|
525
|
1 |
<!DOCTYPE html> |
|
|
2 |
<html lang="en"> |
|
|
3 |
<head> |
|
|
4 |
<meta charset="utf-8"> |
|
|
5 |
<title>Example: Reusing a JSONPRequest Instance to Poll a Remote Server</title> |
|
|
6 |
<link rel="stylesheet" href="http://fonts.googleapis.com/css?family=PT+Sans:400,700,400italic,700italic"> |
|
|
7 |
<link rel="stylesheet" href="../../build/cssgrids/cssgrids-min.css"> |
|
|
8 |
<link rel="stylesheet" href="../assets/css/main.css"> |
|
|
9 |
<link rel="stylesheet" href="../assets/vendor/prettify/prettify-min.css"> |
|
|
10 |
<link rel="shortcut icon" type="image/png" href="../assets/favicon.png"> |
|
|
11 |
<script src="../../build/yui/yui-min.js"></script> |
|
|
12 |
|
|
|
13 |
</head> |
|
|
14 |
<body> |
|
|
15 |
<!-- |
|
|
16 |
<a href="https://github.com/yui/yui3"><img style="position: absolute; top: 0; right: 0; border: 0;" src="https://s3.amazonaws.com/github/ribbons/forkme_right_darkblue_121621.png" alt="Fork me on GitHub"></a> |
|
|
17 |
--> |
|
|
18 |
<div id="doc"> |
|
|
19 |
<div id="hd"> |
|
|
20 |
<h1><img src="http://yuilibrary.com/img/yui-logo.png"></h1> |
|
|
21 |
</div> |
|
|
22 |
|
|
|
23 |
|
|
|
24 |
<h1>Example: Reusing a JSONPRequest Instance to Poll a Remote Server</h1> |
|
|
25 |
<div class="yui3-g"> |
|
|
26 |
<div class="yui3-u-3-4"> |
|
|
27 |
<div id="main"> |
|
|
28 |
<div class="content"><style scoped> |
|
|
29 |
#out { |
|
|
30 |
margin-top: 2em; |
|
|
31 |
} |
|
|
32 |
#out h4 { |
|
|
33 |
border-right: 100px solid #ccc; |
|
|
34 |
} |
|
|
35 |
</style> |
|
|
36 |
|
|
|
37 |
|
|
|
38 |
<div class="intro"> |
|
|
39 |
<p> |
|
|
40 |
This example shows how to create a reusable JSONPRequest for polling as |
|
|
41 |
well as how to configure success and failure callbacks. See the API |
|
|
42 |
docs and user guide for a full listing of available configurations. |
|
|
43 |
</p> |
|
|
44 |
|
|
|
45 |
<p> |
|
|
46 |
For this example, we will use a JSONP service hosted on <a |
|
|
47 |
href="http://yuilibrary.com">YUILibrary</a> to fetch information about |
|
|
48 |
a random Gallery module and render some of the information on the page. |
|
|
49 |
</p> |
|
|
50 |
</div> |
|
|
51 |
|
|
|
52 |
<div class="example yui3-skin-sam"> |
|
|
53 |
<div id="demo"> |
|
|
54 |
<input type="button" id="start" value="Start polling"> |
|
|
55 |
<input type="button" id="stop" value="Stop polling"> |
|
|
56 |
<div id="out"> |
|
|
57 |
</div> |
|
|
58 |
</div> |
|
|
59 |
|
|
|
60 |
<script> |
|
|
61 |
YUI().use("jsonp", "transition",function (Y) { |
|
|
62 |
|
|
|
63 |
var url = "http://yuilibrary.com/gallery/api/random?callback={callback}", |
|
|
64 |
outputDiv = Y.one("#out"), |
|
|
65 |
gallery; |
|
|
66 |
|
|
|
67 |
// Using the configuration object syntax |
|
|
68 |
gallery = new Y.JSONPRequest(url, { |
|
|
69 |
on: { |
|
|
70 |
success: function (response) { |
|
|
71 |
var module = response.modules[0], |
|
|
72 |
author = module.owner; |
|
|
73 |
|
|
|
74 |
// Some users don't have a rank |
|
|
75 |
if (!author.rank) { |
|
|
76 |
author.rank = "user"; |
|
|
77 |
} |
|
|
78 |
|
|
|
79 |
// Format the author info and store as a property of the |
|
|
80 |
// module object for use by Y.Lang.sub |
|
|
81 |
// ('this' refers to the JSONPRequest object by default) |
|
|
82 |
