Given an R Markdown document or HTML file, attempt to determine the set of additional files needed in order to render and display the document.
find_external_resources(input_file, encoding = "UTF-8")
path to the R Markdown document or HTML file to process
the encoding of the document
A data frame with the following columns:
The relative path from the document to the resource
Whether the resource was specified explicitly
(TRUE
) or discovered implicitly (FALSE
)
Whether the resource is needed to display a Web page rendered from the document
This routine applies heuristics in order to scan a document for possible resource references.
In R Markdown documents, it looks for references to files implicitly
referenced in Markdown (e.g. ![alt](img.png)
), in the document's
YAML header, in raw HTML chunks, and as quoted strings in R code chunks
(e.g. read.csv("data.csv")
).
Resources specified explicitly in the YAML header for R Markdown
documents are also returned. To specify resources in YAML, use the
resource_files
key:
--- title: My Document author: My Name resource_files: - data/mydata.csv - images/figure.png ---
Each item in the resource_files
list can refer to:
A single file, such as images/figure.png
, or
A directory, such as resources/data
, in which case all of the
directory's content will be recursively included, or
A wildcard pattern, such as data/*.csv
, in which case all of
the files matching the pattern will be included. No recursion is done in
this case.
In HTML files (and raw HTML chunks in R Markdown documents), this routine
searches for resources specified in common tag attributes, such as
<img src="...">
, <link href="...">
, etc.
In all cases, only resources that exist on disk and are contained in the document's directory (or a child thereof) are returned.