Fixed #4565 -- Changed template rendering to use iterators, rather than

creating large strings, as much as possible. This is all backwards compatible.
Thanks, Brian Harring.


git-svn-id: http://code.djangoproject.com/svn/django/trunk@5482 bcc190cf-cafb-0310-a4f2-bffc1f526a37
This commit is contained in:
Malcolm Tredinnick 2007-06-17 07:11:37 +00:00
parent 44dd91ec6d
commit bccb8897e6
21 changed files with 284 additions and 161 deletions

View File

@ -94,15 +94,15 @@ class FieldWidgetNode(template.Node):
return cls.nodelists[klass]
get_nodelist = classmethod(get_nodelist)
def render(self, context):
def iter_render(self, context):
bound_field = template.resolve_variable(self.bound_field_var, context)
context.push()
context['bound_field'] = bound_field
output = self.get_nodelist(bound_field.field.__class__).render(context)
for chunk in self.get_nodelist(bound_field.field.__class__).iter_render(context):
yield chunk
context.pop()
return output
class FieldWrapper(object):
def __init__(self, field ):
@ -157,7 +157,7 @@ class EditInlineNode(template.Node):
def __init__(self, rel_var):
self.rel_var = rel_var
def render(self, context):
def iter_render(self, context):
relation = template.resolve_variable(self.rel_var, context)
context.push()
if relation.field.rel.edit_inline == models.TABULAR:
@ -169,10 +169,9 @@ class EditInlineNode(template.Node):
original = context.get('original', None)
bound_related_object = relation.bind(context['form'], original, bound_related_object_class)
context['bound_related_object'] = bound_related_object
t = loader.get_template(bound_related_object.template_name())
output = t.render(context)
for chunk in loader.get_template(bound_related_object.template_name()).iter_render(context):
yield chunk
context.pop()
return output
def output_all(form_fields):
return ''.join([str(f) for f in form_fields])

View File

@ -7,7 +7,7 @@ class AdminApplistNode(template.Node):
def __init__(self, varname):
self.varname = varname
def render(self, context):
def iter_render(self, context):
from django.db import models
from django.utils.text import capfirst
app_list = []
@ -54,7 +54,7 @@ class AdminApplistNode(template.Node):
'models': model_list,
})
context[self.varname] = app_list
return ''
return ()
def get_admin_app_list(parser, token):
"""

View File

@ -10,14 +10,14 @@ class AdminLogNode(template.Node):
def __repr__(self):
return "<GetAdminLog Node>"
def render(self, context):
def iter_render(self, context):
if self.user is None:
context[self.varname] = LogEntry.objects.all().select_related()[:self.limit]
else:
if not self.user.isdigit():
self.user = context[self.user].id
context[self.varname] = LogEntry.objects.filter(user__id__exact=self.user).select_related()[:self.limit]
return ''
return ()
class DoGetAdminLog:
"""

View File

@ -24,7 +24,7 @@ class CommentFormNode(template.Node):
self.photo_options, self.rating_options = photo_options, rating_options
self.is_public = is_public
def render(self, context):
def iter_render(self, context):
from django.conf import settings
from django.utils.text import normalize_newlines
import base64
@ -33,7 +33,7 @@ class CommentFormNode(template.Node):
try:
self.obj_id = template.resolve_variable(self.obj_id_lookup_var, context)
except template.VariableDoesNotExist:
return ''
return
# Validate that this object ID is valid for this content-type.
# We only have to do this validation if obj_id_lookup_var is provided,
# because do_comment_form() validates hard-coded object IDs.
@ -67,9 +67,9 @@ class CommentFormNode(template.Node):
context['hash'] = Comment.objects.get_security_hash(context['options'], context['photo_options'], context['rating_options'], context['target'])
context['logout_url'] = settings.LOGOUT_URL
default_form = loader.get_template(COMMENT_FORM)
output = default_form.render(context)
for chunk in default_form.iter_render(context):
yield chunk
context.pop()
return output
class CommentCountNode(template.Node):
def __init__(self, package, module, context_var_name, obj_id, var_name, free):
@ -77,7 +77,7 @@ class CommentCountNode(template.Node):
self.context_var_name, self.obj_id = context_var_name, obj_id
self.var_name, self.free = var_name, free
def render(self, context):
def iter_render(self, context):
from django.conf import settings
manager = self.free and FreeComment.objects or Comment.objects
if self.context_var_name is not None:
@ -86,7 +86,7 @@ class CommentCountNode(template.Node):
content_type__app_label__exact=self.package,
content_type__model__exact=self.module, site__id__exact=settings.SITE_ID).count()
context[self.var_name] = comment_count
return ''
return ()
class CommentListNode(template.Node):
def __init__(self, package, module, context_var_name, obj_id, var_name, free, ordering, extra_kwargs=None):
@ -96,14 +96,14 @@ class CommentListNode(template.Node):
self.ordering = ordering
self.extra_kwargs = extra_kwargs or {}
def render(self, context):
def iter_render(self, context):
from django.conf import settings
get_list_function = self.free and FreeComment.objects.filter or Comment.objects.get_list_with_karma
if self.context_var_name is not None:
try:
self.obj_id = template.resolve_variable(self.context_var_name, context)
except template.VariableDoesNotExist:
return ''
return ()
kwargs = {
'object_id__exact': self.obj_id,
'content_type__app_label__exact': self.package,
@ -127,7 +127,7 @@ class CommentListNode(template.Node):
comment_list = [c for c in comment_list if not c.is_hidden or (user_id == c.user_id)]
context[self.var_name] = comment_list
return ''
return ()
class DoCommentForm:
"""

