String</span>
<span class="n">irb</span><span class="o">></span> <span class="s2">"3"</span><span class="p">.</span><span class="nf">to_i</span> <span class="o">+</span> <span class="mi">5</span>
<span class="mi">8</span>
</code></pre>
<button class="clipboard-button" data-clipboard-text="irb> "3" + 5
TypeError: no implicit conversion of Fixnum into String
irb> "3".to_i + 5
8
">Copy</button>
</div>
<p>Javascript converts types automatically.</p><div class="interstitial code">
<pre><code class="highlight js"><span class="nx">js</span><span class="o">></span> <span class="dl">"</span><span class="s2">3</span><span class="dl">"</span> <span class="o">*</span> <span class="mi">5</span>
<span class="mi">15</span>
<span class="nx">js</span><span class="o">></span> <span class="dl">"</span><span class="s2">3</span><span class="dl">"</span> <span class="o">+</span> <span class="mi">5</span> <span class="c1">// string concatenation!</span>
<span class="dl">"</span><span class="s2">35</span><span class="dl">"</span>
<span class="nx">js</span><span class="o">></span> <span class="mi">3</span> <span class="o">+</span> <span class="mi">5</span> <span class="c1">// addition!</span>
<span class="mi">8</span>
</code></pre>
<button class="clipboard-button" data-clipboard-text="js> "3" * 5
15
js> "3" + 5 // string concatenation!
"35"
js> 3 + 5 // addition!
8
">Copy</button>
</div>
<p>The plus sign is both used for mathematics and for string concatenation in JavaScript.</p></section>
<section><a class='slide_break' href='node_vs_rails.html#slide-4'>▻</a>
<h3 id="functions-vs-blocks"><a class="anchorlink" href="#functions-vs-blocks"><span>1.4</span> functions vs blocks</a></h3><p>Both languages have their ways of organizing the code that is found rarely in other languages:
In JavaScript you will uses <strong>arrow functions</strong> a lot.
Here we use them for handling events:</p><div class="interstitial code">
<pre><code class="highlight js"><span class="nb">window</span><span class="p">.</span><span class="nf">addEventListener</span><span class="p">(</span><span class="dl">'</span><span class="s1">DOMContentLoaded</span><span class="dl">'</span><span class="p">,</span> <span class="p">()</span> <span class="o">=></span> <span class="p">{</span>
<span class="nb">document</span><span class="p">.</span><span class="nf">getElementById</span><span class="p">(</span><span class="dl">'</span><span class="s1">buttonId</span><span class="dl">'</span><span class="p">).</span><span class="nf">addEventListener</span><span class="p">(</span><span class="dl">"</span><span class="s2">click</span><span class="dl">"</span><span class="p">,</span> <span class="p">()</span> <span class="o">=></span> <span class="p">{</span>
<span class="nx">console</span><span class="p">.</span><span class="nf">log</span><span class="p">(</span><span class="dl">'</span><span class="s1">button clicked</span><span class="dl">'</span><span class="p">);</span>
<span class="p">});</span>
<span class="p">});</span>
</code></pre>
<button class="clipboard-button" data-clipboard-text="window.addEventListener('DOMContentLoaded', () => {
document.getElementById('buttonId').addEventListener("click", () => {
console.log('button clicked');
});
});
">Copy</button>
</div>
<p>But let's look at an example that is better for comparing with Ruby:
In Ruby you will use <strong>blocks</strong>:</p><div class="interstitial code">
<pre><code class="highlight ruby"><span class="n">a</span><span class="p">.</span><span class="nf">map</span><span class="p">{</span><span class="o">|</span><span class="n">x</span><span class="o">|</span> <span class="n">x</span> <span class="o">*</span> <span class="mi">2</span><span class="p">}.</span><span class="nf">each</span> <span class="k">do</span> <span class="o">|</span><span class="n">x</span><span class="o">|</span>
<span class="nb">puts</span> <span class="s2">"</span><span class="si">#{</span><span class="n">x</span><span class="si">}</span><span class="s2"> is not a prime"</span>
<span class="k">end</span>
</code></pre>
<button class="clipboard-button" data-clipboard-text="a.map{|x| x * 2}.each do |x|
puts "#{x} is not a prime"
end
">Copy</button>
</div>
<p>This example shows a one-line-block in the curly braces and a big block
delimited by <code>do</code>, <code>end</code>. In JavasScript you can write very simliar code.
