--- /dev/null
+from django import template
+from django.contrib.contenttypes.models import ContentType
+from django.conf import settings
+from django.template.loader_tags import ExtendsNode, BlockContext, BLOCK_CONTEXT_KEY, TextNode, BlockNode
+from philo.utils import LOADED_TEMPLATE_ATTR
+
+
+register = template.Library()
+EMBED_CONTEXT_KEY = 'embed_context'
+
+
+class EmbedContext(object):
+ "Inspired by django.template.loader_tags.BlockContext."
+ def __init__(self):
+ self.embeds = {}
+ self.rendered = []
+
+ def add_embeds(self, embeds):
+ for content_type, embed_list in embeds.iteritems():
+ if content_type in self.embeds:
+ self.embeds[content_type] = embed_list + self.embeds[content_type]
+ else:
+ self.embeds[content_type] = embed_list
+
+ def get_embed_template(self, embed, context):
+ """To return a template for an embed node, find the node's position in the stack
+ and then progress up the stack until a template-defining node is found
+ """
+ ct = embed.get_content_type(context)
+ embeds = self.embeds[ct]
+ embeds = embeds[:embeds.index(embed)][::-1]
+ for e in embeds:
+ template = e.get_template(context)
+ if template:
+ return template
+
+ # No template was found in the current render_context - but perhaps one level up? Or more?
+ # We may be in an inclusion tag.
+ self_found = False
+ for context_dict in context.render_context.dicts[::-1]:
+ if not self_found:
+ if self in context_dict.values():
+ self_found = True
+ continue
+ elif EMBED_CONTEXT_KEY not in context_dict:
+ continue
+ else:
+ embed_context = context_dict[EMBED_CONTEXT_KEY]
+ # We can tell where we are in the list of embeds by which have already been rendered.
+ embeds = embed_context.embeds[ct][:len(embed_context.rendered)][::-1]
+ for e in embeds:
+ template = e.get_template(context)
+ if template:
+ return template
+
+ raise IndexError
+
+
+# Override ExtendsNode render method to have it handle EmbedNodes
+# similarly to BlockNodes.
+old_extends_node_init = ExtendsNode.__init__
+
+
+def get_embed_dict(embed_list, context):
+ embeds = {}
+ for e in embed_list:
+ ct = e.get_content_type(context)
+ if ct is None:
+ # Then the embed doesn't exist for this context.
+ continue
+ if ct not in embeds:
+ embeds[ct] = [e]
+ else:
+ embeds[ct].append(e)
+ return embeds
+
+
+def extends_node_init(self, nodelist, *args, **kwargs):
+ self.embed_list = nodelist.get_nodes_by_type(ConstantEmbedNode)
+ old_extends_node_init(self, nodelist, *args, **kwargs)
+
+
+def render_extends_node(self, context):
+ compiled_parent = self.get_parent(context)
+ embeds = get_embed_dict(self.embed_list, context)
+
+ if BLOCK_CONTEXT_KEY not in context.render_context:
+ context.render_context[BLOCK_CONTEXT_KEY] = BlockContext()
+ block_context = context.render_context[BLOCK_CONTEXT_KEY]
+
+ if EMBED_CONTEXT_KEY not in context.render_context:
+ context.render_context[EMBED_CONTEXT_KEY] = EmbedContext()
+ embed_context = context.render_context[EMBED_CONTEXT_KEY]
+
+ # Add the block nodes from this node to the block context
+ # Do the equivalent for embed nodes
+ block_context.add_blocks(self.blocks)
+ embed_context.add_embeds(embeds)
+
+ # If this block's parent doesn't have an extends node it is the root,
+ # and its block nodes also need to be added to the block context.
+ for node in compiled_parent.nodelist:
+ # The ExtendsNode has to be the first non-text node.
+ if not isinstance(node, TextNode):
+ if not isinstance(node, ExtendsNode):
+ blocks = dict([(n.name, n) for n in compiled_parent.nodelist.get_nodes_by_type(BlockNode)])
+ block_context.add_blocks(blocks)
+ embeds = get_embed_dict(compiled_parent.nodelist.get_nodes_by_type(ConstantEmbedNode), context)
+ embed_context.add_embeds(embeds)
+ break
+
+ # Explicitly render all direct embed children of this node.
