In many ways, authoring a custom visualization is out of the scope of this book. However, it is worthwhile to be aware of the basic steps required to create a visualization from scratch, just in case a requirement for such a chart arises in the future. The general method of creating new visualizations involves knowledge of the HTML DOM (Document Object Model) and a reasonable amount of comfort working with programming abstraction.
To start, it is best to know some basic terminology that will be encountered when attempting to build a custom chart. As mentioned in Chapter 4, Basic Charts, the Google Visualization API is structured as an inheritance-based model. Classes of functions are realized through programming instances. The Visualization API charts, for example, barchart
, geochart
, areachart
, and so on, become instances of a bundle of code when they are used in a program. In programming, the creation of an instance is taken care of by an element of code called the...