Shiny R, Using the downloadButton function - r

Question

I'm trying to figure out how to use a downloadButton to download multiple content to one pdf file. I have in the ui the download button created:
downloadButton('downloadData', 'Download Data'))
and I am trying to get multiple plots and tables into one pdf file. I have in the server file the following
output$downloadData <- downloadHandler(
filename = function() {
paste('data-', Sys.Date(), '.pdf', sep=”)
}
but I think this will save multiple csv files. How do i download multiple plots and tables from renders such as
output$table<-renderTable({
P.Value<- c(lev.p,bart.p,turn.p,shap.p,jar.p,linm.p)
Test.Statistic<-c(lev.s,bart.s,turn.s,shap.s,jar.s,linm.s)
df<-data.frame(P.Value,Test.Statistic)
rownames(df, do.NULL = TRUE, prefix = "row")
rownames(df) <- c("Levene Test","Bartlett Test","Turning Point Test","Shapiro-Wilk Test","Jarque Bera Test","Linear Model Constant Drift Test")
df
})
,
output$qq.line<-renderPlot({
index<-1:length(lg.ret.vec())
model<-lm((lg.ret.vec())~ index)
plot(model,which=2,main="QQ plot of the residuals",xlab="Theoretical Quantiles")
qqline(rstandard(model),col="black")
})
,
output$histogram<-renderPlot({
hist(lg.ret(),main="Histogram of log returns",xlab="Log returns")
})
to name just a few.

Answer 1

You could take advantage of rmarkdown to make a report with all your plots, here is one example.
In your case you could use the following downloadHandler (code adapted from the link):
output$downloadData <- downloadHandler(
filename = function() {
paste('report', sep = '.','html')
},
content = function(file) {
src <- normalizePath('report.Rmd')
owd <- setwd(tempdir())
on.exit(setwd(owd))
file.copy(src, 'report.Rmd')
library(rmarkdown)
out <- render('report.Rmd',html_document())
file.rename(out, file)
}
)
And create a file called report.Rmd in the same folder as your server.R and ui.R:
report.Rmd
---
title: "Your report"
output: html_document
---
This is your plot
```{r echo=FALSE}
index<-1:length(lg.ret.vec())
model<-lm((lg.ret.vec())~ index)
plot(model,which=2,main="QQ plot of the residuals",xlab="Theoretical Quantiles")
qqline(rstandard(model),col="black")
```
This is your histogram
```{r echo=FALSE}
hist(lg.ret(),main="Histogram of log returns",xlab="Log returns")
```

Answer 2

you need to define content to download for downloadHandler. see http://www.inside-r.org/packages/cran/shiny/docs/downloadHandler
How do you mean you are trying to download plots and tables to a single csv file? Do you mean to merge the data? You may be confused about what a csv file is.