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| author | Yves Fischer <yvesf-git@xapek.org> | 2011-10-23 21:14:40 +0200 |
|---|---|---|
| committer | Yves Fischer <yvesf-git@xapek.org> | 2011-10-30 11:33:54 +0100 |
| commit | 770ba5201f5c60b2bb36602ff9d359f641e33125 (patch) | |
| tree | 2200757f04efbc281c4b3714bfe2e4fe911193b6 /schall/static/RGraph/docs/async.html | |
| parent | 77f5e686612898974e13f2a5df57c20e4e529363 (diff) | |
| download | mini-octopus-770ba5201f5c60b2bb36602ff9d359f641e33125.tar.gz mini-octopus-770ba5201f5c60b2bb36602ff9d359f641e33125.zip | |
Charting with flask, rgraph and custom "timeseries database"
Diffstat (limited to 'schall/static/RGraph/docs/async.html')
| -rw-r--r-- | schall/static/RGraph/docs/async.html | 209 |
1 files changed, 209 insertions, 0 deletions
diff --git a/schall/static/RGraph/docs/async.html b/schall/static/RGraph/docs/async.html new file mode 100644 index 0000000..82490e4 --- /dev/null +++ b/schall/static/RGraph/docs/async.html @@ -0,0 +1,209 @@ +<!DOCTYPE html > +<html> +<head> + <meta http-equiv="X-UA-Compatible" content="chrome=1"> + <!-- + /** + * o------------------------------------------------------------------------------o + * | This file is part of the RGraph package - you can learn more at: | + * | | + * | http://www.rgraph.net | + * | | + * | This package is licensed under the RGraph license. For all kinds of business | + * | purposes there is a small one-time licensing fee to pay and for non | + * | commercial purposes it is free to use. You can read the full license here: | + * | | + * | http://www.rgraph.net/LICENSE.txt | + * o------------------------------------------------------------------------------o + */ + --> + <title>RGraph: HTML5 Javascript charts library - Asynchronous processing</title> + + <meta name="keywords" content="rgraph html5 canvas chart docs async asynchronous" /> + <meta name="description" content="RGraph: HTML5 Javascript charts library - Documentation about asynchronous processing" /> + + <meta property="og:title" content="RGraph: HTML5 Javascript charts library" /> + <meta property="og:description" content="A chart library based on the HTML5 canvas tag" /> + <meta property="og:image" content="http://www.rgraph.net/images/logo.png"/> + + <link rel="stylesheet" href="../css/website.css" type="text/css" media="screen" /> + <link rel="icon" type="image/png" href="../images/favicon.png"> + + <!-- Place this tag in your head or just before your close body tag --> + <script type="text/javascript" src="https://apis.google.com/js/plusone.js"></script> + + <script src="../libraries/RGraph.common.core.js"></script> + <script src="../libraries/RGraph.line.js"></script> + <!--[if IE 8]><script src="../excanvas/excanvas.original.js"></script><![endif]--> + + <script> + window.onload = function () + { + var duration = (new Date().getTime() - timer.getTime()) / 1000; + document.getElementById("waiting").innerHTML = '<span style="color: green">Done! Extra time taken: ' + duration.toFixed(1) + ' seconds</span>'; + alert('The window.onload event fired, extra time taken: ' + duration.toFixed(1) + ' seconds'); + } + + // Create a timer to show the difference + timer = new Date(); + </script> + + + <script> + var _gaq = _gaq || []; + _gaq.push(['_setAccount', 'UA-54706-2']); + _gaq.push(['_trackPageview']); + + (function() { + var ga = document.createElement('script'); ga.type = 'text/javascript'; ga.async = true; + ga.src = ('https:' == document.location.protocol ? 'https://ssl' : 'http://www') + '.google-analytics.com/ga.js'; + var s = document.getElementsByTagName('script')[0]; s.parentNode.insertBefore(ga, s); + })(); + </script> +</head> +<body> + + + <!-- Social networking buttons --> + <div id="social_icons" class="warning" style="border-radius: 10px; top: 1px; position: fixed; width: 120px; height: 20px"> + <!-- <a title="Bookmark with delicious" href="http://delicious.com/save?jump=close&v=4&noui&jump=close&url=http://www.rgraph.net¬es=RGraph%20is%20a%20HTML5%20based%20javascript%20charts%20library%20supporting%20a%20wide%20range%20of%20different%20chart%20types&title=RGraph:%20Javascript%20charts%20%26%20graph%20library" target="_blank"><img src="../images/delicious.png" alt="Bookmark with delicious" width="22" height="22" border="0" style="position: relative; top: 1px" /></a> --> + <a href="http://twitter.com/home/?status=RGraph%3A%20Javascript+charts+library+http%3A%2F%2Fwww.rgraph.net+%23rgraph+%23html5+%23canvas+%23javascript+%23charts+@_rgraph" target="_blank" title="Mention RGraph on Twitter"><img src="../images/twitter.png" alt="Mention RGraph on Twitter"/></a> + <iframe src="http://www.facebook.com/plugins/like.php?app_id=253862424642173&href=http%3A%2F%2Fwww.rgraph.net&send=false&layout=button_count&width=450&show_faces=false&action=like&colorscheme=light&font=arial&height=21" scrolling="no" frameborder="0" style="width: 80px; height:21px; position: relative; top: 1px"></iframe> + </div> + + <script> + // Opera fix + if (navigator.userAgent.indexOf('Opera') == -1) { + document.getElementById("social_icons").style.position = 'fixed'; + } + </script> + + <div id="google_plusone"> + <!-- Place this tag where you want the +1 button to render --> + <g:plusone href="http://www.rgraph.net"></g:plusone> + </div> + <!