R:将多个图像添加到数据框/数据表中？

Question

我正在尝试将多个图像添加到 R 中的数据帧中，以在 R Shiny 中以 DT::dataTableOutput 的形式重现。

所需的输出如下所示:

<表类=“s-表”> <标题> 图标 食物 <正文> 葡萄 骨髓

我发现这个问题Adding an image to a datatable in R这允许我添加本地的图像，但前提是我输入路径，如下所示:

df <- read.csv("data.csv")

path = "/Users/name/Documents/remaining_path/"

df%<>%
  mutate(Icon = img_uri("/Users/name/Documents/remaining_path/grapes.png"))

但是我有数百张图像要添加，因此我希望获得稍微自动化一些的东西，如下所示:

df%<>%
  mutate(Image = paste(path, Food, ".png", sep = ""))%>%
  mutate(Icon = img_uri(Image))

这给了我这个错误

Error in `mutate()`:
! Problem while computing `Icon = img_uri(Image)`.
Caused by error in `file()`:
! invalid 'description' argument

我还尝试使用 for 循环创建一个向量:

for (i in df$Image) {
  
  Icon <- img_uri(i)
  
}

抛出此错误

Error in file(con, "rb") : cannot open the connection

9. file(con, "rb")
8. readBin(file, what, n, ...)
7. read_bin(x)
6. base64_encode(x)
5. paste0("data:", mime::guess_type(x), ";base64,", base64_encode(x))
4. xfun::base64_uri(f)
3. knitr::image_uri(x)
2. sprintf("<img src=\"%s\"/>", knitr::image_uri(x))
1. img_uri(i)

并应用:

Icon <- apply(X = df$Image, MARGIN = 1, FUN = img_uri())

这给出了这个错误

Error in knitr::image_uri(x) : argument "x" is missing, with no default

9. basename(file)
8. mime::guess_type(x)
7. paste0("data:", mime::guess_type(x), ";base64,", base64_encode(x))
6. xfun::base64_uri(f)
5. knitr::image_uri(x)
4. sprintf("<img src=\"%s\"/>", knitr::image_uri(x))
3. img_uri()
2. match.fun(FUN)
1. apply(X = df$Image, MARGIN = 1, FUN = img_uri())

非常感谢对此的任何意见。

Answer 1

我会这样做:

library(DT)
library(base64enc)

imgs <- c("img1.png", "img2.png")
b64imgs <- vapply(imgs, function(img){
  dataURI(mime = "image/png", file = img)
}, character(1L))
b64array <- paste0(
  c("[", sprintf("%s", toString(paste0("'", b64imgs, "'"))), "]"), 
  collapse = ""
)

render <- c(
  "function(data, type, row){",
  "  if(type === 'display'){",
  sprintf("var img = %s[data-1];", b64array),
  "    data = '<img src=\"' + img + '\"  width=100>';",
  "  }",
  "  return data;",
  "}"
)

dat <- data.frame(
  image = c(1, 2), 
  file = imgs
)

datatable(
  dat, 
  width = 500,
  options = list(
    columnDefs = list(
      list(targets = 1, render = JS(render)),
      list(targets = "_all", className = "dt-center")
    )
  )
)