module.authorHTML = Y.Lang.sub(this.authorTemplate, author); |
|
|
83 |
|
|
|
84 |
outputDiv.setHTML(Y.Lang.sub(this.moduleTemplate, module)); |
|
|
85 |
|
|
|
86 |
// Add some flare to the poll interval by showing a "time left" |
|
|
87 |
// indicator via the header's border |
|
|
88 |
Y.one("#out h4") |
|
|
89 |
.setStyle("borderRightWidth", "100px") |
|
|
90 |
.transition({ |
|
|
91 |
borderRightWidth: 0, |
|
|
92 |
duration: 7 |
|
|
93 |
}, function () { |
|
|
94 |
if (gallery.polling) { |
|
|
95 |
gallery.send(); |
|
|
96 |
} |
|
|
97 |
}); |
|
|
98 |
}, |
|
|
99 |
|
|
|
100 |
failure: function () { |
|
|
101 |
gallery.polling = false; |
|
|
102 |
outputDiv.setHTML(this.failureTemplate); |
|
|
103 |
|
|
|
104 |
// Wire up the Try again button |
|
|
105 |
outputDiv.one("button").on("click", function () { |
|
|
106 |
gallery.send(); |
|
|
107 |
}); |
|
|
108 |
} |
|
|
109 |
} |
|
|
110 |
}); |
|
|
111 |
|
|
|
112 |
|
|
|
113 |
gallery.moduleTemplate = |
|
|
114 |
'<h4><a href="{url}">{title}</a></h4>' + |
|
|
115 |
'<p class="author">{authorHTML}</p>' + |
|
|
116 |
'<div>{summary}</div>'; |
|
|
117 |
|
|
|
118 |
gallery.authorTemplate = |
|
|
119 |
'<img src="{icon}" height="30" width="30">' + |
|
|
120 |
' {fullname} <span class="rank">({rank})</span>'; |
|
|
121 |
|
|
|
122 |
gallery.failureTemplate = |
|
|
123 |
'<p class="error">Ack, I couldn\'t reach the Gallery web service!</p>' + |
|
|
124 |
'<button>Try again</button>'; |
|
|
125 |
|
|
|
126 |
gallery.polling = false; |
|
|
127 |
|
|
|
128 |
|
|
|
129 |
// Click the button to send the JSONP request |
|
|
130 |
Y.one("#start").on("click", function (e) { |
|
|
131 |
if (!gallery.polling) { |
|
|
132 |
gallery.polling = true; |
|
|
133 |
gallery.send(); |
|
|
134 |
} |
|
|
135 |
}); |
|
|
136 |
|
|
|
137 |
Y.one("#stop").on("click", function (e) { |
|
|
138 |
gallery.polling = false; |
|
|
139 |
}); |
|
|
140 |
|
|
|
141 |
}); |
|
|
142 |
</script> |
|
|
143 |
|
|
|
144 |
</div> |
|
|
145 |
|
|
|
146 |
<h3>The data</h3> |
|
|
147 |
<p>The structure of the JavaScript object returned from YUILibrary's JSONP service will look like this:</p> |
|
|
148 |
|
|
|
149 |
<pre class="code prettyprint">{ |
|
|
150 |
modules: [ |
|
|
151 |
{ |
|
|
152 |
url: (the url to the module), |
|
|
153 |
title: (the title of the module), |
|
|
154 |
summary: (short description of the module), |
|
|
155 |
..., |
|
|
156 |
owner: { |
|
|
157 |
icon: (url to the author's thumb image), |
|
|
158 |
fullname: (the author's full name), |
|
|
159 |
rank: (YUI Team member?, Contributor? etc), |
|
|
160 |
... |
|
|
161 |
} |
|
|
162 |
} |
|
|
163 |
], |
|
|
164 |
... |
|
|
165 |
}</pre> |
|
|
166 |
|
|
|
167 |
|
|
|
168 |
<p>We'll use these objects to populate an HTML template with data <em>{placeholder}</em>s using <code>Y.Lang.sub( template, object )</code>.</p> |
|
|
169 |
|
|
|
170 |
|
|
|
171 |
<h3>Start simple</h3> |
|
|
172 |
<p>To make a single call to the YUILibrary Gallery API, we can just use</p> |
|
|
173 |
|
|
|
174 |
<pre class="code prettyprint">Y.jsonp("http://yuilibrary.com/gallery/api/random?callback={callback}", handleJSONP);</pre> |
|
|
175 |
|
|
|
176 |
|
|
|
177 |
<p>But since each call to <code>Y.jsonp()</code> creates a new instance of <code>Y.JSONPRequest</code>, we may as well store the instance and reuse it.</p> |
