Social

Google Firebase integrates nicely with multiple social sites so users can easily login via:

• Google
• Github
• Facebook
• Twitter

Console

First, these need to be setup in the Firebase console. If you followed the get started guide you should already have enabled Google. Now we’ll setup Github!

1. Head over to the Firebase console
2. Go to your project
3. Open the “Authentication” in the top left
4. Visit the second tab “Sign-in method”
5. Select “Github”

This should present you with the screen below.

It prompts you to enable it and enter your app id and app secret; notice the redirect url at the bottom of that box. These are taken from a Github OAuth application: follow this link to create yours and fill in the form.

Callback URL

Make sure you enter the “Authorization callback URL” given to you by Firebase which resembles https://my-application.firebaseapp.com/__/auth/handler

Package

Once setup in the Firebase console you can use those social services in your shiny app. Let’s create a basic shiny app that prompts the user to login on load; we’ll provide . Remember to import the dependencies in the UI with useFirebase.

library(shiny)
library(firebase)

# define signin
signin <- modalDialog(
  title = "Login",
  actionButton("google", "Google", icon = icon("google"), class = "btn-danger"),
  actionButton("github", "Github", icon = icon("github")),
  footer = NULL
)

ui <- fluidPage(
  useFirebase() # import dependencies
)

server <- function(input, output) {
  showModal(signin)
}

shinyApp(ui, server)

We are then going to initialise the authentication from the FirebaseSocial object.

library(shiny)
library(firebase)

# define signin
signin <- modalDialog(
  title = "Login",
  actionButton("google", "Google", icon = icon("google"), class = "btn-danger"),
  actionButton("github", "Github", icon = icon("github")),
  footer = NULL
)

ui <- fluidPage(
  useFirebase()
)

server <- function(input, output) {
  showModal(signin)
  f <- FirebaseSocial$new()
}

shinyApp(ui, server)

Finally, we can bind our buttons to actual sign in triggers. We do so with the different launch_* methods.

library(shiny)
library(firebase)

# define signin
signin <- modalDialog(
  title = "Login",
  actionButton("google", "Google", icon = icon("google"), class = "btn-danger"),
  actionButton("github", "Github", icon = icon("github")),
  footer = NULL
)

ui <- fluidPage(
  useFirebase()
)

server <- function(input, output) {
  showModal(signin)

  f <- FirebaseSocial$new()

  observeEvent(input$google, {
    f$launch_google()
  })

  observeEvent(input$github, {
    f$launch_github()
  })
}

shinyApp(ui, server)

Then again, we use the method req_sign_in to indicate observers and output that require the user to be logged in. Below we use the latter to remove the modal and display a plot.

library(shiny)
library(firebase)

# define signin
signin <- modalDialog(
  title = "Login",
  actionButton("google", "Google", icon = icon("google"), class = "btn-danger"),
  actionButton("github", "Github", icon = icon("github")),
  footer = NULL
)

ui <- fluidPage(
  useFirebase(),
  plotOutput("plot")
)

server <- function(input, output) {
  showModal(signin)

  f <- FirebaseSocial$new()

  observeEvent(input$google, {
    f$launch_google()
  })

  observeEvent(input$github, {
    f$launch_github()
  })

  observe({
    f$req_sign_in()
    removeModal()
  })

  output$plot <- renderPlot({
    f$req_sign_in()
    plot(cars)
  })
}

shinyApp(ui, server)