View File

@ -309,7 +309,7 @@ class ServerHandler(object):
"""
if not self.result_is_file() and not self.sendfile():
for data in self.result:
self.write(data)
self.write(data, False)
self.finish_content()
self.close()
@ -377,7 +377,7 @@ class ServerHandler(object):
else:
self._write('Status: %s\r\n' % self.status)
def write(self, data):
def write(self, data, flush=True):
"""'write()' callable as specified by PEP 333"""
assert type(data) is StringType,"write() argument must be string"
@ -394,6 +394,7 @@ class ServerHandler(object):
# XXX check Content-Length and truncate if too many bytes written?
self._write(data)
if flush:
self._flush()
def sendfile(self):
@ -421,8 +422,6 @@ class ServerHandler(object):
if not self.headers_sent:
self.headers['Content-Length'] = "0"
self.send_headers()
else:
pass # XXX check if content-length was too short?
def close(self):
try:

View File

@ -222,6 +222,12 @@ class HttpResponse(object):
content = ''.join(self._container)
if isinstance(content, unicode):
content = content.encode(self._charset)
# If self._container was an iterator, we have just exhausted it, so we
# need to save the results for anything else that needs access
if not self._is_string:
self._container = [content]
self._is_string = True
return content
def _set_content(self, value):
@ -231,14 +237,10 @@ class HttpResponse(object):
content = property(_get_content, _set_content)
def __iter__(self):
self._iterator = self._container.__iter__()
return self
def next(self):
chunk = self._iterator.next()
for chunk in self._container:
if isinstance(chunk, unicode):
chunk = chunk.encode(self._charset)
return chunk
yield chunk
def close(self):
if hasattr(self._container, 'close'):

View File

@ -309,6 +309,10 @@ class FormField(object):
return data
html2python = staticmethod(html2python)
def iter_render(self, data):
# this even needed?
return (self.render(data),)
def render(self, data):
raise NotImplementedError

View File

@ -7,7 +7,7 @@ from django.http import HttpResponse, Http404
from django.db.models.manager import Manager
def render_to_response(*args, **kwargs):
return HttpResponse(loader.render_to_string(*args, **kwargs))
return HttpResponse(loader.render_to_iter(*args, **kwargs))
load_and_render = render_to_response # For backwards compatibility.
def get_object_or_404(klass, *args, **kwargs):

