Shiny + bindCache() + editable DT::datatable

... is it possible?

I want to have an editable DT::datatable, that is backed up by a dataframe cached with bindCache. Something along the lines of:

city_data <- reactive({
    fetchData(input$city)
  }) %>%
  bindCache(input$city)

observeEvent(input$city, output$dt = DT::renderDataTable(city_data(), editable = "cell")

observeEvent(input$dt_cell_edit,  city_data()<<-editData(city_data(), input$dt_cell_edit, 'dt')

The last assignment city_data()<<- returns an error of NULL on the left side of the assignment.