I have written a code to read csv or excel file in shiny app. But what is happening is that, whatever I select first (say Excel file), the output is displayed. But once I switch to other (csv) the excel is still there and csv is not displayed. Not sure what wrong is there in the code. Could anyone please help me?
library(shinydashboard)
library(readxl)
ui <- dashboardPage(
dashboardHeader(title = "Loading data"),
dashboardSidebar(fileInput("datafile","Choose the csv file",multiple = TRUE,
accept = c("text/csv","text/comma-separated-values,text/plain",".csv")),
("Or"),
fileInput("datafile1","Choose the excel file",multiple = TRUE,
accept = c(".xlsx"))),
dashboardBody(
fluidRow(box(uiOutput("filter_70"),width = 5000))
))
server <- function(input,output){
output$contents <- renderTable({
file_to_read <- input$datafile
if(is.null(file_to_read))
return(NULL)
read.csv(file_to_read$datapath)
})
output$contents1 <- renderTable({
file_to_read1 <- input$datafile1
if(is.null(file_to_read1))
return(NULL)
read_excel(file_to_read1$datapath)
})
output$filter_70 <- renderUI(
if (!is.null(input$datafile)) {
tableOutput("contents")
} else if (!is.null(input$datafile1)) {
tableOutput("contents1")
}
)
}
shinyApp(ui, server)
as pointed out by #Rohit, reactive value once gets selected, it won't go back to null.
Keep your main structure unchanged, all you need is to monitor which file last changed. This requires creating a reactiveVal (last_selected) and then use observeEvent to track.
last_selected <- reactiveVal(NA)
observeEvent(input$datafile, {
last_selected("csv")
})
observeEvent(input$datafile1, {
last_selected("excel")
})
output$filter_70 <- renderUI({
req(last_selected())
if (last_selected()=="csv") {
tableOutput("contents")
} else if (last_selected()=="excel") {
tableOutput("contents1")
}
})
Related
I have an R shiny app that gets a .csv import from a user and searches the imported data across a built-in data frame, then gives the % match in the output. The UI is very simple, with a few different inputs (import .csv, a slider, and some radio buttons). What I want is to be able to take the reactive table output and print this to a .csv that the user can download to their machine. The server side of the app looks something like this:
server <- function(input, output){
rvals <- reactiveValues()
observeEvent(input$file_1,{
req(input$file_1)
rvals$csv <<- read.csv(input$file_1$datapath, header = TRUE)
#some data processing here
})
output$contents <- renderTable({
if(input$select == 1){
x <- function
}else if(input$select == 2){
x <- function
}else if(input$select == 3){x <- function}
#some more data processing and formatting here
return(x)
},digits = 4)
}
I would like to have the data table x be able to become a .csv that can be downloaded by clicking a download button. In the server, I added the following code, but when I try to download the data it just downloads a blank file and says "SERVER ERROR" in my downloads manager on my machine.
output$downloadData <- downloadHandler(
filename = "thename.csv",
content = function(file){
write.csv(x, file)
}
In the console I also get the error message:
Warning: Error in is.data.frame: object 'x' not found [No stack trace available]
The object you create inside the expression of renderTable is not available outside of it. Instead you could assign it to the reactive values you set up. Below is a working example (note that I have tried to replicate your code so the data will not be available until you click on "Upload CSV", which here just calls mtcars).
library(shiny)
ui = fluidPage(
sidebarPanel(
actionButton(inputId = "uploadCsv", label = "Upload CSV:", icon = icon("upload")),
selectInput(inputId = "preProc", label = "Pre-processing", choices = c("Mean"=1,"Sum"=2)),
downloadButton("downloadData", label = "Download table")
),
mainPanel(
h4("My table:"),
tableOutput("contents")
)
)
server <- function(input, output) {
rvals <- reactiveValues(
csv=NULL,
x=NULL
)
observeEvent(input$uploadCsv,{
rvals$csv <- mtcars # using example data since I don't have your .csv
# rvals$csv <- read.csv(input$file_1$datapath, header = TRUE)
#some data processing here
})
output$contents <- renderTable({
# Assuing the below are functions applied to your data
req(
input$preProc,
!is.null(rvals$csv)
)
if(input$preProc == 1){
rvals$x <- data.frame(t(colMeans(mtcars)))
}else {
rvals$x <- data.frame(t(colSums(mtcars)))
}
return(rvals$x)
},digits = 4)
output$downloadData <- downloadHandler(
filename = "myFile.csv",
content = function(file){
write.csv(rvals$x, file)
}
)
}
shinyApp(ui,server)
EventReactive already outputs a reactive value, you don't need to create an extra reactiveVal, see example below :
library(shiny)
# Define UI
ui <- fluidPage(
# Application title
titlePanel("Test"),
mainPanel(
actionButton("show", "Download"),
textOutput("result")
)
)
server <- function(input, output) {
csvfile <- eventReactive(req(input$show), ignoreNULL = T, {
"Content of file"
})
output$result <- reactive(
paste("result : ",csvfile()))
}
# Run the application
shinyApp(ui = ui, server = server)
I would also avoid to use <<-operator in a reactive expression.
