python - flask 中的 template_rendered 函数

Question

一个 Flask 初学者的疑问。

大家都知道在 Flask 中我们可以通过 render_template 函数来实现渲染模板。在学习过程中意外发现 Flask 下包含了一个与其命名非常相似的 template_rendered 函数。十分的好奇，查了一下文档，文档是这么写的：

flask.template_rendered

This signal is sent when a template was successfully rendered.
The signal is invoked with the instance of the template as template and the context as dictionary (named context).

看来应该是在模板成功渲染后返回一个字典。
但是文档里写的具体使用场景我不是非常理解，所以想请教各位一下，究竟这个函数应在什么情况下使用，该怎么使用呢？

from flask import template_rendered
from contextlib import contextmanager

@contextmanager
def captured_templates(app):
    recorded = []
    def record(sender, template, context, **extra):
        recorded.append((template, context))
    template_rendered.connect(record, app)
    try:
        yield recorded
    finally:
        template_rendered.disconnect(record, app)

Answer 1

This is a signal that will be executed whenever a template is rendered. You can subscribe to this signal to get the value it returns.
ps: Apart from debugging, I can’t think of any situation where it would be used.

Answer 2

template_rendered Signal is the core signal of Flask.

When a template is successfully rendered, this signal will be sent. This signal is called with a template instance template and a dictionary of contexts (named context ).

This blog provides specific instructions https://segmentfault.com/a/11...