Data visualization for Dojo 2

[novemberborn]

Data visualization for Dojo 2 fits in with the widget system. This means being able to declaratively render charts using the app factory, pulling data from stores, being able to mix in behavior, and so forth.

It also utilizes TypeScript. This allows charts to be created that have specific expectations on their input data. Rather than requiring users to compute the numbers needed to render a chart, charts can be plotted based on the objects already used elsewhere in the application.

Dojo 2 provides extensible chart types. Users can then develop chart widgets in accordance with their style guide and data requirements, such that it can be wired into an application without any further configuration.

Initially charts will be rendered as SVG, however the methods that produce the VNodes must be separate from those that compute the plot points. This will make it easier to extend charts using AOP, as well as target different renderings.

As much as possible charts should be styled using CSS, using both semantic and customizable class names. Only where necessary for correct rendering, or because CSS does not have sufficient browser support, should styling options be configured when building charts.

Configuration itself must be flexible, including pulling from stores, taking options, and providing it when creating subclasses.

Charts must be reactive, responding to state changes or subscribing to observables. Indeed observables are used to perform the computations necessary for plotting.

[dylans]

At some point in the near future, it will be time to revisit this and probably refactor the API substantially. Namely:

• We now have a much clearer direction for Widgets
• Stores and data are much further along and will be heavily used by dataviz
• API needs to be clear and intuitive to use, and consistent with other Dojo 2 paradigms