So I want to have a Shiny page which:
A) Allows the user to upload a .xls file;
B) Offers that file back to the user for download as a .csv file;
C) Prints the head of the file in the Shiny app to ensure that it was properly read.
Here is the code I am using:
# Want to read xls files with readxl package
library(readxl)
library(shiny)
## Only run examples in interactive R sessions
if (interactive()) {
ui <- fluidPage(
fileInput("file1", "Choose File", accept = ".xls"),
tags$hr(),
uiOutput("downloader"),
htmlOutput("confirmText", container = tags$h3),
tableOutput("listContents")
)
server <- function(input, output) {
theOutput <- reactiveValues(temp = NULL, df = NULL, msg = NULL, fn = NULL)
observeEvent(input$file1, {
theOutput$fn <- paste('data-', Sys.Date(), '.csv', sep='')
theOutput$temp <- read_xls(input$file1$datapath)
theOutput$msg <- paste("File Contents:")
theOutput$df <- write.csv(theOutput$temp,
file = theOutput$fn,
row.names = FALSE)
})
output$confirmText <- renderText({
theOutput$msg
})
output$listContents <- renderTable({
head(theOutput$temp)
})
output$downloader <- renderUI({
if(!is.null(input$file1)) {
downloadButton("theDownload", label = "Download")
}
})
output$theDownload <- downloadHandler(
filename = theOutput$fn,
content = theOutput$df
)
}
shinyApp(ui, server)
}
The Shiny page renders correctly, it accepts the upload with no problems, it prints out the head of the .csv with no problems, and it creates a properly formatted "data-{today's date}.csv" file in the same directory as the app.R file.
Problem is, when I hit the download button I get the error message:
Warning: Error in download$func: attempt to apply non-function
[No stack trace available]
Can someone tell me what I am doing wrong?
Thanks to the comments above, this is the solution I found (with my comments added, to show where the code changed):
library(readxl)
library(shiny)
if (interactive()) {
ui <- fluidPage(
fileInput("file1", "Choose File", accept = ".xls"),
tags$hr(),
uiOutput("downloader"),
htmlOutput("confirmText", container = tags$h3),
tableOutput("listContents")
)
server <- function(input, output) {
theOutput <- reactiveValues(temp = NULL, msg = NULL)
observeEvent(input$file1, {
# Do not try to automate filename and the write.csv output here!
theOutput$temp <- read_xls(input$file1$datapath)
theOutput$msg <- paste("File Contents:")
})
output$confirmText <- renderText({
theOutput$msg
})
output$listContents <- renderTable({
head(theOutput$temp)
})
output$downloader <- renderUI({
if(!is.null(input$file1)) {
downloadButton("theDownload", label = "Download")
}
})
output$theDownload <- downloadHandler(
# Filename and content need to be defined as functions
# (even if, as with filename here, there are no inputs to those functions)
filename = function() {paste('data-', Sys.Date(), '.csv', sep='')},
content = function(theFile) {write.csv(theOutput$temp, theFile, row.names = FALSE)}
) }
shinyApp(ui, server) }
The fact that content takes an argument (named here "theFile"), which is not called anywhere else, is what was throwing me off.
