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
|
<!DOCTYPE html>
<html xmlns="http://www.w3.org/1999/xhtml" xml:lang="en" lang="en-us">
<head>
<meta http-equiv="content-type" content="text/html; charset=utf-8" />
<title>What is a model? - Backbone.js Tutorials</title>
<link href="/atom.xml" rel="alternate" title="backbone tutorials" type="application/atom+xml">
<meta name="author" content="Backbone Tutorials" />
<!-- syntax highlighting CSS -->
<!-- syntax highlighting CSS -->
<link rel="stylesheet" href="/css/syntax.css" type="text/css" />
<!-- Homepage CSS -->
<link rel="stylesheet" href="//bootswatch.com/sandstone/bootstrap.min.css" type="text/css" media="screen, projection" />
<link rel="stylesheet" href="/css/style.css" type="text/css" media="screen, projection" />
<link href="https://fonts.googleapis.com/css?family=Arvo:400,700&subset=latin" rel="stylesheet" type="text/css">
<!-- Typekit -->
<script type="text/javascript">try{Typekit.load();}catch(e){}</script>
</head>
<body>
<div class="row">
<div class="navbar navbar-default">
<div class="container">
<div class="navbar-header">
<button type="button" class="navbar-toggle" data-toggle="collapse" data-target=".navbar-responsive-collapse">
<span class="icon-bar"></span>
<span class="icon-bar"></span>
<span class="icon-bar"></span>
</button>
<a class="navbar-brand" href="/">Backbone Tutorials</a>
</div>
<div class="navbar-collapse collapse navbar-responsive-collapse">
<ul class="nav navbar-nav">
<li class=""><a href="/">Tutorials</a></li>
</ul>
<ul class="nav navbar-nav navbar-right">
<li><a href="http://prerender.io"><strong>Need SEO?</strong></a></li>
<li><a href="https://leanpub.com/backbonetutorials">Download eBook (.pdf, .MOBI, .ePub)</a></li>
</ul>
</div>
</div>
</div>
<div class="container">
<div class="row">
<div class="panel panel-primary">
<div class="panel-heading">
<h3 class="panel-title">About</h3>
</div>
<div class="panel-body">
<div class="col-lg-4">
<p>Backbone Tutorials is a collection of tutorials written by <a href="http://thomasdav.is">Thomas Davis</a>. Everything is open source and I try my best to keep the tutorials updated. Though I am busy and only work on this is my spare time so many <a href="https://github.com/thomasdavis/backbonetutorials/graphs/contributors">contributors</a> have also help me put this resource together.</p>
<a href="https://twitter.com/neutralthoughts" class="twitter-follow-button" data-show-count="true">Follow @neutralthoughts</a>
<script>!function(d,s,id){var js,fjs=d.getElementsByTagName(s)[0],p=/^http:/.test(d.location)?'http':'https';if(!d.getElementById(id)){js=d.createElement(s);js.id=id;js.src=p+'://platform.twitter.com/widgets.js';fjs.parentNode.insertBefore(js,fjs);}}(document, 'script', 'twitter-wjs');</script>
</div>
<div class="col-lg-8">
<h3 >Backbone.js Beginner Video Tutorial</h3>
<img src="/backbone.png" style="float: left;" /><p>I have put extra effort into making a very easy to understand Backbone.js video which is also free. It is 70mins long and covers everything you need to know when getting started.</p>
<a href="https://www.youtube.com/watch?v=FZSjvWtUxYk" class="btn btn-primary">Watch Video</a>
</div>
</div>
</div>
</div>
<div id="post">
<h1>What is a model?</h1>
<p>Across the internet the definition of <a href="http://en.wikipedia.org/wiki/Model%E2%80%93view%E2%80%93controller">MVC</a> is so diluted that it's hard to tell what exactly your model should be doing. The authors of backbone.js have quite a clear definition of what they believe the model represents in backbone.js.</p>
<blockquote>
<p>Models are the heart of any JavaScript application, containing the interactive data as well as a large part of the logic surrounding it: conversions, validations, computed properties, and access control.</p>
</blockquote>
<p>So for the purpose of the tutorial let's create a model.</p>
<div class="highlight"><pre><code class="language-javascript" data-lang="javascript"><span class="nx">Person</span> <span class="o">=</span> <span class="nx">Backbone</span><span class="p">.</span><span class="nx">Model</span><span class="p">.</span><span class="nx">extend</span><span class="p">({</span>
