在 R Markdown 演示文稿中覆盖reveal.js

Question

我正在尝试在 rmarkdown 中整合一个显示 js 演示文稿，但在覆盖默认 css 主题时遇到了麻烦。我想从我的绘图图像中删除边框。根据文档，这应该可以工作：

但它没有，我猜这是因为这个覆盖不是更具体。但我的问题是我通常的增加特异性的方法也不起作用：

## Slide with Plot
<section class = "no-border">
```{r pressure}
plot(pressure)
```
</section>

这是 YAML 标头：

title: "Title"
author: "..."
date: '`r paste(format(Sys.Date(),"%d")," ", mymonths[sys.man], ", ",
                format(Sys.Date(),"%Y"), sep = "")`'
output:
  revealjs::revealjs_presentation:
    incremental: true
    includes:
      in_header: slidy_bootstrap_header.html
      css: slidyStandard.css

这是 css 覆盖：

section.no-border > img {
  background:none; 
  border:none; 
  box-shadow:none;
 }

有谁知道我做错了什么？

Answer 1

我意识到我将自定义 CSS 放在了 YAML 标头中的错误位置。因此，它没有工作。

以下是自定义 css 的可重现代码：

---
title: "Untitled"
output: 
  revealjs::revealjs_presentation:
    css: custom2.css
---

## R Markdown

This is an R Markdown presentation. Markdown is a simple formatting syntax for authoring HTML, PDF, and MS Word documents. For more details on using R Markdown see <http://rmarkdown.rstudio.com>.

When you click the **Knit** button a document will be generated that includes both content as well as the output of any embedded R code chunks within the document.

## Slide with Bullets

- Bullet 1
- Bullet 2
- Bullet 3

## Slide with R Code and Output

```{r}
summary(cars)
```

## Slide with Plot

```{r, echo=FALSE}
plot(cars)
```

还有css：

.reveal section img {
  margin: 15px 0px;
  background: rgba(255, 255, 255, 0.12);
  border: none;
  box-shadow: none; 
  }

Answer 2

问题似乎是，您的<section> 标记没有被包裹在源代码及其输出周围。你可以做的是使用 jQuery：

---
title: "Title"
author: "..."
output:
  revealjs::revealjs_presentation:
    incremental: true
    includes:
      css: slidyStandard.css
---

<!-- Include jQuery -->
<script src="https://ajax.googleapis.com/ajax/libs/jquery/3.1.1/jquery.min.js"></script>

<!-- Add class to img elements -->
<script type="text/javascript">
$(document).ready(function() {
  $elms = $('p > img');
  $elms.addClass('no-border');
});
</script>

<!-- define no-border class -->
<style>
.no-border {
  border: 0px !important;
}
</style>

```{r pressure}
plot(pressure)
```