example8_ggplot2.png.R

run <- function(HEX, text_colour){
    
    # process inputs, inputs need to not have the "#" as this gets garbled over transmission
    HEX <- paste0("#", HEX) 
    text_colour = paste0("#", text_colour)
    # end process of inputs
    
    df <- data.frame(X = 0:10, Y = 0:10 * 0.8)
    
    df$labelnames <- c(rep("", 5), "This is more readable", rep("", 5))
    
    # very uninteresting plotting example :)
    p <- ggplot(df, aes(x = X, y = Y, label = labelnames)) +
        geom_rect(xmin = -Inf, xmax = Inf,   ymin = -Inf, ymax = Inf,   fill = HEX) +
        geom_text(size = 4, colour = text_colour) +
        theme(axis.line=element_blank(),axis.text.x=element_blank(),
              axis.text.y=element_blank(),axis.ticks=element_blank(),
              axis.title.x=element_blank(),
              axis.title.y=element_blank(),
              legend.position="none",
              #panel.background=element_blank(),
              panel.border=element_blank(),
              panel.grid.major=element_blank(),
              panel.grid.minor=element_blank()#,
              #plot.background=element_blank()
        )
    # now use ggsave to put a temp file into the /var/FastRWeb/tmp/ directory
    # it is good idea to use either a guid or timestamp to save the file, 
    # to avoid clashes from multiple sessions.
    file_name <- gsub("#", "", paste0(HEX,"_",text_colour, "_", gsub("( |:)", "-", Sys.time()), ".png"))
    ggsave(filename = paste0("/var/FastRWeb/tmp/", file_name), plot = p, height = 2.4, width = 3, dpi = 125)
    
    # after the file is loaded, it is deleted from the ../tmp directory
    WebResult(cmd = "tmpfile", payload = file_name, content.type = "image/png")
    
}