I'm in the process of creating a Shiny screening application, which would allow users to type R commands like `filter` and `mutate` on a predetermined dataframe. 

Personally, I think the most user friendly way to do this would be to have a blank dataframe column containing screening parameters, where users could input commands like `filter(mpg >= 21)` or `mutate(cyl_sq = cyl^2)` using the `mtcars` dataset as an example. 

**Simple application to show the intended functionality:**

```
library(shiny)
library(shinydashboard)
library(DT)
library(dplyr)
# Header ------------------------------------------------
header <- dashboardHeader(title = "Example Screening")
# Sidebar ------------------------------------------------
sidebar <- dashboardSidebar()
# Body ------------------------------------------------
body <-
dashboardBody(
  fluidRow(
       column(6,h3("Screening Parameters")),
       column(6,h3("Filtered/Modified Results"))),
  fluidRow(
       column(6,DT::dataTableOutput("screening_params")),
       column(6,DT::dataTableOutput("filtered_results")))
)
# APP ------------------------------------------------
shinyApp(ui <- dashboardPage(
  header,
  sidebar,
  body
),
# Server ----------------------------------------------------------
shinyServer(function(input,output){

  output$screening_params <- renderDataTable({
    tibble(params = c("filter(mpg >= 21)",
                      "mutate(cyl_sq = cyl^2)",
                      rep_len(NA_character_,8))) %>%
      DT::datatable(rownames = F,
                    editable = T)
  })

  output$filtered_results <- renderDataTable({
    mtcars %>%
      # input$screening_params
      DT::datatable()

  })

})) 

```

I would be open to using either the `DT` or `rhandsontable` or any alternative that someone can think of. Unfortunately it doesn't look like you can grab the edited table values in `DT`, but hopefully it provides a good example of what I am after. 

I have tried every combination of quosures and mapping functions that I can think of to no avail. 

Anyone have any ideas?