This is regarding RM3294 which I am working on, where user needs to reset the layout to see the changed preferences parameters. I am able to implement it, and have used the following approach:
1) when preference changed, fire a custom event - prefChangedEvent
We can also fire preference specific event instead of generic event.
I have just sent the overall flow and not the detailed. I am going to make it general event with data as modules whose preferences are changed.
And we can generate event name from preference itself like <module>:<category>:<name>:<event_type>
eg.: browser:display:show_system_objects:update
This will require lot many if clauses and with so many preferences I think we should do it at module level.
2) listent to prefChangedEvent wherever preferences should be reflected in realtime.
3) In the event handler, make the changes as per the module.
4) So whenever the preferences are changed, the event fires, the listener executes the event handler and changes are done.
Benefit of this approach is no polling. But, there is a problem here.
It is not possible to fire event in another tab/new browser window. For example, query tool can be open in another tab. And thus, changes are not reflected there. There are solutions available like updating the localStorage of the browser but those are not reliable and does not work properly on different browsers.
To communicate between browser tabs we can use cookie polling on client side it self (at least it will avoid polling over http).
The main tab will update only preference specific cookie when preference is updated and other tabs will poll required cookies (not all)
with specific interval (1 second can be configurable).
Polling is a solution but I think it should be the last option. http polls will not be required anyway as we have preference cache in the browser object.
Request you to kindly suggest if you any better idea.
Thanks and Regards,
Aditya Toshniwal
Software Engineer | EnterpriseDB Software Solutions | Pune
