inst/shiny-demo/data-set-swap-run/readme.md

In vegawidget: 'Htmlwidget' for 'Vega' and 'Vega-Lite'

This example shows how we can design a chart using Vega-Lite, then use Shiny to run that chart using different datasets. Also, it shows how we can update the data to a chart and delay re-running that chart until we tell it to re-run.

In the server function, we use vw_shiny_set_data() to observe the reactive expression rct_data(), updating the dataset, then re-running the Vega-Lite chart, whenever rct_data() changes.

To do this, we had to name the dataset in the Vega-Lite specification; you will see in the definition of spec_bar that there is a dataset named "source". We use this as the name argument for vw_shiny_set_data().

To delay re-running the chart when the data is updated, we call vw_shiny_set_data() with run = FALSE. This leaves us with the need for a mechanism to run the chart.

We do this using the function vw_shiny_run(), which observes the reactive expression linked to the shiny::actionButton() we create.

vegawidget documentation built on Sept. 3, 2023, 9:07 a.m.