Debugging and error handling

[rezasz969]

Hi there,
I wrote a shiny web app and this app get a table from the database with an ID, but when I importing a ID does not exist in the data, it gives an error. I fixed this error with the tryCatch function. But this function does not work in Golem architecture and The whole app crashes and closes. how can I handling an error in golem?

A part of my code:

output$data <- renderDT({
      tryCatch({
      DT::datatable(r$data, rownames = F,
                    options = list(scrollX = T, fixedHeader = T,
                                   columnDefs = list(list(className = 'dt-center', targets = '_all'))))
      }, error = function(w) {
        shinyalert("Error!", w$message, type = "error")
        return()
      })
    })

A simple example of this problem in app.R:

library(shiny)
library(shinydashboard)
library(shinycustomloader)
library(DT)
library(plotly)
library(DBI)
library(pool)

ui <- dashboardPage(
  dashboardHeader(title = "Error Handling"),
  dashboardSidebar(
    textInput("diet","Write the number of the diet:", value = 5),
    column(3, submitButton("Submit", icon = icon("play")))
  ),
  dashboardBody(
    fluidPage(
      tabBox(
        id = "t1", width = 14,
        tabPanel("Data", fluidRow(box(withLoader(DTOutput("data")), width = 8)), icon = icon("database")),
        tabPanel("Summary", fluidRow(box(withLoader(verbatimTextOutput("sum")), width = 8)), icon = icon("line-chart"))
      )
    )
  )
)

server <- function(input, output){
  df <- reactive({
    df <- datasets::ChickWeight
    df <- df %>% filter(Diet == input$diet)
    df <- cbind(Row = 1:dim(df)[1], df)
    df$Diet <- as.character(df$Diet)
    return(df)
  })
    
  output$data <- renderDT({
    tryCatch({
    DT::datatable(df(),rownames = F,
                  options = list(scrollX = T, fixedHeader = T, 
                                 columnDefs = list(list(className = 'dt-center', targets = '_all'))))
    }, error = function(w) {
      shinyalert("Error!", w$message, type = "error")
      return()
    })
  })
  
  output$sum <- renderPrint({
    tryCatch({
    summary(df())
    }, error = function(w) {
      shinyalert("Error!", w$message, type = "error")
      return()
    })
  })
}

shinyApp(ui = ui, server = server)

This code has no problem and works, but Golem does not work and the whole app crashes.

Golem project can be downloaded from the following address:
https://drive.google.com/file/d/11B2_tOFy-xPwzXsRdI12gqnIJ7jfwubb/view?usp=sharing

[AliMahdian72]

I face with this problem too. but i don't know how solve it.