Call a Flask function from a Dash callback

Dash Python
1

Hi.

So we have this user case that we want to return a file to the user when they press a button.

The event would trigger a Dash callback and then we just want to call to flask.send_file().

How can we do this?

2

bouncing back this: anybody has any idea?

3

You can define routes on the underlying Flask server of your Dash app, so something like this will do the trick

@app.server.route("/download")
def download():
    return flask.send_file("filename.ext")

Then just add a link to your layout with href="/download".

2 Likes
4

We already do that, but we want to use more parameters and data which are given by other dash components, so we need to get them inside a dash callback and return the file from there.

5

Maybe the callback could select the right link (selecting from all possible links which have already been created with flask routes) and return that, updating the layout?

1 Like