Add support for other projections

[gjmooney]

Small fix for issue with the tif layer loading in the wrong location mentioned in #196 Should fix #191

Added support for reading projection info from gqz files.

EPSG:3857

EPSG:4326

[github-actions]

👈 Launch a Binder on branch gjmooney/jupytergis/suport_proj4js

[martinRenou]

Neat!

[martinRenou]

Should fix #191

[gjmooney]

Should fix #191

I saved a qgz using the aitoff projection, and opening that in Jupyter GIS shows the layer with the default projection, but we still need to implement getting the projection from the QGIS and set that properly in JGIS. It seems like it should be straight forward enough, qgz files have the proj string used in proj.def() but I was getting some weird webpack errors when I was playing around with it, so maybe not so straight forward 🤷‍♂️

[martinRenou]

What kind of webpack errors?

[gjmooney]

What kind of webpack errors?

For example, replacing proj4.defs(Array.from(proj4list)) with proj4.defs('EPSG:7030, 'aitoff +lon_0=0 +x_0=0 +y_0=0 +datum=WGS84 +units=m +no_defs'
causes

[martinRenou]

Oo that is really weird. I don't understand how this error message can relate to the code being run.

[gjmooney]

Oo that is really weird. I don't understand how this error message can relate to the code being run.

Especially since proj4.defs(Array.from(proj4list)) works fine! It's bizarre 🫠

[martinRenou]

It says qgisplugin failed to activate. Did you change anything in the plugin implementation?

[gjmooney]

It says qgisplugin failed to activate. Did you change anything in the plugin implementation?

Nope, literally just changed that one line.

[martinRenou]

Can you push the diff loading the projection from the qgz file, then share that file?

I will give it a try locally

[gjmooney]

Can you push the diff loading the projection from the qgz file, then share that file?

I will give it a try locally

I'm not loading from the qgz directly yet, I just looked in the extracted qgz file to get the aitoff +lon_0=0 +x_0=0 +y_0=0 +datum=WGS84 +units=m +no_defs string to create the proj4 def to use for the OpenLayers Projection

[github-actions]

Preview PR at appsharing.space

[github-actions]

Integration tests repot: appsharing.space

[martinRenou]

Can you try running:

proj4.defs('EPSG:7030, 'aitoff +lon_0=0 +x_0=0 +y_0=0 +datum=WGS84 +units=m +no_defs');
register(proj4);

At the constructor of the view instead of at the top of the file? Wondering if the error message would get more useful that way.

[gjmooney]

Moving it to the constructor shows

I did some digging and it seems like the .def() works, but when register gets called
it hits https://github.com/openlayers/openlayers/blob/main/src/ol/proj/proj4.js#L78 which starts https://github.com/proj4js/proj4js/blob/master/lib/core.js#L55 and ends up at https://github.com/proj4js/proj4js/blob/master/lib/core.js#L51 where we get to https://github.com/proj4js/proj4js/blob/master/lib/Proj.js#L24 but "aitoff" isn't in the names object at https://github.com/proj4js/proj4js/blob/master/lib/projections.js#L27 so it throws https://github.com/proj4js/proj4js/blob/master/lib/Proj.js#L26

So maybe proj4js just doesn't support aitoff projections?

[martinRenou]

Thanks!