I have been trying for a long time to reset fileInput in a Shiny app and read solutions to similar problems, but my problem still persists. Most solutions ultimately lead to using Dean Attali's brilliant shinyjs package and the reset() function therein. Here's what my code looks like after following these instructions:
library(shiny)
library(shinyjs)
library(xlsx)
library(tidyverse)
ui <- fluidPage(
useShinyjs(),
fileInput('inFile', 'Choose file'),
actionButton('reset', 'Reset'),
radioButtons("type","Choose file type",choices = c('csv','xls')),
tableOutput('tbl')
)
server <- function(input, output, session) {
rv <- reactiveValues(data = NULL)
observe({
req(input$inFile)
if(input$type=='csv'){
rv$data <- read.csv(input$inFile$datapath)
}
if(input$type=='xls'){
rv$data <- read_excel(input$inFile$datapath)
}
})
observeEvent(input$reset, {
rv$data <- NULL
reset('inFile')
})
output$tbl <- renderTable({
rv$data
})
}
shinyApp(ui, server)
I initially select the csv option and am able to load a csv file. Now when I press the reset button, it clears the data. As soon as I select the xls option, I get an error:
Listening on http://127.0.0.1:4135
Warning: Error in : Unknown file extension: csv
Which makes me believe that input$inFile$datapath still contains the pathname of the csv file that I selected earlier. I have run out of ideas on how to solve this problem and would greatly appreciate some help please.
Ideally fileInput would properly reset, but you can do this as a workaround. Add an explicit flag variable (rv$clear) to indicate whether you're in cleared state, and toggle that on and off in high-priority observers when reset and upload occur, respectively.
library(shiny)
library(shinyjs)
library(xlsx)
library(tidyverse)
ui <- fluidPage(
useShinyjs(),
fileInput('inFile', 'Choose file'),
actionButton('reset', 'Reset'),
radioButtons("type","Choose file type",choices = c('csv','xls')),
tableOutput('tbl')
)
server <- function(input, output, session) {
rv <- reactiveValues(
data = NULL,
clear = FALSE
)
observe({
req(input$inFile)
req(!rv$clear)
if(input$type=='csv'){
rv$data <- read.csv(input$inFile$datapath)
}
if(input$type=='xls'){
rv$data <- read_excel(input$inFile$datapath)
}
})
observeEvent(input$inFile, {
rv$clear <- FALSE
}, priority = 1000)
observeEvent(input$reset, {
rv$data <- NULL
rv$clear <- TRUE
reset('inFile')
}, priority = 1000)
output$tbl <- renderTable({
rv$data
})
}
shinyApp(ui, server)
I am building a rudimentary shiny app.
First, I created a data frame 'x' and saved it in my working directory:
x <- data.frame(a = 1:4, b = 2:5)
write.csv(x, 'x.csv', row.names = F)
In my shiny I'd like to:
Upload file 'x.csv'
Click my action button 'Click Here' and run a few commands upon clicking it.
Get a message printed in the Shiny app itself: "Load a file!" if I click on my button "Click here" after forgetting to upload the file first.
My code works, but I can't figure out how to make my message appear.
My code:
library(shiny)
ui <- fluidPage(
br(),
# User should upload file x here:
fileInput("file_x", label = h5("Upload file 'x'!")),
br(),
# Users clicks the button:
actionButton("do_it", "Click Here"),
br(),
# Print last value of the button 'do_it':
verbatimTextOutput("print_action")
)
server <- function(input, output, session) {
observeEvent(input$do_it, {
# Just a check of my button's actions:
output$print_action <- renderPrint({input$do_it})
# Validating the input - next 5 lines are not working:
# validate(
# need(
# try(is.null(input$file_x), "Load a file!")
# )
# )
# Reading in the file:
fileData <- reactive({
infile <- input$file_x
if (is.null(infile)) {
return(NULL)
}
read.csv(infile$datapath)
})
x <- fileData()
# Writing out the same file - but under a different name:
filename <- paste0("x", input$do_it, ".csv")
write.csv(x, file = filename, row.names = FALSE)
})
}
shinyApp(ui, server)
I think rather than displaying text, maybe modalDialog is better suited for what you are trying to achieve. I have implemented both solutions below, so you can compare.
Note that I also modified the reading of the csv slightly. It is bad practice to set a reactive from inside an observer. In those cases, it is better to use a reactiveVal, and update that from an observer.