View File

@ -55,6 +55,7 @@ times with multiple contexts)
'\n<html>\n\n</html>\n'
"""
import re
import types
from inspect import getargspec
from django.conf import settings
from django.template.context import Context, RequestContext, ContextPopException
@ -167,9 +168,12 @@ class Template(object):
for subnode in node:
yield subnode
def render(self, context):
def iter_render(self, context):
"Display stage -- can be called many times"
return self.nodelist.render(context)
return self.nodelist.iter_render(context)
def render(self, context):
return ''.join(self.iter_render(context))
def compile_string(template_string, origin):
"Compiles template_string into NodeList ready for rendering"
@ -698,10 +702,26 @@ def resolve_variable(path, context):
del bits[0]
return current
class NodeBase(type):
def __new__(cls, name, bases, attrs):
"""
Ensures that either a 'render' or 'render_iter' method is defined on
any Node sub-class. This avoids potential infinite loops at runtime.
"""
if not (isinstance(attrs.get('render'), types.FunctionType) or
isinstance(attrs.get('iter_render'), types.FunctionType)):
raise TypeError('Unable to create Node subclass without either "render" or "iter_render" method.')
return type.__new__(cls, name, bases, attrs)
class Node(object):
__metaclass__ = NodeBase
def iter_render(self, context):
return (self.render(context),)
def render(self, context):
"Return the node rendered as a string"
pass
return ''.join(self.iter_render(context))
def __iter__(self):
yield self
@ -717,13 +737,12 @@ class Node(object):
class NodeList(list):
def render(self, context):
bits = []
return ''.join(self.iter_render(context))
def iter_render(self, context):
for node in self:
if isinstance(node, Node):
bits.append(self.render_node(node, context))
else:
bits.append(node)
return ''.join(bits)
for chunk in node.iter_render(context):
yield chunk
def get_nodes_by_type(self, nodetype):
"Return a list of all nodes of the given type"
@ -732,13 +751,16 @@ class NodeList(list):
nodes.extend(node.get_nodes_by_type(nodetype))
return nodes
def render_node(self, node, context):
return(node.render(context))
class DebugNodeList(NodeList):
def render_node(self, node, context):
def iter_render(self, context):
for node in self:
if not isinstance(node, Node):
yield node
continue
try:
result = node.render(context)
for chunk in node.iter_render(context):
yield chunk
except TemplateSyntaxError, e:
if not hasattr(e, 'source'):
e.source = node.source
@ -749,7 +771,6 @@ class DebugNodeList(NodeList):
wrapped.source = node.source
wrapped.exc_info = exc_info()
raise wrapped
return result
class TextNode(Node):
def __init__(self, s):
@ -758,6 +779,9 @@ class TextNode(Node):
def __repr__(self):
return "<Text Node: '%s'>" % self.s[:25]
def iter_render(self, context):
return (self.s,)
def render(self, context):
return self.s
@ -781,6 +805,9 @@ class VariableNode(Node):
else:
return output
def iter_render(self, context):
return (self.render(context),)
def render(self, context):
output = self.filter_expression.resolve(context)
return self.encode_output(output)
@ -869,6 +896,9 @@ class Library(object):
def __init__(self, vars_to_resolve):
self.vars_to_resolve = vars_to_resolve
#def iter_render(self, context):
# return (self.render(context),)
def render(self, context):
resolved_vars = [resolve_variable(var, context) for var in self.vars_to_resolve]
return func(*resolved_vars)
@ -891,7 +921,7 @@ class Library(object):
def __init__(self, vars_to_resolve):
self.vars_to_resolve = vars_to_resolve
def render(self, context):
def iter_render(self, context):
resolved_vars = [resolve_variable(var, context) for var in self.vars_to_resolve]
if takes_context:
args = [context] + resolved_vars
@ -907,7 +937,7 @@ class Library(object):
else:
t = get_template(file_name)
self.nodelist = t.nodelist
return self.nodelist.render(context_class(dict))
return self.nodelist.iter_render(context_class(dict))
compile_func = curry(generic_tag_compiler, params, defaults, getattr(func, "_decorated_function", func).__name__, InclusionNode)
compile_func.__doc__ = func.__doc__

