Create data frames and plots within shiny using reactive function objects

[SKC]

I am trying to make a simple shiny app where based on the input from selectInput I subset an existing data frame (code below). From this data frame that has been subset, I want to create a few more data frames with some calculations as show in the example below.

The Shiny app

ui = pageWithSidebar(
  headerPanel(""),
  sidebarPanel(
    selectInput('var1', "IP SLNO", choices = rev_21$serial_number)
  ),
  
  mainPanel(
    tableOutput("table")
  )
)
server = function(input, output, session){
  tab = reactive({subset(rev_21,serial_number == input$var1, select = c("serial_number","order_number","follow_up","created_date","completed_data", "which_month",
                                                                              "category","failure_categories","sub_failure_category",
                                                                              "cause","criticallity","order_reason","country","region" ,"...."))})
  
  
  # overview = reactive({ tab()
  #   
  # })
  
  output$table = renderTable({tab()})
  
}


shinyApp(ui, server)

In the app I have been able to subset and create a new data frame from a larger data frame. (all columns are not listed to keep the example df short. I can provide the data if needed)

Using data in this I want to now create two data frames and display them. I am not sure how to access the data passed to the reactive function object tab() to do this.

Examples of the DF I want from this are below (created manually for example purpos)

overview = data.frame(
                      "location" = p1$country[1],
                      "region" = p1$region[1
                      "slno" = p1$serial_number[1]
                      "start_date" = p1$main_start_date[1],
                      "total_order_created" = NROW(unique(p1$order_number)),
                      "days_to_first_order" = p1$first_date[1]-min(p1$created_date),
                      "days_last_recorded_order" = max(p1$created_date) - p1$completed_date[1],
                      "types_of_order_created" = NROW(unique(p1$order_category)),
                      "max_time" = max(p1$completed_on - p1$created_date),
                      "min_time" = min(p1$completed_on - p1$created_date),
                      "total_faults" = NROW((p1$failure_categories[which(!is.na(p1$failure_categories) & p1$failure_categories!="NPF")])),
                      "total_unique_faults" = NROW(unique(p1$failure_categories[which(p1$failure_categories!="NPF")]))
                      )

for (i in 1:length(failure_list) )
  
  {
  days_to_failure$order_number[i] = failure_list[i]
  days_to_failure$failure_name[i] = p1$failure_categories[which(p1$order_number == failure_wo_list[i])]
  days_to_failure$days[i] =  p1$created_date[which(p1$order_number == failure_wo_list[i])]-
    p1$created_date[which(p1$order_number == failure_list[i])]
  days_to_failure$criticality[i] = p1$criticallity[which(p1$order_number == failure_list[i])]

}```


I would like help in understanding how to access the reactive function object (tab) to 
1) create additional DF based on the original subset data frame (tab())
2) how can I have a looping structure as show above to create another data frame,
the looping condition for which is also taken from one of the columns of the subset dataframe. 

Thanks in Advance!!

[pieterjanvc]

Hello,

Here is a dummy example to showcase a way of subsetting reactive data and creating new data frames.

library(shiny)

ui <- fluidPage(
  
  selectInput("input1", "Choose", choices = c('A', 'B', 'C')),
  tableOutput("table1"),
  tableOutput("table2")

)

server <- function(input, output) {
  
  set.seed(1) #Only needed for reproducibility 
  myData = data.frame(
    letter = sample(LETTERS[1:3], 20, replace = T),
    value = runif(20)
  )
  
  #Subset data based-on user input
  subsetData = reactive({
    myData[myData$letter %in% input$input1,]
  })

  #Create new df based on first reactive one
   #For loop can be inside this
  summaryData = reactive({
    data.frame(
      #subsetData() is reactive data frame (note brackets)
      letter = subsetData()$letter[1],
      meanVal = mean(subsetData()$value)
    )
  })
  
  #Render the tables
  output$table1 = renderTable({
    subsetData()
  })
  
  output$table2 = renderTable({
    summaryData()
  })
  
}

shinyApp(ui, server)

Hope this helps,
PJ

[SKC]

Thanks for the response @pieterjanvc . I will work through my solution and let you know