textual app devtools
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I am working through the textual tutorial, and I want to put it in a proper cli that I can pip install and run the command without . This is a fine pattern,...

Date: October 24, 2022

I am working through the textual tutorial, and I want to put it in a proper cli that I can pip install and run the command without textual run --dev app.py. This is a fine pattern, but I also want this to work when I don’t have a file to run.

Image: “An astronaut working in a lab, hacking on a computer terminal, htop is running, shallow depth of field beakers, test tubes, volumetric lighting, pink lighting, by victo ngai, killian eng vibrant colours, dynamic lighting, digital art” -s50 -W768 -H448 -C7.5 -Ak_lms -S3617210203 <https://stable-diffusion.waylonwalker.com/000221.3617210203.webp>

pyproject.toml entrypoints
──────────────────────────

I set up a new project running hatch new, and added the following entrypoint, giving me a tutorial cli command to run.

[code]
  ...

  [project.scripts]
  tutorial = 'textual_tutorial.tui:tui'

https://waylonwalker.com/hatch-new-cli/

setup.py entrypoints
────────────────────

If you are using setup.py, you can set up entrypoints in the setup command.

[code]
  from setuptools import setup
  
  setup(
      ...
      entry_points={
          "console_scripts": ["tutorial = textual_tutorial.tui:tui"],
      },
      ...
  )

https://waylonwalker.com/minimal-python-package/

tui.py
──────

adding features

Now to get devtools through a cli without running through textual run --dev. I pulled open the textual cli source code, and this is what it does at the time of writing.

│ Note: I used sys.argv as a way to implement a --dev quickly tutorial. For a real project, I’d setup argparse, click, or typer. typer is my go to these days, unless I am really trying to limit dependencies, then the standard library argparse might be what I go with.

[code]
  def tui():
  
      from textual.features import parse_features
      import os
      import sys
  
      dev = "--dev" in sys.argv # this works, but putting it behind argparse, click, or typer would be much better
  
      features = set(parse_features(os.environ.get("TEXTUAL", "")))
      if dev:
          features.add("debug")
          features.add("devtools")
  
      os.environ["TEXTUAL"] = ",".join(sorted(features))
      app = StopwatchApp()
      app.run()
  
  
  if __name__ == "__main__":
      tui()

Other Flags???
──────────────

If you look at the source, there is one other flag for headless mode.

[code]
  FEATURES: Final = {"devtools", "debug", "headless"}

Run it
──────

Here it is running with tutorial --dev on the left, and textual console on the right.

Image: textual-tutorial-devtools.webp <https://dropper.waylonwalker.com/api/file/01c4b236-fc55-4760-814a-d61d141ef1db.webp>