Always let user know if page is still loading or not

[jidanni]

Rather often this week, everything works fine, except there is no map data:

I checked DevTools network tab and there were no errors there.
I do only have a 2M/64K ADSL connection, but that shouldn't be the culprit.
And yes, this is a heavily mapped area.

[tyrasd]

Oh, that's pretty odd. Something must have gone wrong while loading the map data…

I checked DevTools network tab and there were no errors there.

Are there also no errors in the developer tools console tab?

[jidanni]

Here it happened again, after an edit.

The console just has a few [Violation] 'requestIdleCallback' handler took 59ms
Clicking the OSM logo to leave iD, then clicking Edit to return, doesn't help.

Closing the browser tab, opening a new one and navigating to the site doesn't help.

Nope. It seems all I can do is a couple edits a day before this starts happening. I bet it is due to a heavily loaded system causing some items to timeout and never load.

[tyrasd]

Does switching to a different browser maybe help? If you can, also trying a different network connection might be worth a try.

One more information to help debug the problem would be to check what the OSM API returns when this happens. Go to the network tab and click on one of the map.json calls to see what the response looks like. It should look like in the screenshot below (Chrome, but Firefox should be quite similar), except that in a working case the elements would not be an empty list ([]) in a well mapped region:

[jidanni]

Bummer.

There are all kinds of *.json...

Just no map.json!

Kind of makes one feel bad.

P.S., it's ChromeOS, so let's debug this for Chrome. P.S.S., those blue streaks above are when the background imagery finally loaded. I.e., I'll keep my system heavily loaded until we can find out what messes up iD in such situations.

[jidanni]

Wait, sometimes there is partial data,

OK, I started DevTools and hit CTRL+R, and alas the data went away.

is the only hint of any map.json. Console: same as previous mention.

[jidanni]

Opinion:

No spinners or anything anywhere to tell the user the page is still loading.

• No spinner seen before imagery loads. User just stares at black screen.

• No spinner seen before map data loads. User just stares at pretty imagery as if the place has never been mapped yet.

• And of course no old fashioned browser built-in spinners, because this is no simple HTML document.

How to reproduce: try iD on a third world network with a third world laptop.

No I will never know if in fact I am still waiting for something to load, as even the bottom of the page,

Gives no clue.

How about putting "Page not fully loaded yet" there, and only clearing it out when all the stuff has finally loaded:

(I recall there used to be a spinner down there last year.)

P.S., don't freak out about the "hidden features" above. Yes, I hid all but roads.

Anyway, let's get those indicators of page loading status into the code. Then we will be able to debug such problems further.

(OK, #8373 ialso ndicates I should also test on another browser. OK, I installed chromium (yes, rhymes with chrome) and indeed my craptop became a CRAY and iD acted like it was on Vi*g*a, no bugs! But that's beside the point.)

But still iD should always have a spinner...