闪亮:仅在上传文件后显示按钮

Question

我正在尝试Shiny而我喜欢它.我构建了一个小应用程序,学生上传一个csv文件,然后选择一个因变量和自变量,然后R计算一个线性回归.它工作正常.我把它上传到:

http://carlosq.shinyapps.io/Regresion

[如果需要,可以使用此文件进行测试."beer"是因变量,除"id"之外的其余变量是独立的]

这是server.R:

# server.R
library(shiny)

shinyServer(function(input, output) {

  filedata <- reactive({
    infile <- input$file1
    if (is.null(infile)){
      return(NULL)      
    }
    read.csv(infile$datapath)
  })

  output$dependent <- renderUI({
    df <- filedata()
    if (is.null(df)) return(NULL)
    items=names(df)
    names(items)=items
    selectInput("dependent","Select ONE variable as dependent variable from:",items)
  })


  output$independents <- renderUI({
    df <- filedata()
    if (is.null(df)) return(NULL)
    items=names(df)
    names(items)=items
    selectInput("independents","Select ONE or MANY independent variables from:",items,multiple=TRUE)
  })


  output$contents <- renderPrint({
    input$action
    isolate({   
      df <- filedata()
      if (is.null(df)) return(NULL)
      fmla <- as.formula(paste(input$dependent," ~ ",paste(input$independents,collapse="+")))
      summary(lm(fmla,data=df))
    })   
  })

}) 

这是ui.R:

# ui.R
library(shiny)

shinyUI(fluidPage(
  titlePanel("Multiple Linear Regression"),
  sidebarLayout(
    sidebarPanel(
      fileInput('file1', 'Choose CSV File',
                accept=c('text/csv', 
                         'text/comma-separated-values,text/plain', 
                         '.csv')),

      tags$hr(),
      uiOutput("dependent"),
      uiOutput("independents"),
      tags$hr(),
      actionButton("action", "Press after reading file and selecting variables")

    ),
    mainPanel(
      verbatimTextOutput('contents')
    )
  )
))

我的问题是:我希望在成功上传的条件下出现按钮"按下阅读文件并选择变量".

我试图使用此处包含的建议:

使conditionalPanel依赖于使用fileInput上传的文件

但我无法让它发挥作用.

我提供任何帮助.

Answer 1

这段代码对我有用

ui.R

 # ui.R
library(shiny)

shinyUI(fluidPage(
  titlePanel("Multiple Linear Regression"),
  sidebarLayout(
    sidebarPanel(
      fileInput('file1', 'Choose CSV File',
                accept=c('text/csv', 
                         'text/comma-separated-values,text/plain', 
                         '.csv')),

      tags$hr(),
      uiOutput("dependent"),
      uiOutput("independents"),
      tags$hr(),
      uiOutput('ui.action') # instead of conditionalPanel
    ),
    mainPanel(
      verbatimTextOutput('contents')
    )
  )
))

server.R

# server.R
library(shiny)

shinyServer(function(input, output) {

  filedata <- reactive({
    infile <- input$file1
    if (is.null(infile)){
      return(NULL)      
    }
    read.csv(infile$datapath)
  })

  output$dependent <- renderUI({
    df <- filedata()
    if (is.null(df)) return(NULL)
    items=names(df)
    names(items)=items
    selectInput("dependent","Select ONE variable as dependent variable from:",items)
  })


  output$independents <- renderUI({
    df <- filedata()
    if (is.null(df)) return(NULL)
    items=names(df)
    names(items)=items
    selectInput("independents","Select ONE or MANY independent variables from:",items,multiple=TRUE)
  })


  output$contents <- renderPrint({
    input$action
    isolate({   
      df <- filedata()
      if (is.null(df)) return(NULL)
      fmla <- as.formula(paste(input$dependent," ~ ",paste(input$independents,collapse="+")))
      summary(lm(fmla,data=df))
    })   
  })


  output$ui.action <- renderUI({
    if (is.null(input$file1)) return()
    actionButton("action", "Press after reading file and selecting variables")
  })

}) 

Answer 2

这是基于Marat提供的所有建议的工作ShinyApp以及ui.R和server.R的最终版本.

首先是ui.R

# ui.R

library(shiny)

shinyUI(fluidPage(
  titlePanel("Multiple Linear Regression with R/Shiny"),
  sidebarLayout(
    sidebarPanel(
      p("Please upload a CSV formatted file with your data."),
      fileInput('file1', label='Click button below to select the file in your computer.',
                accept=c('text/csv', 
                         'text/comma-separated-values,text/plain', 
                         '.csv')),

      tags$hr(),
      uiOutput("dependent"),
      uiOutput("independents"),
      tags$hr(),
      uiOutput('ui.action') # instead of conditionalPanel
    ),
    mainPanel(
      p("Here's the output from your regression:"),
      verbatimTextOutput('contents')
    )
  )
))

和server.R

# server.R

library(shiny)

shinyServer(function(input, output) {

  filedata <- reactive({
    infile <- input$file1
    if (is.null(infile)){
      return(NULL)      
    }
    read.csv(infile$datapath)
  })

  output$ui.action <- renderUI({
    if (is.null(filedata())) return()
    actionButton("action", "Run regression")
  })

  output$dependent <- renderUI({
    df <- filedata()
    if (is.null(df)) return(NULL)
    items=names(df)
    names(items)=items
    selectInput("dependent","Now select ONE variable as dependent variable from:",items)
  })


  output$independents <- renderUI({
    df <- filedata()
    if (is.null(df)) return(NULL)
    items=names(df)
    names(items)=items
    selectInput("independents","Also select ONE or MANY independent variables in the box below. You can change your selection several times:",items,multiple=TRUE)
  })


  output$contents <- renderPrint({
    if (is.null(input$action)) return()
    if (input$action==0) return()
    isolate({
      df <- filedata()
      if (is.null(df)) return(NULL)
      fmla <- as.formula(paste(input$dependent," ~ ",paste(input$independents,collapse="+")))
      summary(lm(fmla,data=df))
    })
  })


}) 

再次感谢你的帮助Marat.