Radio button selection to show table on next output - r

Question

In my shiny app, I am uploading different types of files which I do want to process and display the result on different output sections. But the second output is depended on the first output result. In my second output, I am filtering the first table using column names. Now the problem I have is some files I am uploading don't have the columns I am using to subset for second output, they have been moved to the first row which means once I upload a file with different columns I should replace the columns existing with first row them filter results for the second output. Here is my app :
library(shiny)
library(DT)
ui<- shinyUI(fluidPage(
titlePanel("Uploading Files"),
sidebarLayout(
sidebarPanel(
fileInput('file1', 'Choose CSV File',
accept=c('text/csv',
'text/comma-separated-values,text/plain',
'.csv')),
# radio button to show either row or replaced column table
radioButtons("radio", label = h3("Replace columns"),
choices = list("Raw table" = 1, "change columns" = 2),
selected = 1)
),
mainPanel(
DT::dataTableOutput('contents'),
DT::dataTableOutput('filtered')
)
)
)
)
server <- function(input, output, session){
myData <- reactive({
inFile <- input$file1
if (is.null(inFile)) return(NULL)
data <- read.csv(inFile$datapath, header = TRUE)
data
})
output$contents <- DT::renderDataTable({
DT::datatable(myData())
})
#Replace columns reactive event
replaceColumns <- eventReactive(input$radio,{
#Change row to column and delete first row
colnames(myData()) <-myData()[1,]
df = myData()[-1, ]
df
})
data2<- reactive({
# Select columns of the dataframe
df1 <- select(myData(),mpg,cyl,wt)
df1
})
#Output based on either raw or replaced column table
output$filtered <- DT::renderDataTable({
DT::datatable(data2())
})
}
shinyApp(ui,server)
How can Use radio button or if there is another better way, so that when I upload a file and I see it has right columns, it automatically displays in first output, and when I click raw table In radio button it proceeds to filter and give filtered output and If uploaded file does not have right columns I click on change columns so that to replace columns with the first row of the table then filter and show filtered output?
The way I want my app to behave is, when I upload a file, it displays and if the file has right columns, then I click raw table on radio button which now proceeds to filter and display filtered output in second output but if I can see the file uploaded has wrong columns then I click on change columns in radio button which will replace columns with the first row and then proceed to filtered results in second output. What I simply mean is. I want the second output to depend on what I select on radio button.

Answer 1

In both cases, the first DT output shows the table as loaded (with good or bad names). One approach is to fix the column names silently:
library(shiny)
library(DT)
ui <- shinyUI(fluidPage(
titlePanel("Uploading Files"),
sidebarLayout(
sidebarPanel(fileInput(
'file1',
'Choose CSV File',
accept = c('text/csv',
'text/comma-separated-values,text/plain',
'.csv')
)),
mainPanel(
DT::dataTableOutput('contents'),
DT::dataTableOutput('filtered')
)
)
))
server <- function(input, output, session) {
myData <- reactive({
inFile <- input$file1
if (is.null(inFile))
return(NULL)
data <- read.csv(inFile$datapath, header = TRUE)
data
})
# Approach 1: fix the data silently
# Replace column names if needed
fixData <- reactive({
req(input$file1)
df <- myData()
expectedColumns <- c("mpg", "cyl", "wt")
if (!all(expectedColumns %in% colnames(myData()))) {
#Change row to column and delete first row
colnames(df) <- df[1, ]
df = df[-1,]
}
df
})
output$contents <- DT::renderDataTable({
DT::datatable(myData())
})
data2 <- reactive({
# Select columns of the dataframe
df1 <- select(fixData(), mpg, cyl, wt)
df1
})
#Output based on either raw or replaced column table
output$filtered <- DT::renderDataTable({
DT::datatable(data2())
})
}
runApp(list(ui = ui, server = server))
Another approach is to use radio buttons as you have planned:
library(shiny)
library(DT)
ui<- shinyUI(fluidPage(
titlePanel("Uploading Files"),
sidebarLayout(
sidebarPanel(
fileInput('file1', 'Choose CSV File',
accept=c('text/csv',
'text/comma-separated-values,text/plain',
'.csv')),
# radio button to show either row or replaced column table
radioButtons("radio", label = h3("Replace columns"),
choices = list("Raw table" = 1, "Change column names" = 2),
selected = 1)
),
mainPanel(
DT::dataTableOutput('contents'),
DT::dataTableOutput('filtered')
)
)
)
)
server <- function(input, output, session){
myData <- reactive({
inFile <- input$file1
if (is.null(inFile)) return(NULL)
data <- read.csv(inFile$datapath, header = TRUE)
data
})
# Approach 2: click on an radioButton to fix the data
fixData <- reactive({
req(input$file1)
df <- myData()
if (input$radio == 2) {
#Change row to column and delete first row
colnames(df) <- df[1,]
df = df[-1, ]
}
df
})
output$contents <- DT::renderDataTable({
DT::datatable(myData())
})
data2<- reactive({
# Select columns of the dataframe
df1 <- select(fixData(),mpg,cyl,wt)
df1
})
#Output based on either raw or replaced column table
output$filtered <- DT::renderDataTable({
DT::datatable(data2())
})
}
runApp(list(ui=ui,server=server))