CODEWITHSUNDEEP
rvariablescsvshiny
Redhwan Nacef
Redhwan Nacef

Reputation: 53

How can I use a variable to get an Input$ in Shiny?

I am new to R and I am creating a shiny application to read a csv and filter data. I am reading the csv file, then creating dropdowns with a loop using the column names and the unique values:

          output$dropdowns <- renderUI({
            if (is.null(x())) {
              return(NULL)
            }
            lapply(1:ncol(x()), function(i) {
              selectInput(names(x()[i]), names(x()[i]), c("ALL", unique(as.character(x()[,i]))))
            })

I am now trying to filter the data based on the input from the user. To get the input I am trying to loop through the names (names(x)[i]), which is the ID of the selectinput and get the value. But whenever I use input$names(x)[i], I get the following error:

            Error: attempt to apply non-function.

I have tried to test this using an actual header (e.g. input$testHeader) and this works fine. But when I try to do the same with a variable, e.g.: 

            a < - "testHeader"
            print(input$a).

This returns NULL. I assume it is looking for a selecinput with ID "a" and cannot find it. But I have no idead how else to try?

Any help would be great.

Thanks.

Upvotes: 2

Views: 8021

Answers (1)

zero323
zero323

Reputation: 330453

input is just a reactivevalues object so you can use [[: 

print(input[[a]])

Upvotes: 5

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