<span class="nx">initialize</span><span class="o">:</span> <span class="kd">function</span><span class="p">(){</span>
<span class="nx">alert</span><span class="p">(</span><span class="s2">"Welcome to this world"</span><span class="p">);</span>
<span class="p">}</span>
<span class="p">});</span>
<span class="kd">var</span> <span class="nx">person</span> <span class="o">=</span> <span class="k">new</span> <span class="nx">Person</span><span class="p">;</span></code></pre></div>
<p>So <em>initialize()</em> is triggered whenever you create a new instance of a model( models, collections and views work the same way ). You don't have to include it in your model declaration but you will find yourself using it more often than not.</p>
<h2>Setting attributes</h2>
<p>Now we want to pass some parameters when we create an instance of our model.</p>
<div class="highlight"><pre><code class="language-javascript" data-lang="javascript"><span class="nx">Person</span> <span class="o">=</span> <span class="nx">Backbone</span><span class="p">.</span><span class="nx">Model</span><span class="p">.</span><span class="nx">extend</span><span class="p">({</span>
<span class="nx">initialize</span><span class="o">:</span> <span class="kd">function</span><span class="p">(){</span>
<span class="nx">alert</span><span class="p">(</span><span class="s2">"Welcome to this world"</span><span class="p">);</span>
<span class="p">}</span>
<span class="p">});</span>
<span class="kd">var</span> <span class="nx">person</span> <span class="o">=</span> <span class="k">new</span> <span class="nx">Person</span><span class="p">({</span> <span class="nx">name</span><span class="o">:</span> <span class="s2">"Thomas"</span><span class="p">,</span> <span class="nx">age</span><span class="o">:</span> <span class="mi">67</span><span class="p">});</span>
<span class="c1">// or we can set afterwards, these operations are equivelent</span>
<span class="kd">var</span> <span class="nx">person</span> <span class="o">=</span> <span class="k">new</span> <span class="nx">Person</span><span class="p">();</span>
<span class="nx">person</span><span class="p">.</span><span class="nx">set</span><span class="p">({</span> <span class="nx">name</span><span class="o">:</span> <span class="s2">"Thomas"</span><span class="p">,</span> <span class="nx">age</span><span class="o">:</span> <span class="mi">67</span><span class="p">});</span></code></pre></div>
<p>So passing a JavaScript object to our constructor is the same as calling <em>model.set()</em>. Now that these models have attributes set we need to be able to retrieve them. </p>
<h2>Getting attributes</h2>
<p>Using the <em>model.get()</em> method we can access model properties at anytime.</p>
<div class="highlight"><pre><code class="language-javascript" data-lang="javascript"><span class="nx">Person</span> <span class="o">=</span> <span class="nx">Backbone</span><span class="p">.</span><span class="nx">Model</span><span class="p">.</span><span class="nx">extend</span><span class="p">({</span>
<span class="nx">initialize</span><span class="o">:</span> <span class="kd">function</span><span class="p">(){</span>
<span class="nx">alert</span><span class="p">(</span><span class="s2">"Welcome to this world"</span><span class="p">);</span>
<span class="p">}</span>
<span class="p">});</span>
<span class="kd">var</span> <span class="nx">person</span> <span class="o">=</span> <span class="k">new</span> <span class="nx">Person</span><span class="p">({</span> <span class="nx">name</span><span class="o">:</span> <span class="s2">"Thomas"</span><span class="p">,</span> <span class="nx">age</span><span class="o">:</span> <span class="mi">67</span><span class="p">,</span> <span class="nx">child</span><span class="o">:</span> <span class="s1">'Ryan'</span><span class="p">});</span>
