UI Tasks view: fix per page settings

[mzazrivec]

Configuration -> Tasks -> per page settings and page navigation
wouldn't work correctly:

• the view would always default to 50 items per page
• incorrect numbers shown next to the navigation icons

Fixes #818

https://bugzilla.redhat.com/show_bug.cgi?id=1171150

[h-kataria]

@mzazrivec why do we need unless check here, don't we only call change_tab when tab is changed in UI, i don't see any other callers of this method.

[mzazrivec]

We also call change_tab() when navigating through the tasks list (those next, previous, first, last buttons).

[h-kataria]

@mzazrivec (next,previous..) buttons should not send up action as change_tab, they should send up a transaction to "index" method.

[h-kataria]

@mzazrivec ignore my previous comment, discussing with @AparnaKarve, @dclarizio to see if this should be the correct behavior for paging controls on the screen with multiple tabs and list views.

[mzazrivec]

The paging controls -- as far as I can tell -- are being all rendered from
layouts/_pagingcontrols.html from which we call update_paging_url_parms()
to construct the navigation urls.

update_paging_url_parms() simply takes the relate path from request:

"#{request.path_info}?#{updated_query_string.to_query}"

So what's being called when you hit the navigation buttons depends on the request
that rendered the list view that you're clicking on.

If you initially land on the 'Tasks' page, you're being presented with the 'My VM Analysis Tasks'
tab -- request is by /miq_proxy/index. Paging requests then go to /miq_proxy/index.

If you change the tab to something else ('All Other Tasks' for example), the request changes
to /miq_proxy/change_tab and all subsequent paging request then go to change_tab.

[h-kataria]

@mzazrivec your analysis above is correct, the question here is should we leave it as it is currently working or do we need to figure out a way to change the path so paging controls send up a transaction to index method. @AparnaKarve @dclarizio thoughts?

[AparnaKarve]

@mzazrivec I think a fix might be needed in update_paging_url_parms.
There are essentially two parts to this method - the path and the url params.
The path is what needs to be addressed. Let me get back to you on what could be done to fix the path.

[h-kataria]

@mzazrivec when i go to Tasks screen first time, i selected 5 on Per Page pull down nothing happens. It starts to work after i change tab once.

[mzazrivec]

@h-kataria This is because in this particular case, the per page pull down makes a post request
to /miq_proxy/index -> routing error.

This is fixable in the same way I fixed it for /miq_proxy/change_tab: add the route and
modify the index method -- render unless request.xml_http_request? to avoid double
render error.

[miq-bot]

Checked commit mzazrivec@7cd0e66 with rubocop 0.27.1
3 files checked, 0 offenses detected
Everything looks good. 🍪

[dclarizio]

Closed per @mzazrivec comment in #1231.