将代码放在输入文件上的位置（Shiny，R）

Question

I have difficulties putting some code into a separate file.

The following code works:

ui.R

library(shiny)

shinyUI(fluidPage(
    titlePanel("Uploading Files"),

    sidebarLayout(

        sidebarPanel(

            fileInput('file1', 'Choose CSV File',
                      accept=c('text/csv', 
                               'text/comma-separated-values,text/plain', 
                               '.csv')),

            tags$hr()

        ),
        mainPanel(
            tableOutput('contents')
        )
    )
))

server.R

library(shiny)
library(dplyr)

shinyServer(function(input, output) {

    getData <- reactive({
        inFile <- input$file1
        if (is.null(inFile)) return(NULL)
        data = read.csv(inFile$datapath)
        ### CleanData
        data = data %>%
            mutate_each(funs(toupper)) %>%    
            mutate_each(funs(gsub("[[:punct:]]", " ", .))) %>%
            mutate_each(funs(str_trim)) %>%
            mutate_each(funs(rm_white)) %>%
            sample_frac(1) 

    })

    output$contents = renderTable({
        getData()

    })

})

---

But if I put some code into a separate file, it doesn't work.

ui.R doesn't change

server.R

library(shiny)
library(dplyr)

shinyServer(function(input, output) {

    getData <- reactive({
        inFile <- input$file1
        if (is.null(inFile)) return(NULL)
        data = read.csv(inFile$datapath)
        ### CleanData
        source('CleanData.R')

    })

    output$contents = renderTable({
        getData()

    })

})

CleanData.R (in the same directory in laptop)

data = data %>%
    mutate_each(funs(toupper)) %>%    
    mutate_each(funs(gsub("[[:punct:]]", " ", .))) %>%
    mutate_each(funs(str_trim)) %>%
    mutate_each(funs(rm_white)) %>%
    sample_frac(1) 

It doesn't work, giving an error

Error in UseMethod("tbl_vars") : 
  no applicable method for 'tbl_vars' applied to an object of class "function"

Somebody know how to fix this? Thanks a lot

Answer 1

You are getting that error because when you source the CleanData.R, it is evaluated in the global environment where data hasn't been defined by you, so it is referring to the function data . You can add local=TRUE to the source call to have it evaluated in the calling environment,

    source('CleanData.R', local=TRUE)