R shiny : How to get the callback value from DT::renderDataTable? - r

Question

I made a select table with button in R shiny.
I want to add a submit actionButton to get the select value from DT::renderDataTable though observeEvent() function.
I have tried
observeEvent(input$submit,{
data <- data.frame(output$sel)}
This is not work.
Is it possible to get the value of callback?
The value can been see in the UI, but how can i get in server?
library(shiny)
library(DT)
library(googlesheets4)
c1 <-c("Time in free flow (mins)",
"Time slowed down by other traffic (mins)",
"Percentage of total time spent with other vehicles close behind",
"Curviness",
"Running costs",
"Toll cost")
c2 <- c('50','10','25%','Moderate','$12.00','$0.00')
c3 <- c('38','5','31%','extreame','$10.50','$3.00')
c4 <- c('62','8','19%','Almost straight','$9.00','$0.50')
c5 <- c('56','15','12%','Moderate','$13.50','$0.00')
t <- cbind(c1,c2,c3,c4,c5)
shinyApp(
ui = fluidPage(
title = 'Radio buttons in a table',
DT::dataTableOutput('foo'),
#tt <- textOutput('sel'),
textOutput('sel'),
actionButton("submit", "submit")
),
server = function(input, output, session) {
m = matrix(
as.character(1:4), nrow = 1, ncol = 4, byrow = TRUE,
dimnames = list(' ', LETTERS[1:4])
)
for (i in seq_len(nrow(m))) {
m[i, ] = sprintf(
'<input type="radio" name="%s" value="%s"/>',
' ', m[i, ]
)
}
m <- cbind('Chioce',m)
m<-rbind(t,m)
output$foo = DT::renderDataTable(
m, escape = FALSE, selection = 'none', server = FALSE,
options = list(dom = 't', paging = FALSE, ordering = FALSE),
callback = JS("table.rows().every(function(i, tab, row) {
var $this = $(this.node());
$this.attr('id', this.data()[0]);
$this.addClass('shiny-input-radiogroup');
});
Shiny.unbindAll(table.table().node());
Shiny.bindAll(table.table().node());")
)
output$sel = renderPrint({
str(sapply(' ', function(i) input[[i]]))
})
observeEvent(input$submit,{
})})

Answer 1

You can get the selected row indices (and work forward from there) like this:
ui <- fluidPage(
verbatimTextOutput('log'),
DTOutput('myTable')
)
server <- function(input, output) {
output$myTable <- renderDataTable(iris)
output$log <- renderPrint({
row_indices <- input$myTable_rows_selected
iris[row_indices,]
})
}
shinyApp(ui, server)
edit
You can set server input values via client side javascript.
In your case:
## [...]
for (i in seq_len(nrow(m))) {
m[i, ] = sprintf(
'<input type="radio" name="%s" value="%s"
// set input$selected to m[i,] when clicked:
onClick = "Shiny.setInputValue(\'selected\', %s)" />',
' ', m[i, ], m[i,]
)
}
## now input$selected will be updated upon selection of either radio input
## [...]
see: https://shiny.rstudio.com/articles/communicating-with-js.html