Creating Tabs with the name selected from select input function in shiny - mysql

Question

I want to form tabs dynamically in my app i.e when i will select choices from my drop down menu and as soon as i select one option a tab with the same name should appear.The options which select input is showing is coming from my database.To made the scenario clear i am attaching sample app which is showing tabs dynamically and i later on i will attach my code
Here us sample app:
library(shiny)
ui <- (fluidPage(
titlePanel("Demonstration of renderUI in shiny - Dymanically creating the tabs based on user inputs"),
sidebarLayout(
sidebarPanel(
# Numeric input to enter the number of tabs needed
numericInput("n", 'Enter the number of tabs needed', 1)
),
mainPanel(
uiOutput('tabs')
)
)
))
server <- (function(input,output){
output$tabs = renderUI({
Tabs <- lapply(paste("tab no.", 1:input$n, sep=" "), tabPanel)
do.call(tabsetPanel, Tabs)
})
})
shinyApp(ui, server)
Here tabs are increasing according to numbers incremented and decremented, i have drop down menu which will show tuples of my database table which are as shown here
| name |
+----------------------+
| aaa |
| kart |
and here is my code with error:
library("shiny")
library("shinydashboard")
library("pool")
library("DBI")
pool <- dbPool(drv = RMySQL::MySQL(),dbname = "demo",host = "db.cr7dht.us-east-2.rds.amazonaws.com",username = "kak",password = "1278", port = 3306)
mychoices = dbGetQuery(pool,"select available_scenario from sc;")
ui <- (fluidPage(
titlePanel("Demonstration of renderUI in shiny - Dymanically creating the tabs based on user inputs"),
sidebarLayout(
sidebarPanel(
selectInput('n', "available scenarios", choices = mychoices, multiple = TRUE),
verbatimTextOutput("selected")
),
mainPanel(
uiOutput('tabs')
)
)
))
server <- (function(input,output,session){
output$tabs = renderUI({
observe({
updateSelectInput(
session, "n", choices = mychoices
)
})
Tabs <- lapply(paste("tab name", 1:input$choices, sep=" "), tabPanel)
do.call(tabsetPanel, Tabs)
})
})
shinyApp(ui, server)

Answer 1

First of all you don't want a tabpannel if n is NULL so I added the is.null check. Secondly remove the 1: when you are generating the tabs. the paste function will automatically convert your inpu$n to multiple characters string. No need to insert a range.
In addition, you don't need to put the updateSelectInput in your renderUI function.
Working example
mychoices = 1:10
ui <- (fluidPage(
titlePanel("Demonstration of renderUI in shiny - Dymanically creating the tabs based on user inputs"),
sidebarLayout(
sidebarPanel(
selectInput('n', "available scenarios", choices = mychoices, multiple = TRUE),
verbatimTextOutput("selected")),
mainPanel(
uiOutput('tabs')
)
)
))
server <- (function(input,output,session){
output$tabs = renderUI({
if(!is.null(input$n)){
Tabs <- lapply(paste("tab name", input$n, sep=" "), tabPanel)
do.call(tabsetPanel, Tabs)}
})
})