Change "--config foo:bar" to "--setting foo bar"

[simonw]

I designed the config format before I had a good feel for CLI design using Click. --config max_page_size 2000 is better than --config max_page_size:2000.

[simonw]

If I rename metadata to config in #493 then this should be --setting instead.

[simonw]

I can add this well in advance of Datasette 1.0 as an alias to the existing --config option (but taking two arguments instead of one).

[simonw]

This is blocking progress on other metadata tickets like #860 because I want to split the concept of concrete metadata (source, license, etc) from configuration that currently lives in metadata (default sort order, default facets).

I'm going to solve this next to unblock that stuff.

[simonw]

I'm going to keep --config for the moment but show a deprecation warning that it will be gone in Datasette 1.0.

[simonw]

Need to figure out the --setting foo bar alternative for this --config foo:bar logic:

datasette/datasette/cli.py

Lines 31 to 63 in 4bac9f1

	class Config(click.ParamType):
	name = "config"
	def convert(self, config, param, ctx):
	if ":" not in config:
	self.fail(f'"{config}" should be name:value', param, ctx)
	return
	name, value = config.split(":", 1)
	if name not in DEFAULT_CONFIG:
	self.fail(
	f"{name} is not a valid option (--help-config to see all)",
	param,
	ctx,
	)
	return
	# Type checking
	default = DEFAULT_CONFIG[name]
	if isinstance(default, bool):
	try:
	return name, value_as_boolean(value)
	except ValueAsBooleanError:
	self.fail(f'"{name}" should be on/off/true/false/1/0', param, ctx)
	return
	elif isinstance(default, int):
	if not value.isdigit():
	self.fail(f'"{name}" should be an integer', param, ctx)
	return
	return name, int(value)
	elif isinstance(default, str):
	return name, value
	else:
	# Should never happen:
	self.fail("Invalid option")

[simonw]

Part of #1105