<span class="kd">var</span> <span class="nx">age</span> <span class="o">=</span> <span class="nx">person</span><span class="p">.</span><span class="nx">get</span><span class="p">(</span><span class="s2">"age"</span><span class="p">);</span> <span class="c1">// 67</span>
<span class="kd">var</span> <span class="nx">name</span> <span class="o">=</span> <span class="nx">person</span><span class="p">.</span><span class="nx">get</span><span class="p">(</span><span class="s2">"name"</span><span class="p">);</span> <span class="c1">// "Thomas"</span>
<span class="kd">var</span> <span class="nx">child</span> <span class="o">=</span> <span class="nx">person</span><span class="p">.</span><span class="nx">get</span><span class="p">(</span><span class="s2">"child"</span><span class="p">);</span> <span class="c1">// 'Ryan'</span></code></pre></div>
<h2>Setting model defaults</h2>
<p>Sometimes you will want your model to contain default values. This can easily be accomplished by setting a property name 'defaults' in your model declaration.</p>
<div class="highlight"><pre><code class="language-javascript" data-lang="javascript"><span class="nx">Person</span> <span class="o">=</span> <span class="nx">Backbone</span><span class="p">.</span><span class="nx">Model</span><span class="p">.</span><span class="nx">extend</span><span class="p">({</span>
<span class="nx">defaults</span><span class="o">:</span> <span class="p">{</span>
<span class="nx">name</span><span class="o">:</span> <span class="s1">'Fetus'</span><span class="p">,</span>
<span class="nx">age</span><span class="o">:</span> <span class="mi">0</span><span class="p">,</span>
<span class="nx">child</span><span class="o">:</span> <span class="s1">''</span>
<span class="p">},</span>
<span class="nx">initialize</span><span class="o">:</span> <span class="kd">function</span><span class="p">(){</span>
<span class="nx">alert</span><span class="p">(</span><span class="s2">"Welcome to this world"</span><span class="p">);</span>
<span class="p">}</span>
<span class="p">});</span>
<span class="kd">var</span> <span class="nx">person</span> <span class="o">=</span> <span class="k">new</span> <span class="nx">Person</span><span class="p">({</span> <span class="nx">name</span><span class="o">:</span> <span class="s2">"Thomas"</span><span class="p">,</span> <span class="nx">age</span><span class="o">:</span> <span class="mi">67</span><span class="p">,</span> <span class="nx">child</span><span class="o">:</span> <span class="s1">'Ryan'</span><span class="p">});</span>
<span class="kd">var</span> <span class="nx">age</span> <span class="o">=</span> <span class="nx">person</span><span class="p">.</span><span class="nx">get</span><span class="p">(</span><span class="s2">"age"</span><span class="p">);</span> <span class="c1">// 67</span>
<span class="kd">var</span> <span class="nx">name</span> <span class="o">=</span> <span class="nx">person</span><span class="p">.</span><span class="nx">get</span><span class="p">(</span><span class="s2">"name"</span><span class="p">);</span> <span class="c1">// "Thomas"</span>
<span class="kd">var</span> <span class="nx">child</span> <span class="o">=</span> <span class="nx">person</span><span class="p">.</span><span class="nx">get</span><span class="p">(</span><span class="s2">"child"</span><span class="p">);</span> <span class="c1">// 'Ryan'</span></code></pre></div>
<h2>Manipulating model attributes</h2>
<p>Models can contain as many custom methods as you like to manipulate attributes. By default all methods are public.</p>
<div class="highlight"><pre><code class="language-javascript" data-lang="javascript"><span class="nx">Person</span> <span class="o">=</span> <span class="nx">Backbone</span><span class="p">.</span><span class="nx">Model</span><span class="p">.</span><span class="nx">extend</span><span class="p">({</span>
<span class="nx">defaults</span><span class="o">:</span> <span class="p">{</span>
<span class="nx">name</span><span class="o">:</span> <span class="s1">'Fetus'</span><span class="p">,</span>
<span class="nx">age</span><span class="o">:</span> <span class="mi">0</span><span class="p">,</span>
