A chart is a visual representation of a dataset. As datasets grow in complexity and number of elements, we might want to encapsulate the chart in a reusable piece of code to share it and use it in other projects. The success of the reusability of the chart depends on the choices made during the design process.
Repeatable: A chart can be rendered in a selection that contains several elements, displaying independent visualizations in each node. The update process and the variables associated to the data items must be independent as well.