Launching editors

[jayqi]

Click has the functionality for opening an editor. It would be nice to have that available in Cyclopts as well.

[BrianPugh]

I'm not 100% opposed to the idea, but I like to typically think that it's outside the scope of Cyclopts. For example, for most interactive CLI prompts, I would recommend using questionary. However, this isn't 100% in the scope of questionary either.

With all that said, I took a brief look at Click's edit function, and I'm not sure why it's so complicated. I think below is a "good enough" implementation, but let me know what you think! I also have not really ever implemented this in my own CLIs before, so let me know if there are tweaks that can make it a bit more ergonomic.

import tempfile
import subprocess
import os
from pathlib import Path


class DidNotSaveError(Exception):
    """User did not save upon exiting."""


def edit(initial_text="", default_editor="vim", save=True):

    """Get text input from a user via their default editor."""
    editor = os.environ.get("EDITOR", default_editor)

    with tempfile.NamedTemporaryFile(suffix=".txt", mode="w", delete=False) as tf:
        path = Path(tf.name)
        tf.write(initial_text)

    start_mtime = path.stat().st_mtime

    try:
        subprocess.call([editor, path])
        end_mtime = path.stat().st_mtime
        if save and end_mtime <= start_mtime:
            raise DidNotSaveError
        edited_text = path.read_text()
    finally:
        path.unlink()
    return edited_text


result = edit()
print(f"{result=}")

[BrianPugh]

This is probably generically useful enough, and not exactly available from a focused package. Implementing it had enough "sharp corners" that it's non-trivial enough to include in Cyclopts. Added in v3.3.0