textout/textoutpc/tags/base.py

#!/usr/bin/env python3
#******************************************************************************
# Copyright (C) 2018 Thomas "Cakeisalie5" Touhey <thomas@touhey.fr>
# This file is part of the textoutpc project, which is MIT-licensed.
#******************************************************************************
""" Base class for textout tags. For your class to be used as a textout tag,
	you have to make it inherit one of these (usually `TextoutBlockTag`
	or `TextoutInlineTag`). """

import inspect as _inspect
from functools import partial as _p
from inspect import getargspec as _getargspec

__all__ = ["TextoutTag", "TextoutBlockTag", "TextoutInlineTag",
	"TextoutParagraphTag"]

def _getargscount(func):
	try:
		return len(_inspect.getfullargspec(func).args)
	except:
		return len(_inspect.getargspec(func).args)

# ---
# Main base tag class.
# For more about defining a tag, see `/TAGS.md`.
# ---

class TextoutTag:
	""" The textout tag base class.
		Is initialized with these values:
	
		<name (only special)><content><name>
		[<name (with brackets)>]<content>[/<name>]
		[<name (with brackets)>=<value>]<content>[/<name>] """

	aliases = ()

	def __init__(self, name, value, ot, tweaks):
		""" Initialize the textout tag with the documented members. """

		# Store internal data.

		self.__output_type = ot
		self.__tweaks = tweaks

		self.output_type = ot

		# Call both prepare functions.

		if hasattr(self, 'prepare'):
			try:
				assert _getargscount(self.prepare) == 4
				args = (name, value, ot)
			except:
				args = (name, value)
			self.prepare(*args)
		if hasattr(self, 'prepare_' + ot):
			prep = getattr(self, 'prepare_' + ot)
			try:
				assert len(_getargspec(prep).args) == 4
				args = (name, value, ot)
			except:
				args = (name, value)
			prep(*args)

		# Prepare the preprocessing elements.
		if hasattr(self, 'preprocess'):
			if hasattr(self, 'preprocess_' + ot):
				self.__preprocess0 = self.preprocess
				self.preprocess = self.__preprocess_double
		elif hasattr(self, 'preprocess_' + ot):
			self.preprocess = getattr(self, 'preprocess_' + ot)

		if hasattr(self, 'preprocess'):
			self.__preprocess2 = self.preprocess
			self.preprocess = self.__preprocess_and_prepare
		else:
			self.__after_preprocess()

		if hasattr(self, 'default_' + ot):
			self.default = getattr(self, 'default_' + ot)

	def __preprocess_double(self, content):
		""" Preprocess using the two methods. """

		ct = self.__preprocess0(content)
		if ct != None: content = ct; del ct
		ct = self.__preprocess1(content)
		if ct != None: content = ct; del ct
		return content

	def __preprocess_and_prepare(self, content):
		""" Preprocess and do the things after. """

		ret = self.__preprocess2(content)
		self.__after_preprocess()
		return ret

	def __out(self, name):
		""" Generic function to call two output functions of the same type. """

		getattr(self, '__' + name)()
		getattr(self, name + '_' + self.__output_type)()

	def __after_preprocess(self):
		ot = self.__output_type

		for otype in ('begin', 'content', 'end'):
			if hasattr(self, otype):
				if hasattr(self, otype + '_' + ot):
					setattr(self, '__' + otype, getattr(self, otype))
					setattr(self, otype, _p(self.__out, otype))
			elif hasattr(self, otype + '_' + ot):
				setattr(self, otype, getattr(self, otype + '_' + ot))

	def tweak(self, key, default = None):
		try:
			return self.__tweaks[key]
		except KeyError:
			return default

# ---
# Role-specific base tag classes.
# ---

class TextoutBlockTag(TextoutTag):
	pass
class TextoutInlineTag(TextoutTag):
	pass

# ---
# Default tag: paragraph.
# ---

class TextoutParagraphTag(TextoutBlockTag):
	""" Main tag for basic paragraphs. """

	notempty = True

	def begin_html(self):
		return '<p>'

	def end_html(self):
		return '</p>'

# End of file.