Shiny: Dynamic height adjustment of plot

Question

Problem: In belows Shiny app the user can add information presented in valueboxes depending on the select input. If the user selects all possible choices then the UI looks as in the screenshot.

Question: Is it possible that the plot (which is in the same row as the valueboxes) adjusts in height (so the bottom of the plot is aligned with the bottom of the last valuebox)?

library(shiny)
library(shinydashboard)

ui <- dashboardPage(
  dashboardHeader(),
  
  dashboardSidebar(
    selectizeInput(
      inputId = "select",
      label = "Select country:",
      choices = c("CH", "JP", "GER", "AT", "CA", "HK"),
      multiple = TRUE)
  ),
  
  dashboardBody(
    fluidRow(column(2, uiOutput("ui1")),
             column(10, plotOutput("some_plot"))))#,
                # column(4, uiOutput("ui2")),
                # column(4, uiOutput("ui3")))
)

server <- function(input, output) {
  
  output$ui1 <- renderUI({
    req(input$select)
    
    lapply(seq_along(input$select), function(i) {
      fluidRow(
        valueBox(value = input$select[i],
                 subtitle = "Box 1",
                 width = 12)
      )
    })
  })
  
  output$some_plot <- renderPlot(
    plot(iris)
  )
}

shinyApp(ui = ui, server = server)

Answer 1

You can adjust the height in the renderPlot. I have set the minimum to 3 value box height. So, it starts increasing the height after you add 3 value boxes. You can modify it, as necessary. Try the code below.

  library(shiny)
  library(shinydashboard)
  
  ui <- dashboardPage(
    dashboardHeader(),
    
    dashboardSidebar(
      selectizeInput(
        inputId = "select",
        label = "Select country:",
        choices = c("CH", "JP", "GER", "AT", "CA", "HK"),
        multiple = TRUE)
    ),
    
    dashboardBody(
      fluidRow(column(2, uiOutput("ui1")),
               column(10, plotOutput("some_plot"))))#,
    
    # column(4, uiOutput("ui2")),
    # column(4, uiOutput("ui3")))
  )
  
  server <- function(input, output) {
    plotht <- reactiveVal(360)
    observe({
      req(input$select)
      nvbox <- length(input$select)
      if (nvbox > 3) {
        plotheight <- 360 + (nvbox-3)*120
      }else plotheight <- 360
      plotht(plotheight)
    })
    
    output$ui1 <- renderUI({
      req(input$select)
      
      lapply(seq_along(input$select), function(i) {
        fluidRow(
          valueBox(value = input$select[i],
                   subtitle = "Box 1",
                   width = 12)
        )
      })
    })
    
    observe({
      output$some_plot <- renderPlot({
        plot(iris)
      }, height=plotht())
    })
 
    
  }
  
  shinyApp(ui = ui, server = server)