-- Social networking buttons --> + + <div id="breadcrumb"> + <a href="../index.html">RGraph: HTML5 Javascript charts library</a> + > + <a href="index.html">Documentation</a> + > + Asynchronous processing + </div> + + <h1>RGraph: <span>HTML5 Javascript charts library</span> - Asynchronous processing</h1> + + <script> + if (RGraph.isIE8()) { + document.write('<div style="background-color: #fee; border: 2px dashed red; padding: 5px"><b>Important</b><br /><br /> Internet Explorer 8 does not natively support the HTML5 canvas tag, so if you want to see the charts, you can either:<ul><li>Install <a href="http://code.google.com/chrome/chromeframe/">Google Chrome Frame</a></li><li>Use ExCanvas. This is provided in the RGraph Archive.</li><li>Use another browser entirely. Your choices are Firefox 3.5+, Chrome 2+, Safari 4+ or Opera 10.5+. </li></ul> <b>Note:</b> Internet Explorer 9 fully supports the canvas tag.</div>'); + } + </script> + + <p id="waiting" style="; font-weight: bold; font-size: 16pt"><span style="color: #aa0">Waiting for onload event...</span></p> + + <p style="background-color: #eee; border: 1px dashed gray; padding: 5px; height: 50px;"> + <span style="display: inline-block; margin-left: 10px; float: right"> + <script> + document.write('<img src="http://ie.microsoft.com/testdrive/HTML5/DOMContentLoaded/whidbey.jpg?' + Math.random() + '" width="50" height="50" /> '); + document.write('<img src="http://ie.microsoft.com/testdrive/HTML5/DOMContentLoaded/window.jpg?' + Math.random() + '" width="50" height="50" /> '); + document.write('<img src="http://ie.microsoft.com/testdrive/HTML5/DOMContentLoaded/whidbey2.jpg?' + Math.random() + '" width="50" height="50" />'); + </script> + </span> + + These images are here to pad the page and slow down loading so that the window.onload event is slowed. This makes the + difference far more visible. + </p> + + <canvas id="myCanvas" width="600" height="250" style="float: right">[No canvas support]</canvas> + + <script> + /** + * Create the line chart + */ + function CreateLineGraph () + { + var line = new RGraph.Line('myCanvas', [1,2,4,2,1,3,5,6,6,5,3,5]); + line.Set('chart.title', 'Sales for Acme Inc.'); + line.Set('chart.labels', ['Jan', 'Feb', 'Mar', 'Apr', 'May', 'Jun', 'Jul', 'Aug', 'Sep', 'Oct', 'Nov', 'Dec']); + line.Set('chart.hmargin', 10); + line.Set('chart.linewidth', 5); + line.Set('chart.shadow', true); + line.Set('chart.shadow.offsetx', 0); + line.Set('chart.shadow.offsety', 0); + line.Set('chart.shadow.blur', 15); + line.Draw(); + } + + RGraph.Async(CreateLineGraph); + </script> + + <p> + Asynchronous processing can speed up the display of your charts, because the browser gets to your code, sets it + going and then continues on rendering the page. Particularly if you have a weighty page, + it can make quite a difference. The <i>RGraph.Async()</i> function itself is very simple, but because it can make + a significant difference to the speed of your page, it is documented here. There's an example of it to the right. + One thing to remember is to ensure your canvas tag is defined first before you set the function that creates + the chart going. + </p> + + <p> + Although asynchronous processing can speed up your pages, it can also give the appearance of slower pages due to partial + rendering, (ie your pages render a bit at a time). You therefore will need to experiment to get the best result for you. + </p> + + <br clear="all" /> + + <pre class="code"> +<script src="RGraph.common.js"></script> +<script src="RGraph.line.js"></script> + +<canvas id="myCanvas" width="300" height="100">[No canvas support]</canvas> + +<script> + /** + * Create the line chart + */ + function CreateLineGraph () + { + var line = new RGraph.Line('myCanvas', [1,2,4,2,1,3,5,6,6,5,3,5]); + line.Set('chart.title', 'Sales for Acme Inc.'); + line.Set('chart.labels', ['Jan', 'Feb', 'Mar', 'Apr', 'May', 'Jun', 'Jul', 'Aug', 'Sep', 'Oct', 'Nov', 'Dec']); + line.Set('chart.hmargin', 10); + line.Set('chart.linewidth', 5); + line.Set('chart.shadow', true); + line.Set('chart.shadow.offsetx', 0); + line.Set('chart.shadow.offsety', 0); + line.Set('chart.shadow.blur', 15); + line.Draw(); + } + + RGraph.Async(CreateLineGraph); +</script> +</pre> + + <p><b>Things to remember</b></p> + + <ul> + <li>All your libraries must be loaded first. In the pages <head> for example. If not, you won't be able to create your charts.</li> + <li>Your <canvas> tag must be defined before setting the asynchronous code going. If not, then the canvas may be referenced before it exists, and thus your charts will not be created.</li> + <li> + The users connection speed may be a factor. Slower connections may mean, for example, that the onload event doesn't fire very + quickly. If you're using the onload event to create your charts then asynchronous creation instead may give you more + apparent speed ups. Alternatively, careful placement of the <canvas> tag and the code that creates the chart may suffice + instead. + </li> + <li>Since the MSIE/ExCanvas combo requires you to use the window.onload event, asynchronous chart creation in this case will probably not be any help.</li> + <li> + Since a dev release of version 4, Google Chrome has had an issue when asynchronous processing is used, meaning that + text isn't always displayed. The solution here is simply to not use asynchronous processing. As of 27th March 2010, + Chrome 5 appears to be fine. + </li> + </ul> + + <h4>See also</h4> + + You might also be interested in the alternative, <a href="domcontentloaded.html">DOMContentLoaded</a> event. + +</body> +</html>
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