How to implement a dynamic number of slides using shinydashboardPlus' carousel? - r

Question

I wish to use shinydashboardPlus' carousel to display a number of charts. The number of these charts can vary on a daily basis from one to ten.
A cron job runs the R script daily.
Here is a working example with a fixed number of slides, three.
library(shiny)
library(shinydashboard)
library(shinydashboardPlus)
chart_names <- c( "http://placehold.it/900x500/39CCCC/ffffff&text=Slide+1",
"http://placehold.it/900x500/39CCCC/ffffff&text=Slide+2",
"http://placehold.it/900x500/39CCCC/ffffff&text=Slide+3")
ui <- dashboardPagePlus(
header = dashboardHeaderPlus(disable = TRUE ),
sidebar = dashboardSidebar(width = 0 ),
body = dashboardBody(
carousel(indicators = TRUE,
id = "mycarousel",
carouselItem(
tags$img(src = chart_names[1])
),
carouselItem(
tags$img(src = chart_names[2])
),
carouselItem(
tags$img(src = chart_names[3])
)
)
)
)
server <- function(input, output, session) {}
shinyApp(ui, server)
Is this an example of where do.call could be used?
constructs and executes a function call from a name or a function and a list of arguments to be passed to it.
This attempt:
do.call(carousel, as.list(c(id = "mycarousel", "carouselItem(tag$img(src = chart_names[1])")))
results in this error:
Error: $ operator is invalid for atomic vectors
How do I programmatically add a previously unknown number of slides to a shinydashboardPlus carousel?

Answer 1

The answer was in the doc with the .list parameter ?carousel
library(shiny)
library(shinydashboard)
library(shinydashboardPlus)
nb_items = 5
items = Map(function(i) {carouselItem(
tags$img(src = paste0("http://placehold.it/900x500/39CCCC/ffffff&text=Slide+", i))
)}, 1:5)
ui <- dashboardPagePlus(
header = dashboardHeaderPlus(disable = TRUE ),
sidebar = dashboardSidebar(width = 0 ),
body = dashboardBody(
carousel(indicators = TRUE,
id = "mycarousel",
.list = items
)
)
)
server <- function(input, output, session) {}
shinyApp(ui, server)