R/plotdownload.R

In pinin4fjords/shinyngs: Shiny apps for NGS data

#' The input function of the gene plotdownload module
#'
#' The plotdownload module provides export functionality for panels with plots.
#' This will generally not be called directly, but by other modules
#'
#' @param id Submodule namespace
#' @param label Label for the download button
#'
#' @return output An HTML tag object that can be rendered as HTML using
#' as.character()
#'
#' @keywords shiny
#'
#' @examples
#' plotdownloadInput(ns("heatmap"))
#'
plotdownloadInput <- function(id, label = "Plot") {
  ns <- NS(id)

  downloadButton(ns("plotdownload"), label)
}

#' The server function of the gene set module
#'
#' The plotdownload module provides export functionality for panels with plots.
#' This will generally not be called directly, but by other modules
#'
#' @param input Input object
#' @param output Output object
#' @param session Session object
#' @param makePlot A reactive for generating the plot
#' @param filename A filename (default = 'plot.png')
#' @param plotHeight A number or reactive for calculating the height of the plot
#' @param plotWidth A number or reactive for calculating the width of the plot
#'
#' @keywords shiny
#' @importFrom grDevices dev.off png
#'
#' @examples
#' callModule(plotdownload, "heatmap", makePlot = plotHeatmap, filename = "heatmap.png", plotHeight = plotHeight, plotWidth = plotWidth)
#'
plotdownload <- function(input, output, session, makePlot, filename = "plot.png", plotHeight, plotWidth) {
  if (is.reactive(plotHeight)) {
    plotHeight <- as.numeric(plotHeight())
  }

  if (is.reactive(plotWidth)) {
    plotWidth <- as.numeric(plotWidth())
  }

  output$plotdownload <- downloadHandler(filename = filename, content = function(file) {
    png(file, height = plotHeight, width = plotWidth, units = "px")
    print(makePlot())
    dev.off()
  })
}