shiny DT _row_last_clicked - r

Question

I am having an issue with the _row_last_clicked option provided for tables created in shiny interfaces with the rstudio DT library. I am trying to select a row in a datatable, make modifications to it and output it to the shiny ui.r. It works for the first-time selection, but when I again click on the same table row which I just selected previously, the _row_last_clicked seems to remain unresponsive (=NULL?). Here is a mininmal example (ui.r likely irrelevant) of what I am trying to achieve:
# server.r-side:
table_x<-# ... loads the dataframe
redo_cal<-reactiveValues()
redo_cal$a<-1
observe({
redo_cal$a
output$some_table <- DT::renderDataTable(
table_x,
server = TRUE, # same problem with FALSE
selection =c('single')
)
})
observeEvent(
input$some_table_row_last_clicked,{
s<-input$some_table_row_last_clicked
table_x[s,]<- # some reversible modifications based on the row selection ...
redo_cal$a<-(redo_cal$a+1) # trigger above renderDataTable
})
The issue persists for both the latest github version of DT as well as the release found on CRAN. I have read several related posts but couldn`t figure out a satisfying solution. Thank you very much for your help!

Answer 1

If i understand you right you need some_table_row_selected
and table_x(dd$d - in my example) be reactiveValues
See example where
# some reversible modifications based on the row selection == log of x
Every time you select row value of x in this row log-ed
library(shiny)
library(DT)
data=data.frame(x=1:10,y=2:11)
ui=shinyUI(
fluidPage(
DT::dataTableOutput("tt")
)
)
server=shinyServer(function(input, output) {
dd=reactiveValues(d=data)
output$tt=DT::renderDataTable(
datatable(
dd$d,selection =c('single')
)
)
observeEvent(input$tt_rows_selected,{
dd$d[input$tt_rows_selected,1]<-log(dd$d[input$tt_rows_selected,1])
})
})
shinyApp(ui,server)
In each session your data refreshed
PS
Best minimal example its something which anyone can copy\paste and test.