Server-side function for the downloadFileButton. This is a custom high-functionality button for file downloads supporting single or multiple download types. The server function is used to provide the data for download.
downloadFile(
id,
logger = NULL,
filenameroot = "download",
datafxns = NULL,
aspectratio = 1
)ID of the Module's UI element
logger to use
the base text used for user-downloaded file - can be either a character string or a reactive expression that returns a character string
a named list of functions providing the data as return values. The names for the list should be the same names that were used when the button UI was created.
the downloaded chart image width:height ratio (ex: 1 = square, 1.3 = 4:3, 0.5 = 1:2). Where not applicable for a download type it is ignored (e.g. data downloads).
no return value, called for downloading selected file type
This function is not called directly by consumers - it is accessed in
server.R using the same id provided in downloadFileButton:
downloadFile(id, logger, filenameroot, datafxns)
if (interactive()) {
library(shiny)
library(periscope2)
shinyApp(ui = fluidPage(fluidRow(column(width = 6,
# single download type
downloadFileButton("object_id1",
downloadtypes = c("csv"),
hovertext = "Button 1 Tooltip")),
column(width = 6,
# multiple download types
downloadFileButton("object_id2",
downloadtypes = c("csv", "tsv"),
hovertext = "Button 2 Tooltip")))),
server = function(input, output) {
# single download type
downloadFile(id = "object_id1",
logger = "",
filenameroot = "mydownload1",
datafxns = list(csv = reactiveVal(iris)),
aspectratio = 1)
# multiple download types
downloadFile(id = "object_id2",
logger = "",
filenameroot = "mydownload2",
datafxns = list(csv = reactiveVal(mtcars),
tsv = reactiveVal(mtcars)))
})
}