How to break dependence between tables dynamically rendered in R Shiny App? - r

Question

In the below code, I took one of the examples from https://community.rstudio.com/t/shiny-app-with-dynamic-number-of-datatables/2405/4 for dynamically adding tables. The example used tables rendered with DT and I made minor modifications to use it for rhandsontable.
However, I'm having trouble making the tables independent of one another. When adding a new table, it should be "seeded" with the default values per dataframe data1 and its related rowNames1, but thereafter they should be independent as illustrated below. I'm fairly sure the solution has something to do with creating a dynamic equivalent of the reactive uiTable1 used in the code for holding table values, but I don't know how to do this.
Any ideas for accomplishing this?
Inputs into the base (master) and added tables will be used elsewhere in the full code this is intended for.
Code:
library(rhandsontable)
library(shiny)
rowNames1 <- c('A','B','C','Sum')
data1 <- data.frame(row.names = rowNames1, 'Col 1' = c(1,1,0,2), check.names = FALSE)
ui <- fluidPage(
rHandsontableOutput('hottable1'), # undeletable base table
actionButton("addTbl", "Add table"), # adds new table
tags$div(id = "placeholder")
)
server <- function(input, output) {
uiTable1 <- reactiveVal(data1) # undeletable base table
rv <- reactiveValues() # used for dynamic table add/removal
# records changes to base table and will need same for added tables:
observeEvent(input$hottable1,{uiTable1(hot_to_r(input$hottable1))})
output$hottable1 <- renderRHandsontable({
rhandsontable(uiTable1(),rowHeaderWidth = 100, useTypes = TRUE)
})
# adds column summation to last row of table, will need for all added tables too:
observe({
req(input$hottable1)
DF <- hot_to_r(input$hottable1)
DF[setdiff(rowNames1, "Sum"),]
DF["Sum",] <- colSums(DF[setdiff(rowNames1, "Sum"),, drop = FALSE], na.rm = TRUE)
uiTable1(DF)
})
# dynamically add/remove tables:
observeEvent(input$addTbl, {
divID <- gsub("\\.", "", format(Sys.time(), "%H%M%OS3"))
dtID <- paste0(divID, "DT")
btnID <- paste0(divID, "rmv")
insertUI(
selector = "#placeholder",
ui = tags$div(id = divID,
actionButton(btnID, "Remove table", class = "pull-left btn btn-danger"),
rHandsontableOutput(dtID),
hr()
)
)
output[[dtID]] <- renderRHandsontable({
rhandsontable(uiTable1(),rowHeaderWidth = 100, useTypes = TRUE)
})
# remove table from the app when remove button clicked
observeEvent(input[[btnID]], {
removeUI(selector = paste0("#", divID))
rv[[divID]] <- NULL
}, ignoreInit = TRUE, once = TRUE)
})
}
shinyApp(ui,server)

Answer 1

We can use reactiveValues to store the information of each new table. These tables will start with the values of the base table available at that time. Afterwards they will stop reacting to changes inside the main table.
First we create the base table uiTable1 <- reactiveValues(table_base = data1) # undeletable base table
And finally all the subsequent tables will be created as uiTable1[[glue("{divID}table")]] <- uiTable$table_base
library(rhandsontable)
library(shiny)
library(glue)
rowNames1 <- c("A", "B", "C", "Sum")
data1 <- data.frame(row.names = rowNames1, "Col 1" = c(1, 1, 0, 2), check.names = FALSE)
ui <- fluidPage(
rHandsontableOutput("hottable1"), # undeletable base table
actionButton("addTbl", "Add table"), # adds new table
tags$div(id = "placeholder")
)
server <- function(input, output) {
uiTable1 <- reactiveValues(table_base = data1) # undeletable base table
rv <- reactiveValues() # used for dynamic table add/removal
# records changes to base table and will need same for added tables:
observeEvent(input$hottable1, {
uiTable1$table_base <- hot_to_r(input$hottable1)
})
output$hottable1 <- renderRHandsontable({
rhandsontable(uiTable1$table_base, rowHeaderWidth = 100, useTypes = TRUE)
})
# adds column summation to last row of table, will need for all added tables too:
observe({
req(input$hottable1)
DF <- hot_to_r(input$hottable1)
DF[setdiff(rowNames1, "Sum"), ]
DF["Sum", ] <- colSums(DF[setdiff(rowNames1, "Sum"), , drop = FALSE], na.rm = TRUE)
uiTable1$table_base <- DF
})
# dynamically add/remove tables:
observeEvent(input$addTbl, {
divID <- gsub("\\.", "", format(Sys.time(), "%H%M%OS3"))
dtID <- paste0(divID, "DT")
btnID <- paste0(divID, "rmv")
# capture the current state of the main table
uiTable1[[glue("{divID}table")]] <- uiTable1$table_base
insertUI(
selector = "#placeholder",
ui = tags$div(
id = divID,
actionButton(btnID, "Remove table", class = "pull-left btn btn-danger"),
rHandsontableOutput(dtID),
hr()
)
)
output[[dtID]] <- renderRHandsontable({
req(uiTable1[[glue("{divID}table")]])
rhandsontable(uiTable1[[glue("{divID}table")]], rowHeaderWidth = 100, useTypes = TRUE)
})
# adds column summation to last row of table, will need for all added tables too:
observeEvent(input[[dtID]], {
DF <- hot_to_r(input[[dtID]])
DF[setdiff(rowNames1, "Sum"), ]
DF["Sum", ] <- colSums(DF[setdiff(rowNames1, "Sum"), , drop = FALSE], na.rm = TRUE)
uiTable1[[glue("{divID}table")]] <- DF # update the table with the sum
})
# remove table from the app when remove button clicked
observeEvent(input[[btnID]],
{
removeUI(selector = paste0("#", divID))
rv[[divID]] <- NULL
uiTable1[[glue("{divID}table")]] <- NULL
},
ignoreInit = TRUE,
once = TRUE
)
})
}
shinyApp(ui, server)