View File

@ -14,12 +14,11 @@ if not hasattr(__builtins__, 'reversed'):
for index in xrange(len(data)-1, -1, -1):
yield data[index]
register = Library()
class CommentNode(Node):
def render(self, context):
return ''
def iter_render(self, context):
return ()
class CycleNode(Node):
def __init__(self, cyclevars, variable_name=None):
@ -28,6 +27,9 @@ class CycleNode(Node):
self.counter = -1
self.variable_name = variable_name
def iter_render(self, context):
return (self.render(context),)
def render(self, context):
self.counter += 1
value = self.cyclevars[self.counter % self.cyclevars_len]
@ -36,29 +38,32 @@ class CycleNode(Node):
return value
class DebugNode(Node):
def render(self, context):
def iter_render(self, context):
from pprint import pformat
output = [pformat(val) for val in context]
output.append('\n\n')
output.append(pformat(sys.modules))
return ''.join(output)
for val in context:
yield pformat(val)
yield "\n\n"
yield pformat(sys.modules)
class FilterNode(Node):
def __init__(self, filter_expr, nodelist):
self.filter_expr, self.nodelist = filter_expr, nodelist
def render(self, context):
def iter_render(self, context):
output = self.nodelist.render(context)
# apply filters
context.update({'var': output})
filtered = self.filter_expr.resolve(context)
context.pop()
return filtered
return (filtered,)
class FirstOfNode(Node):
def __init__(self, vars):
self.vars = vars
def iter_render(self, context):
return (self.render(context),)
def render(self, context):
for var in self.vars:
try:
@ -94,8 +99,7 @@ class ForNode(Node):
nodes.extend(self.nodelist_loop.get_nodes_by_type(nodetype))
return nodes
def render(self, context):
nodelist = NodeList()
def iter_render(self, context):
if 'forloop' in context:
parentloop = context['forloop']
else:
@ -103,12 +107,12 @@ class ForNode(Node):
context.push()
try:
values = self.sequence.resolve(context, True)
except VariableDoesNotExist:
values = []
if values is None:
values = []
if not hasattr(values, '__len__'):
values = ()
elif not hasattr(values, '__len__'):
values = list(values)
except VariableDoesNotExist:
values = ()
len_values = len(values)
if self.reversed:
values = reversed(values)
@ -127,12 +131,17 @@ class ForNode(Node):
'parentloop': parentloop,
}
if unpack:
# If there are multiple loop variables, unpack the item into them.
# If there are multiple loop variables, unpack the item into
# them.
context.update(dict(zip(self.loopvars, item)))
else:
context[self.loopvars[0]] = item
# We inline this to avoid the overhead since ForNode is pretty
# common.
for node in self.nodelist_loop:
nodelist.append(node.render(context))
for chunk in node.iter_render(context):
yield chunk
if unpack:
# The loop variables were pushed on to the context so pop them
# off again. This is necessary because the tag lets the length
@ -141,7 +150,6 @@ class ForNode(Node):
# context.
context.pop()
context.pop()
return nodelist.render(context)
class IfChangedNode(Node):
def __init__(self, nodelist, *varlist):
@ -149,7 +157,7 @@ class IfChangedNode(Node):
self._last_seen = None
self._varlist = varlist
def render(self, context):
def iter_render(self, context):
if 'forloop' in context and context['forloop']['first']:
self._last_seen = None
try:
@ -167,11 +175,9 @@ class IfChangedNode(Node):
self._last_seen = compare_to
context.push()
context['ifchanged'] = {'firstloop': firstloop}
content = self.nodelist.render(context)
for chunk in self.nodelist.iter_render(context):
yield chunk
context.pop()
return content
else:
return ''
class IfEqualNode(Node):
def __init__(self, var1, var2, nodelist_true, nodelist_false, negate):
@ -182,7 +188,7 @@ class IfEqualNode(Node):
def __repr__(self):
return "<IfEqualNode>"
def render(self, context):
def iter_render(self, context):
try:
val1 = resolve_variable(self.var1, context)
except VariableDoesNotExist:
@ -192,8 +198,8 @@ class IfEqualNode(Node):
except VariableDoesNotExist:
val2 = None
if (self.negate and val1 != val2) or (not self.negate and val1 == val2):
return self.nodelist_true.render(context)
return self.nodelist_false.render(context)
return self.nodelist_true.iter_render(context)
return self.nodelist_false.iter_render(context)
class IfNode(Node):
def __init__(self, bool_exprs, nodelist_true, nodelist_false, link_type):
@ -218,7 +224,7 @@ class IfNode(Node):
nodes.extend(self.nodelist_false.get_nodes_by_type(nodetype))
return nodes
def render(self, context):
def iter_render(self, context):
if self.link_type == IfNode.LinkTypes.or_:
for ifnot, bool_expr in self.bool_exprs:
try:
@ -226,8 +232,8 @@ class IfNode(Node):
except VariableDoesNotExist:
value = None
if (value and not ifnot) or (ifnot and not value):
return self.nodelist_true.render(context)
return self.nodelist_false.render(context)
return self.nodelist_true.iter_render(context)
return self.nodelist_false.iter_render(context)
else:
for ifnot, bool_expr in self.bool_exprs:
try:
@ -235,8 +241,8 @@ class IfNode(Node):
except VariableDoesNotExist:
value = None
if not ((value and not ifnot) or (ifnot and not value)):
return self.nodelist_false.render(context)
return self.nodelist_true.render(context)
return self.nodelist_false.iter_render(context)
return self.nodelist_true.iter_render(context)
class LinkTypes:
and_ = 0,
@ -247,11 +253,11 @@ class RegroupNode(Node):
self.target, self.expression = target, expression
self.var_name = var_name
def render(self, context):
def iter_render(self, context):
obj_list = self.target.resolve(context, True)
if obj_list == None: # target_var wasn't found in context; fail silently
context[self.var_name] = []
return ''
return ()
output = [] # list of dictionaries in the format {'grouper': 'key', 'list': [list of contents]}
for obj in obj_list:
grouper = self.expression.resolve(obj, True)
@ -261,7 +267,7 @@ class RegroupNode(Node):
else:
output.append({'grouper': grouper, 'list': [obj]})
context[self.var_name] = output
return ''
return ()
def include_is_allowed(filepath):
for root in settings.ALLOWED_INCLUDE_ROOTS:
@ -273,10 +279,10 @@ class SsiNode(Node):
def __init__(self, filepath, parsed):
self.filepath, self.parsed = filepath, parsed
def render(self, context):
def iter_render(self, context):
if not include_is_allowed(self.filepath):
if settings.DEBUG:
return "[Didn't have permission to include file]"
return ("[Didn't have permission to include file]",)
else:
return '' # Fail silently for invalid includes.
try:
@ -287,23 +293,25 @@ class SsiNode(Node):
output = ''
if self.parsed:
try:
t = Template(output, name=self.filepath)
return t.render(context)
return Template(output, name=self.filepath).iter_render(context)
except TemplateSyntaxError, e:
if settings.DEBUG:
return "[Included template had syntax error: %s]" % e
else:
return '' # Fail silently for invalid included templates.
return output
return (output,)
class LoadNode(Node):
def render(self, context):
return ''
def iter_render(self, context):
return ()
class NowNode(Node):
def __init__(self, format_string):
self.format_string = format_string
def iter_render(self, context):
return (self.render(context),)
def render(self, context):
from datetime import datetime
from django.utils.dateformat import DateFormat
@ -332,6 +340,9 @@ class TemplateTagNode(Node):
def __init__(self, tagtype):
self.tagtype = tagtype
def iter_render(self, context):
return (self.render(context),)
def render(self, context):
return self.mapping.get(self.tagtype, '')
@ -341,18 +352,18 @@ class URLNode(Node):
self.args = args
self.kwargs = kwargs
def render(self, context):
def iter_render(self, context):
from django.core.urlresolvers import reverse, NoReverseMatch
args = [arg.resolve(context) for arg in self.args]
kwargs = dict([(k, v.resolve(context)) for k, v in self.kwargs.items()])
try:
return reverse(self.view_name, args=args, kwargs=kwargs)
return (reverse(self.view_name, args=args, kwargs=kwargs),)
except NoReverseMatch:
try:
project_name = settings.SETTINGS_MODULE.split('.')[0]
return reverse(project_name + '.' + self.view_name, args=args, kwargs=kwargs)
except NoReverseMatch:
return ''
return ()
class WidthRatioNode(Node):
def __init__(self, val_expr, max_expr, max_width):
@ -360,6 +371,9 @@ class WidthRatioNode(Node):
self.max_expr = max_expr
self.max_width = max_width
def iter_render(self, context):
return (self.render(context),)
def render(self, context):
try:
value = self.val_expr.resolve(context)
@ -383,13 +397,13 @@ class WithNode(Node):
def __repr__(self):
return "<WithNode>"
def render(self, context):
def iter_render(self, context):
val = self.var.resolve(context)
context.push()
context[self.name] = val
output = self.nodelist.render(context)
for chunk in self.nodelist.iter_render(context):
yield chunk
context.pop()
return output
#@register.tag
def comment(parser, token):

