R shiny conditional panels with multiple file inputs - r

Question

I have come across unusual behavior with the conditional panel in R shiny. I want to have multiple file inputs that the user can upload depending on how many files they want. The below is reducible code. This issue is if the condition is greater than 1 I cannot populate all the files with csv files?? I can for second but not the first
library('shiny')
library('shinythemes')
## adding the conditional statements
ui =
navbarPage("Page Title",
tabPanel("Panel 1",
sidebarPanel(
## Add Name,
## Number of surveys analysising
numericInput("n_values", "Number of columns in next panel:", 1, min = 1, max = 2)
),
mainPanel(
tags$div(
h2("Home Page")
)
)
),
tabPanel("Panel 2",
conditionalPanel(condition = "input.n_values == 1",
fixedPage(theme = "flatly",
fixedRow(
column(2,"First Column",
fileInput("File1", "Choose a CSV files", multiple = F),
p("Click the button to check the data was read in correctly")
),
fixedRow(
column(12,
verbatimTextOutput("errorText1")
)
)
)
)
),
conditionalPanel(condition = "input.n_values == 2",
fixedPage(theme = "flatly",
fixedRow(
column(2,"First Column",
fileInput("File1", "Choose a CSV files", multiple = F),
p("Click the button to check the data was read in correctly")
),
column(2,"Second Column",
fileInput("File2", "Choose a CSV files", multiple = F),
p("Click the button to check the data was read in correctly")
),
fixedRow(
column(12,
verbatimTextOutput("errorText2")
)
)
)
)
)
)
)
server = function(input, output,session) {
## Call the error message function and print
output$errorText1 <- renderText({
validate(
if (input$n_values == 1) {
need(!is.null(input$File1)
, 'You need to input the files before we can validate the data. Please select all the necessary files.')
}
)
validate("allgravy")
})
output$errorText2 <- renderText({
validate(
if (input$n_values == 2) {
need(!is.null(input$File1) & !is.null(input$File2)
, 'You need to input the files before we can validate the data. Please select all the necessary files.')
}
)
validate("allgravy")
})
}
shinyApp(ui, server)
when the condition "number of columns is 2" I can not upload files in the first column, is this a coding issue?
The code works when not in a conditionalPanel, see below for a reproducible example
ui =
navbarPage("Page Title",
tabPanel("Panel 1",
sidebarPanel(
## Add Name,
## Number of surveys analysising
numericInput("n_surveys", "Number of surveys analysing:", 2, min = 1, max = 10)
),
mainPanel(
tags$div(
h2("Home Page")
)
)
),
tabPanel("Panel 2",
fixedPage(theme = "flatly",
fixedRow(
column(2,h4("First Column"),
fileInput("File1", "Choose a CSV files", multiple = F),
actionButton("CheckData", "Validate Input"),
p("Click the button to check the data was read in correctly")
),
column(2,h4("Second Column"),
fileInput("File2", "Choose a CSV files", multiple = F)
),
fixedRow(
column(12,
verbatimTextOutput("errorText")
)
)
)
)
)
)
server = function(input, output,session) {
## Call the error message function and print
output$errorText <- renderText({
validate(
need(!is.null(input$File1)
, 'You need to input the files before we can validate the data. Please select all the necessary files.')
)
validate("seems allgood")
})
}
shinyApp(ui, server)
Chairs

Answer 1

The issue is that you are using the same element twice; you are using the line fileInput("File1", "Choose a CSV files", multiple = F) twice in your code and that is not allowed (I think it has to do with this).
You can solve this by only using the element once, and changing your conditions. For example like this:
library('shiny')
library('shinythemes')
## adding the conditional statements
ui =
navbarPage("Page Title",
tabPanel("Panel 1",
sidebarPanel(
## Add Name,
## Number of surveys analysising
numericInput("n_values", "Number of columns in next panel:", 1, min = 1, max = 2)
),
mainPanel(
tags$div(
h2("Home Page")
)
)
),
tabPanel("Panel 2",
conditionalPanel(condition = "input.n_values == 1 | input.n_values == 2",
fixedPage(theme = "flatly",
fixedRow(
column(2,"First Column",
fileInput("File1", "Choose a CSV files", multiple = F),
p("Click the button to check the data was read in correctly")
),
conditionalPanel(condition = "input.n_values == 2",
column(2,"Second Column",
fileInput("File2", "Choose a CSV files", multiple = F),
p("Click the button to check the data was read in correctly")
)
)
),
fixedRow(
column(12,
verbatimTextOutput("errorText2")
)
)
)
)
)
)
)
server = function(input, output,session) {
## Call the error message function and print
output$errorText1 <- renderText({
validate(
if (input$n_values == 1) {
need(!is.null(input$File1)
, 'You need to input the files before we can validate the data. Please select all the necessary files.')
}
)
validate("allgravy")
})
output$errorText2 <- renderText({
validate(
if (input$n_values == 2) {
need(!is.null(input$File1) & !is.null(input$File2)
, 'You need to input the files before we can validate the data. Please select all the necessary files.')
}
)
validate("allgravy")
})
}
shinyApp(ui, server)
I did not really look at formatting or lay-out, this code is just to illustrate a working example. Hope this helps!