Enable passing Vendor parameters to ows4R::GetFeature()

[annakrystalli]

This PR (I believe) addresses the issues raised in #86 by introducing dots into emodnet_get_layers() which allows passing additional vendor parameters etc. to underlying ows4R::GetFeature() function.

I've started fresh because of merge issues with previous PR #87

This allows, for example, passing a count=1 argument to return just the first feature.

I've now tested this and it works at least with the simple count = 1 request.

@salvafern I tried your example and I'm now getting a different error which has to do with the result being a data.frame:

R.utils::withTimeout({
    
    test_emodnetwfs <- emodnet_get_layers(
        wfs_client,
        layers = "eurobis-obisenv_basic",
        viewParams = viewparams,
        resultType = "results"
        
    )},
    timeout = 10
)

Warning: Download of layer 'eurobis-obisenv_basic' failed: Error in UseMethod("st_crs<-"): no applicable method for 'st_crs<-' applied to an object of class "data.frame"

This is an issue identified in #62 but your input on what @maelle has been thinking as a solution would be useful. Ultimately, WFS is not really the place to serve non spatial data but it seems there are some such datasets so we'll need a strategy to handle them.

Moved vignettes to articles.

I've also gone ahead and moved our docs from vignettes to articles so they don't get rebuilt every time R CMD CHECK is run

[maelle]

Excellent idea! Added a few comments.

[maelle]

why are the dots passed here too?

[annakrystalli]

purrr::map does funny stuff with dots so this was the only way to get it to work: https://stackoverflow.com/questions/48215325/passing-ellipsis-arguments-to-map-function-purrr-package-r

[maelle]

Could you add this as code comment so we don't forget? That sounds good to know 😅

[maelle]

why are there new fixtures, and what is their size?

[annakrystalli]

Because I'm testing a new request. Small because it only returns the first feature

[maelle]

but there is no httptest::with_mock_dir in this test?

[annakrystalli]

Oh yesh. Actually it doesn't seem like there is fixture for it but there probably should be

[salvafern]

Hi @annakrystalli

By requesting eurobis-obisenv_full (which has geometry) I can see that the vendor params work fine. Thanks!!

test_emodnetwfs <- emodnet_get_layers(
        wfs_client,
        layers = "eurobis-obisenv_full",
        viewParams = viewparams,
        resultType = "results"
   )
 class(test_emodnetwfs$`eurobis-obisenv_full`)
#> [1] "sf"         "data.frame"

I agree that WFS is meant to share vector data, so the layers should have a geometry. But there will be cases in which there is no geometry and it would be good to check it as in eblondel/ows4R#65 (comment) (and maybe raise a warning?).

I will check why the basic data don't have geometry. If there is not a serious reason I will add the geom via geoserver (the layer has anyways lon and lat as attributes)

Feel free to merge 🎉