How to incorporate the sufix of an output$sufix name into an input$sufix_rows_selected function in R shiny?

I am trying to get the sufix of an output$sufix name in R Shiny and incorporate it into the input$sufix_rows_selected function. The drilldown table is coming empty. Would someone have any idea of what am I doing wrong?

Function that I am trying to build:

f.drilldata <- function(base.summary, base.drilldown,  sufix.output, group_var){ 

group = enquo(group_var)
base.summary = base.summary %>% mutate(var = !!group)
base.drilldown = base.drilldown %>% mutate(var = !!group)

#input = expr(!!glue("input${sufix.output}_rows_selected"))
input = paste0(sufix.output,'_rows_selected')

validate(need(length(input[[input]]) > 0, ''))
selected_rows <- base.summary[as.integer(input[[input]]), ]$var

base.drilldown[base.drilldown$var %in% selected_rows, ]
}

library("dplyr")
library("shiny")
library("DT")

tbl.summary <- group_by(iris, Species) %>% summarise(Count = n())
tbl.drilldown <- iris

ui <- fluidPage(
DTOutput("output.summary.name")
, DTOutput("output.drilldown.name"))

server <- function(input, output){

# display the data that is available to be drilled down
output$output.summary.name <- renderDT(tbl.summary)

# subset the records to the row that was clicked through f.drilldata function
drilldata <- reactive({ f.drilldata(tbl.summary, tbl.drilldown, 'output.summary.name', Species)  })

# display the subsetted data
output$output.drilldown.name <- renderDT(drilldata())}

shinyApp(ui, server)

library("dplyr")
library("shiny")
library("DT")

tbl.summary <- group_by(iris, Species) %>% summarise(Count = n())
tbl.drilldown <- iris

ui <- fluidPage(
DTOutput("output.summary.name")
, DTOutput("output.drilldown.name"))


server <- function(input, output){

output$output.summary.name <- renderDT(tbl.summary)

drilldata <- reactive({ validate( need(length(input$output.summary.name_rows_selected) > 0, "Select rows to drill down!")) 
selected_species <- 
tbl.summary[as.integer(input$output.summary.name_rows_selected), ]$Species
tbl.drilldown[tbl.drilldown$Species %in% selected_species, ]  })

output$output.drilldown.name <- renderDT(drilldata())}

shinyApp(ui, server)