<span class="nx">child</span><span class="o">:</span> <span class="s1">''</span>
<span class="p">},</span>
<span class="nx">initialize</span><span class="o">:</span> <span class="kd">function</span><span class="p">(){</span>
<span class="nx">alert</span><span class="p">(</span><span class="s2">"Welcome to this world"</span><span class="p">);</span>
<span class="p">},</span>
<span class="nx">adopt</span><span class="o">:</span> <span class="kd">function</span><span class="p">(</span> <span class="nx">newChildsName</span> <span class="p">){</span>
<span class="k">this</span><span class="p">.</span><span class="nx">set</span><span class="p">({</span> <span class="nx">child</span><span class="o">:</span> <span class="nx">newChildsName</span> <span class="p">});</span>
<span class="p">}</span>
<span class="p">});</span>
<span class="kd">var</span> <span class="nx">person</span> <span class="o">=</span> <span class="k">new</span> <span class="nx">Person</span><span class="p">({</span> <span class="nx">name</span><span class="o">:</span> <span class="s2">"Thomas"</span><span class="p">,</span> <span class="nx">age</span><span class="o">:</span> <span class="mi">67</span><span class="p">,</span> <span class="nx">child</span><span class="o">:</span> <span class="s1">'Ryan'</span><span class="p">});</span>
<span class="nx">person</span><span class="p">.</span><span class="nx">adopt</span><span class="p">(</span><span class="s1">'John Resig'</span><span class="p">);</span>
<span class="kd">var</span> <span class="nx">child</span> <span class="o">=</span> <span class="nx">person</span><span class="p">.</span><span class="nx">get</span><span class="p">(</span><span class="s2">"child"</span><span class="p">);</span> <span class="c1">// 'John Resig'</span></code></pre></div>
<p>So we can implement methods to get/set and perform other calculations using attributes from our model at any time. </p>
<h2>Listening for changes to the model</h2>
<p>Now onto one of the more useful parts of using a library such as backbone. All attributes of a model can have listeners bound to them to detect changes to their values. In our initialize function we are going to bind a function call everytime we change the value of our attribute. In this case if the name of our "person" changes we will alert their new name.</p>
<div class="highlight"><pre><code class="language-javascript" data-lang="javascript"><span class="nx">Person</span> <span class="o">=</span> <span class="nx">Backbone</span><span class="p">.</span><span class="nx">Model</span><span class="p">.</span><span class="nx">extend</span><span class="p">({</span>
<span class="nx">defaults</span><span class="o">:</span> <span class="p">{</span>
<span class="nx">name</span><span class="o">:</span> <span class="s1">'Fetus'</span><span class="p">,</span>
<span class="nx">age</span><span class="o">:</span> <span class="mi">0</span>
<span class="p">},</span>
<span class="nx">initialize</span><span class="o">:</span> <span class="kd">function</span><span class="p">(){</span>
<span class="nx">alert</span><span class="p">(</span><span class="s2">"Welcome to this world"</span><span class="p">);</span>
<span class="k">this</span><span class="p">.</span><span class="nx">on</span><span class="p">(</span><span class="s2">"change:name"</span><span class="p">,</span> <span class="kd">function</span><span class="p">(</span><span class="nx">model</span><span class="p">){</span>
<span class="kd">var</span> <span class="nx">name</span> <span class="o">=</span> <span class="nx">model</span><span class="p">.</span><span class="nx">get</span><span class="p">(</span><span class="s2">"name"</span><span class="p">);</span> <span class="c1">// 'Stewie Griffin'</span>
<span class="nx">alert</span><span class="p">(</span><span class="s2">"Changed my name to "</span> <span class="o">+</span> <span class="nx">name</span> <span class="p">);</span>
<span class="p">});</span>
<span class="p">}</span>
<span class="p">});</span>
