Date: 2026-07-09

# Custom logic

#### 2026-07-09

When saving your modifications, eDT will just update the data hereby only checking the data types and foreign tables. Sometimes however, you might want some specific custom behavior or extra checks that `editbl` doesn’t support out of the box. There are two main solutions to write custom logic for the modifications that were made.

    library(shiny)
    library(editbl)

## Option 1

Add your own implementations for `e_rows_update()`, `e_rows_insert()` and/or `e_rows_delete`. This is arguably the most flexible approach since it nicely integrates with the behavior of eDT.

    ui <- fluidPage(eDTOutput("DT"))

    # Define a custom update function
    e_rows_update.mtcars <- function(
        x,
        y,
        by = NULL,
        ...,
        match = match,
        unmatched = c("error", "ignore"),
        copy = FALSE,
        in_place = FALSE){

            # Extra checks
            if(any(y[,"mpg"] < 0)){
                stop("mpg should be a positive value!")
            }

            # Logging
            print("Updated rows:")
            print(y)

            # Drop extra class and execute default code
            class(x) <- class(x)[class(x) != 'mtcars']
            e_rows_update(
              x = x,
              y = y,
              by = by,
              ... ,
              match = match,
              unmatched = unmatched,
              copy = copy,
              in_place = in_place
          )
        }

    server <- function(input, output, session){

        # Add a new class to your data object
        df = tibble::tibble(mtcars)
        class(df) <- c("mtcars", class(df))

          result = eDT(
            id = "DT",
            data = df
        )

    }
    shinyApp(ui, server)

Shiny applications not supported in static R Markdown documents

## Option 2

You can capture the modifications made by editbl and handle them downstream in the app. This is more straightforward, but doesn’t support adding any logic before saving.

    ui <- fluidPage(eDTOutput("DT"))

    server <- function(input, output, session){
          result = eDT(
            id = "DT",
            data = mtcars
          )

          # Some logging
          observe({
            print('These rows have been permanently deleted:')
            print(result$deleted())
          })

    }
    shinyApp(ui, server)

Shiny applications not supported in static R Markdown documents