View File

@ -87,14 +87,12 @@ def get_template_from_string(source, origin=None, name=None):
"""
return Template(source, origin, name)
def render_to_string(template_name, dictionary=None, context_instance=None):
def _render_setup(template_name, dictionary=None, context_instance=None):
"""
Loads the given template_name and renders it with the given dictionary as
context. The template_name may be a string to load a single template using
get_template, or it may be a tuple to use select_template to find one of
the templates in the list. Returns a string.
Common setup code for render_to_string and render_to_iter.
"""
dictionary = dictionary or {}
if dictionary is None:
dictionary = {}
if isinstance(template_name, (list, tuple)):
t = select_template(template_name)
else:
@ -103,7 +101,28 @@ def render_to_string(template_name, dictionary=None, context_instance=None):
context_instance.update(dictionary)
else:
context_instance = Context(dictionary)
return t.render(context_instance)
return t, context_instance
def render_to_string(template_name, dictionary=None, context_instance=None):
"""
Loads the given template_name and renders it with the given dictionary as
context. The template_name may be a string to load a single template using
get_template, or it may be a tuple to use select_template to find one of
the templates in the list. Returns a string.
"""
t, c = _render_setup(template_name, dictionary=dictionary, context_instance=context_instance)
return t.render(c)
def render_to_iter(template_name, dictionary=None, context_instance=None):
"""
Loads the given template_name and renders it with the given dictionary as
context. The template_name may be a string to load a single template using
get_template, or it may be a tuple to use select_template to find one of
the templates in the list. Returns a string.
"""
t, c = _render_setup(template_name, dictionary=dictionary, context_instance=context_instance)
return t.iter_render(c)
def select_template(template_name_list):
"Given a list of template names, returns the first that can be loaded."