|
|
178 |
|
|
|
179 |
<pre class="code prettyprint">var gallery = new Y.JSONPRequest("http://yuilibrary.com/gallery/api/random?callback={callback}", handleJSONP); |
|
|
180 |
|
|
|
181 |
gallery.send();</pre> |
|
|
182 |
|
|
|
183 |
|
|
|
184 |
<h3>Add polling</h3> |
|
|
185 |
<p>JSONPRequest doesn't have any built-in polling mechanism, but <code>Y.later()</code> can handle this for us.</p> |
|
|
186 |
|
|
|
187 |
<pre class="code prettyprint">var url = "http://yuilibrary.com/gallery/api/random?callback={callback}"; |
|
|
188 |
|
|
|
189 |
function handleJSONP(response) { |
|
|
190 |
// populate template from the response object and add to the output div |
|
|
191 |
... |
|
|
192 |
|
|
|
193 |
Y.one("#out").setHTML( Y.Lang.sub(template, module) ); |
|
|
194 |
|
|
|
195 |
// After 7 seconds, call the API for a new module |
|
|
196 |
Y.later(7000, this, this.send); |
|
|
197 |
}; |
|
|
198 |
|
|
|
199 |
var gallery = new Y.JSONPRequest(url, handleJSONP); |
|
|
200 |
gallery.send();</pre> |
|
|
201 |
|
|
|
202 |
|
|
|
203 |
<h3>Add failure protection</h3> |
|
|
204 |
<p>In case the Gallery API is busy or some other problem arises, we'll also want to handle this case and display an error. We can do this by passing a configuration object as the second parameter rather than a simple success callback.</p> |
|
|
205 |
|
|
|
206 |
<pre class="code prettyprint">var gallery = new Y.JSONPRequest(url, { |
|
|
207 |
on: { |
|
|
208 |
success: function (response) { |
|
|
209 |
// populate output div from the template and response object |
|
|
210 |
... |
|
|
211 |
|
|
|
212 |
Y.one("#out").setHTML( Y.Lang.sub(template, module) ); |
|
|
213 |
|
|
|
214 |
// After 7 seconds, call the API for a new module |
|
|
215 |
Y.later(7000, this, this.send); |
|
|
216 |
}, |
|
|
217 |
|
|
|
218 |
failure: function () { |
|
|
219 |
Y.one("#out").setHTML( failureTemplate ); |
|
|
220 |
} |
|
|
221 |
} |
|
|
222 |
}); |
|
|
223 |
|
|
|
224 |
gallery.send();</pre> |
|
|
225 |
|
|
|
226 |
|
|
|
227 |
<h3>Add flare</h3> |
|
|
228 |
<p>Now we'll add a bit of flourish, by adding a visual indicator of how long until the next module is requested. We'll replace the call to <code>Y.later()</code> with a call to <code>node.transition()</code> using a shrinking border to show the remaining time. Then when the transition is complete, we call <code>send()</code> again. |
|
|
229 |
|
|
|
230 |
<pre class="code prettyprint">var gallery = new Y.JSONPRequest(url, { |
|
|
231 |
on: { |
|
|
232 |
success: function (response) { |
|
|
233 |
// populate output div from the template and response object |
|
|
234 |
... |
|
|
235 |
|
|
|
236 |
Y.one("#out").setHTML( Y.Lang.sub(template, module) ); |
|
|
237 |
|
|
|
238 |
// Add some flare to the poll interval by showing a "time left" |
|
|
239 |
// indicator via the header's border |
|
|
240 |
Y.one("#out h4") |
|
|
241 |
.setStyle("borderRightWidth", "100px") |
|
|
242 |
.transition({ |
|
|
243 |
borderRightWidth: 0, |
|
|
244 |
duration: 7 |
|
|
245 |
}, function () { |
|
|
246 |
gallery.send(); |
|
|
247 |
}); |
|
|
248 |
}, |
|
|
249 |
|
|
|
250 |
failure: function () { |
|
|
251 |
Y.one("#out").setHTML( failureTemplate ); |
|
|
252 |
} |
|
|
253 |
} |
|
|
254 |
}); |
