This function is called by knitr when a code chunk's engine is set
to drawio.
This engine uses the draw.io software to export diagrams to images,
and outputs the image into the RMarkdown document.
Arguments
- options
The chunk options. Please refer to the official knitr documentation for more details on these. Several important options for this package are also described in the documentation of
parse.options
Details
This function should normally not be used directly by the user, but rather called by knitr to process chunks.
It is recommended to set the label chunk option with a meaningful
value, as it is used to name the resulting image in the file system.
For a list of accepted options to control the export process, please see
parse.options.
Two additional options are used in this function:
- eval
If set to
FALSE, the engine will not execute the code chunk. The diagram will neither be exported nor rendered in the document. (Default:TRUE)- include
If set to
FALSE, the engine will execute the code chunk (the diagram will therefore be exported), but the result will not be rendered in the document. This is useful if you want to automatically export a diagram but manually use it. (Default:TRUE)
Examples
In a RMarkdown document, type out the following chunks.
Simple chunk with a label ("my-diag1"), and a source file ("diag1.drawio"):
```{drawio my-diag1, src="diag1.drawio"}
```
Setting the output format:
```{drawio my-diag2, src="diag2.drawio", format="pdf"}
```
A few more options, not cropping the result (i.e., the image has the same size as the diagram), using a transparent background, and only exporting the 4th page of the diagram:
```{drawio my-diag3, src="diag3.drawio", format="pdf", crop=FALSE, transparent=TRUE, page.index=4}
```
Setting the options manually with engine.opts:
```{drawio my-diag4, src="diag4.drawio", engine.opts="--embed-diagram --transparent", format="pdf"}
```