R/geom-tacofancy.R

In tlevine/geom_tacofancy: A taco geom for ggplot

geom_tacofancy <- function (mapping = NULL, data = NULL, stat = "identity", position = "identity",
na.rm = FALSE, ...) {
  GeomTacoFancy$new(mapping = mapping, data = data, stat = stat, position = position, 
  na.rm = na.rm, ...)
}
      
GeomTacoFancy <- proto(ggplot2:::Geom, {
  objname <- "tacofancy"

  draw_groups <- function(., ...) .$draw(...)
  draw <- function(., data, scales, coordinates, na.rm = FALSE, ...) {    

    convert.vec <- function(vec, slugs, naoe) {
      new.vec <- factor(vec)
      if (length(levels(new.vec)) > length(slugs)) {
        stop('Too many different values for ', name)
      }
      levels(new.vec) <- slugs
      new.vec
    }
    
    directory <- function(directory.name) {
      fn <- '.tmp.json'
      url <- paste0('http://www.randomtaco.me/', directory.name, '/')
      download.file(url, fn)
      xs <- fromJSON(fn)
      file.remove(fn)
      unname(sapply(xs, function(x) { x['slug'] }))
    }
    
    cached.directories <- function(directory.names) {
      fn <- '.geom_tacofancy.rda' 
      if (file.exists(fn)) {
        load(fn)
      } else {
        directories <- lapply(directory.names, directory)
        names(directories) <- directory.names
        save(directories, file = '.geom_tacofancy.rda')
      }
      directories
    }

    directory.names <- c('base_layers', 'mixins', 'condiments', 'seasonings', 'shells')

    data <- remove_missing(data, na.rm, 
      c("label", directory.names), name = "geom_tacofancy")
    if (empty(data)) return(zeroGrob())

    directories <- cached.directories(directory.names)
    mapped.data <- data.frame(label = data$label)
    for (col in names(directories)) {
      if (col %in% names(data)) {
        mapped.data[,col] <- convert.vec(data[,col], directories[[col]], col)
      } else {
        mapped.data[,col] <- convert.vec(rep(TRUE, nrow(data)), directories[[col]], col)
      }
    }

    # Replace this with do.call eventually.
    recipes <- data.frame(
      label = data$label,
      url = paste('http://www.randomtaco.me',
        mapped.data$base_layers, mapped.data$mixins,
        mapped.data$condiments, mapped.data$seasonings,
        mapped.data$shells, '',
        sep = '/')
    )
    print(recipes)
  }

  draw_legend <- function(., data, ...) {}
  default_stat <- function(.) StatIdentity
  required_aes <- c()
  default_aes <- function(.) list()
})