Winston Chang wch

Hi everyone -

This mailing list is great for communicating ideas and problems, but when it comes to sharing code examples, it can be a bit tedious for app authors to cut and paste their files into an email message, and it can be even more tedious for readers to re-create the files from the email message.

I've written a set of functions that makes this easier:

shinySerialize() turns your Shiny app into text that can be cut-and-pasted into an email message.
shinyDeserialize() does the reverse: it turns that text into a set of files, in an application directory (and subdirectories, if needed).
shinyRun() is a wrapper function that first calls shinyDeserialize() to write out the app, then calls runApp() to run it.

These functions aren't part of the Shiny package; for now they're just things I've been playing with. They're defined here:

	shinyServer(
	function(input, output) {
	output$result <- reactivePrint( function() {
	length(input$vars)
	})
	}
	)

	# History files
	.Rhistory

	# Example code in package build process
	*-Ex.R

	shinyServer(function(input, output) {

	output$main_plot <- reactivePlot(function() {

	plot(1:10, 1:10)
	})
	})

	shinyServer(function(input, output) {
	output$distPlot <- renderPlot({
	# Take a dependency on input$goButton
	input$goButton

	# Use isolate() to avoid dependency on input$obs
	dist <- isolate(rnorm(input$obs))
	hist(dist)
	})
	})

	# The inverse of shinyDeserialize(): this function will read files from a Shiny
	# application and convert them to quoted expressions and strings, and place
	# those within a call to shinyRun().
	# This function returns the seralized app as a string, and also writes it to
	# outfile. By default, outfile is stdout (the console). You can set it to
	# a filename, or NULL for no output.
	shinySerialize <- function(appdir = NULL, outfile = stdout()) {
	if (is.null(appdir))
	stop("Need a path")

	Getting started
	===============
	# Make sure you have ggplot2 installed
	install.packages("ggplot2")
	library(ggplot2)


	Basic examples
	==============

	shinyServer(function(input, output, clientData) {

	output$image <- renderImage({
	width <- clientData$output_plot_width
	height <- clientData$output_plot_height

	# A temp file to save the output. This file will be removed later by renderImage
	outfile <- tempfile(fileext='.png')

	png(outfile, width=width, height=height)

	library(grid)

	makecircles <- function(gp) {
	grid.rect(gp=gpar(fill="grey60"))
	n <- 40
	grid.circle(x=seq(0.1, 0.9, length=n),
	y=0.5 + 0.4sin(seq(0,2pi, length=n)),
	r=abs(0.1cos(seq(0,2pi, length=n))),
	gp=gp)
	}