Using a selected row to subset another table in r shiny - r

Question

I am new to using DT in R shiny.Basically what i am trying to do here is to use the select value from the first table to filter the second table.
my Ui.r is
library(shiny)
library(shinydashboard)
ui <- dashboardPage(skin="green",
dashboardHeader(title="Inventory Management"),
dashboardSidebar(disable = TRUE),
dashboardBody(fluidRow(column(4,box(status="success",
uiOutput("Firstselection"),
br(),
uiOutput("Secondselection"))
),
column(4,infoBoxOutput("salesbox")),
column(4,infoBoxOutput("Runoutbox")),
column(4,infoBoxOutput("Excessbox"))),
actionButton("actionbtn","Run"),
fluidRow(tabBox(tabPanel(
DT::dataTableOutput(outputId="table"),title = "Stock Available for the category chosen",width = 12),
tabPanel(DT::dataTableOutput(outputId="asso"),title = "Associated products",width = 12)))
))
and my server is
server <-function(input, output, session) {
observeEvent(input$actionbtn, {source('global.r',local = TRUE)
#choose sub category based on category
output$Firstselection<-renderUI({selectInput("ray",
"Category:",
c("All",unique(as.character(bestpred$lib_ray))))})
output$Secondselection<-renderUI({selectInput("sray",
"Sub Category:",
c("All",unique(as.character(bestpred[bestpred$lib_ray==input$ray,"lib_sray"]))))})
# Filter data based on selections
output$table <- DT::renderDataTable({
data <- bestpred
if (input$ray != "All"){
data <- data[data$lib_ray == input$ray,]
}
if (input$sray != "All"){
data <- data[data$lib_sray == input$sray,]
}
data
},filter="top"
)
output$salesbox<-renderInfoBox({infoBox("Total Sales",sum(data()$Total_Sales),icon = icon("line-chart"))})
output$Runoutbox<-renderInfoBox({infoBox("Total Runout",sum(data()$status=="Runout"),icon = icon("battery-quarter"))})
output$Excessbox<-renderInfoBox({infoBox("Total excess",sum(data()$status=="Excess"),icon = icon("exclamation-triangle"))})
output$asso <- DT::renderDataTable({
asso <- test1
s=data[input$tablatable_rows_selected,1]
asso <- asso[asso$num_art == s,]
asso
},filter="top")
})}
So when i select a row in the output table i wanna use that as an filter for my asso table
this code dosent poup any error but the output table asso is always empty

Answer 1

Find a generalized solution in the following:
Adapted from here: https://yihui.shinyapps.io/DT-rows/
library(shiny)
library(DT)
server <- shinyServer(function(input, output, session) {
output$x1 = DT::renderDataTable(cars, server = FALSE)
output$x2 = DT::renderDataTable({
sel <- input$x1_rows_selected
if(length(cars)){
cars[sel, ]
}
}, server = FALSE)
})
ui <- fluidPage(
fluidRow(
column(6, DT::dataTableOutput('x1')),
column(6, DT::dataTableOutput('x2'))
)
)
shinyApp(ui, server)