How to save values to json file?

Dear,
Take Todo sample app as example. I can now push value from input into tasks object. However, each time I refresh the page, they are cleared. Therefore, can anyone show me how to save the object as JSON file so that I can call it each time I open the app or refresh it.
Thanks.

Have you tried using window.localStorage to persist your data on the device as described in the last part of the tutorial?

yes, I have tried it. But I read some articles saying that localStorage will be cleared if user clear all web cookies… so I would like to store and save them into an existing json file.
Is there any way to do this?

I see. Good to know actually.

Have you seen this thread yet? A few other options are covered there.