<span class="kd">var</span> <span class="nx">person</span> <span class="o">=</span> <span class="k">new</span> <span class="nx">Person</span><span class="p">({</span> <span class="nx">name</span><span class="o">:</span> <span class="s2">"Thomas"</span><span class="p">,</span> <span class="nx">age</span><span class="o">:</span> <span class="mi">67</span><span class="p">});</span>
<span class="nx">person</span><span class="p">.</span><span class="nx">set</span><span class="p">({</span><span class="nx">name</span><span class="o">:</span> <span class="s1">'Stewie Griffin'</span><span class="p">});</span> <span class="c1">// This triggers a change and will alert()</span></code></pre></div>
<p>So we can bind the change listener to individual attributes, or, if we like, simply '<em>this.on("change", function(model){});</em>' to listen for changes to all attributes of the model.</p>
<h2>Interacting with the server</h2>
<p>Models are used to represent data from your server and actions you perform on them will be translated to RESTful operations.</p>
<p>The <code>id</code> attribute of a model identifies how to find it on the database usually mapping to the <a href="http://en.wikipedia.org/wiki/Surrogate_key">surrogate key</a>.</p>
<p>For the purpose of this tutorial imagine that we have a mysql table called <code>Users</code> with the columns <code>id</code>, <code>name</code>, <code>email</code>.</p>
<p>The server has implemented a RESTful URL <code>/user</code> which allows us to interact with it.</p>
<p>Our model definition shall thus look like;</p>
<div class="highlight"><pre><code class="language-javascript" data-lang="javascript"><span class="kd">var</span> <span class="nx">UserModel</span> <span class="o">=</span> <span class="nx">Backbone</span><span class="p">.</span><span class="nx">Model</span><span class="p">.</span><span class="nx">extend</span><span class="p">({</span>
<span class="nx">urlRoot</span><span class="o">:</span> <span class="s1">'/user'</span><span class="p">,</span>
<span class="nx">defaults</span><span class="o">:</span> <span class="p">{</span>
<span class="nx">name</span><span class="o">:</span> <span class="s1">''</span><span class="p">,</span>
<span class="nx">email</span><span class="o">:</span> <span class="s1">''</span>
<span class="p">}</span>
<span class="p">});</span></code></pre></div>
<h3>Creating a new model</h3>
<p>If we wish to create a new user on the server then we will instantiate a new UserModel and call <code>save</code>. If the <code>id</code> attribute of the model is <code>null</code>, Backbone.js will send a POST request to the urlRoot of the server. </p>
<div class="highlight"><pre><code class="language-javascript" data-lang="javascript"><span class="kd">var</span> <span class="nx">UserModel</span> <span class="o">=</span> <span class="nx">Backbone</span><span class="p">.</span><span class="nx">Model</span><span class="p">.</span><span class="nx">extend</span><span class="p">({</span>
<span class="nx">urlRoot</span><span class="o">:</span> <span class="s1">'/user'</span><span class="p">,</span>
<span class="nx">defaults</span><span class="o">:</span> <span class="p">{</span>
<span class="nx">name</span><span class="o">:</span> <span class="s1">''</span><span class="p">,</span>
<span class="nx">email</span><span class="o">:</span> <span class="s1">''</span>
<span class="p">}</span>
<span class="p">});</span>
<span class="kd">var</span> <span class="nx">user</span> <span class="o">=</span> <span class="k">new</span> <span class="nx">Usermodel</span><span class="p">();</span>
<span class="c1">// Notice that we haven't set an `id`</span>
<span class="kd">var</span> <span class="nx">userDetails</span> <span class="o">=</span> <span class="p">{</span>
<span class="nx">name</span><span class="o">:</span> <span class="s1">'Thomas'</span><span class="p">,</span>
<span class="nx">email</span><span class="o">:</span> <span class="s1">'thomasalwyndavis@gmail.com'</span>
<span class="p">};</span>
<span class="c1">// Because we have not set a `id` the server will call</span>
