eburones

User sessions for ambiorix.

Installation

Get it from Github.

# install.packages("remotes")
remotes::install_github("devOpifex/eburones")

Example

⚠️ You are strongly advised to use scilis secure your cookies.

Simply use the eburones middleware.

Local

⚠️ The local backend should only be used for local development, never in production. It will also not properly track sessions with belgic, across machines, and data will be lost when the server is restarted.

library(eburones)
library(ambiorix)

app <- Ambiorix$new()

app$use(eburones())

app$get("/", \(req, res){
  print(req$session)
  res$send("Hello there!")
})

app$start()

Below is an example to track page views. We create a callback function that returns a list containing the number of page views. This callback is run at every request for the session, we increment it at every visit.

library(eburones)
library(ambiorix)

app <- Ambiorix$new()

pv <- \(req, res) {

  # no session = new user
  if(is.null(req$session))
    return(
      list(
        page_views = 1L
      )
    )

  # existing user = increment
  list(
    page_views = req$session$page_views + 1L
  ) 
}

app$use(
  eburones(callback = pv)
)

app$get("/", \(req, res){
  res$sendf("Hello there for the %s time", req$session$page_views)
})

app$start()

DBI

There is a DBI backend. We implement the same page view tracker as above. One difference is that the DBI backend expects the callback to return a data.frame of 1 row.

library(eburones)
library(ambiorix)

app <- Ambiorix$new()

pv <- \(req, res) {

  # new user return a data.frame
  if(is.null(req$session))
    return(
      data.frame(
        page_views = 1L
      )
    )

  # we need to return a data.frame (1 row)
  data.frame(
    page_views = req$session$page_views + 1L
  ) 
}

# we create a connection to a database (SQLite in this case)
con <- DBI::dbConnect(RSQLite::SQLite(), ":memory:"o)

# we need to create the table we'll use to store sessions
# it must contain a key column where user token will be stored
DBI::dbExecute(
  con,
  "CREATE TABLE sessions (
    key TEXT,
    page_views INTEGER
  )"
)

backend <- DBI$new(con, "sessions")

app$use(
  eburones(backend = backend, callback = pv)
)

app$get("/", \(req, res){
  res$sendf("Hello there for the %s time", req$session$page_views)
})

app$start()

Mongodb

library(eburones)
library(ambiorix)
library(mongolite)

m <- mongo(
  url = "mongodb://localhost/?ssl=true", 
  options = ssl_options(
    weak_cert_validation = TRUE
  )
)

mongo <- Mongo$new(m, "user")

app <- Ambiorix$new()

pv <- \(req, res) {

  # no session = new user
  if(is.null(req$session))
    return(
      list(
        page_views = 1L
      )
    )

  # existing user = increment
  list(
    page_views = req$session$page_views + 1L
  ) 
}

app$use(
  eburones(
    backend = mongo, 
    callback = pv
  )
)

app$get("/", \(req, res){
  res$sendf("Hello there for the %s time", req$session$page_views)
})

app$start()