[Feature]: Create `shiny.app_dir()`

Category

Other

Scope

Quality of Life

Problem

Knowing where a Shiny application is running is quite difficult.

Some situations, we know where the app.py file is. Others, we do not.

It would be nice to have access to the "application directory" for things like bookmarking or finding files relatively.

Solution

I'd like for shiny.app_dir() to a function that returns a directory.

This directory is defined as the first value of:

• The value of SHINY_APP_DIR sys environ
• The parent directory of the input file being processed
• The current working directory.

Todo:

• App.app_dir should be initialized to the value of app_dir().
• Add the "show notification and update clipboard" method to session.bookmark

Alternatives (Optional)

• Just use the current working directory.

This fails for multiple app applications.

Example (Optional)

Impact (Optional)

No response

Contribution? (Optional)

None

Start by locating the existing app.App and session.bookmark entry points, then trace how the application input file and current working directory are handled. Define the precedence for SHINY_APP_DIR, the input file's parent, and the working directory, initialize App.app_dir from it, and address the listed session.bookmark notification and clipboard work.