templatetags/nodes.py

   1 from django import template
   2 from django.conf import settings
   3 from django.contrib.sites.models import Site
   4 from django.core.urlresolvers import reverse, NoReverseMatch
   5 from django.template.defaulttags import kwarg_re
   6 from django.utils.encoding import smart_str
   7 from philo.exceptions import ViewCanNotProvideSubpath
   8
   9
  10 register = template.Library()
  11
  12
  13 class NodeURLNode(template.Node):
  14         def __init__(self, node, as_var, with_obj=None, view_name=None, args=None, kwargs=None):
  15                 self.as_var = as_var
  16                 self.view_name = view_name
  17
  18                 # Because the following variables have already been compiled as filters if they exist, they don't need to be re-scanned as template variables.
  19                 self.node = node
  20                 self.with_obj = with_obj
  21                 self.args = args
  22                 self.kwargs = kwargs
  23
  24         def render(self, context):
  25                 if self.node:
  26                         node = self.node.resolve(context)
  27                 else:
  28                         node = context.get('node', None)
  29
  30                 if not node:
  31                         return settings.TEMPLATE_STRING_IF_INVALID
  32
  33                 if self.with_obj is None and self.view_name is None:
  34                         url = node.get_absolute_url()
  35                 else:
  36                         if not node.view.accepts_subpath:
  37                                 return settings.TEMPLATE_STRING_IF_INVALID
  38
  39                         if self.with_obj is not None:
  40                                 try:
  41                                         view_name, args, kwargs = node.view.get_reverse_params(self.with_obj.resolve(context))
  42                                 except ViewCanNotProvideSubpath:
  43                                         return settings.TEMPLATE_STRING_IF_INVALID
  44                         else: # self.view_name is not None
  45                                 view_name = self.view_name
  46                                 args = [arg.resolve(context) for arg in self.args]
  47                                 kwargs = dict([(smart_str(k, 'ascii'), v.resolve(context)) for k, v in self.kwargs.items()])
  48
  49                         url = ''
  50                         try:
  51                                 subpath = reverse(view_name, urlconf=node.view, args=args, kwargs=kwargs)
  52                         except NoReverseMatch:
  53                                 if self.as_var is None:
  54                                         raise
  55                         else:
  56                                 if subpath[0] == '/':
  57                                         subpath = subpath[1:]
  58
  59                                 url = node.get_absolute_url() + subpath
  60
  61                 if self.as_var:
  62                         context[self.as_var] = url
  63                         return ''
  64                 else:
  65                         return url
  66
  67
  68 @register.tag(name='node_url')
  69 def do_node_url(parser, token):
  70         """
  71         {% node_url [for <node>] [as <var>] %}
  72         {% node_url with <obj> [for <node>] [as <var>] %}
  73         {% node_url <view_name> [<arg1> [<arg2> ...] ] [for <node>] [as <var>] %}
  74         {% node_url <view_name> [<key1>=<value1> [<key2>=<value2> ...] ] [for <node>] [as <var>]%}
  75         """
  76         params = token.split_contents()
  77         tag = params[0]
  78         as_var = None
  79         with_obj = None
  80         node = None
  81         params = params[1:]
  82
  83         if len(params) >= 2 and params[-2] == 'as':
  84                 as_var = params[-1]
  85                 params = params[:-2]
  86
  87         if len(params) >= 2 and params[-2] == 'for':
  88                 node = parser.compile_filter(params[-1])
  89                 params = params[:-2]
  90
  91         if len(params) >= 2 and params[-2] == 'with':
  92                 with_obj = parser.compile_filter(params[-1])
  93                 params = params[:-2]
  94
  95         if with_obj is not None:
  96                 if params:
  97                         raise template.TemplateSyntaxError('`%s` template tag accepts no arguments or keyword arguments if with <obj> is specified.' % tag)
  98                 return NodeURLNode(with_obj=with_obj, node=node, as_var=as_var)
  99
 100         if params:
 101                 args = []
 102                 kwargs = {}
 103                 view_name = params.pop(0)
 104                 for param in params:
 105                         match = kwarg_re.match(param)
 106                         if not match:
 107                                 raise TemplateSyntaxError("Malformed arguments to `%s` tag" % tag)
 108                         name, value = match.groups()
 109                         if name:
 110                                 kwargs[name] = parser.compile_filter(value)
 111                         else:
 112                                 args.append(parser.compile_filter(value))
 113                 return NodeURLNode(view_name=view_name, args=args, kwargs=kwargs, node=node, as_var=as_var)
 114
 115         return NodeURLNode(node=node, as_var=as_var)