Here the fat arrow-notation for anonymous functions is used:</p><div class="interstitial code">
<pre><code class="highlight js"><span class="nx">a</span><span class="p">.</span><span class="nf">map</span><span class="p">(</span><span class="nx">x</span> <span class="o">=></span> <span class="nx">x</span> <span class="o">*</span> <span class="mi">2</span><span class="p">).</span><span class="nf">forEach</span><span class="p">(</span><span class="nx">x</span> <span class="o">=></span> <span class="p">{</span>
<span class="nx">console</span><span class="p">.</span><span class="nf">log</span><span class="p">(</span><span class="s2">`</span><span class="p">${</span><span class="nx">x</span><span class="p">}</span><span class="s2"> is not a prime`</span><span class="p">)</span>
<span class="p">});</span>
</code></pre>
<button class="clipboard-button" data-clipboard-text="a.map(x => x * 2).forEach(x => {
console.log(`${x} is not a prime`)
});
">Copy</button>
</div>
</section>
<section><a class='slide_break' href='node_vs_rails.html#slide-5'>▻</a>
<h2 id="node-vs-rails"><a class="anchorlink" href="#node-vs-rails"><span>2</span> Node vs Rails:</a></h2></section>
<section><a class='slide_break' href='node_vs_rails.html#slide-6'>▻</a>
<h3 id="apples-vs-oranges"><a class="anchorlink" href="#apples-vs-oranges"><span>2.1</span> apples vs. oranges</a></h3><p>Comparing Node to Rails is not quite a fair comparison:</p><p>Rails is a complete web backend framework, with ORM, templates,
testing setup and a lot of other features that are already decided and set up for you.</p><p>Node is a building block for a web backend. If you want an ORM, you can pick one.
There are three templating systems to choose from. If you need testing, you have to set it up yourself.
And you have to put all these pieces together to build your web application.</p><p>It would be more appropriate to compare Rails to nest.js (a complete node
backend framework), or Express (a minimal Node.js backend) to Sinatra
(a minimal Ruby backend).</p></section>
<section><a class='slide_break' href='node_vs_rails.html#slide-7'>▻</a>
<h3 id="processing-model-for-plain-http-rest"><a class="anchorlink" href="#processing-model-for-plain-http-rest"><span>2.2</span> processing model for plain HTTP / REST</a></h3><p>Following the classic model of backend languages, Ruby on Rails
takes advantage of the stateless nature of HTTP: as a developer, you can
developer, you can treat each HTTP request separately.
Your mental model of the program might be</p>
<ol>
<li>a request comes in</li>
<li>the framework gives me the session and parameters</li>
<li>my program runs</li>
<li>it may store some things in the database or in the session</li>
<li>then it writes out the resulting HTML (or JSON, or whatever)</li>
<li>and then my program exits, clearing all variables and freeing all memory.</li>
</ol>
<p>With Node, you not only write a backend program, you also write the
web server. The variables you manipulate are shared between all HTTP
requests. Your mental model needs to be much more complex:</p>
<ol>
<li>my Node application starts</li>
<li>it needs to load configuration, make database connections, organise them in a pool, prepare some global variables</li>
<li>then I spin up a web server that handles HTTP requests</li>
<li>for each request
<ol>
<li>the middleware gives me the request</li>
<li>I can store some things in the database or in global variables to hold for the next request</li>
<li>then I return the resulting HTML (or JSON, or whatever)</li>
</ol></li>
<li><p>I might want to respond to signals to re-read the configuration, or do some cleanup before shutdown.
This goes back to the stateless nature of HTTP: as a developer
you can treat each HTTP request separately.
Your mental model of the program might be</p></li>
<li><p>a request comes in</p></li>
<li><p>the framework gives me the session and parameters</p></li>
<li><p>my program runs</p></li>
<li><p>it may store some things in the database or in the session</p></li>
<li><p>then it writes out the resulting HTML (or JSON, or whatever)</p></li>
<li><p>and then my program exits, clearing all variables and freeing all memory.</p></li>
</ol>
</section>
<section><a class='slide_break' href='node_vs_rails.html#slide-8'>▻</a>
<h3 id="asyn-vs-sync"><a class="anchorlink" href="#asyn-vs-sync"><span>2.3</span> asyn vs sync</a></h3><p>Node relies heavily on asynchronous processing. As a programmer
you have to write asynchronous code for common actions like:</p>
<ul>
<li>sending a request to a database + handling the results</li>
<li>reading from a file + handling the data that has been read</li>
</ul>
<div class="interstitial code">
<pre><code class="highlight js"><span class="nx">db</span><span class="p">.</span><span class="nf">get</span><span class="p">(</span><span class="dl">'</span><span class="s1">users</span><span class="dl">'</span><span class="p">,</span> <span class="nx">userId</span><span class="p">,</span> <span class="kd">function</span><span class="p">(</span><span class="nx">err</span><span class="p">,</span> <span class="nx">user</span><span class="p">)</span> <span class="p">{</span>
<span class="k">if</span><span class="p">(</span><span class="o">!</span><span class="nx">err</span><span class="p">)</span> <span class="p">{</span>
<span class="nx">fs</span><span class="p">.</span><span class="nf">readFile</span><span class="p">(</span><span class="nx">user</span><span class="p">.</span><span class="nx">profilepic</span><span class="p">,</span> <span class="kd">function</span><span class="p">(</span><span class="nx">err</span><span class="p">,</span><span class="nx">data</span><span class="p">){</span>
<span class="k">if</span><span class="p">(</span><span class="o">!</span><span class="nx">err</span><span class="p">)</span> <span class="p">{</span>
<span class="c1">// create thumbnail from profile pic</span>
<span class="p">}</span>
<span class="p">});</span>
<span class="p">});</span>
</code></pre>
<button class="clipboard-button" data-clipboard-text="db.get('users', userId, function(err, user) {
if(!err) {
fs.readFile(user.profilepic, function(err,data){
if(!err) {
// create thumbnail from profile pic
}
});
});
">Copy</button>
</div>
<p>There are several different programming styles to handle asynchronicity,
chaining asynchronous actions, and handling errors from asynchronous
actions in JavaScript. For many years
<a href="https://fredkschott.com/post/2014/03/understanding-error-first-callbacks-in-node-js/">error first callbacks</a>
were the preferred style in node. sind 2015 Promises are supported natively, and since
2014 async await is fully supported.</p><p>In Rails you access files and databases in a synchronous fashion.
