pfSense

Some activities output their text progress to a text box in the UI (e.g. package installation). If the user navigates away from the relevant page then stuff goes wrong with the "background" process that is doing the work. It would be nice to avoid that - put the output of such things into a text file somewhere and display that output when the user comes back to the "package installation..." page so they can see what happened without having broken the background process.
And as Stilez has said above, provide a consistent status banner thing.

The "notices" in the banner in 2.3 alpha is an improvement on 2.2.x, in this area, for what it's worth.

(sorry, I hit "submit" early)

... To expand a bit following PD's comment, part of the issue is that it shouldn't only display "when the user comes back to the package installation page". Not only some background activities (reload rules etc) allow the user to navigate away and do other things at the same time, but also the user might log out then log back in, they may not remember, other colleagues may log in who may not be aware in the first place. So relying on them to revisit the same page in order to be aware something's happening, and allow for it, isn't really as good as consistent banner info visible whatever page one is on.

So if something major of these kinds (including but not limited to maintenance/updates/reinstall/etc) is going on, I think that either the UI shouldn't allow them to see anything but the banner while it's happening, or - if they can navigate elsewhere while it's happening - then it should remain apparent in the UI header that something is going on, not break the "background" process, and be viewable what is going on and where it's up to.

Perhaps an elegant "fix" would be something a bit reminiscent of the "dirty" flag system, where any activity can be added to a list of "activities running in background" along with a list of pages that won't be operable until it's completed. For example:

// ...reinstall of all packages gets kicked off...
/* note the new activity:
     parameters: activity brief description, pages inoperable until completed, banner for these pages if accessed
     return value: an ID so this can be cancelled and updated as we progress
*/
$notice_id = background_activity_start("Reinstall all packages", array("pkg_mgr.php", "pkg_mgr_installed.php"),"Packages are being reinstalled, you cannot change packages until this is complete");

// ... reinstall progresses...
/* update the info as required:
     parameters: the notice ID, description of this stage, % of current stage complete, % overall completed
*/
background_activity_update($notice_id, "Package 3/10, installing Perl X.Y.Z", 30, 45);

// ...reinstall ends, successfully or otherwise...
/* final result and close this activity, which automatically re-enables any disabled pages
     parameters: the notice ID, final message, and an error code or 0=success
*/

background_activity_end($notice_id, "All packages reinstalled", 0);

The effect is that there's a single system which anything using background processes can use consistently. Not sure the details but would "something like this" work?

Not sure the details but would "something like this" work?
Yes, basically a combination of the existing components that:
a) Presents the message about "Packages are reinstalling in the background..." - expand that to use it in more places, give updated progress...
b) The file_notice() function that presents important messages that the GUI user needs to look at and clear - use it judiciously for telling when something important has finished.
c) Re-engineer "inline GUI" code that is doing real stuff so that it works away in the background and uses (a) and (b) as appropriate to communicate with the user.

The progress system used in pkg_mgr_install.php will allow the user to navigate away from the page, then come back later and pick up the progress. I may encapsulate this system to make it easy to use on other pages, but I need to finish the system base firmware update first. It does store the progress in a server file and fetch it via ajax.