ShinyFriendlyCaptcha

The goal of ShinyFriendlyCaptcha is to provide Friendly Captcha to Shiny apps.

Features

Friendly Captcha is an European alternative to Google Recaptcha. It allow to protect websites against spam and bots in a privacy-embedded design.

Friendly Captcha features :

Cryptographic bot protection
No labeling tasks for users
No tracking and cookies
Fully accessible
Guaranteed availability with SLA
GDPR compliance agreements

ShinyFriendlyCaptcha additional features :

Theme optimized for Bootstrap 5 delivered by the bslib package.
Compatible with server validation of inputs based on shinyvalidate package.

Installation

You can install the development version of ShinyFriendlyCaptcha from GitHub with:

# install.packages("devtools")
devtools::install_github("mhanf/ShinyFriendlyCaptcha")

Setup

In order to use the ShinyFriendlyCaptcha library, you’ll need to subscribe a friendly Captcha plan to obtain valid SITEKEY and SECRET strings. A free plan is proposed to developers for non-commercial use (protection of 1 website with up to 1,000 requests/month). For more details go to their website.

ShinyFriendlyCaptcha exports two main functions: sfc_output() and sfc_server().

The sfc_output() function accept the following parameters :

id: Module id
sitekey: Friendly Captcha sitekey
lang: Language attribute for the Friendly Captcha input. Available values are “en”, “fr”, “de”, “it”, “nl”, “pt”, “es”, “ca”, “da”, “ja”, “ru”, “sv”, “el”, “uk”, “bg”, “cs”, “sk”, “no”, “fi”, “lt”, “lt”, “pl”, “et”, “hr”, “sr”, “sl”, “hu”, “ro”, “zh”, “zh_TW”, and “vi” for English, French, German, Italian, Dutch, Portuguese, Spanish, Catalan, Danish, Japanese, Russian, Swedish, Greek, Ukrainian, Bulgarian, Czech, Slovak, Norwegian, Finnish, Latvian, Lithuanian, Polish, Estonian, Croatian, Serbian, Slovenian, Hungarian, Romanian, Chinese (Simplified), Chinese (Traditional), and Vietnamese respectively.
dark_mode: logical. Enable dark mode (FALSE or TRUE)
eu_endpoint: Logical. Use the EU endpoint (FALSE or TRUE). Only for Professional Plans.
theme_bs5: Logical. Use a theme compatible with Bootstrap 5 (FALSE or TRUE).

It is also possible to use a personalized theme. As specified on the Friendly Captcha website, You can create your own stylesheet for the Friendly Captcha widget. The existing css file is probably a good start. To use your own custom theme you could add the following to the ui part of your shiny App:

 tags$link(rel="stylesheet", id="frc-style", href="www/my-custom-widget-theme.css")

The sfc_server() function accept the following parameters :

id: Module id
sitekey: Friendly Captcha sitekey
secret: The Friendly Captcha secret
eu_endpoint: Logical. Use the EU endpoint (FALSE or TRUE). Only for Professional Plans.

Example

A minimalist Shiny app example using these functions can be created as follows :

# libraries
library(shiny)
library(ShinyFriendlyCaptcha)
library(bslib)
library(shinyjs)
library(shinyvalidate)
# UI
ui <- fluidPage(
  theme = bs_theme(
    version=5,
    bootswatch = "flatly"
    ),
  useShinyjs(),
  br(),
  fluidRow(
    column(width = 4, class = "mx-auto",
           # hidden final message
           hidden(
             h4(
               id ="final-msg", 
               class = "text-primary text-center", "Thank you !"
             )
           ),
           # contact form
           card(
             id = "form-contact",
             card_header("Contact form"),
             card_body(
               tagList(
                 textInput(
                   inputId = "name",
                   label = "Name",
                   width = "100%"
                 ),
                 textInput(
                   inputId = "surname",
                   label = "Surname",
                   width = "100%"
                 ),
                 textInput(
                   inputId = "mail",
                   label = "Mail",
                   width = "100%"
                 ),
                 textAreaInput(
                   inputId = "msg",
                   label = "Message",
                   width = "100%",
                   height = "150px"
                 ),
                 sfc_output(
                   id = "test",
                   sitekey = Sys.getenv("captcha_sitekey"),
                   lang = "en",
                   dark_mode = FALSE,
                   eu_endpoint = FALSE,
                   theme_bs5 = TRUE
                 ),
                 br(),
                 actionButton(
                   inputId = "ok",
                   label= "Submit",
                   width = "100%",
                   class="bg-primary"
                 )
               )
             )
           )
    )
  )
)
# Server
server <- function(input, output) {
  # shinyvalidate
  iv <- InputValidator$new()
  iv$add_rule("name", sv_required())
  iv$add_rule("surname", sv_required())
  iv$add_rule("mail", sv_required())
  iv$add_rule("mail", sv_email())
  iv$add_rule("msg", sv_required())
  iv$add_rule(
    "test-captchaId", 
    sv_equal(TRUE,message_fmt ="Captcha validation required")
    )
  # captcha response
  captcha_result <- sfc_server(
    id = "test",
    secret = Sys.getenv("captcha_secret"),
    sitekey = Sys.getenv("captcha_sitekey"),
    eu_endpoint = FALSE
  )
  # action on button click
  observeEvent(input$ok,{
    iv$enable()
    req(iv$is_valid())
    #req(captcha_result()$success)
    hide(id = "form-contact")
    show(id="final-msg")
  })
}
# Run the application
shinyApp(ui = ui, server = server)

Contributions

The developer and maintainer of ShinyFriendlyCaptcha is mhanf. External contributions are welcome. Please keep in mind that I am not a professional R developer but an enthusiastic R data scientist who plays with shiny and javascript as a pretext to learn new stuffs. Unfortunately, so is my code. Please note that the ShinyFriendlyCaptcha project is released with a Contributor Code of Conduct. By contributing to this project, you agree to abide by its terms.

License

The ShinyFriendlyCaptcha package as a whole is licensed under the MIT license.