RGraph is a HTML5 canvas graph library. It uses features that became available in HTML5 (specifically, the CANVAS tag) to produce a wide variety of graph types: bar chart, bi-polar chart (also known as an age frequency chart), donut chart, funnel chart, gantt chart, horizontal bar chart, LED display, line graph, meter, odometer, pie chart, progress bar, pseudo radar chart, scatter graph and traditional radar chart.
HTML5 introduces a new HTML element – the CANVAS tag. This tag allows for two dimensional drawing easily using Javascript. This makes it perfect for producing graphs. Because Javascript runs on your users computer, none of the stress on your server normally associated with producing graphs (as is currently the norm) is incurred. Not only that but because of the greater processing power that is typically available on users’ computers, they will appear to be much, much faster. And, because the code can be both compressed (for example if you’re using Apache, mod_gzip will do this automatically for you) and cached, bandwidth usage can be massively reduced. This makes it economically attractive to employ, (ie it can save you money…).
Imagine, you are creating 100,000 graphs a day and the data is such that the resulting graphs cannot be cached. With the RGraph library you can reduce that figure to zero. All the processing and graph creation is done by each individual client, much like rendering the HTML you send to them. So you don’t have to send any images, you simply send the Javascript libraries once. So, much lower bandwidth bills and far less strain on your webserver.
And if that wasn’t enough, because the graphs are created using Javascript, they will work offline if you view a .html page on your own PC. Download the archive and see! Useful if you need to do a presentation for example and want to use the same graph(s) as your website.
* Cross browser support.
* 15 Different base graph types (Examples).
* Graphs work on and off-line.
* Interactive features.
* Graphs are created on the client – no server load.
* Very easy setup (see Implementing RGraph).
* Fully documented.
* Very easy to learn.
Browser support
Since the graphs are produced using HTML5 features (the new canvas tag), client support is currently limited to:
* Mozilla Firefox 3.0+
* Google Chrome 1+
* Apple Safari 3+
* Opera 9.5+
* Microsoft Internet Explorer 8 (see note)
The HTML5 canvas tag is part of the HTML5 specification, and all of the above browsers have some sort of support for it.
Canvas & Microsoft Internet Explorer (MSIE)
Microsoft Internet Explorer doesn’t natively support the HTML5 <canvas> tag. To support MSIE you will need to use either Google Chrome Frame or ExCanvas from Google (which is included in the RGraph archive). Read more about Internet Explorer compatibility here. Note that you MUST use a webserver for the graphs to work.
RGraph and older browsers
Older browsers (eg Chrome 1, Firefox 3, Safari 3, Opera 9.5) are supported, however if they don’t support the canvas shadow or text APIs, these will naturally be unavailable. Earlier versions of these browsers may work, but are untested.
