Showing and hiding inputs based on checkboxGroupInput - r

Question

My shiny app begins with a checkboxGroupInput which contains the names of three companies: A, B and C. It also has 3 hidden numeric inputs, each corresponding to a company. Potential investors may select the name of the company they wish to invest in and specifiy the amount they are willing to invest. When the name of a company is checked, the corresponding numeric input shows up. Also, when the company name is unchecked, the numeric input disappears.
The checkboxGroupInput is called company. The 3 numericInput fields are respectively called amountA, amountB and amountC and are all generated inside a uiOutput. They are hidden with the hidden function of shinyjs.
library(shiny)
library(shinyjs)
library(magrittr)
ui <- fluidPage(
useShinyjs(),
checkboxGroupInput(inputId = "company", label = "Select a company", choices = LETTERS[1:3]),
uiOutput(outputId = "amounts")
)
server <- function(input, output){
company_names <- LETTERS[1:3]
num_ids <- paste0("amount", LETTERS[1:3])
output$amounts <- renderUI({
num_inputs <- lapply(1:3, function(i){
numericInput(inputId = num_ids[i], label = paste0("Investment in ", company_names[i]), value = 0, min = 0, max = 5000)
}) %>% tagList
shinyjs::hidden(num_inputs)
})
observeEvent(eventExpr = input$company, handlerExpr = {
if(length(input$company) == 0){
for(i in num_ids){
shinyjs::hide(id = i)
}
} else {
for(i in input$company){
shinyjs::toggle(id = paste0("amount", i), condition = input$company)
}
}
})
}
shinyApp(ui = ui, server = server)
The problem with my app is that the intended dynamics between the checkboxGroupInput and the numericInput fields are not working as intended. For instance, once a numericInput is shown, it cannot be hidden anymore by unchecking the boxes. How can I handle this?
The code pasted above is fully functional. Thank you very much.

Answer 1

I fixed your code by explicitly show/hide the numericInput when the corresponding check box is selected/unselected. Also I change the observeEvent with observe to make sure that the observer reacts when none of the check boxes are selected.
library(shiny)
library(shinyjs)
library(magrittr)
ui <- fluidPage(
useShinyjs(),
checkboxGroupInput(inputId = "company", label = "Select a company", choices = LETTERS[1:3]),
uiOutput(outputId = "amounts")
)
server <- function(input, output){
company_names <- LETTERS[1:3]
num_ids <- paste0("amount", LETTERS[1:3])
output$amounts <- renderUI({
num_inputs <- lapply(1:3, function(i){
numericInput(inputId = num_ids[i], label = paste0("Investment in ", company_names[i]), value = 0, min = 0, max = 5000)
}) %>% tagList
shinyjs::hidden(num_inputs)
})
observe({
for(i in company_names){
if (i %in% input$company) {
shinyjs::show(id = paste0("amount", i))
} else {
shinyjs::hide(id = paste0("amount", i))
}
}
})
}
shinyApp(ui = ui, server = server)