VisualForté - Frequently Asked Questions

VisualForte Servlet

Q. How do I define a chart?

Q. How do I display a chart that I have defined?

Q. How do I add a chart image into my web page?

How do I define a chart?

VisualForte charts are defined by templates using an XML language called the VisualForte Markup Language (VFML). VFML templates are stored on the server. A VFML template defines the content of a chart including the graphs displayed, static data to be used, and any formatting and visual effect etc. Dynamic data and any run-time customizations may be provided as URL parameters at run-time.

For more information, please consult the following documents:

VisualForte User Guide - includes a step by step guide on how to create your own charts.

VisualForte Markup Language (VFML) Reference Manual - provides detail information about VFML and customizing charts.

Ready to use VFML templates can be downloaded from here.

How do I display a chart that I have defined?

Charts are generated when a HTTP request is made to the application server running VisualForte servlet.

Assuming your application server is running. To generate a chart, all you have to do is make a request from your browser. Assuming all default parameters were used during installation, and "myhost" is your host machine, the request would then be:

http://myhost/vfchart/chart.png?template=my-chart.xml

The VFML template to be used should be specified in the URL parameter "template". In this case "template=my-chart.xml".

Additional URL parameters may be required depending on the design of your template.

How do I add a dynamically generated chart image into my web page?

Charts can be added to your web pages using the the "<img>" HTML tag with the chart URL as the source. For example if the chart URL was

http://myhost/vfchart/chart.png?template=sales-chart.xml?data=[[Jan,Feb],[Sales,20,43]]

then the HTML tag which would display this chart on your web page would be

<img src="http://myhost/vfchart/chart.png?template=sales-chart.xml?data=[[Jan,Feb],[Sales,20,43]]">

In the above example, the chart template defines the URL parameter "data", which supplies the data to be charted. Any VFML attributes can be parameterized and supplied at run-time.