README.md
In firesale: Datastore for 'fiery' Web Servers

firesale

firesale is a plugin for fiery that provides a (potentially persistent) data store based on path parameters and client id.

It builds upon the storr package and thus provides a multitude of storage backends to suit your need while providing the same interface for your server logic.

# You can install marquee from CRAN
pak::pak("firesale")

# Or get the development version from Github
pak::pak("thomasp85/firesale")

Using firesale is quite simple. You initialise the plugin and then attach it to your fiery server:

library(firesale)

ds <- FireSale$new(storr::driver_environment())

ds
#> <FireSale plugin (environment)>

Once created you attach it like any other plugin

app <- fiery::Fire$new()

app$attach(ds)

app
#> 🔥 A fiery webserver
#> 🔥  💥   💥   💥
#> 🔥           Running on: 127.0.0.1:8080
#> 🔥     Plugins attached: firesale
#> 🔥 Event handlers added
#> 🔥       before-request: 1

Now, your request handlers will have access to a datastore element in their arg_list argument which will grant you access to the datastore. The datastore will itself contain two elements: global and session. The former gives access to a datastore shared by all sessions, while the latter is scoped to the session of the request being handled

app$on("request", function(request, response, arg_list, ...) {
  response$status <- 200L

  # Use `session` to see if this is the first time
  if (!isFALSE(arg_list$datastore$session$first)) {
    # Store number of unique visitors in `global`
    arg_list$datastore$global$count <- (arg_list$datastore$global$count %||% 0) + 1

    response$body <- paste0(
      "This is your first visit\n",
      "You are visiter number ",
      arg_list$datastore$global$count
    )
    arg_list$datastore$session$first <- FALSE
  } else {
    response$body <- "You've been here before"
  }
})

As can be seen, the datastore and its element are list-like and you can treat session and global pretty much how you would a normal list in terms of getting and setting values.