Annotation Feature

I think having an annotation feature that lets you put some extra data available on the chart would be very helpful. It could be a target with callbacks similar to tooltips, so you could choose to have extra data displayed on hover. There are a lot of different ways to make annotations, here are a few:

Axis Marker

Series Marker

Horizontal / Vertical Lines

I’m torn on whether these should exist in a data series, but that usually only works for either horizontal or vertical

Alternative implementations

Google Charts has implemented this by adding Role as an option -https://developers.google.com/chart/interactive/docs/roles?hl=en. @etimberg & @tannerlinsley - I think we should seriously take a look at how we plan on supporting those options beyond just annotations while we still have some API flexibility.

[derekperkins]

It won’t be a part of the initial 2.0 release, but should make it for 2.1.

[etimberg]

Annotation plugin is https://github.com/chartjs/Chart.Annotation.js and all feature requests should be there. It already has the ability to do horizontal and vertical lines