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
  17         def render(self, context):
  18                 content = settings.TEMPLATE_STRING_IF_INVALID
  19                 if 'page' in context:
  20                         container_content = self.get_container_content(context)
  21                 else:
  22                         container_content = None
  23
  24                 if self.as_var:
  25                         context[self.as_var] = container_content
  26                         return ''
  27
  28                 if not container_content:
  29                         return ''
  30
  31                 return container_content
  32
  33         def get_container_content(self, context):
  34                 page = context['page']
  35                 if self.references:
  36                         # Then it's a content reference.
  37                         try:
  38                                 contentreference = page.contentreferences.get(name__exact=self.name, content_type=self.references)
  39                                 content = contentreference.content
  40                         except ObjectDoesNotExist:
  41                                 content = ''
  42                 else:
  43                         # Otherwise it's a contentlet.
  44                         try:
  45                                 contentlet = page.contentlets.get(name__exact=self.name)
  46                                 if '{%' in contentlet.content or '{{' in contentlet.content:
  47                                         try:
  48                                                 content = template.Template(contentlet.content, name=contentlet.name).render(context)
  49                                         except template.TemplateSyntaxError, error:
  50                                                 if settings.DEBUG:
  51                                                         content = ('[Error parsing contentlet \'%s\': %s]' % (self.name, error))
  52                                                 else:
  53                                                         content = settings.TEMPLATE_STRING_IF_INVALID
  54                                 else:
  55                                         content = contentlet.content
  56                         except ObjectDoesNotExist:
  57                                 content = settings.TEMPLATE_STRING_IF_INVALID
  58                         content = mark_safe(content)
  59                 return content
  60
  61
  62 def do_container(parser, token):
  63         """
  64         {% container <name> [[references <type>] as <variable>] %}
  65         """
  66         params = token.split_contents()
  67         if len(params) >= 2:
  68                 tag = params[0]
  69                 name = params[1].strip('"')
  70                 references = None
  71                 as_var = None
  72                 if len(params) > 2:
  73                         remaining_tokens = params[2:]
  74                         while remaining_tokens:
  75                                 option_token = remaining_tokens.pop(0)
  76                                 if option_token == 'references':
  77                                         try:
  78                                                 app_label, model = remaining_tokens.pop(0).strip('"').split('.')
  79                                                 references = ContentType.objects.get(app_label=app_label, model=model)
  80                                         except IndexError:
  81                                                 raise template.TemplateSyntaxError('"%s" template tag option "references" requires an argument specifying a content type' % tag)
  82                                         except ValueError:
  83                                                 raise template.TemplateSyntaxError('"%s" template tag option "references" requires an argument of the form app_label.model (see django.contrib.contenttypes)' % tag)
  84                                         except ObjectDoesNotExist:
  85                                                 raise template.TemplateSyntaxError('"%s" template tag option "references" requires an argument of the form app_label.model which refers to an installed content type (see django.contrib.contenttypes)' % tag)
  86                                 elif option_token == 'as':
  87                                         try:
  88                                                 as_var = remaining_tokens.pop(0)
  89                                         except IndexError:
  90                                                 raise template.TemplateSyntaxError('"%s" template tag option "as" requires an argument specifying a variable name' % tag)
  91                         if references and not as_var:
  92                                 raise template.TemplateSyntaxError('"%s" template tags using "references" option require additional use of the "as" option specifying a variable name' % tag)
  93                 return ContainerNode(name, references, as_var)
  94
  95         else: # error
  96                 raise template.TemplateSyntaxError('"%s" template tag provided without arguments (at least one required)' % tag)
  97
  98
  99 register.tag('container', do_container)