Problem description: I have a modularized Shiny App, written in English, which has a translation for Portuguese (translated using the shiny.i18n package). Its' base is written in a mainPanel/tabPanel format and each tabPanel, which corresponds to each module, has an UI that is translated and a textOutput which is based in a multicolumn dataset filtered by language. I use the same input (input$language) to both translate the UI and define the value of the two_languages_dataset$languagecolumn that will produce the output.
The translation works fine but when I change panels, the second panel "inherits" the UI translation from the first, but the input$languageis not updated, thus leaving the UI "inconsistent".
For a minimal example (code in the end):
(1) This is the original homepage for the app.
(2) I translate it to Portuguese (works fine)
(3) When I switch to the second panel, the UI "inherits" the Portuguese translation but the textOutputis in English, since it's the app's base-language (and first choice for the input$language.
Question: how can I update the input$language when changing tabs/modules, so that the language chosen is the same for the whole UI?. It seems that a good option might be inserting a "translation button" on the homepage but I couldn't figure out how to carry this information to every module.
[The problem is adapted from a more complex app in a way that I hope helps other users understand my issue, so I can adapt the solution to the "larger app". This means that changing the tabPanel structure, eliminate modules or inserting a new language input are not attractive solutions for me.]
Code:
Module 1:
# MODULE 1
mod1_server <- function(id, global_session) {
shiny::moduleServer(
id,
function(input, output, session) {
observeEvent(input$language, {
# Here is where we update language in session
shiny.i18n::update_lang(global_session, input$language)
})
output$initial_text1 <- renderText({
two_languages_dataset <- data.frame(language = c("en", "pt"),
text = c("Welcome!", "Bem-vindo!"))
two_languages_dataset %>%
filter(language == input$language) %>%
.$text
})
}
)
}
mod1_ui <- function(id, i18n){
ns <- NS(id)
tagList(
# Page title and description
tags$div(class = "sheet_topper",
tags$div(tags$h1(i18n$t("Initial text"), style = "text-align:center"),
tags$p(i18n$t("This text is an example")),
tags$br(),
selectInput(inputId = ns("language"),
label = tags$div(icon("language", class = "icons"), i18n$t('Choose language')),
c("Português" = "pt",
"English" = "en"),
selected = i18n$get_key_translation())
)),
textOutput(ns("initial_text1"))
)
}
Module 2:
### MODULE 2
mod2_server <- function(id, global_session) {
shiny::moduleServer(
id,
function(input, output, session) {
observeEvent(input$language, {
# Here is where we update language in session
shiny.i18n::update_lang(global_session, input$language)
})
output$initial_text2 <- renderText({
two_languages_dataset <- data.frame(language = c("en", "pt"),
text = c("Welcome!", "Bem-vindo!"))
two_languages_dataset %>%
filter(language == input$language) %>%
.$text
})
}
)
}
mod2_ui <- function(id, i18n){
ns <- NS(id)
tagList(
# Page title and description
tags$div(class = "sheet_topper",
tags$div(tags$h1(i18n$t("Initial text 2"), style = "text-align:center"),
tags$p(i18n$t("This text is an example 2")),
tags$br(),
selectInput(inputId = ns("language"),
label = tags$div(icon("language", class = "icons"), i18n$t('Choose language')),
c("Português" = "pt",
"English" = "en"),
selected = i18n$get_key_translation())
)),
textOutput(ns("initial_text2"))
)
}
app.R:
library(shiny)
library(tidyverse)
library(shiny.i18n)
i18n <- Translator$new(translation_csvs_path = "data")
# FINAL APP
server <- function(input, output, session){
mod1_server("module1", global_session = session)
mod2_server("module2", global_session = session)
}
ui <- fluidPage(
shiny.i18n::usei18n(i18n),
mainPanel(
tabsetPanel(
tabPanel(i18n$t("First subset of data"),
mod1_ui("module1", i18n = i18n)),
tabPanel(i18n$t("Second subset of data"),
mod2_ui("module2", i18n = i18n))
# Close tabset
)
# Close mainPanel
)
# Close fluidPage
)
###################################################################################################
shinyApp(ui = ui, server = server)