Plugging edited Datatable values in a shiny app - r

Question

I am trying to understand how to use the values from an edited data table and do some calculation.
I have a data frame which loads by default. When you click on 'run' it updates the tables based on the input value.
I want the user to edit the values manually in the table and then click on 'run'. Next, I want the app to take the edited values in the data table, run some calculations, and update the table. In this way the user can dynamically see the result their input makes on the table.
library(shiny)
library(DT)
library(dplyr)
#### Module 1 renders the first table
tableMod <- function(input, output, session, modelRun,modelData,budget){
output$x1 <- DT::renderDataTable({
modelRun()
isolate(
datatable(
modelData %>%
mutate(New_Membership = as.numeric(Modified * 0.01)*(budget())),
selection = 'none', editable = TRUE
)
)
})
observeEvent(input$x1_cell_edit, {
df[input$x1_cell_edit$row,input$x1_cell_edit$col] <<- input$x1_cell_edit$value
})
}
tableUI <- function(id) {
ns <- NS(id)
dataTableOutput(ns("x1"))
}
ui <- function(request) {
fluidPage(
tableUI("opfun"),
numericInput("budget_input", "Total Forecast", value = 2),
actionButton("opt_run", "Run")
)
}
server <- function(input, output, session) {
df <- data.frame(Channel = c("A", "B","C"),
Current = c(2000, 3000, 4000),
Modified = c(2500, 3500,3000),
New_Membership = c(450, 650,700),
stringsAsFactors = FALSE)
callModule( tableMod,"opfun",
modelRun = reactive(input$opt_run),
modelData = df,
budget = reactive(input$budget_input))
observeEvent(input$opt_run, {
cat('HJE')
})
}
shinyApp(ui, server, enableBookmarking = "url")

Answer 1

A clean solution (rather than assigning values in other environments) would be to use a reactiveVal in your module which is in sync with the datatable. You can return this reactive from your module to make use of it also in the main application:
library(shiny)
library(DT)
library(dplyr)
#### Module 1 renders the first table
tableMod <- function(input, output, session, modelRun, modelData, budget){
df <- reactiveVal(modelData) ## this variable will be in sync with your datatable
output$x1 <- DT::renderDataTable({
modelRun()
isolate(
datatable(
df() %>% ## ...you always use the synced version here
mutate(New_Membership = as.numeric(Modified * 0.01)*(budget())),
selection = 'none', editable = TRUE
)
)
})
observeEvent(input$x1_cell_edit, {
new_df <- df()
row <- input$x1_cell_edit$row
col <- input$x1_cell_edit$col
value <- as.numeric(input$x1_cell_edit$value)
new_df[row, col] <- value
df(new_df) ## ...and you make sure that 'df' stays in sync
})
list(updated_df = df) ## ...finally you return it to make use of it in the main app too
}
tableUI <- function(id) {
ns <- NS(id)
dataTableOutput(ns("x1"))
}
ui <- function(request) {
fluidPage(
tableUI("opfun"),
numericInput("budget_input", "Total Forecast", value = 2),
actionButton("opt_run", "Run")
)
}
server <- function(input, output, session) {
df <- data.frame(Channel = c("A", "B","C"),
Current = c(2000, 3000, 4000),
Modified = c(2500, 3500,3000),
New_Membership = c(450, 650,700),
stringsAsFactors = FALSE)
result <- callModule( tableMod,"opfun",
modelRun = reactive(input$opt_run),
modelData = df,
budget = reactive(input$budget_input))
observeEvent(input$opt_run, {
str(result$updated_df())
})
}
shinyApp(ui, server, enableBookmarking = "url")

Answer 2

This should work, but not the "cleanest" implementation:
I had to take df out of shiny to make your code work. Used assign to replace df in global environment (not the best idea...) once datatable is edited. But, data is not recalculated untill Run is pressed. Once Run is pressed modelData is overwritten: (modelData <- df). Again not the best idea, probably making modelData reactive will be better idea.
Also, have a look at DT::replaceData. It might be better idea than regenerating full table.
library(shiny)
library(DT)
library(dplyr)
df <- data.frame(Channel = c("A", "B","C"),
Current = c(2000, 3000, 4000),
Modified = c(2500, 3500,3000),
New_Membership = c(450, 650,700),
stringsAsFactors = FALSE)
#### Module 1 renders the first table
tableMod <- function(input, output, session, modelRun,modelData,budget){
observeEvent( input$x1_cell_edit, {
cat ('input$x1_cell_edit \n')
info = input$x1_cell_edit
str(info)
i = info$row
j = info$col
v = info$value
df[i, j] <- DT:::coerceValue(v, df[i, j])
assign("df", df, envir = .GlobalEnv)
})
output$x1 <- DT::renderDataTable({
modelRun()
modelData <- df
isolate(
datatable(
modelData %>%
mutate(New_Membership = as.numeric(Modified * 0.01)*(budget())),
selection = 'none', editable = TRUE
)
)
})
}
tableUI <- function(id) {
ns <- NS(id)
dataTableOutput(ns("x1"))
}
ui <- function(request) {
fluidPage(
tableUI("opfun"),
numericInput("budget_input", "Total Forecast", value = 2),
actionButton("opt_run", "Run")
)
}
server <- function(input, output, session) {
callModule( tableMod,"opfun",
modelRun = reactive(input$opt_run),
modelData = df,
budget = reactive(input$budget_input))
observeEvent(input$opt_run, {
cat('HJE')
})
}
shinyApp(ui, server, enableBookmarking = "url")