Django的文档里面有这么一句
The app that contains the custom tags must be in INSTALLED_APPS
in order for the {% load %} tag to work.
当第一次load一个template的时候,调用源码
def get_templatetags_modules():
"""
Return the list of all available template tag modules.
Caches the result for faster access.
"""
global templatetags_modules
if not templatetags_modules:
_templatetags_modules = []
# Populate list once per process. Mutate the local list first, and
# then assign it to the global name to ensure there are no cases where
# two threads try to populate it simultaneously.
for app_module in ['django'] + list(settings.INSTALLED_APPS):
try:
templatetag_module = '%s.templatetags' % app_module
import_module(templatetag_module)
_templatetags_modules.append(templatetag_module)
except ImportError:
continue
templatetags_modules = _templatetags_modules
return templatetags_modules
Load类型的Node 输出的定义
class LoadNode(Node):
def render(self, context):
return ''
可见他是一个空白字符串,也就是在输出的html中"抹掉"了
example
<html>
<head>
{% load blog_extras %}
Hi my double value is <b>{{myvalue|mycut}}</b>
</head>
</html>
will be tokenized as
Then the block token will be set to LoadNode, var token to Variable Node in my case, done byParser
最后把每一个node render出来