Hope this helps!
library(shiny)
ui <- fluidPage(
br(),
# User should upload file x here:
fileInput("file_x", label = h5("Upload file 'x'!")),
br(),
# Users clicks the button:
actionButton("do_it", "Click Here"),
br(),
br(),
# Print last value of the button 'do_it':
verbatimTextOutput("print_action")
)
server <- function(input, output, session) {
observeEvent(input$do_it, {
if(is.null(input$file_x))
{
# show pop-up ...
showModal(modalDialog(
title = "Oh no!",
paste0("You have not uploaded a file, silly person!"),
easyClose = TRUE,
footer = NULL
))
# ... or update the text
my_text('Please upload a file.')
}
else
{
# Reading in the file:
infile <- input$file_x
if (is.null(infile)) {
return(NULL)
}
x <- read.csv(infile$datapath)
fileData(x) # set the reactiveVal called fileData to the file inputs.
# Writing out the same file - but under a different name:
filename <- paste0("x", input$do_it, ".csv")
write.csv(x, file = filename, row.names = FALSE)
my_text('Succes!')
}
})
fileData <- reactiveVal()
my_text <- reactiveVal('')
output$print_action <- renderText({my_text()})
}
shinyApp(ui, server)
Here are the requirements.
1)I need to browse and upload an excel file (with package readxl), which is used to arrive at some calculations which I need to display in shiny window as a different table output
2) Manually edit some data in the uploaded file and it should automatically reflect in the results displayed
3) We should be able to download the edited file.
I have written so far. I have columns ID, exposure and frequency in input data. For each ID I need to calculate a variable using corresponding exposure and frequency which would be displayed. I need to manually edit frequency and Exposure using ID ( which is unique ). I have added an "update" button. But change is not permanent. It goes back as soon as I click update button once more
library(shiny)
ui = fluidPage(
titlePanel("HEllo world"),
sidebarLayout(
sidebarPanel(
fileInput('file1', 'Choose xlsx file',
accept = c(".xlsx")),
actionButton("go", "update"),
numericInput('NewVal', 'Enter new Frequency',NULL),
numericInput('NewExp', 'Enter new Exposure',NULL)),
mainPanel(
textInput('ID', 'Enter ID'),
dataTableOutput('contents')
)))
server = function(input,output){
ef <- eventReactive(input$go, {
infile <- input$file1
if(is.null(infile))
return(NULL)
file.rename(infile$datapath,paste(infile$datapath, ".xlsx", sep=""))
data<-read_excel(paste(infile$datapath, ".xlsx", sep=""), 1)
if(input$ID!="" && input$go>0){
for( i in 1:nrow(data)){
if( input$ID == data$'ID'[i]){
if(!is.na(input$NewVal)){
data$' Frequency'[i] <- input$NewVal
}
if(!is.na(input$NewExp)){
data$'Exposure'[i] <- input$NewExp
}
}}}
data
}, ignoreNULL = FALSE)
output$contents <- renderDataTable({ef()})}
shinyApp(ui,server)
UPDATE!:As per one answer, I have made some changes to my code. The new code seems to be working fine. Here is the working code, for anyone who might need help with the same issue.
ui = fluidPage(
titlePanel("HEllo world"),
sidebarLayout(
sidebarPanel(
fileInput('file1', 'Choose xlsx file',
accept = c(".xlsx")),
actionButton("go", "update"),
numericInput('NewVal', 'Enter new Frequency',NULL),
numericInput('NewExp', 'Enter new Exposure',NULL)),
mainPanel(
textInput('ID', 'Enter ID'),
tableOutput('contents')
)))
server = function(input,output){
# Reactive value to save input data frame for use elsewhere
original <- reactiveValues()
observeEvent(input$file1, {
theFile <- input$file1
if(is.null(theFile)) {
return(NULL)}
**file.rename(theFile$datapath,paste(theFile$datapath, ".xlsx", sep=""))**
original$oldData <- read_excel(paste(theFile$datapath, ".xlsx", sep = ""), 1)
})
observeEvent(input$go, {
original$newData <- original$oldData
if(input$ID !="") {
for( i in 1:nrow(original$oldData)){
if( input$ID == original$oldData$'ID'[i]){
if(!is.na(input$NewVal)){
original$newData$'Frequency'[i] <- input$NewVal
}
if(!is.na(input$NewExp)){
original$newData$'Exposure'[i] <- input$NewExp
}
}
}
**original$oldData<-original$newData** }
})
output$contents <- renderTable({
if(!is.null(original$newData)) {
original$newData}
else {
original$oldData}
})
}
shinyApp(ui = ui, server = server)
Some of the comments seem to be on the right track of what's going on here. There's several solutions that could be used, but I'll just share what's most intuitive to me. Also, I'll only be changing the server function.
