make owmloading.gif configurable option

[jywarren]

Supercedes #473

We should be able to set this when we initialize LEL here using:

options.imageLoadingUrl = "someGifAnimation.gif"

For example in plots2, here:
https://github.com/publiclab/plots2/blob/30fb69618430b589889f7e20cb8ce845e0b89e8d/app/assets/javascripts/leafletHelper.js#L116-L122

[gitpod-io]

[RuthNjeri]

From the leaflet documentation, it states that

imageLoadingUrl: URL ( 'owmloading.gif' ). URL of the loading image, or a path relative to the HTML document. This is important when the image is not in the same directory as the HTML document!

And from #473 @Tlazypanda wrote images/owmloading.gif that somehow adds the path...

I tried looking for the leaflet-openweathermap in the public/lib folder but could not find it...

Perhaps it should be added to load the owmloading.gif?

[jywarren]

I think the issue is that we aren't even actually including the weathermap dependency -- it may only be compiled in? In any case i think i'll just merge in the version which includes the actual image into the LEL lib and then we'll be able to link to it from /lib/leaflet-environmental-layers/... from within Rails.

Gosh this was a can of worms, with getting the tests to pass again! i thought it was going to be quick -- 😅

hopefully almost done though!

[gitpod-io]

[jywarren]

Hmm, purple air marker failing. I wonder if these tests are cross-wired, if they're specific enough to be testing for the layer they say they are, or if they are somehow interconnected and testing for the wrong markers...

  1) Purple layer - markers
       has circle markers in minimal mode:
     AssertionError: Timed out retrying: Expected to find element: `.leaflet-overlay-pane svg g`, but never found it.
      at Context.eval (http://localhost:8080/__cypress/tests?p=cypress/integration/purpleAirMarker.spec.js:33:10)

  2) Purple layer - markers
       shows popup:
     AssertionError: Timed out retrying: Expected to find element: `.leaflet-overlay-pane svg g`, but never found it.
      at Context.eval (http://localhost:8080/__cypress/tests?p=cypress/integration/purpleAirMarker.spec.js:41:8)

  3) Purple layer - markers
       removes markers from the map and the layer name from the hash when clicked again:
     AssertionError: Timed out retrying: Expected to find element: `.leaflet-overlay-pane svg g`, but never found it.
      at Context.eval (http://localhost:8080/__cypress/tests?p=cypress/integration/purpleAirMarker.spec.js:53:8)

[jywarren]

Got it! I wonder if it was just a timeout issue, we can work that later.

[jywarren]

OK, modifying this in #508