One of the starting points of the visualizations of vis.js is that they can deal with dynamic data, and allow manipulation of the data. To enable this, vis.js includes a flexible key/value based DataSet and DataView to handle unstructured JSON data.
By providing a DataSet with data to the visualizations, they can subscribe on changes in the DataSet and automatically reflect the changes in their view. Changes in the data can be caused by a server pushing updates to a client, or by other interactive components in the web application. Vice versa, data can be manipulated in one of the visualizations. For example a REST-client can listen for changes and automatically write changes to the server. Or changes can be propagated to other parts of the web application.
A DataSet can be used to store JSON objects by id. Objects can be added, updated and removed from the DataSet, and one can subscribe to changes in the DataSet.
The data in the DataSet can be filtered and ordered, and fields (like
dates) can be converted to a specific type. Data can be normalized when
appending it to the DataSet as well.
Go to the documentation of DataSet
A DataView offers a filtered and/or formatted view on a DataSet.
One can subscribe to changes in a DataView, and easily get filtered or
formatted data without having to specify filters and field types all
the time.