Qualtrics Ping Method Proposal

qualtrics_methods.R

############# FUNCTIONS

#' A ping function that returns an object of say `qualtricsDemands`
#' @param ids Vector of survey ids 
demand_downloads <- function(ids){
	# simulate ping
	pinged <- purrr::map(ids, function(x) sample(c("failure", "success"), 1))

	# construct object
	# note that it inherits from class `list`
	# otherwise not other method/function will work =/
	structure(
		pinged,
		class = c("qualtricsDemands", "list")
	)
}

#' method
download <- function(demands) UseMethod("download")

#' An object of class `qualtricsDemands`
download.qualtricsDemands <- function(demands){
	if(!inherits(demands, "qualtricsDemands"))
		stop("demands must be of class qualtricsDemand", call. = FALSE)
	purrr::map(
		demands, 
		function(x){
			if(x == "success")
				runif(10) # data
			else
				NULL # no data
		}
	)
}

#' Cool thing is with new class we can define other methods
#' for instance print
print.qualtricsDemands <- function(x, ...){
	print(
		table(
			unlist(x)
		)
	)
}

############# EXAMPLES

# demand download for surveys id 1:10
demands <- demand_downloads(1:10)

print(demands) # print demand results

# download based on demands
download(demands)