使用Flask时缓存的JSON文件

Question

I'm trying to do a visualization app in js + python. My app works like this:

1. in browser I have a textbox where I introduce an url

2. I send that url to python using Flask

3. in python I take that url, I process it, and I create a JSON file

4. in js I take that JSON file and I display the result in browser

The problem I encounter: I introduce the url in browser, click submit, and it shows me the result, this is ok. But the next time when I introduce another url, it shows me the same result as the previous, if I introduce another url, still the same result. So the JSON file is somehow cached somewhere. To resolve this I have to delete everytime the old JSON file and rename the new one in python code.

My question is, where should I put this JSON file to prevent caching? Or is there another way?

I have this hierarchy of files:

project
   |--- static
           |--- file.js
           |--- file.json
   |--- templates
           |--- file.html
   |--- file.py

This is what I am trying to do: http://whichlight.github.io/reddit-network-vis/

Answer 1

You have one file file.json catering to multiple urls. This can only work if you are only dealing with one user at a time. I assume you're trying to cache the result, and for that you would need a different file for each url. A slightly better way would be to use an in-memory database like redis for that.

But if all you want to do is busting the cache, then instead of calling file.json in your ajax call, use file.json?<randomstring> like file.json?t=<timestamp>

$.ajax({
  dataType: "json",
  url: url + "?" + (new Date()).getTime(),
  data: data,
  success: success
});