from django import template
from django.template.loader import render_to_string
from django.conf import settings
from django.contrib.contenttypes.models import ContentType
from django.contrib import comments
from django.utils.encoding import smart_unicode
register = template.Library()
class BaseCommentNode(template.Node):
"""
Base helper class (abstract) for handling the get_comment_* template tags.
Looks a bit strange, but the subclasses below should make this a bit more
obvious.
"""
#@classmethod
def handle_token(cls, parser, token):
"""Class method to parse get_comment_list/count/form and return a Node."""
tokens = token.contents.split()
if tokens[1] != 'for':
raise template.TemplateSyntaxError("Second argument in %r tag must be 'for'" % tokens[0])
# {% get_whatever for obj as varname %}
if len(tokens) == 5:
if tokens[3] != 'as':
raise template.TemplateSyntaxError("Third argument in %r must be 'as'" % tokens[0])
return cls(
object_expr = parser.compile_filter(tokens[2]),
as_varname = tokens[4],
)
# {% get_whatever for app.model pk as varname %}
elif len(tokens) == 6:
if tokens[4] != 'as':
raise template.TemplateSyntaxError("Fourth argument in %r must be 'as'" % tokens[0])
return cls(
ctype = BaseCommentNode.lookup_content_type(tokens[2], tokens[0]),
object_pk_expr = parser.compile_filter(tokens[3]),
as_varname = tokens[5]
)
else:
raise template.TemplateSyntaxError("%r tag requires 4 or 5 arguments" % tokens[0])
handle_token = classmethod(handle_token)
#@staticmethod
def lookup_content_type(token, tagname):
try:
app, model = token.split('.')
return ContentType.objects.get(app_label=app, model=model)
except ValueError:
raise template.TemplateSyntaxError("Third argument in %r must be in the format 'app.model'" % tagname)
except ContentType.DoesNotExist:
raise template.TemplateSyntaxError("%r tag has non-existant content-type: '%s.%s'" % (tagname, app, model))
lookup_content_type = staticmethod(lookup_content_type)
def __init__(self, ctype=None, object_pk_expr=None, object_expr=None, as_varname=None, comment=None):
if ctype is None and object_expr is None:
raise template.TemplateSyntaxError("Comment nodes must be given either a literal object or a ctype and object pk.")
self.comment_model = comments.get_model()
self.as_varname = as_varname
self.ctype = ctype
self.object_pk_expr = object_pk_expr
self.object_expr = object_expr
self.comment = comment
def render(self, context):
qs = self.get_query_set(context)
context[self.as_varname] = self.get_context_value_from_queryset(context, qs)
return ''
def get_query_set(self, context):
ctype, object_pk = self.get_target_ctype_pk(context)
if not object_pk:
return self.comment_model.objects.none()
qs = self.comment_model.objects.filter(
content_type = ctype,
object_pk = smart_unicode(object_pk),
site__pk = settings.SITE_ID,
)
# The is_public and is_removed fields are implementation details of the
# built-in comment model's spam filtering system, so they might not
# be present on a custom comment model subclass. If they exist, we
# should filter on them.
field_names = [f.name for f in self.comment_model._meta.fields]
if 'is_public' in field_names:
qs = qs.filter(is_public=True)
if getattr(settings, 'COMMENTS_HIDE_REMOVED', True) and 'is_removed' in field_names:
qs = qs.filter(is_removed=False)
return qs
def get_target_ctype_pk(self, context):
if self.object_expr:
try:
obj = self.object_expr.resolve(context)
except template.VariableDoesNotExist:
return None, None
return ContentType.objects.get_for_model(obj), obj.pk
else:
return self.ctype, self.object_pk_expr.resolve(context, ignore_failures=True)
def get_context_value_from_queryset(self, context, qs):
"""Subclasses should override this."""
raise NotImplementedError
class CommentListNode(BaseCommentNode):
"""Insert a list of comments into the context."""
def get_context_value_from_queryset(self, context, qs):
return list(qs)
class CommentCountNode(BaseCommentNode):
"""Insert a count of comments into the context."""
def get_context_value_from_queryset(self, context, qs):
return qs.count()
class CommentFormNode(BaseCommentNode):
"""Insert a form for the comment model into the context."""
def get_form(self, context):
ctype, object_pk = self.get_target_ctype_pk(context)
if object_pk:
return comments.get_form()(ctype.get_object_for_this_type(pk=object_pk))
else:
return None
def render(self, context):
context[self.as_varname] = self.get_form(context)
return ''
class RenderCommentFormNode(CommentFormNode):
"""Render the comment form directly"""
#@classmethod
def handle_token(cls, parser, token):
"""Class method to parse render_comment_form and return a Node."""