Only actions that would take longer than the user
is willing to wait for a response are handled by "workers":</p><div class="interstitial code">
<pre><code class="highlight ruby"><span class="k">class</span> <span class="nc">ThumbnailJob</span> <span class="o"><</span> <span class="no">ActiveJob</span><span class="o">::</span><span class="no">Base</span>
<span class="n">queue_as</span> <span class="ss">:default</span>
<span class="k">def</span> <span class="nf">perform</span><span class="p">(</span><span class="n">user</span><span class="p">)</span>
<span class="n">img</span> <span class="o">=</span> <span class="no">Magick</span><span class="o">::</span><span class="no">Image</span><span class="p">.</span><span class="nf">read</span><span class="p">(</span><span class="n">user</span><span class="p">.</span><span class="nf">profilepic</span><span class="p">).</span><span class="nf">first</span>
<span class="c1"># create a thumbnail</span>
<span class="k">end</span>
<span class="k">end</span>
<span class="c1"># in a controller somewhere:</span>
<span class="no">ThumbnailJob</span><span class="p">.</span><span class="nf">perform_later</span> <span class="n">current_user</span>
</code></pre>
<button class="clipboard-button" data-clipboard-text="class ThumbnailJob < ActiveJob::Base
queue_as :default
def perform(user)
img = Magick::Image.read(user.profilepic).first
# create a thumbnail
end
end
# in a controller somewhere:
ThumbnailJob.perform_later current_user
">Copy</button>
</div>
</section>
<section><a class='slide_break' href='node_vs_rails.html#slide-9'>▻</a>
<h2 id="summary"><a class="anchorlink" href="#summary"><span>3</span> Summary</a></h2><p>Ruby and JavaScript are similar programming languages.</p><p>node.js and Rails represent two very different approaches for programming a web backend.
As a developer, nodes.js will confront you with harder problems to solve,
while Rails will try to solve the hard problems for you
and give you a simple programming model to work with.</p><p>For beginners I would recommend Ruby and Rails in the backend and
plain JavaScript in the frontend.</p><p>This text was first published as <a href="https://www.quora.com/Is-Ruby-on-Rails-easier-to-learn-than-Node">an answer on quora in 2016</a>.
The version on this website was
updated in 2023.</p></div></section>
</div>
</div>
<!-- End slides. -->
<!-- Required JS files. -->
<script src="javascripts/reveal.js"></script>
<script src="javascripts/search.js"></script>
<script src="javascripts/markdown.js"></script>
<script>
// Also available as an ES module, see:
// https://revealjs.com/initialization/
Reveal.initialize({
controls: false,
progress: true,
center: false,
hash: true,
// The "normal" size of the presentation, aspect ratio will
// be preserved when the presentation is scaled to fit different
// resolutions. Can be specified using percentage units.
width: 1000,
height: 600,
disableLayout: false,
// Factor of the display size that should remain empty around
// the content
margin: 0.05,
// Bounds for smallest/largest possible scale to apply to content
minScale: 0.2,
maxScale: 10.0,
keyboard: {
27: () => {
// do something custom when ESC is pressed
var new_url = window.location.pathname.replace('slides_', '') + window.location.hash.replace('/','slide-');
window.location = new_url;
},
191: 'toggleHelp',
13: 'next', // go to the next slide when the ENTER key is pressed
},
// Learn about plugins: https://revealjs.com/plugins/
plugins: [ RevealSearch, RevealMarkdown ]
});
</script>
</body>
</html>