I have an Shiny app where the users upload data to be processed. The user can choose a data source (like a file or a connection to a cloud service like google sheets). The number of types of data sources will increase in future. My plan was to make a module for every type of data source (local files, cloud services, databases, etc.). The problem is that everything has to go to the same object in output. I cannot seem to get this working with modules. Below is an example that doesn't work.
library(shiny)
library(googlesheets4)
# Google Sheets module
read_google_sheets_ui <- function(id){
ns <- shiny::NS(id)
shiny::tagList(
shiny::textInput(ns("google_txt"), "Enter google identifier:")
)
}
read_google_sheets_server <- function(input, output, session, rv, iid = NULL){
ns <- session$ns
txtnm <- paste0(ifelse(is.null(iid), "", paste0(iid, "-")), "google_txt")
chosenURL <- reactive({
validate(need(input[[txtnm]], message = "No URL selected"))
print("txtnm is:", txtnm)
input[[txtnm]]
})
chosenGS <- reactive({
ID <- as_sheets_id(chosenURL())
read_sheet(ID)
})
return(chosenGS())
}
# File reading module
load_all_ui <- function(id){
ns <- NS(id)
shiny::tagList(
fileInput(inputId = ns("fn"), label = "Choose your file"),
actionButton("laai", label = "Load")
)
}
load_all_server <- function(input, output, session, rv, iid = NULL){
ns <- session$ns
fnn <- paste0(ifelse(is.null(iid), "", paste0(iid, "-")), "fn")
chosenD <- reactive({
shiny::validate(need(input[[fnn]], message = "No file selected"))
dp <- as.character(input[[fnn]]$datapath)
print("\ndp is: ", dp)
rio::import(file = dp, setclass = "data.frame")
}, domain = session)
chosenD()
}
Now make a module that calls the appropriate data-loading modulde depending on the choice of the user
# Module UI
multi_source_ui <- function(id){
ns <- NS(id)
shiny::tagList(
selectInput(inputId = ns("input_type_select"),
label = "Choose data input type",
choices = c("File" = "file",
"Cloud" = "cloud")
),
uiOutput(ns("multiUI"))
)
}
# Module Server
multi_source_server <- function(input, output, session){
ns <- session$ns
filelist <- list(fileInput(inputId = "fn", label = "Choose your file!!!"),
actionButton(inputId = "fn_go", label = "Load file"))
googlelist <- list(textInput("google_txt", "Enter google identifier:"),
actionButton(inputId = "google_go", label = "Load from Google Sheet"))
output$the_ui <- eventReactive(
eventExpr = input$input_type_select,
valueExpr = ifelse(input$input_type_select == "file",
tagList(filelist),
tagList(googlelist))
)
}
multi_source_data <- function(input, output, session, rv, iid ){
ns <- session$ns
observeEvent(ns(input$google_txt), { rv$the_data <- callModule(read_google_sheets_server, id = iid, iid = iid)})
observeEvent(ns(input$fn$datapath),{ rv$the_data <- callModule(load_all_server, id = iid)})
}
Test the approach
# Test
multi_source_test <- function(){
uii <- fluidPage(
multi_source_ui("id1"),
uiOutput("multiUI"),
h2("The data"),
tableOutput("multidata")
)
serverr <- function(input, output, session){
the_ui <- callModule(multi_source_server, "id1")
the_data <- callModule(module = multi_source_data, id = "id2", rv = rv, iid = "id1")
# outputs
output$multiUI <- renderUI({ the_ui() })
output$multidata <- renderTable({ the_data() })
}
shinyApp(uii, serverr, options =list(test.mode = TRUE))
}
I want the user to be able to choose either a file or a google sheet and the data to be displayed.