server = function(input,output){
# Reactive value to save input data frame for use elsewhere
original <- reactiveValues()
observeEvent(input$file1, {
theFile <- input$file1
if(is.null(theFile)) {return(NULL)}
original$oldData <- read_excel(paste(theFile$datapath, ".xlsx", sep = ""), 1)
})
observeEvent(input$goButton2, {
original$newData <- original$oldData
if(input$ID !="") {
for( i in 1:nrow(data)){
if( input$ID == dat$'ID'[i]){
if(!is.na(input$NewVal)){
original$newData$' Frequency'[i] <- input$NewVal
}
if(!is.na(input$NewExp)){
original$newData$'Exposure'[i] <- input$NewExp
}
}
}
}
})
output$contents <- renderDataTable({
if(!is.null(original$newData)) {original$newData}
else {original$oldData}
})
}
This won't change the table output until the go button is clicked. I haven't tested it fully, since I don't have your data, but I believe this should set you on the right track at the bare minimum... I like observe statements, because they cause side effects and seem more open ended than eventReactives or functions.
This only helps with the initial issues of having the correct changes made and continued showing in the output. If this works, it should be fairly easy to add a download function, which saves the file whenever it's updated.
Update 1
The code below should do what you would want it to do. I've added two different capabilities for saving the new data frame. The commented out code saves the data automatically whenever the update button is pressed. The code that's there without comments around it creates a download button for downloading the data. I've also added a line that calculates a new value based off frequency and exposure. Named this column Value in data set. Hope this helps!
#### Example app for Exchange answer
library(shiny)
library(readxl)
ui = fluidPage(
titlePanel("HEllo world"),
sidebarLayout(
sidebarPanel(
fileInput('file1', 'Choose xlsx file',
accept = c(".xlsx")),
actionButton("go", "update"),
numericInput('NewVal', 'Enter new Frequency',NULL),
numericInput('NewExp', 'Enter new Exposure',NULL),
# Download button (goes with download handler below)
# Use if desire is to save at press of button
downloadButton("save", "Download")
),
mainPanel(
textInput('ID', 'Enter ID'),
dataTableOutput('contents')
)
)
)
server = function(input,output){
# Reactive value to save input data frame for use elsewhere
original <- reactiveValues()
observeEvent(input$file1, {
theFile <- input$file1
if(is.null(theFile)) {
original$oldData <- NULL
} else {
original$oldData <- read_excel(theFile$datapath, 1)
}
})
observeEvent(input$go, {
original$newData <- original$oldData
if(input$ID !="") {
for(i in 1:nrow(original$oldData)){
if(input$ID == original$oldData$'ID'[i]){
if(!is.na(input$NewVal)){
original$newData$'Frequency'[i] <- input$NewVal
}
if(!is.na(input$NewExp)){
original$newData$'Exposure'[i] <- input$NewExp
}
### Make sure a column in your data set is named Value for this
# Calculate a new column
original$newData$'Value'[i] <- (original$newData$'Exposure'[i]*
original$newData$'Frequency'[i])
}
}
original$oldData<-original$newData
}
### Use this to automatically save table when update is clicked
# write.csv(original$newData,
# file = #Desired Pathname,
# row.names = FALSE)
})
output$contents <- renderDataTable({
if(!is.null(original$newData)) {
original$newData}
else {
original$oldData
}
})
### Use this code below if desired saving is through download button
# Server code for download button
output$save <- downloadHandler(
filename = function() {
paste0("newData - ", Sys.Date(), ".csv")
},
content = function(con) {
if (!is.null(original$newData)) {
dataSave <- original$newData
} else {
dataSave <- original$oldData
}
con <- ## Desired save location... could just use `getwd()` to
# save to working directory
write.csv(dataSave, con)
}
)
}
shinyApp(ui = ui, server = server)