contrib/shipherd/templatetags/shipherd.py

   1 from django import template
   2 from django.conf import settings
   3 from django.utils.safestring import mark_safe
   4 from philo.contrib.shipherd.models import Navigation
   5 from philo.models import Node
   6 from django.utils.translation import ugettext as _
   7
   8
   9 register = template.Library()
  10
  11
  12 class LazyNavigationRecurser(object):
  13         def __init__(self, template_nodes, items, context, request):
  14                 self.template_nodes = template_nodes
  15                 self.items = items
  16                 self.context = context
  17                 self.request = request
  18
  19         def __call__(self):
  20                 items = self.items
  21                 context = self.context
  22                 request = self.request
  23
  24                 if not items:
  25                         return ''
  26
  27                 if 'navloop' in context:
  28                         parentloop = context['navloop']
  29                 else:
  30                         parentloop = {}
  31                 context.push()
  32
  33                 depth = items[0].get_level()
  34                 len_items = len(items)
  35
  36                 loop_dict = context['navloop'] = {
  37                         'parentloop': parentloop,
  38                         'depth': depth + 1,
  39                         'depth0': depth
  40                 }
  41
  42                 bits = []
  43
  44                 for i, item in enumerate(items):
  45                         # First set context variables.
  46                         loop_dict['counter0'] = i
  47                         loop_dict['counter'] = i + 1
  48                         loop_dict['revcounter'] = len_items - i
  49                         loop_dict['revcounter0'] = len_items - i - 1
  50                         loop_dict['first'] = (i == 0)
  51                         loop_dict['last'] = (i == len_items - 1)
  52
  53                         # Set on loop_dict and context for backwards-compatibility.
  54                         # Eventually only allow access through the loop_dict.
  55                         loop_dict['active'] = context['active'] = item.is_active(request)
  56                         loop_dict['active_descendants'] = context['active_descendants'] = item.has_active_descendants(request)
  57
  58                         # Set these directly in the context for easy access.
  59                         context['item'] = item
  60                         context['children'] = self.__class__(self.template_nodes, item.get_children(), context, request)
  61
  62                         # Then render the nodelist bit by bit.
  63                         for node in self.template_nodes:
  64                                 bits.append(node.render(context))
  65                 context.pop()
  66                 return ''.join(bits)
  67
  68
  69 class RecurseNavigationNode(template.Node):
  70         def __init__(self, template_nodes, instance_var, key):
  71                 self.template_nodes = template_nodes
  72                 self.instance_var = instance_var
  73                 self.key = key
  74
  75         def render(self, context):
  76                 try:
  77                         request = context['request']
  78                 except KeyError:
  79                         return ''
  80
  81                 instance = self.instance_var.resolve(context)
  82
  83                 try:
  84                         items = instance.navigation[self.key]
  85                 except:
  86                         return settings.TEMPLATE_STRING_IF_INVALID
  87
  88                 return LazyNavigationRecurser(self.template_nodes, items, context, request)()
  89
  90
  91 @register.tag
  92 def recursenavigation(parser, token):
  93         """
  94         The recursenavigation templatetag takes two arguments:
  95         - the node for which the navigation should be found
  96         - the navigation's key.
  97
  98         It will then recursively loop over each item in the navigation and render the template
  99         chunk within the block. recursenavigation sets the following variables in the context:
 100
 101                 ==============================  ================================================
 102                 Variable                        Description
 103                 ==============================  ================================================
 104                 ``navloop.depth``               The current depth of the loop (1 is the top level)
 105                 ``navloop.depth0``              The current depth of the loop (0 is the top level)
 106                 ``navloop.counter``             The current iteration of the current level(1-indexed)
 107                 ``navloop.counter0``            The current iteration of the current level(0-indexed)
 108                 ``navloop.first``               True if this is the first time through the current level
 109                 ``navloop.last``                True if this is the last time through the current level
 110                 ``navloop.parentloop``          This is the loop one level "above" the current one
 111                 ==============================  ================================================
 112                 ``item``                        The current item in the loop (a NavigationItem instance)
 113                 ``children``                    If accessed, performs the next level of recursion.
 114                 ``navloop.active``              True if the item is active for this request
 115                 ``navloop.active_descendants``  True if the item has active descendants for this request
 116                 ==============================  ================================================
 117
 118         Example:
 119                 <ul>
 120                         {% recursenavigation node main %}
 121                                 <li{% if navloop.active %} class='active'{% endif %}>
 122                                         {{ navloop.item.text }}
 123                                         {% if item.get_children %}
 124                                                 <ul>
 125                                                         {{ children }}
 126                                                 </ul>
 127                                         {% endif %}
 128                                 </li>
 129                         {% endrecursenavigation %}
 130                 </ul>
 131         """
 132         bits = token.contents.split()
 133         if len(bits) != 3:
 134                 raise template.TemplateSyntaxError(_('%s tag requires two arguments: a node and a navigation section name') % bits[0])
 135
 136         instance_var = parser.compile_filter(bits[1])
 137         key = bits[2]
 138
 139         template_nodes = parser.parse(('recurse', 'endrecursenavigation',))
 140
 141         token = parser.next_token()
 142         if token.contents == 'recurse':
 143                 template_nodes.append(RecurseNavigationMarker())
 144                 template_nodes.extend(parser.parse(('endrecursenavigation')))
 145                 parser.delete_first_token()
 146
 147         return RecurseNavigationNode(template_nodes, instance_var, key)
 148
 149
 150 @register.filter
 151 def has_navigation(node, key=None):
 152         try:
 153                 nav = node.navigation
 154                 if key is not None:
 155                         if key in nav and bool(node.navigation[key]):
 156                                 return True
 157                         elif key not in node.navigation:
 158                                 return False
 159                 return bool(node.navigation)
 160         except:
 161                 return False
 162
 163
 164 @register.filter
 165 def navigation_host(node, key):
 166         try:
 167                 return Navigation.objects.filter(node__in=node.get_ancestors(include_self=True), key=key).order_by('-node__level')[0].node
 168         except:
 169                 if settings.TEMPLATE_DEBUG:
 170                         raise
 171                 return node