View File

@ -15,14 +15,14 @@ class BlockNode(Node):
def __repr__(self):
return "<Block Node: %s. Contents: %r>" % (self.name, self.nodelist)
def render(self, context):
def iter_render(self, context):
context.push()
# Save context in case of block.super().
self.context = context
context['block'] = self
result = self.nodelist.render(context)
for chunk in self.nodelist.iter_render(context):
yield chunk
context.pop()
return result
def super(self):
if self.parent:
@ -59,7 +59,7 @@ class ExtendsNode(Node):
else:
return get_template_from_string(source, origin, parent)
def render(self, context):
def iter_render(self, context):
compiled_parent = self.get_parent(context)
parent_is_child = isinstance(compiled_parent.nodelist[0], ExtendsNode)
parent_blocks = dict([(n.name, n) for n in compiled_parent.nodelist.get_nodes_by_type(BlockNode)])
@ -79,7 +79,7 @@ class ExtendsNode(Node):
parent_block.parent = block_node.parent
parent_block.add_parent(parent_block.nodelist)
parent_block.nodelist = block_node.nodelist
return compiled_parent.render(context)
return compiled_parent.iter_render(context)
class ConstantIncludeNode(Node):
def __init__(self, template_path):
@ -91,27 +91,26 @@ class ConstantIncludeNode(Node):
raise
self.template = None
def render(self, context):
def iter_render(self, context):
if self.template:
return self.template.render(context)
else:
return ''
return self.template.iter_render(context)
return ()
class IncludeNode(Node):
def __init__(self, template_name):
self.template_name = template_name
def render(self, context):
def iter_render(self, context):
try:
template_name = resolve_variable(self.template_name, context)
t = get_template(template_name)
return t.render(context)
return t.iter_render(context)
except TemplateSyntaxError, e:
if settings.TEMPLATE_DEBUG:
raise
return ''
return ()
except:
return '' # Fail silently for invalid included templates.
return () # Fail silently for invalid included templates.
def do_block(parser, token):
"""

View File

@ -11,13 +11,22 @@ from django.template import Template
TEST_DATABASE_PREFIX = 'test_'
def instrumented_test_render(self, context):
"""An instrumented Template render method, providing a signal
that can be intercepted by the test system Client
"""
An instrumented Template render method, providing a signal that can be
intercepted by the test system Client.
"""
dispatcher.send(signal=signals.template_rendered, sender=self, template=self, context=context)
return self.nodelist.render(context)
def instrumented_test_iter_render(self, context):
"""
An instrumented Template iter_render method, providing a signal that can be
intercepted by the test system Client.
"""
for chunk in self.nodelist.iter_render(context):
yield chunk
dispatcher.send(signal=signals.template_rendered, sender=self, template=self, context=context)
class TestSMTPConnection(object):
"""A substitute SMTP connection for use during test sessions.
The test connection stores email messages in a dummy outbox,
@ -44,7 +53,9 @@ def setup_test_environment():
"""
Template.original_render = Template.render
Template.original_iter_render = Template.iter_render
Template.render = instrumented_test_render
Template.iter_render = instrumented_test_render
mail.original_SMTPConnection = mail.SMTPConnection
mail.SMTPConnection = TestSMTPConnection
@ -59,7 +70,8 @@ def teardown_test_environment():
"""
Template.render = Template.original_render
del Template.original_render
Template.iter_render = Template.original_iter_render
del Template.original_render, Template.original_iter_render
mail.SMTPConnection = mail.original_SMTPConnection
del mail.original_SMTPConnection

View File

@ -137,7 +137,7 @@ def technical_500_response(request, exc_type, exc_value, tb):
'template_does_not_exist': template_does_not_exist,
'loader_debug_info': loader_debug_info,
})
return HttpResponseServerError(t.render(c), mimetype='text/html')
return HttpResponseServerError(t.iter_render(c), mimetype='text/html')
def technical_404_response(request, exception):
"Create a technical 404 error response. The exception should be the Http404."
@ -160,7 +160,7 @@ def technical_404_response(request, exception):
'request_protocol': request.is_secure() and "https" or "http",
'settings': get_safe_settings(),
})
return HttpResponseNotFound(t.render(c), mimetype='text/html')
return HttpResponseNotFound(t.iter_render(c), mimetype='text/html')
def empty_urlconf(request):
"Create an empty URLconf 404 error response."
@ -168,7 +168,7 @@ def empty_urlconf(request):
c = Context({
'project_name': settings.SETTINGS_MODULE.split('.')[0]
})
return HttpResponseNotFound(t.render(c), mimetype='text/html')
return HttpResponseNotFound(t.iter_render(c), mimetype='text/html')
def _get_lines_from_file(filename, lineno, context_lines, loader=None, module_name=None):
"""