Below is a working, but quite modified, version of your application. A few comments:
What you are trying to do with txtnm <- paste0(ifelse(is.null(iid), "", paste0(iid, "-")), "google_txt") and fnn <- paste0(ifelse(is.null(iid), "", paste0(iid, "-")), "fn") is unnecessary - Shiny's namespace functionality handles all of that on your behalf. Consequently, I have removed those lines of code; I have also removed the 'iid' parameters from functions 'read_google_sheets_server' and 'load_all_server', as you do not seem to use the arguments passed to the 'iid' parameters for anything else.
Extracting the namespace in 'read_google_sheets_server' and 'load_all_server' (as you are doing by ns <- session$ns) serves no purpose. It is usually only necessary when you want to use uiOutput/renderUI in your module (e.g. as in your "multi_source" module); I have therefore removed the ns <- session$ns calls from 'read_google_sheets_server' and 'load_all_server'.
I added an actionButton to 'read_google_sheets_ui', identical to the one you had in 'load_all_ui', to prevent code in 'load_all_server' from being executed with every character typed into the textInput.
I renamed "load_all_" to "read_file_" to minimise confusion.
There is generally no need to wrap calls to input$... in a reactive statement if you really just want to extract the value of an input item, because 'input' is inherently reactive. Since we have added an actionButton to 'read_google_sheets_ui' and moved the validate(need(...)) statement there, the code for determining 'chosenURL' can thus be simplified to chosenURL <- input[["google_txt"]]
In module 'load_all_ui' (which I renamed to 'read_file_ui') you forgot to wrap the ID of the actionButton in a call to ns().
Your 'load_all_server' (which I renamed to 'read_file_server') lacked an observeEvent for the actionButton which you put in the module's UI.
Things derailed a bit in module "multi_source" and the code for the ui and server functions of the app itself, so I combined the code for that module with the code for the app (for starters, it seemed like you intended to render either a 'read_google_sheets_ui' or a 'read_file_ui' for uiOutput "multiUI", but the tag lists that you constructed contained neither of those components).
I think it may help you a lot to carefully read through the following article: https://shiny.rstudio.com/articles/modules.html
library(shiny)
library(googlesheets4)
read_google_sheets_ui <- function(id){
ns <- NS(id)
tagList(
textInput(ns("google_txt"), "Enter google identifier:"),
actionButton(ns("laai"), label = "Load")
)
}
read_google_sheets_server <- function(input, output, session){
chosenGS <- reactiveVal()
observeEvent(input$laai, {
validate(need(input[["google_txt"]], message = "No URL selected"))
chosenURL <- input[["google_txt"]]
ID <- as_sheets_id(chosenURL)
chosenGS(read_sheet(ID))
#chosenGS(data.frame(stringsAsFactors = FALSE, x = c(1:4), y = 5:8))
})
return(chosenGS)
}
read_file_ui <- function(id){
ns <- NS(id)
shiny::tagList(
fileInput(inputId = ns("fn"), label = "Choose your file"),
actionButton(inputId = ns("laai"), label = "Load")
)
}
read_file_server <- function(input, output, session){
chosenD <- reactiveVal()
observeEvent(input$laai, {
validate(need(input[["fn"]], message = "No file selected"))
dp <- as.character(input[["fn"]]$datapath)
chosenD(rio::import(file = dp, setclass = "data.frame"))
})
return(chosenD)
}
uii <- fluidPage(
selectInput(inputId = "input_type_select",
label = "Choose data input type",
choices = c("File" = "file",
"Cloud" = "cloud")),
uiOutput("multiUI"),
h2("The data"),
tableOutput("multidata")
)
serverr <- function(input, output, session){
theData <- reactiveVal(NULL)
output$multiUI <- renderUI({
switch(input$input_type_select,
file = read_file_ui(id = "readFile_ui"),
cloud = read_google_sheets_ui(id = "readGS_ui"))
})
observeEvent(input$input_type_select, {
theData(switch(input$input_type_select,
file = callModule(read_file_server, id = "readFile_ui"),
cloud = callModule(read_google_sheets_server, id = "readGS_ui")))
})
output$multidata <- renderTable({ theData()() })
}
shinyApp(uii, serverr, options = list(test.mode = TRUE))