[Bug] Slow UI performance when closing a case

[DrJohn1]

When closing a case, the list of open/in progress tasks takes too long to load, causing issues if pressing "Close tasks and case" before it completely loads (bug)

Request Type

Bug

Work Environment

Question	Answer
OS version (server)	Ubuntu 18.04
OS version (client)	Ubuntu 18.04
TheHive version / git hash	4.0.0-1
Package Type	DEB

Problem Description

When selecting "Close" case button, the first dialog listing open/in progress tasks will appear empty and take a long time (>10 seconds) to appear. If you select "Close tasks and case" before the list appears, the close dialog will appear twice, losing any changes you enter and not closing the case when pressing "Close case":

Example shows no tasks, however this case still has three tasks open.

The logs show it takes, in this test case, 7 seconds to populate the list (but it increases exponentially as more cases and tasks are created on the TheHive instance):

Steps to Reproduce

1. Create a new instance and add multiple cases and tasks to the cases.
2. Load a high number of cases and tasks (100 cases, 2000 tasks).
3. Press Close in a case and on the next dialog press "Close tasks and case" before the list appears.
4. Changes made to the close dialog will not be saved as the dialog resets.

[rriclet]

This issue has been fixed with #1731, included in release 4.1.0.
Feel free to re-open this issue if you still notice slow performance.

[scottbrazil]

I'm using release 4.1.24 and it takes 60s just to open the popup for closing the case