Subset a data frame based on user-input, Shiny

Question

I\'m trying to build a Shiny app that subsets a data frame (to only include rows where a categorical variable matches the user-select input from the UI) before the data is proce

Answer 1

I had the same issue and spent a couple of hours trying to figure it out. Once you have assigned the reactive object, you need to use target_inventory() in order to refer to it (as BenBarnes mentioned in the comment section).

Here is a MWE (minimum working example)

ui.R

#ui
library(shiny)

shinyUI(fluidPage(
  #User dropbox
  selectInput("state", "Choose state", choices=c("MA", "CA", "NY"))
  #Print table to UI
  ,tableOutput("table1")
))

server.r

 #server
library(shiny)

shinyServer(function(input,output){

  category <- c("MA", "CA", "NY")
  population <- c(3,8,4)

  df <- data.frame(category,population)

  df_subset <- reactive({
    a <- subset(df, category == input$state)
    return(a)
  })

  output$table1 <- renderTable(df_subset()) #Note how df_subset() was used and not df_subset


})