templatetags/containers.py

   1 from django import template
   2 from django.conf import settings
   3 from django.utils.safestring import SafeUnicode, mark_safe
   4 from django.core.exceptions import ObjectDoesNotExist
   5 from django.contrib.contenttypes.models import ContentType
   6
   7
   8 register = template.Library()
   9
  10
  11 class ContainerNode(template.Node):
  12         def __init__(self, name, references=None, as_var=None):
  13                 self.name = name
  14                 self.as_var = as_var
  15                 self.references = references
  16         def render(self, context):
  17                 content = settings.TEMPLATE_STRING_IF_INVALID
  18                 if 'page' in context:
  19                         page = context['page']
  20                         if self.references:
  21                                 try:
  22                                         contentreference = page.contentreferences.get(name__exact=self.name, content_type=self.references)
  23                                         content = contentreference.content
  24                                 except ObjectDoesNotExist:
  25                                         pass
  26                         else:
  27                                 try:
  28                                         contentlet = page.contentlets.get(name__exact=self.name)
  29                                         if contentlet.dynamic:
  30                                                 try:
  31                                                         content = mark_safe(template.Template(contentlet.content, name=contentlet.name).render(context))
  32                                                 except template.TemplateSyntaxError, error:
  33                                                         if settings.DEBUG:
  34                                                                 content = ('[Error parsing contentlet \'%s\': %s]' % self.name, error)
  35                                         else:
  36                                                 content = contentlet.content
  37                                 except ObjectDoesNotExist:
  38                                         pass
  39                 if content and self.as_var:
  40                         context[self.as_var] = content
  41                         return ''
  42                 return content
  43
  44
  45 def do_container(parser, token):
  46         """
  47         {% container <name> [[references <type>] as <variable>] %}
  48         """
  49         params = token.split_contents()
  50         if len(params) >= 2:
  51                 name = params[1].strip('"')
  52                 references = None
  53                 as_var = None
  54                 if len(params) > 2:
  55                         remaining_tokens = params[2:]
  56                         while remaining_tokens:
  57                                 option_token = remaining_tokens.pop(0)
  58                                 if option_token == 'references':
  59                                         try:
  60                                                 app_label, model = remaining_tokens.pop(0).strip('"').split('.')
  61                                                 references = ContentType.objects.get(app_label=app_label, model=model)
  62                                         except IndexError:
  63                                                 raise template.TemplateSyntaxError('"container" template tag option "references" requires an argument specifying a content type')
  64                                         except ValueError:
  65                                                 raise template.TemplateSyntaxError('"container" template tag option "references" requires an argument of the form app_label.model (see django.contrib.contenttypes)')
  66                                         except ObjectDoesNotExist:
  67                                                 raise template.TemplateSyntaxError('"container" template tag option "references" requires an argument of the form app_label.model which refers to an installed content type (see django.contrib.contenttypes)')
  68                                 elif option_token == 'as':
  69                                         try:
  70                                                 as_var = remaining_tokens.pop(0)
  71                                         except IndexError:
  72                                                 raise template.TemplateSyntaxError('"container" template tag option "as" requires an argument specifying a variable name')
  73                         if references and not as_var:
  74                                 raise template.TemplateSyntaxError('"container" template tags using "references" option require additional use of the "as" option specifying a variable name')
  75                 return ContainerNode(name, references, as_var)
  76         else: # error
  77                 raise template.TemplateSyntaxError('"container" template tag provided without arguments (at least one required)')
  78 register.tag('container', do_container)