Download xls file with multiple sheets as data frames Shiny R - r

Question

I am using the R package Shiny to develop my own web application.
I have a download button which permits me to export the data into a excel file. In the excel file, there are 4 sheets and in each of them there is a data frame.
For example, in sheet1 there is dataTab1, in sheet2 there is dataTab2, in sheet 3 there is dataTab3 and in sheet4 there is dataTab4.
For doing this, I am using the function downloadHeader() in shiny server.R.
I have used two methods to do this.
Method 1: using the R package xlsx
output$downloadTab <- downloadHandler(
filename = "dataxls.xlsx",
content = function(file) {
#creation of the workbook
dataxls=createWorkbook(file)
#creation of the sheets
dataTabs1=createSheet(wb=dataxls,sheetName="Compartiments-simulation_sans_changement")
dataTabs2=createSheet(wb=dataxls,sheetName="Esperance-simulation_sans_changement")
dataTabs3=createSheet(wb=dataxls,sheetName="Compartiments-simulation_avec_changement")
dataTabs4=createSheet(wb=dataxls,sheetName="Esperance-simulation_avec_changement")
#add the dataframes to the sheets
writeWorksheet(dataxls, dataTab1, sheet = "Compartiments-simulation_sans_changement")
writeWorksheet(dataxls, dataTab2, sheet = "Esperance-simulation_sans_changement")
writeWorksheet(dataxls, dataTab3, sheet = "Compartiments-simulation_avec_changement")
writeWorksheet(dataxls, dataTab4, sheet = "Esperance-simulation_avec_changement")
saveWorkbook(dataxls,file)
}
)
The problem is that I have the following error:
Error in createWorkbook(file) :
Unknown format C:\Users\Baramova\AppData\Local\Temp\Rtmpmyqyeh\fileafc6d2b5998.xlsx
I have tried to fix it using the following example:
content = function(file) {
fname = paste(file,"xlsx",sep=".")
wb = loadWorkbook(fname, create = TRUE)
createSheet(wb, name = "Sheet1")
writeWorksheet(wb, c(1:3), sheet = "Sheet1")
saveWorkbook(wb)
file.rename(fname,file)
}
But it doesn't work for me. Maybe I am omitting something.
Do you have any idea?
Method 2: using RODBC package
output$downloadTab <- downloadHandler(
filename ="Tab.xls",
content = function(fname) {
tmpdir <- tempdir()
db <- paste(tmpdir,fname,sep="/")
channel <- odbcConnectExcel(xls.file = db,readOnly=FALSE)
sqlSave(channel, Compartiments_simulation_sans_changement, tablename = "Compartiments_simulation_sans_changement")
sqlSave(channel, Esperance_simulation_sans_changement, tablename = "Esperance_simulation_sans_changement")
sqlSave(channel, Compartiments_simulation_avec_changement, tablename = "Compartiments_simulation_avec_changement")
sqlSave(channel, Esperance_simulation_avec_changement, tablename = "Esperance_simulation_avec_changement")
odbcClose(channel)
},
contentType="application/csv"
)
The problem is that the odbcConnectExcel() function is not recognized even if I have called the RODBC package by typing:
library(RODBC)
Do you have any idea why is that so?

Answer 1

I have found the solution of my problem.
Firstly you have to call the XLConnect and the RODBC packages.
After that, you could use the following example:
output$downloadTab <- downloadHandler(
filename ="Tab.xls",
content = function(file) {
write.csv(Compartiments_simulation_sans_changement, file="Compartiments-simulation_sans_changement.csv")
write.csv(Esperance_simulation_sans_changement, file="Esperance-simulation_sans_changement.csv")
write.csv(Compartiments_simulation_avec_changement, file="Compartiments-simulation_avec_changement.csv")
write.csv(Esperance_simulation_avec_changement, file="Esperance-simulation_avec_changement.csv")
channel <- odbcConnectExcel(xls.file = file,readOnly=FALSE)
sqlSave(channel, Compartiments_simulation_sans_changement, tablename = "Compartiments_simulation_sans_changement")
sqlSave(channel, Esperance_simulation_sans_changement, tablename = "Esperance_simulation_sans_changement")
sqlSave(channel, Compartiments_simulation_avec_changement, tablename = "Compartiments_simulation_avec_changement")
sqlSave(channel, Esperance_simulation_avec_changement, tablename = "Esperance_simulation_avec_changement")
odbcClose(channel)
},
contentType="application/xls"
)