Clearing Dash cache?

Dash Python
1

Let’s say you have an app setup to cache some data. But you need to clear that data, re-compute, and update a graph if a “Submit” button is clicked. What is the proper code for it? cache.clear() doesn’t seem to clear the cache, so I think I might be doing it wrong. This is an example code I have that I’m thinking about:

app = dash.Dash(__name__, external_stylesheets=external_stylesheets)
cache = Cache(app.server, config={
    #'CACHE_TYPE': 'redis',
    # Note that filesystem cache doesn't work on systems with ephemeral
    # filesystems like Heroku.
    'CACHE_TYPE': 'filesystem',
    'CACHE_DIR': 'cache',

    # should be equal to maximum number of users on the app at a single time
    # higher numbers will store more data in the filesystem / redis cache
    'CACHE_THRESHOLD': 200
})

def get_data(session_id, value):
    @cache.memoize()
    def serialize(session_id, value):

        # do my expensive computations

    return pd.read_json(serialize(session_id, value))

@callback for my button
def my_button():
    cache.clear()
2 Likes
2

Having looked into this recently, I do not believe deleting/clearing memoize()'d data is possible at the moment.

However, the dcc.Storage component has just come out for storing data, and it allows a separate callback to delete its contents, with an example in this post, which you could possibly do before updating it.