Watchdog timer broken when using browser's back button #384
Description
Issue reproduction
- start CDPedia
- navigate to an article
- return to the first page by pressing the browser's back button
- wait at least 2 minutes and try to navigate to another article
- the browser can't connect to CDPedia because the process ended
This is unexpected. The process should not be terminated while there's a CDPedia page opened in the browser.
Current behaviour
The current watchdog mechanism is implemented by embedding an iframe in each page:
CDPedia/src/web/templates/cdpedia_base.html
Lines 27 to 31 in 61f73b4
This iframe requests a dummy empty page that reloads itself every x seconds:
Lines 254 to 261 in 61f73b4
CDPedia will exit if more than BROWSER_WD_SECONDS seconds pass without hitting this endpoint.
This works great for all situation except the one described above.
Possible solutions
Adding {"Cache-Control": "no-cache, no-store, must-revalidate"} to the response headers of the watchdog endpoint fixes the issue in Chrome but not in Firefox. Maybe a solution with javascript should be explored.