Sometimes it is useful to build a pdf export option into a Shiny app. I built a basic app at first (every important notes was included as comment) to show how to do it easily:
library(shiny)
library(Cairo)
server <- function(input, output) {
### create the plots.
# No need to duplicate the plot functions if You use this kind of form
hist_plot <- function(){
hist(mtcars$mpg, main = "")
}
scatter_plot <- function(){
plot(mtcars$disp, mtcars$hp)
}
box_plot <- function(){
boxplot(mtcars$drat)
}
### make UI objects
output$exp_plot1 <- renderPlot({
hist_plot()
})
output$exp_plot2 <- renderPlot({
scatter_plot()
})
output$exp_plot3 <- renderPlot({
box_plot()
})
### function to do the pdf export
output$export <- downloadHandler("test.pdf", function(theFile) {
makePdf <- function(filename){
# I use Cairo instead of the the basic pdf function. It is much more complex and it supports special characters like "ű"
Cairo(type = 'pdf', file = filename, width = 21, height = 29.7, units='cm', bg='transparent')
# configure the layout like this
################
# plot1 plot2 #
# plot3 #
################
lo = matrix(c(1,2,3,4),2,2)
layout(lo)
# call the plots
hist_plot()
scatter_plot()
box_plot()
dev.off()
}
makePdf(theFile)
})
}
library(shiny)
library(ggplot2)
ui <- fluidPage(
downloadButton("export", label = "download content"),
titlePanel("PDF export example"),
mainPanel(
plotOutput(outputId = "exp_plot1"),
plotOutput(outputId = "exp_plot2"),
plotOutput(outputId = "exp_plot3")
)
)
library(shiny)
library(Cairo)
library(ggplot2)
library(gridExtra)
server <- function(input, output) {
### create the plots.
# No need to duplicate the plot functions if You use this kind of form
hist_plot <- function(){
ggplot(mtcars, aes(mpg)) + geom_histogram()
}
scatter_plot <- function(){
ggplot(mtcars, aes(x=disp, y=hp)) + geom_point()
}
box_plot <- function(){
ggplot(mtcars, aes(x=factor(""), y = drat)) + geom_boxplot()
}
### make UI objects
output$exp_plot1 <- renderPlot({
hist_plot()
})
output$exp_plot2 <- renderPlot({
scatter_plot()
})
output$exp_plot3 <- renderPlot({
box_plot()
})
### function to do the pdf export
output$export <- downloadHandler("test.pdf", function(theFile) {
makePdf <- function(filename){
# I use Cairo instead of the the basic pdf function. It is much more complex and it supports special characters like "ű"
Cairo(type = 'pdf', file = filename, width = 21, height = 29.7, units='cm', bg='transparent')
p1 <- hist_plot()
p2 <- scatter_plot()
p3 <- box_plot()
# configure the layout like this
################
# plot1 plot2 #
# plot3 #
################
p <- grid.arrange(p1, p2, p3, ncol=2)
print(p)
dev.off()
}
makePdf(theFile)
})
}
