How to save and load state with insertUI modules? - r

Question

I'm trying to save and load state of a shiny app using bookmarks. However, it doesn't work and I wonder whether it is because of inserting dynamic UI. If there are other ways to save and load dynamically rendered ui and resulting output, that would be great too. I don't know where to start and this is as far as I could come.
Simple example
library(shiny)
ui <- function(request){fluidPage(
actionButton("add", "Add UI"),
bookmarkButton()
)}
# Server logic
server <- function(input, output, session) {
observeEvent(input$add, {
insertUI(
selector = "#add",
where = "afterEnd",
ui = textInput(paste0("txt", input$add),
"Insert some text")
)
})
}
# Complete app with UI and server components
shinyApp(ui, server, enableBookmarking = "server")
Complex example
library(shiny)
one_plotUI <- function(id) {
ns <- NS(id)
plotOutput(ns("plot"))
}
one_plot <- function(id, x, y, type, breaks, break_counts) {
moduleServer(
id,
function(input, output, session) {
output$plot <- renderPlot({
if (type == "scatter") {
plot(x, y)
} else {
if (breaks == "custom") {
breaks <- break_counts
}
hist(x, breaks = breaks)
}
})
}
)
}
ui <- fluidPage(
sidebarPanel(
bookmarkButton(),
selectInput("plotType", "Plot Type",
c(Scatter = "scatter", Histogram = "hist")
),
# Only show this panel if the plot type is a histogram
conditionalPanel(
condition = "input.plotType == 'hist'",
selectInput(
"breaks", "Breaks",
c("Sturges", "Scott", "Freedman-Diaconis", "[Custom]" = "custom")
),
# Only show this panel if Custom is selected
conditionalPanel(
condition = "input.breaks == 'custom'",
sliderInput("breakCount", "Break Count", min = 1, max = 50, value = 10)
)
),
actionButton("make_plot", "Insert new plot")
),
mainPanel(
div(id = "add_here")
)
)
server <- function(input, output) {
x <- rnorm(100)
y <- rnorm(100)
counter_plots <- 1
observeEvent(input$make_plot, {
current_id <- paste0("plot_", counter_plots)
# call the logic for one plot
one_plot(id = current_id,
x = x,
y = y,
type = input$plotType,
breaks = input$breaks,
break_counts = input$breakCount)
# show the plot
insertUI(selector = "#add_here",
ui = one_plotUI(current_id))
# update the counter
counter_plots <<- counter_plots + 1
})
}
shinyApp(ui, server, enableBookmarking = "server")

Answer 1

edit: Found another solution emulating what insertUI does but with renderUI:
library(shiny)
library(purrr)
ui <- function(request){fluidPage(
actionButton("add", "Add UI"),
uiOutput('dynamic_ui'),
bookmarkButton()
)}
# Server logic
server <- function(input, output, session) {
input_contents <- reactive({reactiveValuesToList(input)})
observeEvent(input$add, {
# a new ui will be rendered with one extra input each time add button is pressed
output$dynamic_ui <- renderUI({
map(1:input$add, ~textInput(inputId = paste0("txt", .x), label = paste0("txt", .x) ))
})
#add the old values, otherwise all the inputs will be empty agin.
input_contents() %>%
names() %>%
map(~ updateTextInput(session = session, inputId = .x, label = .x, value = input_contents()[[.x]]))
})
}
# Complete app with UI and server components
shinyApp(ui, server, enableBookmarking = "server")
insertUI might be broken. The only way i could "fix" it was to drop function(request) of the ui, that caused that all the values in the inputs have to be saved between stances (in state$values$input_restore). Also a warning is showed in the console, but it doesn't affect the functionality.
library(shiny)
library(tidyverse)
library(stringr)
ui <- fluidPage(
actionButton("add", "Add UI"),
uiOutput('restored_ui'), #this is very important
bookmarkButton())
# Server logic
server <- function(input, output, session) {
counter <- reactiveValues()
counter$n <- c(0) #This value is only used to initialize the object.
total_ui_count <- reactiveValues()
total_ui_count$info <- 0 #because input$add will reset to zero this will count the number of uis to remember.
#When bookmark button is pressed
onBookmark(function(state) {
state$values$currentCounter <- counter$n
state$values$input_restore <- reactiveValuesToList(input)
print(names(input) %>% str_subset('^txt'))
state$values$total_uis_to_restore <- counter$n[[length(counter$n)]]
})
#rerender the previous outputs and their values
onRestore(function(state) {
#restore values from previous state
counter$n <- state$values$currentCounter
vals <- state$values$input_restore
print(str_subset(names(vals), '^txt.*$')) #for debugging
total_ui_count$info <- state$values$total_uis_to_restore
print(total_ui_count$info)
#render back a ui with the previous values.
output$restored_ui <- renderUI({
str_subset(names(vals), '^txt.*$') %>%
sort(decreasing = TRUE) %>% #to avoid order reversal of the inputs
map(~ textInput(.x, label = .x, value = vals[[.x]])) #render the last inputs
})
})
observeEvent(input$add, {
#input$add starts as 1 in the next state (because ui is not wrapped in function(request)) that's why total_ui_count is present
counter$n <- c(counter$n, input$add + total_ui_count$info)
print(counter$n) #for debugging
insertUI(
selector = "#add",
where = "afterEnd",
ui = textInput(inputId = paste0("txt", counter$n[[length(counter$n)]]),
label = "Insert some text")
)})
}
# Complete app with UI and server components
shinyApp(ui, server, enableBookmarking = "server")