創建和顯示數據表在閃亮之間的競爭條件

Question

我在創建數據表和創建數據表之間存在爭用條件。有沒有辦法在顯示數據表之前確保數據表存在。 流動是

1. 從列表的reactiveValues列表創建數據

2. 顯示該新的數據

---

library(shiny) 
library(data.table) 
library(foreach) 
library(DT) 

ui <- fluidPage(DT::dataTableOutput("table")) 

server <- function(input, output, session) { 

    values <- reactiveValues() 

    # Adding lists dynamically 
    values[["A"]] <- list(info = 1, data = data.table(i = 1, j = 2)) 
    values[["B"]] <- list(info = 10, data = data.table(i = 10, j = 20)) 

    observe({ 
    # Update data everytime new elements are added to values 
    # This is just adding all data.tables as rows to one data.table 
    data <- rbindlist(foreach(list = reactiveValuesToList(values)) %do% list$data) 
    }) 

    output$table <- DT::renderDataTable(data) 

} 

shinyApp(ui, server) 

數據內的觀察功能，然後創建使用DT :: renderDataTable進行渲染

Answer 1

的data應該是反應性爲好，

observe({ 
    values$data <- rbindlist(foreach(list = reactiveValuesToList(values)) %do% list$data) 
}) 

output$table <- DT::renderDataTable(values$data)