|
|
255 |
|
|
|
256 |
gallery.send();</pre> |
|
|
257 |
|
|
|
258 |
|
|
|
259 |
<h3>Stop the poll</h3> |
|
|
260 |
<p>The final step is to add the ability to start and stop the polling. We'll manage this by adding a property to the <code>gallery</code> JSONPRequest instance named <code>gallery.polling</code>. See the full code listing below for the implementation. |
|
|
261 |
|
|
|
262 |
<h3 id="fullcode">Full Code Listing</h3> |
|
|
263 |
<h4>HTML</h4> |
|
|
264 |
<pre class="code prettyprint"><div id="demo"> |
|
|
265 |
<input type="button" id="start" value="Start polling"> |
|
|
266 |
<input type="button" id="stop" value="Stop polling"> |
|
|
267 |
<div id="out"> |
|
|
268 |
</div> |
|
|
269 |
</div></pre> |
|
|
270 |
|
|
|
271 |
|
|
|
272 |
<h4>JavaScript</h4> |
|
|
273 |
<pre class="code prettyprint"><script> |
|
|
274 |
YUI().use("jsonp", "transition",function (Y) { |
|
|
275 |
|
|
|
276 |
var url = "http://yuilibrary.com/gallery/api/random?callback={callback}", |
|
|
277 |
outputDiv = Y.one("#out"), |
|
|
278 |
gallery; |
|
|
279 |
|
|
|
280 |
// Using the configuration object syntax |
|
|
281 |
gallery = new Y.JSONPRequest(url, { |
|
|
282 |
on: { |
|
|
283 |
success: function (response) { |
|
|
284 |
var module = response.modules[0], |
|
|
285 |
author = module.owner; |
|
|
286 |
|
|
|
287 |
// Some users don't have a rank |
|
|
288 |
if (!author.rank) { |
|
|
289 |
author.rank = "user"; |
|
|
290 |
} |
|
|
291 |
|
|
|
292 |
// Format the author info and store as a property of the |
|
|
293 |
// module object for use by Y.Lang.sub |
|
|
294 |
// ('this' refers to the JSONPRequest object by default) |
|
|
295 |
module.authorHTML = Y.Lang.sub(this.authorTemplate, author); |
|
|
296 |
|
|
|
297 |
outputDiv.setHTML(Y.Lang.sub(this.moduleTemplate, module)); |
|
|
298 |
|
|
|
299 |
// Add some flare to the poll interval by showing a "time left" |
|
|
300 |
// indicator via the header's border |
|
|
301 |
Y.one("#out h4") |
|
|
302 |
.setStyle("borderRightWidth", "100px") |
|
|
303 |
.transition({ |
|
|
304 |
borderRightWidth: 0, |
|
|
305 |
duration: 7 |
|
|
306 |
}, function () { |
|
|
307 |
if (gallery.polling) { |
|
|
308 |
gallery.send(); |
|
|
309 |
} |
|
|
310 |
}); |
|
|
311 |
}, |
|
|
312 |
|
|
|
313 |
failure: function () { |
|
|
314 |
gallery.polling = false; |
|
|
315 |
outputDiv.setHTML(this.failureTemplate); |
|
|
316 |
|
|
|
317 |
// Wire up the Try again button |
|
|
318 |
outputDiv.one("button").on("click", function () { |
|
|
319 |
gallery.send(); |
|
|
320 |
}); |
|
|
321 |
} |
|
|
322 |
} |
|
|
323 |
}); |
|
|
324 |
|
|
|
325 |
|
|
|
326 |
gallery.moduleTemplate = |
|
|
327 |
'<h4><a href="{url}">{title}</a></h4>' + |
|
|
328 |
'<p class="author">{authorHTML}</p>' + |
|
|
329 |
'<div>{summary}</div>'; |
|
|
330 |
|
|
|
331 |
gallery.authorTemplate = |
|
|
332 |
'<img src="{icon}" height="30" width="30">' + |
|
|
333 |
' {fullname} <span class="rank">({rank})</span>'; |
|
|
334 |
|
|
|
335 |
gallery.failureTemplate = |
|
|
336 |
'<p class="error">Ack, I couldn\'t reach the Gallery web service!</p>' + |
|
|
337 |
'<button>Try again</button>'; |
|
|
338 |
|
|
|
339 |
gallery.polling = false; |
|
|
340 |
|
|
|
341 |
|
|
|
342 |
// Click the button to send the JSONP request |
|
|
343 |
