Welcome to OGeek Q&A Community for programmer and developer-Open, Learning and Share
Welcome To Ask or Share your Answers For Others

Categories

0 votes
1.2k views
in Technique[技术] by (71.8m points)

python - Disable cache on a specific page using Flask

I have a template showing various entries that the author can edit/delete. Users can delete their posts clicking on Delete

After the deletion the user gets redirected to the entries page, but the item is still there, and the page needs to be reloaded again to show the deletion effect. If i disable caching the problem disappears, but i really want to have caches in all the other pages...

adding these tags didn't work, i think my browser just ignores them

<meta http-equiv="Cache-Control" content="no-cache, no-store, must-revalidate" />
<meta http-equiv="Pragma" content="no-cache" />
<meta http-equiv="Expires" content="0" />

I'm enabling the cache trough:

@app.after_request
def add_header(response):    
response.headers['X-UA-Compatible'] = 'IE=Edge,chrome=1'
response.headers['Cache-Control'] = 'public, max-age=600'
return response

Is there a way I can disable it for a specific page?

edit

as suggested i tried using a wrapper:

def no_cache(f):
    def new_func(*args, **kwargs):
        resp = make_response(f(*args, **kwargs))
        resp.cache_control.no_cache = True
        return resp
    return update_wrapper(new_func, f)

and wrap the page i want wihtout cache in a @no_cache decorator, still had no luck...

See Question&Answers more detail:os

与恶龙缠斗过久,自身亦成为恶龙;凝视深渊过久,深渊将回以凝视…
Welcome To Ask or Share your Answers For Others

1 Reply

0 votes
by (71.8m points)

You can try adding cache control headers only if there are no such headers for a specific page:

@app.after_request
def add_header(response):    
  response.headers['X-UA-Compatible'] = 'IE=Edge,chrome=1'
  if ('Cache-Control' not in response.headers):
    response.headers['Cache-Control'] = 'public, max-age=600'
  return response

And in your page code - e.g.:

@app.route('/page_without_cache')
def page_without_cache():
   response.headers['Cache-Control'] = 'no-cache, no-store, must-revalidate'
   response.headers['Pragma'] = 'no-cache'
   return 'hello'

The point is that you shouldn't override your headers in @app.after_request for all pages - only for those where cache isn't turned off explicitly.

Further, you might want to move the code adding headers to a wrapper such as @no_cache - so you can use it just like that:

 @app.route('/page_without_cache')
 @no_cache
 def page_without_cache():
   return 'hello'

与恶龙缠斗过久,自身亦成为恶龙;凝视深渊过久,深渊将回以凝视…
OGeek|极客中国-欢迎来到极客的世界,一个免费开放的程序员编程交流平台!开放,进步,分享!让技术改变生活,让极客改变未来! Welcome to OGeek Q&A Community for programmer and developer-Open, Learning and Share
Click Here to Ask a Question

...