editable table with shinyTable and submitButton - r

Question

I have a shinyTable in a shiny app. It is editable, but because of a submitButton elsewhere in the app the edits are not saved until the button is pressed. If more than one change is made and the button is pressed only the last change is saved.
My question is how can I get it to save all the changes that have been made ?
Perhaps there is a way that I can get at the contents of the whole table in the UI so I can workaround ?
Or would I be better off using shinysky or something else ?
Below is a reproducible example based on an example from the package. You'll see that if you make 2 changes to the upper table and then press the button only the 2nd change gets copied to the lower table.
library(shiny)
library(shinyTable)
server <- function(input, output, session) {
rv <- reactiveValues(cachedTbl = NULL)
output$tbl <- renderHtable({
if (is.null(input$tbl)){
#fill table with 0
tbl <- matrix(0, nrow=3, ncol=3)
rv$cachedTbl <<- tbl
print(tbl)
return(tbl)
} else{
rv$cachedTbl <<- input$tbl
print(input$tbl)
return(input$tbl)
}
})
output$tblNonEdit <- renderTable({
rv$cachedTbl
})
}
ui <- shinyUI(pageWithSidebar(
headerPanel("Simple Shiny Table!"),
sidebarPanel(
helpText(HTML("A simple editable matrix with an update button.
Shows that only most recent change is saved.
<p>Created using shinyTable."))
),
# Show the simple table
mainPanel(
#editable table
htable("tbl"),
#update button
submitButton("apply table edits"),
#to show saved edits
tableOutput("tblNonEdit")
)
))
shinyApp(ui = ui, server = server)
Thanks for your time.
Andy

Answer 1

Following advice from Joe Cheng at RStudio on a related question, it appears that submitButton is not advised and can cause pain.
Switching to actionButton and isolate was relatively straightforward in this simple example and in my application.
Solution below.
library(shiny)
library(shinyTable)
server <- function(input, output, session) {
rv <- reactiveValues(cachedTbl = NULL)
output$tbl <- renderHtable({
if (is.null(input$tbl)){
#fill table with 0
tbl <- matrix(0, nrow=3, ncol=3)
rv$cachedTbl <<- tbl
return(tbl)
} else{
rv$cachedTbl <<- input$tbl
return(input$tbl)
}
})
output$tblNonEdit <- renderTable({
#add dependence on button
input$actionButtonID
#isolate the cached table so it only responds when the button is pressed
isolate({
rv$cachedTbl
})
})
}
ui <- shinyUI(pageWithSidebar(
headerPanel("shinyTable with actionButton to apply changes"),
sidebarPanel(
helpText(HTML("A simple editable matrix with a functioning update button.
Using actionButton not submitButton.
Make changes to the upper table, press the button and they will appear in the lower.
<p>Created using shinyTable."))
),
# Show the simple table
mainPanel(
#editable table
htable("tbl"),
#update button
actionButton("actionButtonID","apply table edits"),
#to show saved edits
tableOutput("tblNonEdit")
)
))
shinyApp(ui = ui, server = server)