Y.one("#start").on("click", function (e) { |
|
|
344 |
if (!gallery.polling) { |
|
|
345 |
gallery.polling = true; |
|
|
346 |
gallery.send(); |
|
|
347 |
} |
|
|
348 |
}); |
|
|
349 |
|
|
|
350 |
Y.one("#stop").on("click", function (e) { |
|
|
351 |
gallery.polling = false; |
|
|
352 |
}); |
|
|
353 |
|
|
|
354 |
}); |
|
|
355 |
</script></pre> |
|
|
356 |
|
|
|
357 |
</div> |
|
|
358 |
</div> |
|
|
359 |
</div> |
|
|
360 |
|
|
|
361 |
<div class="yui3-u-1-4"> |
|
|
362 |
<div class="sidebar"> |
|
|
363 |
|
|
|
364 |
|
|
|
365 |
|
|
|
366 |
<div class="sidebox"> |
|
|
367 |
<div class="hd"> |
|
|
368 |
<h2 class="no-toc">Examples</h2> |
|
|
369 |
</div> |
|
|
370 |
|
|
|
371 |
<div class="bd"> |
|
|
372 |
<ul class="examples"> |
|
|
373 |
|
|
|
374 |
|
|
|
375 |
<li data-description="Get basic GitHub user info using a Y.jsonp(url, callback)."> |
|
|
376 |
<a href="jsonp-github.html">Getting Cross Domain JSON Data Using Y.jsonp()</a> |
|
|
377 |
</li> |
|
|
378 |
|
|
|
379 |
|
|
|
380 |
|
|
|
381 |
<li data-description="Create a reusable JSONPRequest object to poll the YUILibrary.com Gallery web service, fetching info on a random Gallery module."> |
|
|
382 |
<a href="jsonp-gallery.html">Reusing a JSONPRequest Instance to Poll a Remote Server</a> |
|
|
383 |
</li> |
|
|
384 |
|
|
|
385 |
|
|
|
386 |
|
|
|
387 |
|
|
|
388 |
|
|
|
389 |
|
|
|
390 |
</ul> |
|
|
391 |
</div> |
|
|
392 |
</div> |
|
|
393 |
|
|
|
394 |
|
|
|
395 |
|
|
|
396 |
<div class="sidebox"> |
|
|
397 |
<div class="hd"> |
|
|
398 |
<h2 class="no-toc">Examples That Use This Component</h2> |
|
|
399 |
</div> |
|
|
400 |
|
|
|
401 |
<div class="bd"> |
|
|
402 |
<ul class="examples"> |
|
|
403 |
|
|
|
404 |
|
|
|
405 |
|
|
|
406 |
|
|
|
407 |
|
|
|
408 |
|
|
|
409 |
<li data-description="Wrapping async transactions with promises"> |
|
|
410 |
<a href="../promise/basic-example.html">Wrapping async transactions with promises</a> |
|
|
411 |
</li> |
|
|
412 |
|
|
|
413 |
|
|
|
414 |
|
|
|
415 |
<li data-description="Extend Y.Promise to create classes that encapsulate standard transaction logic in descriptive method names"> |
|
|
416 |
<a href="../promise/subclass-example.html">Subclassing Y.Promise</a> |
|
|
417 |
</li> |
|
|
418 |
|
|
|
419 |
|
|
|
420 |
</ul> |
|
|
421 |
</div> |
|
|
422 |
</div> |
|
|
423 |
|
|
|
424 |
</div> |
|
|
425 |
</div> |
|
|
426 |
</div> |
|
|
427 |
</div> |
|
|
428 |
|
|
|
429 |
<script src="../assets/vendor/prettify/prettify-min.js"></script> |
|
|
430 |
<script>prettyPrint();</script> |
|
|
431 |
|
|
|
432 |
<script> |
|
|
433 |
YUI.Env.Tests = { |
|
|
434 |
examples: [], |
|
|
435 |
project: '../assets', |
|
|
436 |
assets: '../assets/jsonp', |
|
|
437 |
name: 'jsonp-gallery', |
|
|
438 |
title: 'Reusing a JSONPRequest Instance to Poll a Remote Server', |
|
|
439 |
newWindow: '', |
|
|
440 |
auto: false |
|
|
441 |
}; |
|
|
442 |
YUI.Env.Tests.examples.push('jsonp-github'); |
|
|
443 |
YUI.Env.Tests.examples.push('jsonp-gallery'); |
|
|
444 |
YUI.Env.Tests.examples.push('basic-example'); |
|
|
445 |
YUI.Env.Tests.examples.push('subclass-example'); |
|
|
446 |
|
|
|
447 |
</script> |
|
|
448 |
<script src="../assets/yui/test-runner.js"></script> |
|
|
449 |
|
|
|
450 |
|
|
|
451 |
|
|
|
452 |
</body> |
|
|
453 |
</html> |