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