+ if self.embed_list:
+ for node in self.nodelist:
+ if isinstance(node, ConstantEmbedNode):
+ node.render(context)
+
+ # Call Template._render explicitly so the parser context stays
+ # the same.
+ return compiled_parent._render(context)
+
+
+ExtendsNode.__init__ = extends_node_init
+ExtendsNode.render = render_extends_node
+
+
+class ConstantEmbedNode(template.Node):
+ """Analogous to the ConstantIncludeNode, this node precompiles several variables necessary for correct rendering - namely the referenced instance or the included template."""
+ def __init__(self, content_type, object_pk=None, template_name=None, kwargs=None):
+ assert template_name is not None or object_pk is not None
+ self.content_type = content_type
+
+ kwargs = kwargs or {}
+ for k, v in kwargs.items():
+ kwargs[k] = v
+ self.kwargs = kwargs
+
+ if object_pk is not None:
+ self.instance = self.compile_instance(object_pk)
+ else:
+ self.instance = None
+
+ if template_name is not None:
+ self.template = self.compile_template(template_name[1:-1])
+ else:
+ self.template = None
+
+ def compile_instance(self, object_pk):
+ model = self.content_type.model_class()
+ try:
+ return model.objects.get(pk=object_pk)
+ except model.DoesNotExist:
+ if not hasattr(self, 'object_pk') and settings.TEMPLATE_DEBUG:
+ # Then it's a constant node.
+ raise
+ return False
+
+ def get_instance(self, context):
+ return self.instance
+
+ def compile_template(self, template_name):
+ try:
+ return template.loader.get_template(template_name)
+ except template.TemplateDoesNotExist:
+ if hasattr(self, 'template') and settings.TEMPLATE_DEBUG:
+ # Then it's a constant node.
+ raise
+ return False
+
+ def get_template(self, context):
+ return self.template
+
+ def get_content_type(self, context):
+ return self.content_type
+
+ def check_context(self, context):
+ if EMBED_CONTEXT_KEY not in context.render_context:
+ context.render_context[EMBED_CONTEXT_KEY] = EmbedContext()
+ embed_context = context.render_context[EMBED_CONTEXT_KEY]
+
+ ct = self.get_content_type(context)
+ if ct not in embed_context.embeds:
+ embed_context.embeds[ct] = [self]
+ elif self not in embed_context.embeds[ct]:
+ embed_context.embeds[ct].append(self)
+
+ def mark_rendered_for(self, context):
+ context.render_context[EMBED_CONTEXT_KEY].rendered.append(self)
+
+ def render(self, context):
+ self.check_context(context)
+
+ template = self.get_template(context)
+ if template is not None:
+ self.mark_rendered_for(context)
+ if template is False:
+ return settings.TEMPLATE_STRING_IF_INVALID
+ return ''
+
+ # Otherwise an instance should be available. Render the instance with the appropriate template!
