Fix loading text if naturalEvents is not set

[PacoDu]

Fixes #627 .

Changes in this pull request:

• Split div wv-events into wv-events and wv-loading for consistency
• Added loading hide() after sidebar rendering

@nasa-gibs/worldview

[ZachTRice]

Perhaps this div should go below #wv-data, since "Loading..." is actually indicating that any part of the sidebar is in a loading state and, it contains less important information than what is in the data tab. Otherwise, this looks good to me.

[PacoDu]

Yes I agree, I'll push that in a minute

[localjo]

I originally added the "Loading..." text to fix an issue; when switching to the events tab, there is a delay while events information loads and the tab was empty with no indication that anything was loading. On some connections, it would take several seconds for anything to display in the tab, which made it seem like there were no events and would lead to users switching tabs again before anything loaded. You can reproduce that issue by setting your dev tools to emulate a slow connection, disabling cache, reloading the page and then clicking on the events tab. On master you should see "Loading..." until the events load. This PR removes that text from the events tab, so it reintroduces the original problem.

[PacoDu]

Oh ok I see, so should I just add an else condition after

worldview/web/js/layers/wv.layers.sidebar.js

Lines 199 to 210 in a85692d

	if (config.features.dataDownload) {
	var $downloadTab = $('<li></li>')
	.addClass('layerPicker')
	.addClass('third')
	.attr('data-tab', 'download');
	var $downloadLink = $('<a></a>')
	.attr('href', '#wv-data')
	.addClass('tab')
	.html('<i class=\'productsIcon selected icon-download\' title=\'Data\'></i> Data');
	$downloadTab.append($downloadLink);
	$tabs.append($downloadTab);
	}

Something like:

else{
   $('#wv-events').hide()
}

[Benjaki2]

@PacoDu I think that condition could go here for a quick fix: https://github.com/nasa-gibs/worldview/blob/master/web/js/wv.main.js#L147-L149

But it would probably be better to take the Loading... text out of the index.html and actually append that when wv.naturalEvents.ui is initiated. What do you think?

[PacoDu]

@Benjaki2 Yes the code would be more consistent. I don't have time now but I'll take a look tomorrow.

[PacoDu]

Well, sorry for the delay :).
I've moved the Loading string to naturalEvents init, this Fixes #627 and still display "Loading..." on NaturalEvent tab for slow connections (tested with 3G network settings on chrome).

[Benjaki2]

@PacoDu We are in the process of merging and releasing #503 which should be on Production Monday (if all goes as planned 🤞 ). We will try to get this merged in right after. Thanks for the contribution!

[localjo]

Looks good. We may have a little trouble merging due to other changes that might conflict.

[localjo]

This file has changed in the module-loaders branch. Let's try to change the target of this pull request to that branch, and manually adjust it if necessary.