块选项class.output无法处理错误消息

I am preparing a tutorial for a course and I want to change the colour of the error to be red. I am using BookDown and gitbook as my output format. But I found that the option class.output is not working. I want to add a class to the output for the error message I get. How can I do that? You can use this as an example:

我正在准备课程的教程,我想将错误的颜色更改为红色。我使用BookDown和gitbook作为输出格式。但是我发现选项class.output不起作用。我想在输出中为我得到的错误消息添加一个类。我怎样才能做到这一点?您可以将此作为示例:

---
title: "Test Book"
author: "therimalaya"
site: bookdown::bookdown_site
output: bookdown::gitbook
---

# Hello World

```{r, error = TRUE, class.output="red"}
rnorm(-10)
```

This works if there is no error.

如果没有错误,这可以工作。

1 个解决方案

#1

class.output is not applied to errors (see here).
Following this answer, I suggest you to use an error hook:

class.output不适用于错误(请参阅此处)。根据这个答案,我建议你使用错误钩子:

```{r error-hook, echo=FALSE}
knitr::knit_hooks$set(error = function(x, options) {
  paste0(
    "```{", 
    ifelse(is.null(options$class.error), 
           "", 
           paste0(" .", gsub(" ", " .", options$class.error))
    ),
    "}\n",
    x,
    "\n```"
  )
})
```

Now, you can use a "new" class.error option in your chunk.

现在,您可以在块中使用“new”class.error选项。

```{r, error = TRUE, class.error="red"}
rnorm(-10)
```

Feel free to open a feature request here.

欢迎在这里打开功能请求。

#1