An example "trivial" Contentment component. Note in particular that this is all "data model" — HTML is merely one possible serialization of the data. View is not defined here, there are no presentation details, but a method is provided to permit introspection of the view capabilities or requirements.

address-component.py

from marrow.mongo import Document, utcnow
from marrow.mongo.field import Date, Link

from ..asset import Depend


class Address(Document):
	"""An embedded document representing a verified e-mail address.
	
	Intended for use in an Array() embedding these sub-documents.
	"""
	
	__pk__ = 'address'
	__vary__ = ('address', 'verified')  # The attributes to fetch for cache key generation.
	
	address = Link(required=True, protocols={'mailto'})  # The e-mail address itself.
	added = Date(default=utcnow, write=False)  # When was this address added?
	verified = Date(default=None, write=False)  # Has the user verified the address, and if so, when?
	
	@Depend.declare  # self may actually be the class, not an instance!
	def __depends__(self, only=Depend.ALL):
		"""Declare bundle, themeing, and interaction points for this widget."""
		
		if Depend.STYLE in only:
			# Hard theme selectors; this is always present.
			yield Depend.STYLE, '.email'
			
			# Conditional theme selectors; announce all anyway, but hint.
			if issubclass(self, Address):  # Class-level identification.
				yield Depend.STYLE, '.verified'
				yield Depend.STYLE, '.unverified'
			else:  # Conditional actual use when querying an instance specifically.
				yield Depend.STYLE, '.verified', bool(self.verified)
				yield Depend.STYLE, '.unverified', not self.verified
		
		if Depend.EVENT in only:
			# Client- and server-side events that may fire.
			yield Depend.EVENT, 'com.illico.common.email.verified'
	
	def __str__(self):
		"""Return a plain text representation of this location; just the name, if present."""
		
		return self.address.path.name
	
	def __html__(self):
		"""Return a microdata-compliant e-mail link.
		
		If the e-mail address is fully-formed with a name component, the name will be used for presentation.
		"""
		
		return f'<a href="mailto:{self.address}" class="email {'' if self.verified else 'un'}verified">{self}</a>'
	
	def __link__(self):
		"""Return a valid URI representitive of this widget."""
		
		return self.address