r语言 - 如何在Shiny上通过下载处理程序下载工作簿?

Question

我们如何将工作簿保存在某个文件夹中并使其可供用户下载？

裁判： Shiny + downloadHandler + Openxlsx 不生成 xlsx 文件

程序：

• 创建数据
• 另存为工作簿
• 使其可供下载 将其读取为.xlsx文件

即使工作簿已写入文件夹， 下载该工作簿时出错。

library(shiny)
library(openxlsx)
library(writexl)
library(tidyverse)
ui <- fluidPage(
downloadButton("dl", "Download")
)
server <- function(input, output) {
data1 = mtcars[,c(1,2)] %>% head() # data for Col 1 ,until Row 6
data2 = gapminder::gapminder[,c(1,4)] %>% head() # data for Col 1 , Row from 8 until Row 13
data3 = mtcars[,c(1,2)] %>% tail() # data for Col 1 , Row from 15 until Row 20

# Creating a workbook for user to download
wb <- createWorkbook()
addWorksheet(wb, sheetName = "sheet1")
writeData(wb, sheet = 1, x = data1, startCol = 1, startRow = 1)
writeData(wb, sheet = 1, x = data2, startCol = 1, startRow = 8)
writeData(wb, sheet = 1, x = data3, startCol = 1, startRow = 15)
ex_wb <- paste0("example", ".xlsx")
saveWorkbook(wb, file = ex_wb, overwrite = TRUE)

output$dl <- downloadHandler(
filename = function(){ex_wb # filename
},
content = function(file) {
# Content to be available for user to download 
read.xlsx(ex_wb) # Making dataframe available for user to download
})
}
shinyApp(ui, server)

Answer 1

试试这个：

library(shiny)
library(openxlsx)
library(writexl)
library(tidyverse)
ui <- fluidPage(
downloadButton("dl", "Download")
)
server <- function(input, output) {
data1 <- mtcars[, c(1, 2)] %>% head() # data for Col 1 ,until Row 6
data2 <- gapminder::gapminder[, c(1, 4)] %>% head() # data for Col 1 , Row from 8 until Row 13
data3 <- mtcars[, c(1, 2)] %>% tail() # data for Col 1 , Row from 15 until Row 20
# Creating a workbook for user to download
wb <- createWorkbook()
addWorksheet(wb, sheetName = "sheet1")
writeData(wb, sheet = 1, x = data1, startCol = 1, startRow = 1)
writeData(wb, sheet = 1, x = data2, startCol = 1, startRow = 8)
writeData(wb, sheet = 1, x = data3, startCol = 1, startRow = 15)

output$dl <- downloadHandler(
filename = function() {
paste0("example", ".xlsx")
},
content = function(file) {
saveWorkbook(wb, file = file, overwrite = TRUE)
}
)
}
shinyApp(ui, server)