Shiny: Add new series to Highcharts plot on button click

Question

How can I add a new series in a plot made by Highcharts? I want to do it by clicking on the button named "shux", created in Shiny.

Example data DF1:

DF1 <- data.frame(
  Date = c(as.Date("2017-12-01"), as.Date("2017-12-06"), as.Date("2017-12-11")),
  Value = c(95,97,96)
) 

Structure:

     Date       Value

1  2017-12-01      95
2  2017-12-06      97
3  2017-12-11      96

I want to add similar data DF2 (dataframe with 2 columns) to the plot.

My code:

library(shiny)
library(highcharter)

ui <- fluidPage(
  titlePanel("Example"),
  sidebarLayout(
    sidebarPanel(
      actionButton("shux", label = "Add")
    ),
    mainPanel(
      highchartOutput("hcontainer1", height = "800px")
    )
  )
)

server = function(input, output, session) {

  output$hcontainer1 <- renderHighchart({
    hc <- highchart() %>%
    hc_add_series(
      name = 'first',
      data = DF1,
      hcaes(x= Date, y = Value),
      type = 'line'
    )
  })
}

shinyApp(ui = ui, server = server)

I tried:

observe({
  input$shux
  hc_add_series(
    name = 'second',
    data = DF2,
    hcaes(x= Date, y = Value),
    type = 'line'
  )
})

But it didn't work. What approach should I use?

Answer 1

Something like this do, please note that when you use renderHighchart the chart will be redrawn.

library(shiny)
library(highcharter)

DF1 <- data.frame(
  Date = c(as.Date("2017-12-01"), as.Date("2017-12-06"), as.Date("2017-12-11")),
  Value = c(95,97,96)
) 

DF2 <- data.frame(
  Date = c(as.Date("2017-12-01"), as.Date("2017-12-06"), as.Date("2017-12-11")),
  Value = c(75,77,76)
) 

ui <- fluidPage(
  titlePanel("Example"),
  sidebarLayout(
    sidebarPanel(
      actionButton("shux",label = "Add")
    ),
    mainPanel(
      highchartOutput("hcontainer1", height = "800px")
    )
  )
)

server = function(input, output, session) {

  hc <- reactive({
    highchart() %>% hc_add_series(name = 'first',id = "1",data = DF1,hcaes(x= Date, y = Value),type = 'line')
  })

  hcadd <- eventReactive(input$shux,{
    hc() %>% hc_add_series(name = 'second',id = "2",data = DF2,hcaes(x= Date, y = Value),type = 'line')
  })

  output$hcontainer1 <- renderHighchart({
    if(input$shux == 0){
      return(hc())
    }
    hcadd()
  })
}

shinyApp(ui = ui, server = server)