How to use user input to obtain a data.frame from my environment in Shiny?

Question

Hi i am trying to figure out how to use the user input i generate to call an existing table in R shiny. Each user input options is the name of a table, i want to use this in

Answer 1

You could use get() to obtain the data.frame. Also, note that input is not a good name for a reactive variable, since it is already defined, therefore I renamed in to inputx. In this case, you could even do without the reactive and simply use output$table<-renderTable({get(input$location)})

Hope this helps!

Dublin=Head(mtcars,5)
Cork=head(mtcars,10)
Galway=head(mtcars,15)
Belfast=head(mtcars,2)

ui=fluidPage( 
  selectInput(inputId="location",label="Please Choose location", 
              choices=c("Dublin"="Dublin","Cork"="Cork","Galway"="Galway","Belfast"="Belfast")), 
  tableOutput("table") ) 

server=function(input, output){

  inputx=reactive({get(input$location)}) 
  output$table<-renderTable(inputx())

}
shinyApp(ui,server)

---

The cleanest solution would probably be to store your dataframes in a list, and subset from that list as follows:

Dublin=Head(mtcars,5)
Cork=head(mtcars,10)
Galway=head(mtcars,15)
Belfast=head(mtcars,2)

mylist = list(Dublin=Dublin,Cork=Cork,Galway=Galway,Belfast=Belfast)

ui=fluidPage( 
  selectInput(inputId="location",label="Please Choose location", 
              choices=c("Dublin"="Dublin","Cork"="Cork","Galway"="Galway","Belfast"="Belfast")), 
  tableOutput("table") ) 

server=function(input, output){
  output$table<-renderTable(mylist[input$location])
}
shinyApp(ui,server)