kable 无法在 pdf_book (bookdown) 中输出 unicode 字符

Question

我正在尝试在 bookdown 项目中 kable 呈现的表格中使用复选标记 unicode 字符 (\u2713)。一个 MWE 由以下 2 个文件（index.Rmd、preamble.tex）组成，是生成的最小 bookdown 项目的一部分。

index.Rmd

    --- 
    title: "A Minimal Book Example"
    subtitle: "subtitle"
    lang: fr
    author: "Yihui Xie"
    date: "`r Sys.Date()`"
    site: bookdown::bookdown_site
    documentclass: book
    mainfont: Arial
    mathfont: Arial
    bibliography: [book.bib, packages.bib]
    biblio-style: apalike
    link-citations: yes
    subparagraph: yes
    description: "This is a minimal example of using the bookdown package to write a book. The output format for this example is bookdown::gitbook."
    ---
    
    ```{r setup, include=FALSE}
    # Set locale to french for month and day names (calendar plots)
    Sys.setlocale(locale = 'French')
    
    # Load all needed libraries
    if(!require('pacman'))install.packages('pacman')
    pacman::p_load(kableExtra)
    ```
    
    (ref:O3) O~3~
    
    # Prerequisites
    
    ✓
    
    ```{r stations-polluants, echo=FALSE}
    stations_polluants_table <- data.frame(
      stations = c("41B001", "41B004", "41B011", "41MEU1", "41N043", "41R001", "41R002", "41R012", "41WOL1", "Total / polluant"),
      O3   = c("", rep("✓", 5), "", rep("\u2713", 2), "7")
    )
    kable(stations_polluants_table, col.names = c("Station", "(ref:O3)"), booktabs = T, align = "c", caption = "Caption text") %>%
      row_spec(0, bold = T) %>%
      row_spec(10, bold = T) %>%
      collapse_rows(columns = 1, latex_hline = "major", valign = "top")
    ```
    
    
    ```{r include=FALSE}
    # automatically create a bib database for R packages
    knitr::write_bib(c(
      .packages(), 'bookdown', 'knitr', 'rmarkdown'
    ), 'packages.bib')
    ```

preamble.tex

\usepackage{booktabs}

\newfontfamily{\unicodefont}{Arial Unicode MS}
\usepackage{newunicodechar}
\newunicodechar{✓}{{\unicodefont{✓}}}

通过使用rmarkdown::render_site(output_format = 'bookdown::pdf_book', encoding = 'UTF-8') 编译PDF，可以注意到✓ 在文本中正确呈现，而在生成的表格中它被替换为。我还尝试在表格中使用\u2713，但没有取得更多成功。

我做错了什么？请注意，即使首选输出是 PDF，我也想编译为 gitbook（因此 Rmd 文件需要保持独立于输出格式）。

非常感谢。

Answer 1

在明确了片刻之后，解决方案只是在 bookdown 中使用文本引用，即(ref:check) ✓ 并使用表格中的引用。

index.Rmd

    ```{r setup, include=FALSE}
    # Set locale to french for month and day names (calendar plots)
    Sys.setlocale(locale = 'French')
    
    # Load all needed libraries
    if(!require('pacman'))install.packages('pacman')
    pacman::p_load(kableExtra)
    ```
    
    (ref:O3) O~3~
    
    # Prerequisites
    
    ✓

    (ref:check) ✓
    
    ```{r stations-polluants, echo=FALSE}
    stations_polluants_table <- data.frame(
      stations = c("41B001", "41B004", "41B011", "41MEU1", "41N043", "41R001", "41R002", "41R012", "41WOL1", "Total / polluant"),
      O3   = c("", rep("(ref:check)", 5), "", rep("(ref:check)", 2), "7")
    )
    kable(stations_polluants_table, col.names = c("Station", "(ref:O3)"), booktabs = T, align = "c", caption = "Caption text") %>%
      row_spec(0, bold = T) %>%
      row_spec(10, bold = T) %>%
      collapse_rows(columns = 1, latex_hline = "major", valign = "top")
    ```
    
    
    ```{r include=FALSE}
    # automatically create a bib database for R packages
    knitr::write_bib(c(
      .packages(), 'bookdown', 'knitr', 'rmarkdown'
    ), 'packages.bib')
    ```