Abstracted the Template container fetcher to a nodelist_crawler which takes a callbac...

[philo.git] / utils.py

diff --git a/utils.py b/utils.py
index 6fc2cff..a63ac74 100644 (file)
--- a/utils.py
+++ b/utils.py
@@ -1,6 +1,8 @@
 from django.db import models
 from django.contrib.contenttypes.models import ContentType
 from django.core.paginator import Paginator, EmptyPage
+from django.template import Context
+from django.template.loader_tags import ExtendsNode, ConstantIncludeNode
 
 
 class ContentTypeLimiter(object):
@@ -103,3 +105,46 @@ def paginate(objects, per_page=None, page_number=1):
                objects = page.object_list
        
        return paginator, page, objects
+
+
+LOADED_TEMPLATE_ATTR = '_philo_loaded_template'
+BLANK_CONTEXT = Context()
+
+
+def get_extended(self):
+       return self.get_parent(BLANK_CONTEXT)
+
+
+def get_included(self):
+       return self.template
+
+
+# We ignore the IncludeNode because it will never work in a blank context.
+setattr(ExtendsNode, LOADED_TEMPLATE_ATTR, property(get_extended))
+setattr(ConstantIncludeNode, LOADED_TEMPLATE_ATTR, property(get_included))
+
+
+def nodelist_crawl(nodelist, callback):
+       """This function crawls through a template's nodelist and the nodelists of any included or extended
+       templates, as determined by the presence and value of <LOADED_TEMPLATE_ATTR> on a node. Each node
+       will also be passed to a callback function for additional processing."""
+       nodes = []
+       for node in nodelist:
+               try:
+                       if hasattr(node, 'child_nodelists'):
+                               for nodelist_name in node.child_nodelists:
+                                       if hasattr(node, nodelist_name):
+                                               nodes.extend(nodelist_crawl(getattr(node, nodelist_name), callback))
+                       
+                       # LOADED_TEMPLATE_ATTR contains the name of an attribute philo uses to declare a
+                       # node as rendering an additional template. Philo monkeypatches the attribute onto
+                       # the relevant default nodes and declares it on any native nodes.
+                       if hasattr(node, LOADED_TEMPLATE_ATTR):
+                               loaded_template = getattr(node, LOADED_TEMPLATE_ATTR)
+                               if loaded_template:
+                                       nodes.extend(nodelist_crawl(loaded_template.nodelist, callback))
+                       
+                       callback(node, nodes)
+               except:
+                       raise # fail for this node
+       return nodes
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