tokens = token.contents.split()
if tokens[1] != 'for':
raise template.TemplateSyntaxError("Second argument in %r tag must be 'for'" % tokens[0])
# {% render_comment_form for obj %}
if len(tokens) == 3:
return cls(object_expr=parser.compile_filter(tokens[2]))
# {% render_comment_form for app.models pk %}
elif len(tokens) == 4:
return cls(
ctype = BaseCommentNode.lookup_content_type(tokens[2], tokens[0]),
object_pk_expr = parser.compile_filter(tokens[3])
)
handle_token = classmethod(handle_token)
def render(self, context):
ctype, object_pk = self.get_target_ctype_pk(context)
if object_pk:
template_search_list = [
"comments/%s/%s/form.html" % (ctype.app_label, ctype.model),
"comments/%s/form.html" % ctype.app_label,
"comments/form.html"
]
context.push()
formstr = render_to_string(template_search_list, {"form" : self.get_form(context)}, context)
context.pop()
return formstr
else:
return ''
class RenderCommentListNode(CommentListNode):
"""Render the comment list directly"""
#@classmethod
def handle_token(cls, parser, token):
"""Class method to parse render_comment_list and return a Node."""
tokens = token.contents.split()
if tokens[1] != 'for':
raise template.TemplateSyntaxError("Second argument in %r tag must be 'for'" % tokens[0])
# {% render_comment_list for obj %}
if len(tokens) == 3:
return cls(object_expr=parser.compile_filter(tokens[2]))
# {% render_comment_list for app.models pk %}
elif len(tokens) == 4:
return cls(
ctype = BaseCommentNode.lookup_content_type(tokens[2], tokens[0]),
object_pk_expr = parser.compile_filter(tokens[3])
)
handle_token = classmethod(handle_token)
def render(self, context):
ctype, object_pk = self.get_target_ctype_pk(context)
if object_pk:
template_search_list = [
"comments/%s/%s/list.html" % (ctype.app_label, ctype.model),
"comments/%s/list.html" % ctype.app_label,
"comments/list.html"
]
qs = self.get_query_set(context)
context.push()
liststr = render_to_string(template_search_list, {
"comment_list" : self.get_context_value_from_queryset(context, qs)
}, context)
context.pop()
return liststr
else:
return ''
# We could just register each classmethod directly, but then we'd lose out on
# the automagic docstrings-into-admin-docs tricks. So each node gets a cute
# wrapper function that just exists to hold the docstring.
#@register.tag
def get_comment_count(parser, token):
"""
Gets the comment count for the given params and populates the template
context with a variable containing that value, whose name is defined by the
'as' clause.
Syntax::
{% get_comment_count for [object] as [varname] %}
{% get_comment_count for [app].[model] [object_id] as [varname] %}
Example usage::
{% get_comment_count for event as comment_count %}
{% get_comment_count for calendar.event event.id as comment_count %}
{% get_comment_count for calendar.event 17 as comment_count %}
"""
return CommentCountNode.handle_token(parser, token)
#@register.tag
def get_comment_list(parser, token):
"""
Gets the list of comments for the given params and populates the template
context with a variable containing that value, whose name is defined by the
'as' clause.
Syntax::
{% get_comment_list for [object] as [varname] %}
{% get_comment_list for [app].[model] [object_id] as [varname] %}
Example usage::
{% get_comment_list for event as comment_list %}
{% for comment in comment_list %}
...
{% endfor %}
"""
return CommentListNode.handle_token(parser, token)
#@register.tag
def render_comment_list(parser, token):
"""
Render the comment list (as returned by ``{% get_comment_list %}``)
through the ``comments/list.html`` template
Syntax::
{% render_comment_list for [object] %}
{% render_comment_list for [app].[model] [object_id] %}
Example usage::
{% render_comment_list for event %}
"""
return RenderCommentListNode.handle_token(parser, token)
#@register.tag
def get_comment_form(parser, token):
"""
Get a (new) form object to post a new comment.
Syntax::
{% get_comment_form for [object] as [varname] %}
{% get_comment_form for [app].[model] [object_id] as [varname] %}
"""
return CommentFormNode.handle_token(parser, token)
#@register.tag
def render_comment_form(parser, token):
"""
Render the comment form (as returned by ``{% render_comment_form %}``) through
the ``comments/form.html`` template.
Syntax::
{% render_comment_form for [object] %}
{% render_comment_form for [app].[model] [object_id] %}
"""
return RenderCommentFormNode.handle_token(parser, token)
#@register.simple_tag
def comment_form_target():
"""
Get the target URL for the comment form.
Example::
<form action="{% comment_form_target %}" method="post">
"""
return comments.get_form_target()
#@register.simple_tag
def get_comment_permalink(comment, anchor_pattern=None):
"""
Get the permalink for a comment, optionally specifying the format of the
named anchor to be appended to the end of the URL.
Example::
{{ get_comment_permalink comment "#c%(id)s-by-%(user_name)s" }}
"""
if anchor_pattern:
return comment.get_absolute_url(anchor_pattern)
return comment.get_absolute_url()
register.tag(get_comment_count)
register.tag(get_comment_list)
register.tag(get_comment_form)
register.tag(render_comment_form)
register.simple_tag(comment_form_target)
register.simple_tag(get_comment_permalink)
register.tag(render_comment_list)
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