10.2. Recommended Approach for Using Chart API

EspressChart provides API through which charts can be generated programmatically from scratch. However, this generally involves a significant amount of code. We recommend using Designer and creating chart templates (.TPL file) first. The chart template can be passed in the QbChart constructor and thus have its look and feel applied to the newly created chart object. Therefore, most of the look and feel will have been set at the time of the chart generation. You can then write code to modify, add, or remove the properties. This approach will save you coding time and improve performance as well.

When using EspressChart Chart API, you have the option of connecting to EspressManager or of not connecting to it. While a connection is required when using Designer, you do not need to connect to EspressManager when running any application that utilizes EspressChart Chart API. We generally recommend that you do not connect to EspressManager and thereby avoid another layer in your architecture. For more details, please refer to the next section.

All examples and code given in the manual follow the above two recommendations: a template based approach and no connection to EspressManager. Unless otherwise noted, all code examples will use a template (can be downloaded in corresponding chapters) and will not connect to EspressManager.

Also note that if you have applets that use EspressChart Chart API, the browser must have at least a 1.5 JVM plugin.