Get path relative to project root (Quarto-aware)

This function constructs file paths relative to the project root when running in a Quarto context (using QUARTO_PROJECT_ROOT or QUARTO_PROJECT_DIR environment variables), or falls back to intelligent project root detection when not in a Quarto context.

It is experimental and subject to change in future releases. The automatic project root detection may not work reliably in all contexts, especially when projects have complex directory structures or when running in non-standard environments. For a more explicit and potentially more robust approach, consider using here::i_am() to declare your project structure, followed by here::here() for path construction. See examples for comparison.

Usage

project_path(..., root = NULL)

Arguments

...

Character vectors of path components to be joined

root

Project root directory. If NULL (default), automatic detection is used following the hierarchy described above

Value

A character vector of the normalized file path relative to the project root.

Details

The function uses the following fallback hierarchy to determine the project root:

• Quarto environment variables set during Quarto commands (e.g., quarto render):

  • QUARTO_PROJECT_ROOT environment variable (set by Quarto commands)

  • QUARTO_PROJECT_DIR environment variable (alternative Quarto variable)

• Fallback to intelligent project root detection using xfun::proj_root() for interactive sessions:

  • _quarto.yml or _quarto.yaml (Quarto project files)

  • DESCRIPTION file with Package: field (R package or Project)

  • .Rproj files with Version: field (RStudio projects)

Last fallback is the current working directory if no project root can be determined. A warning is issued to alert users that behavior may differ between interactive use and Quarto rendering, as in this case the computed path may be wrong.

Use in Quarto document cells

This function is particularly useful in Quarto document cells where you want to use a path relative to the project root dynamically during rendering.

```{r}`r ''`
 # Get a csv path from data directory in the Quarto project root
 data <- project_path("data", "my_data.csv")
```

See also

• here::here() and here::i_am() for a similar function that works with R projects

• find_project_root() to search for Quarto Project configuration in parents directories

• get_running_project_root() for detecting the project root in Quarto commands

• xfun::from_root() for the underlying path construction

• xfun::proj_root() for project root detection logic

Examples

if (FALSE) { # \dontrun{
# Create a dummy Quarto project structure for example
tmpdir <- tempfile("quarto_project")
dir.create(tmpdir)
quarto::quarto_create_project(
  'test project', type = 'blog',
  dir = tmpdir, no_prompt = TRUE, quiet = TRUE
)
project_dir <- file.path(tmpdir, "test project")

# Simulate working within a blog post
xfun::in_dir(
  dir = file.path(project_dir, "posts", "welcome"), {

  # Reference a data file from project root
  # ../../data/my_data.csv
  quarto::project_path("data", "my_data.csv")

  # Reference a script from project root
  # ../../R/analysis.R
  quarto::project_path("R", "analysis.R")

  # Explicitly specify root (overrides automatic detection)
  # ../../data/file.csv
  quarto::project_path("data", "file.csv", root = "../..")

  # Alternative approach using here::i_am() (potentially more robust)
  # This approach requires you to declare where you are in the project:
  if (requireNamespace("here", quietly = TRUE)) {
    # Declare that this document is in the project root or subdirectory
    here::i_am("posts/welcome/index.qmd")

    # Now here::here() will work reliably from the project root
    here::here("data", "my_data.csv")
    here::here("R", "analysis.R")
  }
})

} # }