如何在RMarkdown生成的HTML中仅嵌入用到的Font Awesome图标？

在RMarkdown中使用reactable()构建表格时，通过reactablefmtr的icon_sets()添加Font Awesome图标，仅用到4个核心图标，但生成的HTML文件却嵌入了完整的Font Awesome库，导致文件体积从约1MB暴涨至近5MB。如何配置才能只嵌入实际使用到的图标？

最小复现代码 #

---
title: "embedded_fa_icons"
output: html_document
---
  
```{r setup, include=FALSE}
library(reactable)
library(reactablefmtr)
library(palmerpenguins)
library(dplyr)

knitr::opts_chunk$set(echo = FALSE)

Penguin stats #

data <- sample_n(penguins, 50) %>% 
  filter(!is.na(bill_length_mm)) %>% 
  select(species, bill_length_mm, bill_depth_mm, flipper_length_mm, body_mass_g)

reactable(
  data,
  columns = list(
    bill_length_mm = colDef(cell = icon_sets(data, icons = c("ruler"))),
    bill_depth_mm = colDef(cell = icon_sets(data, icons = c("ruler-vertical"))),
    flipper_length_mm = colDef(cell = icon_sets(data, 
                                                icons = c("ruler-horizontal"))),
    body_mass_g = colDef(cell = icon_sets(data, 
                                          icons = c("balance-scale-left", 
                                                    "balance-scale", 
                                                    "balance-scale-right")))
  )
)

## 解决方案
### 方法一：禁用内置图标嵌入，改用CDN加载（最简便）
`reactablefmtr`的`icon_sets()`函数默认会将完整的Font Awesome库嵌入HTML（参数`embed_fontawesome = TRUE`），只需将该参数设为`FALSE`，并手动引入Font Awesome的CDN链接即可避免体积膨胀。

1. 在RMarkdown的YAML下方添加CDN引入：
```html
<link rel="stylesheet" href="https://cdnjs.cloudflare.com/ajax/libs/font-awesome/6.4.0/css/all.min.css">

2. 修改icon_sets()调用，添加embed_fontawesome = FALSE参数：

reactable(
  data,
  columns = list(
    bill_length_mm = colDef(cell = icon_sets(data, icons = c("ruler"), embed_fontawesome = FALSE)),
    bill_depth_mm = colDef(cell = icon_sets(data, icons = c("ruler-vertical"), embed_fontawesome = FALSE)),
    flipper_length_mm = colDef(cell = icon_sets(data, 
                                                icons = c("ruler-horizontal"), embed_fontawesome = FALSE)),
    body_mass_g = colDef(cell = icon_sets(data, 
                                          icons = c("balance-scale-left", 
                                                    "balance-scale", 
                                                    "balance-scale-right"), embed_fontawesome = FALSE))
  )
)

这种方式下，HTML不再打包完整图标库，而是通过CDN按需加载所需图标，文件体积会回到1MB左右，且CDN资源有缓存加持，加载速度更快。

方法二：手动嵌入所需图标SVG（无外部依赖） #

如果不想依赖CDN，可以直接将用到的图标SVG代码嵌入表格，完全避免加载多余资源：

1. 从Font Awesome官网下载所需图标的SVG代码（如ruler、ruler-vertical等）；
2. 在R代码中定义SVG字符串，传入icon_sets()并禁用内置嵌入：

# 示例：定义ruler图标的SVG
ruler_svg <- '<svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 512 512"><path d="M496 64c17.7 0 32 14.3 32 32v320c0 17.7-14.3 32-32 32H160c-17.7 0-32-14.3-32-32V96c0-17.7 14.3-32 32-32H496zM160 32C71.6 32 0 103.6 0 192V320c0 88.4 71.6 160 160 160H496c88.4 0 160-71.6 160-160V192c0-88.4-71.6-160-160-160H160zm32 128c0-8.8 7.2-16 16-16H464c8.8 0 16 7.2 16 16s-7.2 16-16 16H208c-8.8 0-16-7.2-16-16zm0 64c0-8.8 7.2-16 16-16H464c8.8 0 16 7.2 16 16s-7.2 16-16 16H208c-8.8 0-16-7.2-16-16zm0 64c0-8.8 7.2-16 16-16H464c8.8 0 16 7.2 16 16s-7.2 16-16 16H208c-8.8 0-16-7.2-16-16z"/></svg>'

reactable(
  data,
  columns = list(
    bill_length_mm = colDef(cell = icon_sets(data, icons = c(ruler_svg), embed_fontawesome = FALSE)),
    # 其他列同理替换为对应SVG
  )
)

方法三：使用fontawesome包按需导出图标 #

借助R的fontawesome包，可以精准导出所需图标，再传入icon_sets()：

1. 安装并加载包：

install.packages("fontawesome")
library(fontawesome)

2. 导出所需图标为SVG字符串：

ruler <- fa(name = "ruler", output = "svg")
ruler_vertical <- fa(name = "ruler-vertical", output = "svg")
ruler_horizontal <- fa(name = "ruler-horizontal", output = "svg")
balance_scale_left <- fa(name = "balance-scale-left", output = "svg")
balance_scale <- fa(name = "balance-scale", output = "svg")
balance_scale_right <- fa(name = "balance-scale-right", output = "svg")

3. 传入icon_sets()并禁用内置嵌入：

reactable(
  data,
  columns = list(
    bill_length_mm = colDef(cell = icon_sets(data, icons = c(ruler), embed_fontawesome = FALSE)),
    bill_depth_mm = colDef(cell = icon_sets(data, icons = c(ruler_vertical), embed_fontawesome = FALSE)),
    flipper_length_mm = colDef(cell = icon_sets(data, icons = c(ruler_horizontal), embed_fontawesome = FALSE)),
    body_mass_g = colDef(cell = icon_sets(data, icons = c(balance_scale_left, balance_scale, balance_scale_right), embed_fontawesome = FALSE))
  )
)

内容的提问来源于stack exchange，提问作者MarkusN