#!/usr/bin/env python
# -*- coding: UTF-8 -*-
import re
import six
from django.db import models
from django.utils.translation import ugettext_lazy as _
from django.utils.html import conditional_escape
from djangoseo.utils import escape_tags, NotSet, Literal
VALID_HEAD_TAGS = "head title base link meta script".split()
VALID_INLINE_TAGS = (
"area img object map param "
"a abbr acronym dfn em strong "
"code samp kbd var "
"b i big small tt " # would like to leave these out :-)
"span br bdo cite del ins q sub sup"
# NB: deliberately leaving out iframe and script
).split()
class MetadataField(object):
creation_counter = 0
def __init__(self, name, head, editable, populate_from, valid_tags, choices, help_text, verbose_name, field, field_kwargs):
self.name = name
self.head = head
self.editable = editable
self.populate_from = populate_from
self.help_text = help_text
self.field = field or models.CharField
self.verbose_name = verbose_name
if field_kwargs is None:
field_kwargs = {}
self.field_kwargs = field_kwargs
if choices and isinstance(choices[0], six.string_types):
choices = [(c, c) for c in choices]
field_kwargs.setdefault('choices', choices)
# If valid_tags is a string, tags are space separated words
if isinstance(valid_tags, six.string_types):
valid_tags = valid_tags.split()
if valid_tags is not None:
valid_tags = set(valid_tags)
self.valid_tags = valid_tags
# Track creation order for field ordering
self.creation_counter = MetadataField.creation_counter
MetadataField.creation_counter += 1
def contribute_to_class(self, cls, name):
if not self.name:
self.name = name
# Populate the hep text from populate_from if it's missing
if not self.help_text and self.populate_from is not NotSet:
if callable(self.populate_from) and hasattr(self.populate_from, 'short_description'):
self.help_text = _('If empty, %s') % self.populate_from.short_description
elif isinstance(self.populate_from, Literal):
self.help_text = _('If empty, \"%s\" will be used.') % self.populate_from.value
elif isinstance(self.populate_from, six.string_types) and self.populate_from in cls._meta.elements:
field = cls._meta.elements[self.populate_from]
self.help_text = _('If empty, %s will be used.') % field.verbose_name or field.name
elif isinstance(self.populate_from, six.string_types) and hasattr(cls, self.populate_from):
populate_from = getattr(cls, self.populate_from, None)
if callable(populate_from) and hasattr(populate_from, 'short_description'):
self.help_text = _('If empty, %s') % populate_from.short_description
self.validate()
def validate(self):
""" Discover certain illegal configurations """
if not self.editable:
assert self.populate_from is not NotSet, u"If field (%s) is not editable, you must set populate_from" % self.name
def get_field(self):
kwargs = self.field_kwargs
if self.help_text:
kwargs.setdefault('help_text', self.help_text)
if self.verbose_name:
kwargs.setdefault('verbose_name', self.verbose_name)
return self.field(**kwargs)
def clean(self, value):
return value
def render(self, value):
raise NotImplementedError
class Tag(MetadataField):
def __init__(self, name=None, head=False, escape_value=True,
editable=True, verbose_name=None, valid_tags=None, max_length=511,
choices=None, populate_from=NotSet, field=models.CharField,
field_kwargs=None, help_text=None):
self.escape_value = escape_value
if field_kwargs is None:
field_kwargs = {}
field_kwargs.setdefault('max_length', max_length)
field_kwargs.setdefault('default', "")
field_kwargs.setdefault('blank', True)
super(Tag, self).__init__(name, head, editable, populate_from, valid_tags, choices, help_text, verbose_name, field, field_kwargs)
def clean(self, value):
value = escape_tags(value, self.valid_tags or VALID_INLINE_TAGS)
return value.strip()
def render(self, value):
return u'<%s>%s</%s>' % (self.name, value, self.name)
VALID_META_NAME = re.compile(r"[A-z][A-z0-9_:.-]*$")
class MetaTag(MetadataField):
def __init__(self, name=None, head=True, verbose_name=None, editable=True,
populate_from=NotSet, valid_tags=None, max_length=511, choices=None,
field=models.CharField, field_kwargs=None, help_text=None):
if field_kwargs is None:
field_kwargs = {}
field_kwargs.setdefault('max_length', max_length)
field_kwargs.setdefault('default', "")
field_kwargs.setdefault('blank', True)
if name is not None:
assert VALID_META_NAME.match(name) is not None, u"Invalid name for MetaTag: '%s'" % name
super(MetaTag, self).__init__(name, head, editable, populate_from, valid_tags, choices, help_text, verbose_name, field, field_kwargs)
def clean(self, value):
value = escape_tags(value, self.valid_tags)
# Replace newlines with spaces
return value.replace("\n", " ").strip()
def render(self, value):
# TODO: HTML/XHTML?
return u'<meta name="%s" content="%s" />' % (self.name, value)
class KeywordTag(MetaTag):
def __init__(self, name=None, head=True, verbose_name=None, editable=True,
populate_from=NotSet, valid_tags=None, max_length=511, choices=None,
field=models.CharField, field_kwargs=None, help_text=None):
if name is None:
name = "keywords"
if valid_tags is None:
valid_tags = []
super(KeywordTag, self).__init__(name, head, verbose_name, editable,
populate_from, valid_tags, max_length, choices, field,
field_kwargs, help_text)
def clean(self, value):
value = escape_tags(value, self.valid_tags)
# Remove double quote, replace newlines with commas
return value.replace('"', '"').replace("\n", ", ").strip()
# TODO: if max_length is given, use a CharField and pass it through
class Raw(MetadataField):
def __init__(self, head=True, editable=True, populate_from=NotSet,
verbose_name=None, valid_tags=None, choices=None, field=models.TextField,
field_kwargs=None, help_text=None):
if field_kwargs is None:
field_kwargs = {}
field_kwargs.setdefault('default', "")
field_kwargs.setdefault('blank', True)
super(Raw, self).__init__(None, head, editable, populate_from, valid_tags, choices, help_text, verbose_name, field, field_kwargs)
def clean(self, value):
# Find a suitable set of valid tags using self.head and self.valid_tags
if self.head:
valid_tags = set(VALID_HEAD_TAGS)
if self.valid_tags is not None:
valid_tags = valid_tags & self.valid_tags
else:
valid_tags = self.valid_tags
value = escape_tags(value, valid_tags)
if self.head:
# Remove text before tags
before_tags = re.compile("^([^<>]*)<")
value = before_tags.sub('<', value)
# Remove text after tags
after_tags = re.compile(">([^<>]*)$")
value = after_tags.sub('>', value)
return value
def render(self, value):
return value
