tableHTML in Shiny app - can't handle NULL - shiny

Question

I'm trying to output a table via tableHTML that depends on some input in a Shiny app. In the example below, I want the table to depend on the radio button. I'm getting an error saying "Error: no function to return from, jumping to top level", so it seems it doesn't like my two return-statements. Any ideas how to go about this?
library(shiny)
library(tableHTML)
ui = fluidPage(
fluidRow(
radioButtons("radio", label = h3("Data on/off"),
choices = list("On", "Off"),
selected = "Off"),
tableHTML_output("mytable")
)
)
server = function(input, output) {
output$mytable <- render_tableHTML({
if ((input$radio == "On")) {
return(tableHTML(mtcars))
}
else {
return(NULL)
}
})
}
shinyApp(ui, server)
The above works when replacing tableHTML_output by tableOutput and render_tableHTML by renderTable and removing the tableHMTL() function.

Answer 1

It seems a package related issue.
Since we are dealing with plain html, we can use shiny::htmlOutput.
library(shiny)
library(tableHTML)
ui <- fluidPage(
fluidRow(
radioButtons("radio",
label = h3("Data on/off"),
choices = list("On", "Off"),
selected = "On"
),
htmlOutput("mytable")
)
)
server <- function(input, output) {
html_table <- eventReactive(input$radio, {
table <- if (input$radio == "On") {
tableHTML(mtcars)
}
return(table)
})
output$mytable <- renderText(
html_table()
)
}
shinyApp(ui, server)
Another workaround is to have two render_tableHTML inside an observeEvent like this:
library(shiny)
library(tableHTML)
ui <- fluidPage(
fluidRow(
radioButtons("radio",
label = h3("Data on/off"),
choices = list("On", "Off"),
selected = "Off"
),
tableHTML_output("mytable")
)
)
server <- function(input, output) {
observeEvent(input$radio, {
if (input$radio == "On") {
output$mytable <- render_tableHTML({
tableHTML(mtcars)
})
} else {
output$mytable <- render_tableHTML({
NULL
})
}
})
}
shinyApp(ui, server)