Design A Bilingual Shiny Application

October 17, 2014
By

(This article was first published on Category: R | Huidong Tian's Blog, and kindly contributed to R-bloggers)

It’s a common requirement that your Shiny application should be bilingual. I have tried several methods and finally I got one which is not so difficult to maintain.

My idea is:

  • Create a bilingual dictionary or a lookup table which contains three columns: value, English name and Norwegian name, like this one:

“` ruby
value EN NO
time Time Tid
day Day Dag
week Week Uke
month Month Måned

“`

  • Create a radio input with English and Norsk two options in file ui.R.

ruby
radioButtons(inputId = "lang", label = "",
choices = c("English" = "en", "Norsk" = "no"),
selected = "English"),

  • Create a function that converts value’s name to Norsk if user choose the Norsk radio.

“` ruby
## Bilingual lookup table;
LANG <- unique(read.csv(“www/lang.csv”, sep = “;”, stringsAsFactors = FALSE))
E2N <- function(en, D = LANG) {
for (i in 1:length(en)) {
id <- which(D$value %in% en[i])
if (length(id) == 0) {
id <- which(D$EN %in% en[i])
if (length(id) == 1) {
en[i] <- ifelse(input$lang == “no”, D$NO[id], D$EN[id])
} else if (length(id) > 1) {
print(“Mulit-variable matched!”)
}
} else if (length(id) == 1) {
en[i] <- ifelse(input$lang == “no”, D$NO[id], D$EN[id])
} else if (length(id) > 1) {
print(“Mulit-variable matched!”)
}
}
return(en)
}

“`

The ui.R file can be written as follow:

“` ruby
shinyUI(pageWithSidebar(
## English or Norwegain?
radioButtons(inputId = “lang”, label = “”,
choices = c(“English” = “en”, “Norsk” = “no”),
selected = “English”),
# Select unit;
sidebarPanel(
uiOutput(“uiUnit”)
),
mainPanel(
h1(textOutput(“text1”))
)
))

“`

In server.R file, we need load the E2N function first:

“` ruby
shinyServer(function(input, output, session) {
LANG <- data.frame(value = c(“time”, “day”, “week”, “month”),
EN = c(“Time”, “Day”, “Week”, “Month”),
NO = c(“Tid”, “Dag”, “Uke”, “Maaned”),
stringsAsFactors = FALSE)
observe({
E2N <- function(en, D = LANG) {
for (i in 1:length(en)) {
id <- which(D$value %in% en[i])
if (length(id) == 0) {
id <- which(D$EN %in% en[i])
if (length(id) == 1) {
en[i] <- ifelse(input$lang == “no”, D$NO[id], D$EN[id])
} else if (length(id) > 1) {
print(“Mulit-variable matched!”)
}
} else if (length(id) == 1) {
en[i] <- ifelse(input$lang == “no”, D$NO[id], D$EN[id])
} else if (length(id) > 1) {
print(“Mulit-variable matched!”)
}
}
return(en)
}
## Input;
output$uiUnit <- renderUI({
Items <- c(“day”, “week”, “month”)
selectInput(inputId = “unit”,
label = E2N(“time”),
choices = E2N(Items),
multiple = TRUE)
})
## Output;
output$text1 <- renderText({
E2N(input$unit)
})
})
})

“`

One shortcoming of this method is: when switching language, the application goes back to its original state.
You can run above demo in R console:

“` ruby
library(shiny)
runGist(“https://gist.github.com/withr/3c01413b70b8a82706ab”)

“`

To leave a comment for the author, please follow the link and comment on their blog: Category: R | Huidong Tian's Blog.

R-bloggers.com offers daily e-mail updates about R news and tutorials on topics such as: Data science, Big Data, R jobs, visualization (ggplot2, Boxplots, maps, animation), programming (RStudio, Sweave, LaTeX, SQL, Eclipse, git, hadoop, Web Scraping) statistics (regression, PCA, time series, trading) and more...



If you got this far, why not subscribe for updates from the site? Choose your flavor: e-mail, twitter, RSS, or facebook...

Comments are closed.

Sponsors

Never miss an update!
Subscribe to R-bloggers to receive
e-mails with the latest R posts.
(You will not see this message again.)

Click here to close (This popup will not appear again)