View File

@ -76,7 +76,7 @@ def page_not_found(request, template_name='404.html'):
The path of the requested URL (e.g., '/app/pages/bad_page/')
"""
t = loader.get_template(template_name) # You need to create a 404.html template.
return http.HttpResponseNotFound(t.render(RequestContext(request, {'request_path': request.path})))
return http.HttpResponseNotFound(t.iter_render(RequestContext(request, {'request_path': request.path})))
def server_error(request, template_name='500.html'):
"""
@ -86,4 +86,4 @@ def server_error(request, template_name='500.html'):
Context: None
"""
t = loader.get_template(template_name) # You need to create a 500.html template.
return http.HttpResponseServerError(t.render(Context({})))
return http.HttpResponseServerError(t.iter_render(Context({})))

View File

@ -68,7 +68,7 @@ def create_object(request, model, template_name=None,
c[key] = value()
else:
c[key] = value
return HttpResponse(t.render(c))
return HttpResponse(t.iter_render(c))
def update_object(request, model, object_id=None, slug=None,
slug_field=None, template_name=None, template_loader=loader,
@ -141,7 +141,7 @@ def update_object(request, model, object_id=None, slug=None,
c[key] = value()
else:
c[key] = value
response = HttpResponse(t.render(c))
response = HttpResponse(t.iter_render(c))
populate_xheaders(request, response, model, getattr(object, object._meta.pk.attname))
return response
@ -195,6 +195,6 @@ def delete_object(request, model, post_delete_redirect,
c[key] = value()
else:
c[key] = value
response = HttpResponse(t.render(c))
response = HttpResponse(t.iter_render(c))
populate_xheaders(request, response, model, getattr(object, object._meta.pk.attname))
return response

View File

@ -44,7 +44,7 @@ def archive_index(request, queryset, date_field, num_latest=15,
c[key] = value()
else:
c[key] = value
return HttpResponse(t.render(c), mimetype=mimetype)
return HttpResponse(t.iter_render(c), mimetype=mimetype)
def archive_year(request, year, queryset, date_field, template_name=None,
template_loader=loader, extra_context=None, allow_empty=False,
@ -92,7 +92,7 @@ def archive_year(request, year, queryset, date_field, template_name=None,
c[key] = value()
else:
c[key] = value
return HttpResponse(t.render(c), mimetype=mimetype)
return HttpResponse(t.iter_render(c), mimetype=mimetype)
def archive_month(request, year, month, queryset, date_field,
month_format='%b', template_name=None, template_loader=loader,
@ -158,7 +158,7 @@ def archive_month(request, year, month, queryset, date_field,
c[key] = value()
else:
c[key] = value
return HttpResponse(t.render(c), mimetype=mimetype)
return HttpResponse(t.iter_render(c), mimetype=mimetype)
def archive_week(request, year, week, queryset, date_field,
template_name=None, template_loader=loader,
@ -206,7 +206,7 @@ def archive_week(request, year, week, queryset, date_field,
c[key] = value()
else:
c[key] = value
return HttpResponse(t.render(c), mimetype=mimetype)
return HttpResponse(t.iter_render(c), mimetype=mimetype)
def archive_day(request, year, month, day, queryset, date_field,
month_format='%b', day_format='%d', template_name=None,
@ -270,7 +270,7 @@ def archive_day(request, year, month, day, queryset, date_field,
c[key] = value()
else:
c[key] = value
return HttpResponse(t.render(c), mimetype=mimetype)
return HttpResponse(t.iter_render(c), mimetype=mimetype)
def archive_today(request, **kwargs):
"""
@ -339,6 +339,6 @@ def object_detail(request, year, month, day, queryset, date_field,
c[key] = value()
else:
c[key] = value
response = HttpResponse(t.render(c), mimetype=mimetype)
response = HttpResponse(t.iter_render(c), mimetype=mimetype)
populate_xheaders(request, response, model, getattr(obj, obj._meta.pk.name))
return response

