Placing ifelse statements into a render expression Shiny - r

Question

In the below code, I am attempting to create an input to show all of my markets, or just a selection within a plot and a data table. I am doing this through, or attempting, through ifelse statements within my render functions, however I am getting errors, and neither the plot or data table will render. They do render without the if else statements. I have included an Example data set to hopefully help place in context.
ui <- dashboardPage(
dashboardHeader(title = "Example"),
dashboardSidebar(
sidebarMenu(
menuItem("Dashboard", tabName = "Dashboard"),
menuItem("Example", tabName = "example"))),
dashboardBody(
tabItems(
tabItem(tabName = "Dashboard",
fluidRow(
valueBoxOutput("example"))),
tabItem(tabName = "example",
fluidRow(
box(title = "Example",
plotOutput("plotexample"), width = 12),
box(title = "Data Selection",
selectInput("market","Market(s): ", c(unique(data$marketnum),"All"),multiple = T, selectize = T, selected = "All"))),
fluidRow(
box(DT::dataTableOutput("markettable"), width = 12))))))
server <- function(input,output) {
ExampleAllMarkets <- reactive({
ExampleData %>%
group_by(Event,marketnum) %>%
summarise(ItemCount = n_distinct(ItemNumber))
})
Example <- reactive({
ExampleData %>%
filter(marketnum == input$market) %>%
group_by(Event,marketnum) %>%
summarise(PolicyCount = n_distinct(Policy_Number_9_Digit))
})
output$example <- renderValueBox({
valueBox(
paste0("44", "%"), "example", icon = icon("car"),
color = "red"
)
})
I am placing ifelse statements within my render blocks reactive to whether or not "All" is selected.
output$plotexample <- renderPlot({
ifelse(input$market=="All",
ggplot(Example(), aes(x=MBC_Number, y=ItemCount)) +
geom_bar(stat="identity"),
ggplot(ExampleAllMarkets(), aes(x=marketnum, y=ItemCount))
+
geom_bar(stat="identity"))
})
output$markettable <- DT::renderDataTable({
ifelse(input$market == "All",
ExampleAllMarkets(),
Example())
})
}
shinyApp(ui,server)
Example Data in csv format
marketnum,ItemNumber
2,118
7,101
1,109
2,109
10,101
4,102
8,100
12,103
5,106
13,116
5,112
10,103
7,113
9,114
10,112
6,114
2,116
11,113
3,107
13,102
8,107
10,109
12,110
1,120
4,106
8,116
2,112
2,106
11,101
6,108
11,107
10,111
6,120
10,118
11,119
13,117

Answer 1

You probably cannot use ifelse in this scenario.
Analyzing the source code for ifelse, since a plot object is not so simple, it does not just return the plot itself, but
rep(plot, length.out = 1)
or equivalently plot[1] which is just the dataset of the plot. A plot object has a length > 1 and for those, ifelse only returns its first element.
This can be easily confirmed by evaluating
> ifelse(T, c(1, 2), c(3, 4))
[1] 1
So the render function cannot draw anything, since it's input is just this dataset.
You will simply have to use the regular if else.