addItem: Add a single item to a timeline
In westdana/Timeline: Create Interactive Timeline Visualizations in R

Add a single item to a timeline

1	addItem(id, data)

`id`	Timeline id or a `timevis` object (the output from `timevis()`)
`data`	A named list containing the item data to add.

timevis() %>%
  addItem(list(start = Sys.Date(), content = "Today"))

if (interactive()) {
library(shiny)
shinyApp(
  ui = fluidPage(
    timevisOutput("timeline"),
    actionButton("btn", "Add item today")
  ),
  server = function(input, output) {
    output$timeline <- renderTimevis(
      timevis()
    )
    observeEvent(input$btn, {
      addItem("timeline", list(start = Sys.Date(), content = "Today"))
    })
  }
)
}