View File

@ -84,7 +84,7 @@ def object_list(request, queryset, paginate_by=None, page=None,
model = queryset.model
template_name = "%s/%s_list.html" % (model._meta.app_label, model._meta.object_name.lower())
t = template_loader.get_template(template_name)
return HttpResponse(t.render(c), mimetype=mimetype)
return HttpResponse(t.iter_render(c), mimetype=mimetype)
def object_detail(request, queryset, object_id=None, slug=None,
slug_field=None, template_name=None, template_name_field=None,
@ -126,6 +126,6 @@ def object_detail(request, queryset, object_id=None, slug=None,
c[key] = value()
else:
c[key] = value
response = HttpResponse(t.render(c), mimetype=mimetype)
response = HttpResponse(t.iter_render(c), mimetype=mimetype)
populate_xheaders(request, response, model, getattr(obj, obj._meta.pk.name))
return response

View File

@ -15,7 +15,7 @@ def direct_to_template(request, template, extra_context={}, mimetype=None, **kwa
dictionary[key] = value
c = RequestContext(request, dictionary)
t = loader.get_template(template)
return HttpResponse(t.render(c), mimetype=mimetype)
return HttpResponse(t.iter_render(c), mimetype=mimetype)
def redirect_to(request, url, **kwargs):
"""

View File

@ -92,7 +92,7 @@ def directory_index(path, fullpath):
'directory' : path + '/',
'file_list' : files,
})
return HttpResponse(t.render(c))
return HttpResponse(t.iter_render(c))
def was_modified_since(header=None, mtime=0, size=0):
"""

View File

@ -693,14 +693,15 @@ how the compilation works and how the rendering works.
When Django compiles a template, it splits the raw template text into
''nodes''. Each node is an instance of ``django.template.Node`` and has
a ``render()`` method. A compiled template is, simply, a list of ``Node``
objects. When you call ``render()`` on a compiled template object, the template
calls ``render()`` on each ``Node`` in its node list, with the given context.
The results are all concatenated together to form the output of the template.
either a ``render()`` or ``iter_render()`` method. A compiled template is,
simply, a list of ``Node`` objects. When you call ``render()`` on a compiled
template object, the template calls ``render()`` on each ``Node`` in its node
list, with the given context. The results are all concatenated together to
form the output of the template.
Thus, to define a custom template tag, you specify how the raw template tag is
converted into a ``Node`` (the compilation function), and what the node's
``render()`` method does.
``render()`` or ``iter_render()`` method does.
Writing the compilation function
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
@ -770,7 +771,8 @@ Writing the renderer
~~~~~~~~~~~~~~~~~~~~
The second step in writing custom tags is to define a ``Node`` subclass that
has a ``render()`` method.
has a ``render()`` method (we will discuss the ``iter_render()`` alternative
in `Improving rendering speed`_, below).
Continuing the above example, we need to define ``CurrentTimeNode``::
@ -1175,6 +1177,48 @@ For more examples of complex rendering, see the source code for ``{% if %}``,
.. _configuration:
Improving rendering speed
~~~~~~~~~~~~~~~~~~~~~~~~~
For most practical purposes, the ``render()`` method on a ``Node`` will be
sufficient and the simplest way to implement a new tag. However, if your
template tag is expected to produce large strings via ``render()``, you can
speed up the rendering process (and reduce memory usage) using iterative
rendering via the ``iter_render()`` method.
The ``iter_render()`` method should either be an iterator that yields string
chunks, one at a time, or a method that returns a sequence of string chunks.
The template renderer will join the successive chunks together when creating
the final output. The improvement over the ``render()`` method here is that
you do not need to create one large string containing all the output of the
``Node``, instead you can produce the output in smaller chunks.
By way of example, here's a trivial ``Node`` subclass that simply returns the
contents of a file it is given::
class FileNode(Node):
def __init__(self, filename):
self.filename = filename
def iter_render(self):
for line in file(self.filename):
yield line
For very large files, the full file contents will never be read entirely into
memory when this tag is used, which is a useful optimisation.
If you define an ``iter_render()`` method on your ``Node`` subclass, you do
not need to define a ``render()`` method. The reverse is true as well: the
default ``Node.iter_render()`` method will call your ``render()`` method if
necessary. A useful side-effect of this is that you can develop a new tag
using ``render()`` and producing all the output at once, which is easy to
debug. Then you can rewrite the method as an iterator, rename it to
``iter_render()`` and everything will still work.
It is compulsory, however, to define *either* ``render()`` or ``iter_render()``
in your subclass. If you omit them both, a ``TypeError`` will be raised when
the code is imported.
Configuring the template system in standalone mode
==================================================
@ -1206,3 +1250,4 @@ is of obvious interest.
.. _settings file: ../settings/#using-settings-without-the-django-settings-module-environment-variable
.. _settings documentation: ../settings/