Retrieving unique id and input values from datatable in Shiny - shiny

Question

I am attempting to use DT in R to create a table for user review with an appended column (new_column) including a selectInput drop-down that allows them to designate the event as either keep or delete. I am stuck on how to retrieve both the unique id and the user input from the datatable to be able to apply the change to a separate dataframe in Shiny. I would like for the user to push a button ('submit') for the app to know when to capture the values -- with this am I able to circumvent rerending the table or is that a necessary part of capturing the value?
I have worked with Shiny quite a bit but am not super familiar with javascript or datatables in general so have been stuck on this for some time and would appreciate any pointers.
Here is a simplified version of my data and code:
library(DT)
library(tidyverse)
library(shiny)
ui <- fluidPage(
DTOutput('myTableOutput'),
br(),
actionButton("submit", "Apply Changes"))
server <- function(input, output, session) {
for (i in 1:nrow(df)) {
df$new_column[i] <- as.character(selectInput(inputId = df$unique_id[i], label=NULL, choices = c('keep'=TRUE, 'delete'=FALSE)))
}
output$myTableOutput <- DT::renderDataTable({
datatable(
df,
escape = FALSE,
filter = "none",
editable = 'new_column',
selection = "none",
options = list(
dom = "t",
initComplete = JS(
"function(settings, json) {",
"$(this.api().table().header()).css({'background-color': 'DimGray', 'color': 'white'});",
"}"),
drawCallback = JS('function() { Shiny.bindAll(this.api().table().node()); } '))
)
}, server = FALSE)
observeEvent(input$submit,{
#need to retrieve changes (preferably in a df) so I can apply them to another dataframe
reviewed_table <- as.data.frame(input$mytable_cell_edit)
})
}

Answer 1

You can add reactive value (lgl_vec) that has values of all selectInput's inside your table:
server <- function(input, output, session) {
rv <- reactiveValues()
df[["new_column"]] <- map_chr(
map(
df[["unique_id"]],
selectInput,
label = NULL,
choices = c(keep = TRUE, delete = FALSE)
),
as.character
)
output$myTableOutput <- DT::renderDataTable({
datatable(
df,
escape = FALSE,
filter = "none",
selection = "none",
options = list(
dom = "t",
preDrawCallback =JS(
'function(){Shiny.unbindAll(this.api().table().node());}'
),
drawCallback = JS(
'function(){Shiny.bindAll(this.api().table().node());}'
)
)
)
}
)
observeEvent(input$submit, {
lgl_vec <- as.logical(map_chr(df[["unique_id"]], ~input[[.x]]))
rv$reviewed_table <- df[lgl_vec, -ncol(df), drop = FALSE]
print(rv$reviewed_table)
})
}