Interactive Column/Table Updates with textInput in R Shiny - r

Question

UPDATE
I've gotten to what I think is the root problem. The following R Shiny App produces a UI with 2 text input boxes, as well as event observers that print messages to the console as the text changes in their respective text input boxes. The issue is that only one of these event observers works correctly, and I can't figure out why.
ui.R (shortened)
library(shiny)
library(shinydashboard)
library(DT)
library(data.table)
shinyUI(
renderUI({
fluidPage(
column(12, dataTableOutput("Main_table")),
box(textInput("TEST_BOX", label=NULL, value="TEST"))
)
})
)
server.R (shortened)
shinyServer(function(input, output) {
test <- reactiveValues()
test$data <- data.table(ID = 1, Group = 1)
output$Main_table <- renderDataTable({
datatable(data.frame(test$data,
New_Group=as.character(textInput("BOX_ID", label = NULL, value = "TEST2",
width = '100px'))), escape=F
)})
observeEvent(input$TEST_BOX, {
print("Test Box Success")
})
observeEvent(input$BOX_ID, {
print("Box ID Success")
})
})
Original Post:
I'm attempting to create a simple app in R Shiny to allow the user to interactively update the values in a column of a small table, then be able to hit a "Save Changes" button and update the table to include their selections.
I've gotten really close with the code below (I think), but for some reason the inputs cbox_1 to cbox_10 always come back as NULL.
ui.R
library(shiny)
library(shinydashboard)
library(DT)
library(data.table)
shinyUI(fluidPage(
dashboardBody(uiOutput("MainBody")
)
))
server.R
# Load libraries
library(shiny)
library(shinydashboard)
library(DT)
library(data.table)
# Define server logic
shinyServer(function(input, output) {
# Create sample data
vals <- reactiveValues()
vals$Data <- data.table(ID = 1:10, Group = 1:1)
# Create main UI with Save Changes button and additional text input box for testing.
output$MainBody <- renderUI({
fluidPage(
box(width=12,
h3(strong("Group Testing"),align="center"),
hr(),
box(textInput("test", label=NULL, value="TESTING")),
column(6, offset = 5, actionButton("save_changes","Save changes")),
column(12, dataTableOutput("Main_table"))
)
)
})
# Function to be used to create multiple text input boxes.
shinyInput = function(FUN, len, id, ...) {
inputs = character(len)
for (i in seq_len(len)) {
inputs[i] = as.character(FUN(paste0(id, i), label = NULL, value = vals$Data$Group[i], width = '100px', ...))
}
inputs
}
# Renders table to include column with text input boxes. Uses function above.
output$Main_table <- renderDataTable({
datatable(data.frame(vals$Data, New_Group=shinyInput(textInput, nrow(vals$Data),"cbox_")), options = list(dom = 't', pageLength = nrow(vals$Data), paging=FALSE, searching=FALSE), rownames=FALSE,
escape=F)
}
)
# Tests if the test input box works.
observeEvent(input$test, {
print("Success1")
})
# Tests if the first input box in the table works.
observeEvent(input$cbox_1, {
print("Success2")
})
# Tests if the Save Changes button works.
observeEvent(input$save_changes, {
print("Success3")
# Assigns the values in the input boxes (New_Group) to the existing Group column.
for (i in 1:nrow(vals$Data)) {
vals$Data$Group[i] <- eval(paste0("input$cbox_", i))
}
datatable(data.frame(vals$Data, New_Group=shinyInput(textInput, nrow(vals$Data),"cbox_")), options = list(pageLength = nrow(vals$Data), paging=FALSE, searching=FALSE), rownames=FALSE,
escape=F)
})
})
The first two observeEvents at the end of the code are solely for testing purposes. "Success2" is never printed even when the contents of the first box are changed. "Success1" is printed when the test box is changed, but I'm not sure why one works and the other doesn't. I've tried inserting a browser() statement in various places of the code to check the value of cbox_1, but it always comes back NULL. I'd also be open to alternate solutions to this problem if I'm approaching it completely wrong. Thanks.

Answer 1

After further research, an approach utilizing the rhandsontable package seemed like the best solution. I modeled my code after this example:
Data input via shinyTable in R shiny application
I also utilized several of the options described here:
https://jrowen.github.io/rhandsontable/#introduction