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, nodelist_main=None, nodelist_empty=None):
  13                 self.name = name
  14                 self.as_var = as_var
  15                 self.references = references
  16                 self.nodelist_main = nodelist_main
  17                 self.nodelist_empty = nodelist_empty
  18
  19         def render(self, context):
  20                 content = settings.TEMPLATE_STRING_IF_INVALID
  21                 if 'page' in context:
  22                         container_content = self.get_container_content(context['page'])
  23
  24                 if self.nodelist_main is None:
  25                         if container_content and self.as_var:
  26                                 context[self.as_var] = container_content
  27                                 return ''
  28                         return container_content
  29
  30                 if container_content:
  31                         if self.as_var is None:
  32                                 self.as_var = self.name
  33                         context.push()
  34                         context[self.as_var] = container_content
  35                         return nodelist_main.render(context)
  36
  37                 if nodelist_empty is not None:
  38                         return nodelist_empty.render(context)
  39
  40                 return ''
  41
  42         def get_container_content(self, page):
  43                 if self.references:
  44                         try:
  45                                 contentreference = page.contentreferences.get(name__exact=self.name, content_type=self.references)
  46                                 content = contentreference.content
  47                         except ObjectDoesNotExist:
  48                                 content = ''
  49                 else:
  50                         try:
  51                                 contentlet = page.contentlets.get(name__exact=self.name)
  52                                 if contentlet.dynamic:
  53                                         try:
  54                                                 content = mark_safe(template.Template(contentlet.content, name=contentlet.name).render(context))
  55                                         except template.TemplateSyntaxError, error:
  56                                                 if settings.DEBUG:
  57                                                         content = ('[Error parsing contentlet \'%s\': %s]' % self.name, error)
  58                                 else:
  59                                         content = contentlet.content
  60                         except ObjectDoesNotExist:
  61                                 content = ''
  62                 return content
  63
  64 def do_container(parser, token):
  65         """
  66         {% container <name> [[references <type>] as <variable>] %}
  67         {% blockcontainer <name> [[references <type>] as <variable>] %} [ {% empty %} ] {% endblockcontainer %}
  68         """
  69         params = token.split_contents()
  70         if len(params) >= 2:
  71                 tag = params[0]
  72                 name = params[1].strip('"')
  73                 references = None
  74                 as_var = None
  75                 if len(params) > 2:
  76                         remaining_tokens = params[2:]
  77                         while remaining_tokens:
  78                                 option_token = remaining_tokens.pop(0)
  79                                 if option_token == 'references':
  80                                         try:
  81                                                 app_label, model = remaining_tokens.pop(0).strip('"').split('.')
  82                                                 references = ContentType.objects.get(app_label=app_label, model=model)
  83                                         except IndexError:
  84                                                 raise template.TemplateSyntaxError('"%s" template tag option "references" requires an argument specifying a content type' % tag)
  85                                         except ValueError:
  86                                                 raise template.TemplateSyntaxError('"%s" template tag option "references" requires an argument of the form app_label.model (see django.contrib.contenttypes)' % tag)
  87                                         except ObjectDoesNotExist:
  88                                                 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)
  89                                 elif option_token == 'as':
  90                                         try:
  91                                                 as_var = remaining_tokens.pop(0)
  92                                         except IndexError:
  93                                                 raise template.TemplateSyntaxError('"%s" template tag option "as" requires an argument specifying a variable name' % tag)
  94                         if references and not as_var:
  95                                 raise template.TemplateSyntaxError('"%s" template tags using "references" option require additional use of the "as" option specifying a variable name' % tag)
  96                 if tag == 'container':
  97                         return ContainerNode(name, references, as_var)
  98
  99                 nodelist_main = parser.parse(('empty','endblockcontainer',))
 100                 token = parser.next_token()
 101
 102                 if token.contents == 'empty':
 103                         nodelist_empty = parser.parse(('endblockcontainer',))
 104                         parser.delete_first_token()
 105                 else:
 106                         nodelist_empty = None
 107                 return BlockContainerNode(name, references, as_var, nodelist_main, nodelist_empty)
 108
 109         else: # error
 110                 raise template.TemplateSyntaxError('"%s" template tag provided without arguments (at least one required)' % tag)
 111 register.tag('container', do_container)