<span class="c1">// POST /user with a payload of {name:'Thomas', email: 'thomasalwyndavis@gmail.com'}</span>
<span class="c1">// The server should save the data and return a response containing the new `id`</span>
<span class="nx">user</span><span class="p">.</span><span class="nx">save</span><span class="p">(</span><span class="nx">userDetails</span><span class="p">,</span> <span class="p">{</span>
<span class="nx">success</span><span class="o">:</span> <span class="kd">function</span> <span class="p">(</span><span class="nx">user</span><span class="p">)</span> <span class="p">{</span>
<span class="nx">alert</span><span class="p">(</span><span class="nx">user</span><span class="p">.</span><span class="nx">toJSON</span><span class="p">());</span>
<span class="p">}</span>
<span class="p">})</span></code></pre></div>
<p>Our table should now have the values</p>
<p>1, 'Thomas', 'thomasalwyndavis@gmail.com'</p>
<h3>Getting a model</h3>
<p>Now that we have saved a new user model, we can retrieve it from the server. We know that the <code>id</code> is 1 from the above example.</p>
<p>If we instantiate a model with an <code>id</code>, Backbone.js will automatically perform a get request to the urlRoot + '/id' (conforming to RESTful conventions)</p>
<div class="highlight"><pre><code class="language-javascript" data-lang="javascript"><span class="c1">// Here we have set the `id` of the model</span>
<span class="kd">var</span> <span class="nx">user</span> <span class="o">=</span> <span class="k">new</span> <span class="nx">Usermodel</span><span class="p">({</span><span class="nx">id</span><span class="o">:</span> <span class="mi">1</span><span class="p">});</span>
<span class="c1">// The fetch below will perform GET /user/1</span>
<span class="c1">// The server should return the id, name and email from the database</span>
<span class="nx">user</span><span class="p">.</span><span class="nx">fetch</span><span class="p">({</span>
<span class="nx">success</span><span class="o">:</span> <span class="kd">function</span> <span class="p">(</span><span class="nx">user</span><span class="p">)</span> <span class="p">{</span>
<span class="nx">alert</span><span class="p">(</span><span class="nx">user</span><span class="p">.</span><span class="nx">toJSON</span><span class="p">());</span>
<span class="p">}</span>
<span class="p">})</span></code></pre></div>
<h3>Updating a model</h3>
<p>Now that we have a model that exist on the server we can perform an update using a PUT request.
We will use the <code>save</code> api call which is intelligent and will send a PUT request instead of a POST request if an <code>id</code> is present(conforming to RESTful conventions)</p>
<div class="highlight"><pre><code class="language-javascript" data-lang="javascript"><span class="c1">// Here we have set the `id` of the model</span>
<span class="kd">var</span> <span class="nx">user</span> <span class="o">=</span> <span class="k">new</span> <span class="nx">Usermodel</span><span class="p">({</span>
<span class="nx">id</span><span class="o">:</span> <span class="mi">1</span><span class="p">,</span>
<span class="nx">name</span><span class="o">:</span> <span class="s1">'Thomas'</span><span class="p">,</span>
<span class="nx">email</span><span class="o">:</span> <span class="s1">'thomasalwyndavis@gmail.com'</span>
<span class="p">});</span>
<span class="c1">// Let's change the name and update the server</span>
<span class="c1">// Because there is `id` present, Backbone.js will fire</span>
<span class="c1">// PUT /user/1 with a payload of `{name: 'Davis', email: 'thomasalwyndavis@gmail.com'}`</span>
<span class="nx">user</span><span class="p">.</span><span class="nx">save</span><span class="p">({</span><span class="nx">name</span><span class="o">:</span> <span class="s1">'Davis'</span><span class="p">},</span> <span class="p">{</span>
<span class="nx">success</span><span class="o">:</span> <span class="kd">function</span> <span class="p">(</span><span class="nx">model</span><span class="p">)</span> <span class="p">{</span>
