multi-select-filter_selection_app.R

library(shiny)
library(tibble)
library(dplyr)

df <- tibble(
  ID = 1:5,
  age = c("21-30", "21-30", "31-40", "31-40", "70+"),
  hispanic_bin = c(1, 0, 1, 0, 1),
  white_bin    = c(1, 1, 1, 0, 0),
  black_bin    = c(0, 0, 0, 1, 1)
)
# df
# # A tibble: 5 × 5
#      ID  age  hispanic_bin white_bin black_bin
#   <int> <chr>        <dbl>     <dbl>     <dbl>
# 1     1 21-30            1         1         0
# 2     2 21-30            0         1         0
# 3     3 31-40            1         1         0
# 4     4 31-40            0         0         1
# 5     5 80+              1         0         1

# Define UI 
ui <- fluidPage(
  # Sidebar with select widgets 
  sidebarLayout(
    sidebarPanel(
      selectInput(
        "age",
        "age",
        choices = c("21-30", "31-40", "41-50", "51-60", "61-70", "70+"),
        multiple = TRUE
      ),
      selectInput(
        "race",
        "race/ethnicity",
        choices = c(
          #what shows up in the app = binary column name in dataset
          "White"    = "white_bin", 
          "Black"    = "black_bin",
          "Hispanic" = "hispanic_bin"
        ),
        multiple = TRUE
      )
    ),
    # filtered data output
    tableOutput("df_filtered")
  )
)

# Define server logic to do filtering
server <- function(input, output) {
  
  output$df_filtered <- renderTable({
    df |> 
      filter(
        
        # you are right that you need the if else statment here, ifelse()
        # doesn't work, but checking that input isn't NULL is enough
        if (!is.null(input$age)) age %in% input$age else TRUE,
        
        # This should show all race values if nothing is selected
        if_any(input$race, \(x) x == 1)
      )
  })
}

# Run the application 
shinyApp(ui = ui, server = server)


# https://gist.github.com/Aariq/8e5222abd08f147242dc30dba5d0cafd