Capture selectize Input value in R shiny module - r

Question

I am building a shiny app with a selectize input.
The choices in the input are dependent upon the ids in the underlying data.
In my real app, the data updates with a call to an API.
I would like the selected id choice in the selectize input to hold constant when I hit the "update data" button.
I was able to do this prior to using shiny modules. However, when I tried to transform my code to use a shiny module, it fails to hold the selected id value, and resets the selectize input each time I update the underlying data.
The following example was helpful without the module, but when I use the module it doesn't seem to work...link here
Below is a reprex. Thanks for any help.
library(shiny)
library(tidyverse)
# module UI
mymod_ui <- function(id){
ns <- NS(id)
tagList(
uiOutput(ns("ids_lookup")),
)
}
# module server
mymod_server <- function(input, output, session, data, actionb){
ns <-session$ns
ids <- reactive(
data() %>%
filter(!is.na(first_name) & !is.na(last_name) & !is.na(ages)) %>%
mutate(ids = paste(first_name, last_name, sep = " ")) %>%
select(ids)
)
output$ids_lookup <- renderUI({
selectizeInput(ns("lookup"),
label = "Enter id:",
choices = c("Type here ...", ids()), multiple = FALSE)
})
# here is where I would like to hold on to the selected ids when updating the table
# when I click the "reload_data" button I don't want the name to change
# I pass the button from the main server section into the module
current_id_selection <- reactiveVal("NULL")
observeEvent(actionb(), {
current_id_selection(ns(input$ids_lookup))
updateSelectizeInput(session,
inputId = ns("lookup"),
choices = ids(),
selected = current_id_selection())
})
}
ui <- fluidPage(
titlePanel("Test module app"),
br(),
# this button reloads the data
actionButton(
inputId = "reload_data",
label = "Reload data"
),
br(),
br(),
# have a look at the data
h4("Raw data"),
tableOutput("mytable"),
br(),
# now select a single id for further analysis in a much larger app
mymod_ui("mymod"),
)
server <- function(input, output, session) {
df <- eventReactive(input$reload_data, {
# in reality, df is a dataframe which is updated from an API call everytime you press the action button
df <- tibble(
first_name = c("john", "james", "jenny", "steph"),
last_name = c("x", "y", "z", NA),
ages = runif(4, 30, 60)
)
return(df)
}
)
output$mytable <- renderTable({
df()
})
# make the reload data button a reactive val that can be passed to the module for the selectize Input
mybutton <- reactive(input$reload_data)
callModule(mymod_server, "mymod", data = df, actionb = mybutton)
}
shinyApp(ui, server)

Answer 1

Just using inputId = "lookup" instead of inputId = ns("lookup") in updateSelectizeInput() will do it. Also, you had another typo in there. Try this
library(shiny)
library(tidyverse)
# module UI
mymod_ui <- function(id){
ns <- NS(id)
tagList(
uiOutput(ns("ids_lookup")),
verbatimTextOutput(ns("t1"))
)
}
# module server
mymod_server <- function(input, output, session, data, actionb){
ns <-session$ns
ids <- reactive(
data() %>%
filter(!is.na(first_name) & !is.na(last_name) & !is.na(ages)) %>%
mutate(ids = paste(first_name, last_name, sep = " ")) %>%
select(ids)
)
output$ids_lookup <- renderUI({
selectizeInput(ns("lookup"),
label = "Enter id:",
choices = c("Type here ...", ids()), multiple = FALSE)
})
# here is where I would like to hold on to the selected ids when updating the table
# when I click the "reload_data" button I don't want the name to change
# I pass the button from the main server section into the module
current_id_selection <- reactiveValues(v=NULL)
observeEvent(actionb(), {
req(input$lookup)
current_id_selection$v <- input$lookup
output$t1 <- renderPrint(paste0("Current select is ",current_id_selection$v))
updateSelectizeInput(session,
inputId = "lookup",
choices = ids(),
selected = current_id_selection$v )
})
}
ui <- fluidPage(
titlePanel("Test module app"),
br(),
# this button reloads the data
actionButton(inputId = "reload_data", label = "Reload data"
),
br(),
br(),
# have a look at the data
h4("Raw data"),
tableOutput("mytable"),
br(),
# now select a single id for further analysis in a much larger app
mymod_ui("mymod")
)
server <- function(input, output, session) {
df <- eventReactive(input$reload_data, {
# in reality, df is a dataframe which is updated from an API call everytime you press the action button
df <- tibble(
first_name = c("john", "james", "jenny", "steph"),
last_name = c("x", "y", "z", NA),
ages = runif(4, 30, 60)
)
return(df)
})
output$mytable <- renderTable({
df()
})
# make the reload data button a reactive val that can be passed to the module for the selectize Input
mybutton <- reactive(input$reload_data)
callModule(mymod_server, "mymod", data = df, actionb = mybutton)
}
shinyApp(ui, server)