bug with reactive data in dq_render_handsontable

[FrankSchiro]

When running dq_render_handsontable with a reactive input that changes the number of columns, I get an error when I add too many columns.

In the reproducible example below, you can add columns with the drop down bar. When I add columns with the app, I get this error: Warning: Error in [[: subscript out of bounds

library("rlist")
library(shinyWidgets)
library(shiny)
library(dqshiny)

shinyApp(
    ui = fluidPage(
        dq_handsontable_output("randomTable"),
        pickerInput(
            inputId = "extraCols", 
            label = "Add Columns", 
            choices = c(1, 5:10),
            selected = 0,
            multiple = FALSE
        )
    ),
    server = function(input, output, session) {
        colParams__ <- reactive({
            colParams_ = list()
            for(i in 1:ncol(df0())){
                colParams_ = list.append(colParams_,
                    list(
                        col = names(df0())[i], 
                        type = "dropdown", source = unique(df0()[, i])
                    )
                )
            }
            colParams_
        })
        df0 <- reactive({
            hw <- c("Hello", "my", "funny", "world!")
            df <- data.frame(A = rep(hw, 8), B = hw[c(2,3,4,1)],
            C = 1:8, D = 1:8, stringsAsFactors = FALSE)
            df$D = as.character(df$D)
            n <- as.numeric(input$extraCols)
            print(n)
            for(i in 1:n){
                df <- cbind(df, df[, 1])
            }
            names(df) = letters[1:ncol(df)]
            df
        })
        observeEvent(colParams__(), {
            dq_render_handsontable(
                "randomTable", 
                df0,
                filters = "T",
                page_size = NULL,
                width_align = TRUE,
                col_param = colParams__(),
                horizontal_scroll = TRUE
            )}
        )
    }
)

I noticed this problem is coming from the dq_render_handsontable function.

Below is a small segment of code from the dq_render_handsontable function. This part of the function is producing the error because it is running update_filters() without first adding filters for the new columns. I modified the code to add new filters to the list like so : filters <<- correct_filters(filters, shiny::isolate(dqv$full[, columns, drop = FALSE]))

This modification makes the app work.

else if (shiny::is.reactive(table_data)) {
          shiny::observeEvent(table_data(), {
              if (no_update) {
                  no_update <<- FALSE
              }
              else {
                  dqv$full <- as.data.frame(table_data())
                  # ----- I added the following 2 lines:
                  filters <<- correct_filters(filters, shiny::isolate(dqv$full[, 
                              columns, drop = FALSE]))
                  # ----- end of addition
                  if (!is.null(filters)) {
                    update_filters(dqv$full[, columns, drop = FALSE], 
                      filters, session)
                  }
              }
          }, ignoreInit = TRUE)
          dqv$full <- as.data.frame(shiny::isolate(table_data()))
      }

One issue with this mod is that it seems to make shiny::observeEvent(app_input[[id]], ...) run more frequently than it should.

I noticed that this observeEvent actually runs 2 + 2 * n times each time I update a cell in the table, where n is the number of times I update columns.

For example, if I add a column once (n=1), then try to edit a cell in the table, observeEvent(app_input[[id]], ...) will run twice and update dqv$full twice. Then it will run the observeEvent two more times, but the second two times nothing gets updated.

If I add another column so that (n=2), 2 + 2 * 2 = 4, so there will be 2 dqv$full update events (where the same data gets update twice. Then there will be 2 more observeEvents where dqv$full does not update. I assume !is.null(app_input[[id]]$changes$source is maybe NULL.

Do you know why this observeEvent runs more when I add more columns ? Also, do you think the way I fixed this bug is okay, or would you recommend something else?