+ instance = self.get_instance(context)
+ if instance is None or instance is False:
+ self.mark_rendered_for(context)
+ return settings.TEMPLATE_STRING_IF_INVALID
+
+ return self.render_instance(context, instance)
+
+ def render_instance(self, context, instance):
+ try:
+ t = context.render_context[EMBED_CONTEXT_KEY].get_embed_template(self, context)
+ except (KeyError, IndexError):
+ self.mark_rendered_for(context)
+ return settings.TEMPLATE_STRING_IF_INVALID
+
+ context.push()
+ context['embedded'] = instance
+ for k, v in self.kwargs.items():
+ context[k] = v.resolve(context)
+ t_rendered = t.render(context)
+ context.pop()
+ self.mark_rendered_for(context)
+ return t_rendered
+
+
+class EmbedNode(ConstantEmbedNode):
+ def __init__(self, content_type, object_pk=None, template_name=None, kwargs=None):
+ assert template_name is not None or object_pk is not None
+ self.content_type = content_type
+ self.kwargs = kwargs or {}
+
+ if object_pk is not None:
+ self.object_pk = object_pk
+ else:
+ self.object_pk = None
+
+ if template_name is not None:
+ self.template_name = template_name
+ else:
+ self.template_name = None
+
+ def get_instance(self, context):
+ if self.object_pk is None:
+ return None
+ return self.compile_instance(self.object_pk.resolve(context))
+
+ def get_template(self, context):
+ if self.template_name is None:
+ return None
+ return self.compile_template(self.template_name.resolve(context))
+
+
+class InstanceEmbedNode(EmbedNode):
+ def __init__(self, instance, kwargs=None):
+ self.instance = instance
+ self.kwargs = kwargs or {}
+
+ def get_template(self, context):
+ return None
+
+ def get_instance(self, context):
+ return self.instance.resolve(context)
+
+ def get_content_type(self, context):
+ instance = self.get_instance(context)
+ if not instance:
+ return None
+ return ContentType.objects.get_for_model(instance)
+
+
+def get_embedded(self):
+ return self.template
+
+
+setattr(ConstantEmbedNode, LOADED_TEMPLATE_ATTR, property(get_embedded))
+
+
+def parse_content_type(bit, tagname):
+ try:
+ app_label, model = bit.split('.')
+ except ValueError:
+ raise template.TemplateSyntaxError('"%s" template tag expects the first argument to be of the form app_label.model' % tagname)
+ try:
+ ct = ContentType.objects.get(app_label=app_label, model=model)
+ except ContentType.DoesNotExist:
+ raise template.TemplateSyntaxError('"%s" template tag requires an argument of the form app_label.model which refers to an installed content type (see django.contrib.contenttypes)' % tagname)
+ return ct
+
+
+def do_embed(parser, token):
+ """
+ The {% embed %} tag can be used in two ways:
+ {% embed <app_label>.<model_name> with <template> %} :: Sets which template will be used to render a particular model.
+ {% embed (<app_label>.<model_name> <object_pk> || <instance>) [<argname>=<value> ...] %} :: Embeds the instance specified by the given parameters in the document with the previously-specified template. Any kwargs provided will be passed into the context of the template.
+ """
+ bits = token.split_contents()
+ tag = bits.pop(0)
+
+ if len(bits) < 1:
+ raise template.TemplateSyntaxError('"%s" template tag must have at least two arguments.' % tag)
+
+ if len(bits) == 3 and bits[-2] == 'with':
+ ct = parse_content_type(bits[0], tag)
+
+ if bits[2][0] in ['"', "'"] and bits[2][0] == bits[2][-1]:
+ return ConstantEmbedNode(ct, template_name=bits[2])
+ return EmbedNode(ct, template_name=bits[2])
+
+ # Otherwise they're trying to embed a certain instance.
+ kwargs = {}
+ try:
+ bit = bits.pop()
+ while '=' in bit:
+ k, v = bit.split('=')
+ kwargs[k] = parser.compile_filter(v)
+ bit = bits.pop()
+ bits.append(bit)
+ except IndexError:
+ raise template.TemplateSyntaxError('"%s" template tag expects at least one non-keyword argument when embedding instances.')
+
+ if len(bits) == 1:
+ instance = parser.compile_filter(bits[0])
+ return InstanceEmbedNode(instance, kwargs)
+ elif len(bits) > 2:
+ raise template.TemplateSyntaxError('"%s" template tag expects at most 2 non-keyword arguments when embedding instances.')
+ ct = parse_content_type(bits[0], tag)
+ pk = bits[1]
+
+ try:
+ int(pk)
+ except ValueError:
+ return EmbedNode(ct, object_pk=parser.compile_filter(pk), kwargs=kwargs)
+ else:
+ return ConstantEmbedNode(ct, object_pk=pk, kwargs=kwargs)
+
+
+register.tag('embed', do_embed)
\ No newline at end of file
git.ithinksw.org / philo.git / blobdiff