Import as

[ewels]

Start playing with the import rich_click as click concept suggested by @willmcgugan in #8

[ewels]

Hmm, did a speed back-of-the-car attempt just now @willmcgugan (I'm away travelling this weekend 😅) but no dice. Any ideas?

[willmcgugan]

That looks like it should work. Were you getting any errors?

[ewels]

No errors, but just default click behaviour - no customisation.

I need to import click but I guess the custom rich-click imports aren't overwriting those classes for some reason? I guess I could sort of do monkey-patching in this file to make it work 🤔

[ewels]

eg. Running the minimal example, just get the default click output:

$ python examples/03_simple_importas.py
Usage: 03_simple_importas.py [OPTIONS] COMMAND [ARGS]...

  My amazing tool does all the things.

  This is a minimal example based on documentation from the 'click' package.

  You can try using --help at the top level and also for specific group
  subcommands.

Options:
  -d, --debug / -n, --no-debug  Enable debug mode
  --help                        Show this message and exit.

Commands:
  download  Pretend to download some files from somewhere
  sync      Synchronise all your files between two places

I've tried a few things by trial and error, but I can't get the rich-click objects to be used with this method. I think I need a Python wizard with more skills than I have.. 👀

[ewels]

Ok I can get it to work if do this in the __init__.py:

from click import *
from .rich_click import rich_format_help

Group.format_help = rich_format_help
Command.format_help = rich_format_help

Then the import rich_click as click works nicely. Definitely an improvement for the end-user (less typing, less to get wrong), but it's still monkey patching - just in a different place. Which is kind of what we were trying to avoid with this...

I'll leave this open a little longer in case anyone has any ideas why the sequential import doesn't overwrite the class names in the way I expect, but if not I'll merge with this change.

[grst]

I don't think the current approach can work, as click never get's to know that there's a new Group and Command class in rich_click.

You could try something along the lines of:

__init__.py:

from click import * 
from .rich_click import rich_format_help
from .rich_click import Group
from .rich_click import Command

def group(*args, cls=Group, **kwargs):
    from click import group as group_
    return group_(*args, cls=cls, **kwargs)

[ewels]

Right, so because we're not overwriting the group() function it's still using the default click Group class. Gotcha 👌🏻

I don't really know if this is any better than the monkey patching approach 🤔 - seems sort of the same? We are again overwriting things in the click namespace, either way.

[grst]

We are again overwriting things in the click namespace, either way.

I wouldn't say so. My example only modifies the rich_click namespace.
So if a user did

import click as cl
import rich_click as rcl

they could still use

@cl.command()
def cli():
   pass

@rcl.command()
def cli2():
   pass

and one would be rich-click formatted and the other not. Whereas with monkey-patching, both would be rich-click formatted.

[ewels]

Whereas with monkey-patching, both would be rich-click formatted.

Is that true even when we're doing the monkey patching within the rich-click package? As in #10 (comment) ?

[ewels]

Damn, just tried it and you're right. Even when I do Command.format_help = rich_format_help within the rich_click/__init__.py it affects the class with the vanilla import click as cl import 😞

[ewels]

Ok, so I had a stab at implementing your suggestion in edb2156 @grst

It seems to mostly work - at least, the top-level stuff. So if you have one command or if you do the top-level group it formats it. However, if you try to get the help for a command within a group it uses the default click handling still.

Also need to figure out how to do this approach for printing error messages. That doesn't use decorator functions, so I'm less clear on how to get that to work.

[grst]

However, if you try to get the help for a command within a group it uses the default click handling still.

There's a command_class attribute, it seems:
https://github.com/pallets/click/blob/49164faca678dd476f1b11a2584fd0e1c6be70b2/src/click/core.py#L1757-L1762

Maybe it's possible to set it as keyword argument:

return rich_group(*args, cls=cls, command_class=cls, **kwargs)

Otherwise it should be possible to override it in the Group class.

[ewels]

Maybe it's possible to set it as keyword argument:

Nope: TypeError: __init__() got an unexpected keyword argument 'command_class'

Otherwise it should be possible to override it in the Group class.

Yup, this seems to work! I guess it makes things less customisable with custom classes etc, but then if you want to do that stuff you probably won't be using this package.

[ewels]

ok awesome, just need to figure out how to handle the help now (ClickException.show). Need to run now..

[grst]

I guess it makes things less customisable with custom classes etc

I don't think it would prevent you from overriding the class in cli.comman(cls=...) anyway. It just sets another default.

[ewels]

I'm not sure that we're going to be able to get at the error message printing code any way other than monkey patching the exception classes.. :/

Code is nestled in the main() function:

except ClickException as e:
    if not standalone_mode:
        raise
    e.show()
    sys.exit(e.exit_code)

I don't really fancy trying to replicate the massive main() function so I'm not sure that there's really any other way.. Unless anyone else has any smart ideas? 👀

[grst]

Looks tough! I can't think of any better way either.

[ewels]

Figured it out 💥 4384217

Click hops about all over the place but managed to track back to the main() function call and override standalone_mode so that it allows the exceptions to raise. Then we can catch them with our custom code and handle the output nicely 🚀