在 Shiny 中显示多个 Excel 文件的头部

Question

我正在尝试在 Shiny 应用程序中上传两个 Excel 文件。上传后它应该显示

head

那些文件。我正在尝试以下块：

library(shiny)
library(readxl)

# UI component

ui <- fluidPage(
  
  titlePanel("Upload Excel file"),
  
  sidebarLayout(sidebarPanel(
    
    fileInput('file1', 'Choose first file',
              accept = c(".xlsx"),
              buttonLabel = "Upload",
              multiple = TRUE),
    
    fileInput('file2', 'Choose second file',
              accept = c(".xlsx"),
              buttonLabel = "Upload",
              multiple = TRUE)
    ),

    mainPanel(
      tableOutput('contents')
    )
    
    
  ))

# Server component 

server <- function(input, output, session){
  
  output$contents <- renderTable({
    
    req(input$file1)
    
    inFile <- input$file1
    
    read_excel(inFile$datapath, 1)
    
    req(input$file2)
    
    inFile <- input$file2
    
    read_excel(inFile$datapath, 1)
    }
  )
  }

# Run the application 
shinyApp(ui = ui, server = server)

可以看到，它只显示一个文件。

有什么办法可以看到两个文件的头部吗？

Answer 1

问题是您的

renderTable

仅返回或呈现第二个

read_excel

读取的第二个表。如果你想呈现多个表，你必须将它们绑定到一个或使用多个

renderTable

s，就像我在下面的代码中所做的那样，这可以很容易地推广到两个以上的表：

library(shiny)
library(readxl)

writexl::write_xlsx(mtcars, "mtcars.xlsx")
writexl::write_xlsx(iris, "iris.xlsx")

ui <- fluidPage(
  titlePanel("Upload Excel file"),
  sidebarLayout(
    sidebarPanel(
      fileInput("file1", "Choose first file",
        accept = c(".xlsx"),
        buttonLabel = "Upload",
        multiple = TRUE
      ),
      fileInput("file2", "Choose second file",
        accept = c(".xlsx"),
        buttonLabel = "Upload",
        multiple = TRUE
      )
    ),
    mainPanel(
      uiOutput("tables")
    )
  )
)

datasets <- list(mtcars, iris)

server <- function(input, output, session) {
  output$tables <- renderUI({
    table_output_list <- lapply(1:2, function(i) {
      table_name <- paste0("table", i)
      tableOutput(table_name)
    })

    do.call(tagList, table_output_list)
  })

  lapply(1:2, function(i) {
    table_name <- paste0("table", i)
    output[[table_name]] <- renderTable({
      req(input[[paste0("file", i)]])
      
      inFile <- input[[paste0("file", i)]]
      
      head(read_excel(inFile$datapath, 1))
    })
  })
}

shinyApp(ui = ui, server = server)