r闪亮 - 通过选择值减少上传的数据集

Question

我正在尝试编写一个脚本来上传.csv文件并在UI中引发子选项（以复选框的形式）。上传后，显示以前不可见的复选框，显示实际的数据值。同时，还会出现一个动作按钮，在选定的数据值（通过复选框）（可能）改变之后被点击。

那么我有什么？
1）上传 - 确定。
2）选择并显示复选框 - 确定。
3）显示操作按钮 - 确定。
4）正确执行所需的操作（=数据子集） - 不正确;子集显然会返回空或NULL数据帧。

任何帮助将不胜感激。

这是代码。

我会补充说，我基于子集的Dte字段是一个日期字段，它最初在csv中为dd/mm/yyyy格式且不含引号。

library(shiny) 
library(lubridate) 

ui = fluidPage(sidebarPanel(width = 2, 
          fileInput('files', '', accept = c('text/csv','text/comma-separated-values','text/tab-separated-values','text/plain','.csv','.tsv')), 
          checkboxInput('header', 'Header', TRUE), 
          radioButtons('sep', 'Separator', c(Comma=',',Semicolon=';',Tab='\t'), selected=';'), 
          radioButtons('quote', 'Quote', c(None='','Double Quote'='"','Single Quote'="'"), selected='"'), 
          uiOutput('apply')), 
       mainPanel(width = 10, uiOutput('years'), dataTableOutput("tabel4") 
       ) 
) 

server = function(input, output, session) { 
    ### if a csv is selected (through fileInput()), it is read 
    vis0 <- eventReactive(input$files, { 
    vis <- read.csv(input$files$datapath, header = input$header, sep = input$sep, quote = input$quote, 
          stringsAsFactors =FALSE) 
    vis$Dte <- as.Date(as.character(vis$Dte), "%d/%m/%Y") 
    vis$year <- factor(year(vis$Dte)) 
    vis 
    }) 
    ### button appearing only after 
    output$apply <- renderUI({ 
    if (is.null(input$files)) return() 
    actionButton("Load", "APPLY DATA") 
    }) 
    ### get checkbox values from data and throw them back to UI 
    output$years <- renderUI({ 
    df <- vis0() 
    df$year <- as.character(df$year) 
    if (is.null(df)) return(NULL) 
    items= sort(unique(df$year)) 
    names(items)=items 
    checkboxGroupInput("dependent","Check or uncheck years to be included or excluded", 
         choices=items, selected = items, inline = TRUE) 
    }) 
    ### use selected checkbox values to reduce initial dataset 
    vis1 <- reactive({ 
    if (is.null(input$Load)) return() 
    if (input$Load==0) return() 
    data <- vis0() 
    data <- subset(data, as.character(year) %in% input$years) 
    data 
    }) 
    ### using the checkbox-reduced data to create a table 
    output$tabel4 <- renderDataTable({ 
    vis1() 
    }) 
    } 

shinyApp(ui = ui, server = server, options = list(launch.browser=TRUE)) 

Answer 1

我找到了解决方案！

一个愚蠢的错误（至少）是dependent必须是years。也许有更多（特别是在if检查），我修正了，但没有正确跟踪，但下面的代码工作。

library(shiny) 
library(lubridate) 

ui = fluidPage(sidebarPanel(width = 2, 
          fileInput('files', '', accept = c('text/csv','text/comma-separated-values','text/tab-separated-values','text/plain','.csv','.tsv')), 
          checkboxInput('header', 'Header', TRUE), 
          radioButtons('sep', 'Separator', c(Comma=',',Semicolon=';',Tab='\t'), selected=';'), 
          radioButtons('quote', 'Quote', c(None='','Double Quote'='"','Single Quote'="'"), selected='"'), 
          uiOutput('apply')), 
       mainPanel(width = 10, uiOutput('years'),tags$br(),tags$br(), 
         textOutput('showyrs'),tags$br(),tags$br(), 
         textOutput('yrz'),tags$br(),tags$br(), 
         dataTableOutput("tabel4") 
       ) 
) 


###################################################################### 

server = function(input, output, session) { 
    ### if a csv is selected (through fileInput()), it is read 
    vis0 <- reactive({ 
    req(input$files) 
    vis <- read.csv(input$files$datapath, header = input$header, sep = input$sep, quote = input$quote, 
          stringsAsFactors =FALSE) 
    vis$Dte <- as.Date(as.character(vis$Dte), "%d/%m/%Y") 
    vis$year <- factor(year(vis$Dte)) 
    vis 
    }) 

    ### button appearing only after 
    output$apply <- renderUI({ 
    if (is.null(input$files)) return() 
    actionButton("Load", "APPLY DATA") 
    }) 

    ### get checkbox values from data and throw them back to UI 
    output$years <- renderUI({ 
    req(vis0) 
    df <- vis0() 
    df$year <- as.character(df$year) 
    if (is.null(df)) return(NULL) 
    items= sort(unique(df$year)) 
    names(items)=items 
    checkboxGroupInput("years","Check or uncheck years to be included or excluded", 
         choices=items, selected = items, inline = TRUE) 
    }) 

    ### show input$years 
    output$showyrs <- renderText({ 
    req(input$files) 
    if (is.null(input$years)) { 
     "Nothing..." 
    } else if (input$years==0) { 
     "Nothing..." 
    } else {input$years} 
    }) 

    ### use selected checkbox values to reduce initial dataset 
    vis1 <- reactive({ 
    req(input$years) 
    if (is.null(input$Load)) return() 
    if (input$Load==0) return() 
    data <- vis0() 
    data <- subset(data, as.character(year) %in% input$years) 
    data 
    }) 

    ### using the checkbox-reduced data to create a table 
    output$tabel4 <- renderDataTable({ 
    vis1() 
    }) 
    } 

shinyApp(ui = ui, server = server, options = list(launch.browser=TRUE))