<span class="nx">alert</span><span class="p">(</span><span class="nx">user</span><span class="p">.</span><span class="nx">toJSON</span><span class="p">());</span>
<span class="p">}</span>
<span class="p">});</span></code></pre></div>
<h3>Deleting a model</h3>
<p>When a model has an <code>id</code> we know that it exist on the server, so if we wish to remove it from the server we can call <code>destroy</code>. <code>destroy</code> will fire off a DELETE /user/id (conforming to RESTful conventions).</p>
<div class="highlight"><pre><code class="language-javascript" data-lang="javascript"><span class="c1">// Here we have set the `id` of the model</span>
<span class="kd">var</span> <span class="nx">user</span> <span class="o">=</span> <span class="k">new</span> <span class="nx">Usermodel</span><span class="p">({</span>
<span class="nx">id</span><span class="o">:</span> <span class="mi">1</span><span class="p">,</span>
<span class="nx">name</span><span class="o">:</span> <span class="s1">'Thomas'</span><span class="p">,</span>
<span class="nx">email</span><span class="o">:</span> <span class="s1">'thomasalwyndavis@gmail.com'</span>
<span class="p">});</span>
<span class="c1">// Because there is `id` present, Backbone.js will fire</span>
<span class="c1">// DELETE /user/1 </span>
<span class="nx">user</span><span class="p">.</span><span class="nx">destroy</span><span class="p">({</span>
<span class="nx">success</span><span class="o">:</span> <span class="kd">function</span> <span class="p">()</span> <span class="p">{</span>
<span class="nx">alert</span><span class="p">(</span><span class="s1">'Destroyed'</span><span class="p">);</span>
<span class="p">}</span>
<span class="p">});</span></code></pre></div>
<h3>Tips and Tricks</h3>
<p><em>Get all the current attributes</em></p>
<div class="highlight"><pre><code class="language-javascript" data-lang="javascript"><span class="kd">var</span> <span class="nx">person</span> <span class="o">=</span> <span class="k">new</span> <span class="nx">Person</span><span class="p">({</span> <span class="nx">name</span><span class="o">:</span> <span class="s2">"Thomas"</span><span class="p">,</span> <span class="nx">age</span><span class="o">:</span> <span class="mi">67</span><span class="p">});</span>
<span class="kd">var</span> <span class="nx">attributes</span> <span class="o">=</span> <span class="nx">person</span><span class="p">.</span><span class="nx">toJSON</span><span class="p">();</span> <span class="c1">// { name: "Thomas", age: 67}</span>
<span class="cm">/* This simply returns a copy of the current attributes. */</span>
<span class="kd">var</span> <span class="nx">attributes</span> <span class="o">=</span> <span class="nx">person</span><span class="p">.</span><span class="nx">attributes</span><span class="p">;</span>
<span class="cm">/* The line above gives a direct reference to the attributes and you should be careful when playing with it. Best practise would suggest that you use .set() to edit attributes of a model to take advantage of backbone listeners. */</span></code></pre></div>
<p><em>Validate data before you set or save it</em></p>
<div class="highlight"><pre><code class="language-javascript" data-lang="javascript"><span class="nx">Person</span> <span class="o">=</span> <span class="nx">Backbone</span><span class="p">.</span><span class="nx">Model</span><span class="p">.</span><span class="nx">extend</span><span class="p">({</span>
<span class="c1">// If you return a string from the validate function,</span>
<span class="c1">// Backbone will throw an error</span>
<span class="nx">validate</span><span class="o">:</span> <span class="kd">function</span><span class="p">(</span> <span class="nx">attributes</span> <span class="p">){</span>
<span class="k">if</span><span class="p">(</span> <span class="nx">attributes</span><span class="p">.</span><span class="nx">age</span> <span class="o"><</span> <span class="mi">0</span> <span class="o">&&</span> <span class="nx">attributes</span><span class="p">.</span><span class="nx">name</span> <span class="o">!=</span> <span class="s2">"Dr Manhatten"</span> <span class="p">){</span>
