Open Flash Chart, is open source. It is free to use and you get the source code to fiddle with!
How does it work?
- User browses to your web site.
- The browser downloads the web page which contains the Open Flash Chart.
- Open Flash Chart downloads the data file and displays the chart.
Why is that great?
When the user downloads the web page, Open Flash Chart requests the chart data from the server. The server knows who the user is so it can generate a chart for that particular user showing up to the minute data.
Is it complicated to set up?
You will need to include the Open Flash Chart in your HTML, and you also need to provide the data file on the server. The data file is either a text file, or a .php, Perl, Python, Java (or another flavour of dynamic) page.
For a simple chart you would just drop the data.txt file on your website and point the Open Flash Chart to this URL.
But what we really want is dynamic data that is pulled from a database or calculated or something. To do this you need to create the data file when it is requested. To do this we point the Open Flash Chart to a .php page and this PHP page does your calculations and/or database lookups, then outputs the data file.
To make this a bit easier there are PHP, Perl, Python and Java classes to write the data file for you.