Reactive dataframe + reactive (user selected) column?

[pathos]

There are various threads about uploaded data but with given columns like this thread:

Subset a reactive dataframe in R SHINY

Hello I want to find the correlation coefficient of two columns of my dataset. If I use cor(subset(iris, select=c("Sepal.Length")),subset(iris, select=c("Sepal.Width"))) the correlation is being found but I cannot subset with my actual dataset which comes as a CSV file input and is in a reactive expression. cor(subset(rt(), select=c("Sepal.Length")),subset(rt(), select=c("Sepal.Width"))) So how could I subset a data frame of this reactive form? rt<-reactive({ req(input$file1) csvdata <- read.csv(input$file1$datapath, header = input$header ) csvdata }) I put my whole code if that helps understand the question #ui.r library(shiny) library(ggplot2) l…

How can I call the column name of user-selected column that doesn't have a given column name? Let's say the column name is saved as input$user_selected. I can't call the column by using df()$input$user_selected or df$input$user_selected so I was wondering how this can be done.

[nirgrahamuk]

An example for you

library(shiny)

ui <- fluidPage(
  uiOutput("u_selector"),
  p("first 10 values are : "),
  verbatimTextOutput("result")
)

server <- function(input, output, session) {
  
  df <- reactive(iris)
  
  output$u_selector <- renderUI({
    df_local <- req(df())
    selectInput("user_selected","make a selection",
                choices=names(df_local),
                selected = names(df_local)[[1]])
  })
  
  
 output$result <- renderText({
   df_local <- req(df())
   u_sel <- req(input$user_selected)

   dfh <- head(df_local,n=10)
   dfh[[u_sel]]
 })
   
}

shinyApp(ui, server)