<span class="k">return</span> <span class="s2">"You can't be negative years old"</span><span class="p">;</span>
<span class="p">}</span>
<span class="p">},</span>
<span class="nx">initialize</span><span class="o">:</span> <span class="kd">function</span><span class="p">(){</span>
<span class="nx">alert</span><span class="p">(</span><span class="s2">"Welcome to this world"</span><span class="p">);</span>
<span class="k">this</span><span class="p">.</span><span class="nx">bind</span><span class="p">(</span><span class="s2">"error"</span><span class="p">,</span> <span class="kd">function</span><span class="p">(</span><span class="nx">model</span><span class="p">,</span> <span class="nx">error</span><span class="p">){</span>
<span class="c1">// We have received an error, log it, alert it or forget it :)</span>
<span class="nx">alert</span><span class="p">(</span> <span class="nx">error</span> <span class="p">);</span>
<span class="p">});</span>
<span class="p">}</span>
<span class="p">});</span>
<span class="kd">var</span> <span class="nx">person</span> <span class="o">=</span> <span class="k">new</span> <span class="nx">Person</span><span class="p">;</span>
<span class="nx">person</span><span class="p">.</span><span class="nx">set</span><span class="p">({</span> <span class="nx">name</span><span class="o">:</span> <span class="s2">"Mary Poppins"</span><span class="p">,</span> <span class="nx">age</span><span class="o">:</span> <span class="o">-</span><span class="mi">1</span> <span class="p">});</span>
<span class="c1">// Will trigger an alert outputting the error</span>
<span class="kd">var</span> <span class="nx">person</span> <span class="o">=</span> <span class="k">new</span> <span class="nx">Person</span><span class="p">;</span>
<span class="nx">person</span><span class="p">.</span><span class="nx">set</span><span class="p">({</span> <span class="nx">name</span><span class="o">:</span> <span class="s2">"Dr Manhatten"</span><span class="p">,</span> <span class="nx">age</span><span class="o">:</span> <span class="o">-</span><span class="mi">1</span> <span class="p">});</span>
<span class="c1">// God have mercy on our souls</span></code></pre></div>
<h3>Contributors</h3>
<ul>
<li><a href="https://github.com/utkarshkukreti">Utkarsh Kukreti</a></li>
</ul>
</div>
<hr />
<div class="row">
<div class="col-lg-4 col-lg-offset-4">
<div style="text-align: center;">
<img src="https://secure.gravatar.com/avatar/cff733cf90823edd218a834980379c61?s=170" class="img-circle" style=" padding:2px; border: 1px solid #ddd; width: 100px;">
<h2>Thomas Davis</h2>
<p>Founder of <a href="http://cdnjs.com">cdnjs.com</a>, <a href="http://jsonresume.org">jsonresume.org</a></p>
<p>Work with Drones, Open Source, Tech Policy, Javascript and Music. </p>
<div class="addthis_horizontal_follow_toolbox" style="padding-left: 33px;"></div>
<br />
<a href="https://github.com/thomasdavis">github.com/thomasdavis</a>
</div>
</div>
</div>
<hr />
<script type="text/javascript" src="//s7.addthis.com/js/300/addthis_widget.js#pubid=thomasdavis" async="async"></script>
<div id="disqus_thread"></div>
<script type="text/javascript">
/* * * CONFIGURATION VARIABLES: EDIT BEFORE PASTING INTO YOUR WEBPAGE * * */
var disqus_shortname = 'bbtutes'; // required: replace example with your forum shortname
var disqus_url = 'http://backbonetutorials.com/what-is-a-model';
/* * * DON'T EDIT BELOW THIS LINE * * */
(function() {
var dsq = document.createElement('script'); dsq.type = 'text/javascript'; dsq.async = true;
dsq.src = 'http://' + disqus_shortname + '.disqus.com/embed.js';
(document.getElementsByTagName('head')[0] || document.getElementsByTagName('body')[0]).appendChild(dsq);
})();
</script>
</div>
<script src="//static.getclicky.com/js" type="text/javascript"></script>
<script type="text/javascript">try{ clicky.init(66406579); }catch(e){}</script>
<noscript><p><img alt="Clicky" width="1" height="1" src="//in.getclicky.com/66406579ns.gif" /></p></noscript>
</body>
</html>
|
