将图像添加到要使用 knitr 生成的 flextable 失败但在 RMarkdown 块中有效

Posted 2023-02-14

【中文标题】将图像添加到要使用 knitr 生成的 flextable 失败但在 RMarkdown 块中有效

【英文标题】：Adding image to flextable to be generated with knitr fails but works in RMarkdown chunk

【发布时间】：2021-12-30 15:27:37

【问题描述】：

运行 R4.1.2 和 Windows 10：

我正在尝试编织一个文档，该文档具有一个带有通过 ggsave 创建的 ggplot 图像的 flextable。当我在 RMarkdown 中运行代码块时，它可以正常工作，但是当我尝试编写 word 文档时，出现以下错误。如果我不包含图像，knitr 工作正常。

    Quitting from lines 350-376 (RPOPS_Draft_Test2.0.Rmd) 
    Error in read_xml.raw(charToRaw(enc2utf8(x)), "UTF-8", ..., as_html = as_html,  : 
      xmlParseEntityRef: no name [68]
    Calls: <Anonymous> ... as_xml_document -> as_xml_document.character -> read_xml.raw
    
    Execution halted

以下是 yaml 标头。我正在使用 officedown，因为我知道这个包需要在 Word 中呈现 flextables 中的图像。

    ---
    title: "something: `r params$program`"
    output:
      officedown::rdocx_document: 
        reference_docx: P:/Reference_doc
    params:
      program: "something"
    ---

这是导致问题的代码块。

    ```r overall1_flextable
    
    # chart creation
    plot_overall1 <- f_overall_cht(overall_chart1)
    plot_overall1_img_out <- ggsave(filename = "plotoverall1img.png", plot = plot_overall1, width = 3.05, height = 0.37, dpi = 600, device = "png")
    
    plot_overall1_in <- file.path(getwd(), "plotoverall1img.png")
    
    example_tibble <- tibble(
      col_name = "chart to the right",
      chart = ""
    )
    
    ft <- flextable(example_tibble)
    
    ft <- compose(ft, i=1, j=2,
                  value = as_paragraph(
                    as_image(src = plot_overall1_in, width = 3.05, height = 0.37),
                    as_chunk(chart)),
                  part = "body"
                  )
    
    autofit(ft)
    ```

我在这个问题上找不到太多信息，因此我们将不胜感激。

【参考方案1】：

我无法重现您的错误。在生成表格的代码下方。有两种解决方案，我推荐的解决方案（记录在此：https://ardata-fr.github.io/flextable-book/cell-content-1.html#base-plots-and-ggplot-objects）和更接近您所写的解决方案。

---
title: "test"
output: officedown::rdocx_document
---

```r setup, include=FALSE
library(officedown)
library(officer)
library(flextable)
library(ggplot2)
library(tibble)
# chart creation
plot_overall1 <- ggplot(iris, aes(Sepal.Length, Petal.Length)) +
  geom_point()+
  theme_void()
```

## Recommanded 


The solution below is corresponding to the recommanded way.

```r
example_tibble <- tibble(
  col_name = "chart to the right",
  chart = list(plot_overall1)
)

ft <- flextable(example_tibble)

ft <- compose(ft,
  j = "chart",
  value = as_paragraph(
    gg_chunk(value = chart, width = 3.05, height = 0.37, unit = "in")
  ),
  part = "body"
)

autofit(ft)
```


## From scratch 

The solution below is corresponding to the way you tried.

```r
png_file <- tempfile(fileext = ".png")

plot_overall1_img_out <- ggsave(
  filename = png_file, 
  plot = plot_overall1, 
  width = 3.05, height = 0.37, 
  dpi = 600, device = "png")

example_tibble <- tibble(
  col_name = "chart to the right"
)

ft <- flextable(example_tibble,
                col_keys = c("col_name", "chart"))

ft <- compose(ft,
  i = 1, j = "chart",
  value = as_paragraph(
    as_image(src = png_file, width = 3.05, height = 0.37, unit = "in")
  ),
  part = "body"
)

autofit(ft)
```

【讨论】：

这太棒了，大卫！非常感谢您的回复和您的工作！我会尝试推荐的方式。