Search results map

[julian-schneider]

What this PR does / why we need it:

Adds a browsable map of all search results with geospatial information. It is located in a tab on the search results page, as an alternative to the normal list of search results. The map displays one pin per dataset, which can be clicked for a small preview that leads the user to the details page. Clusters of pins are grouped to declutter the area.

This implementation is entirely based on the proof of concept by @PaulBoon described in detail here. That PoC uses a custom footer to inject the map into the classic UI, while this implementation is based on react-leaflet.

This PR is a work-in-progress draft version. Some open issues I'm aware of:

• The geospatial metadata block contains any number of bounding boxes, while the map is currently designed to display one point. This current prototype simply displays the southwest corner of the first bounding box.
• The current prototype only displays published datasets
• Performance with large amounts of datasets still untested
• i18n should be used

Which issue(s) this PR closes:

• Closes Feature Request/Idea: Display dataset search results on a geographical map  #580

Suggestions on how to test this:

Populate an installation with datasets filling out the official geospatial metadata block, and the map should display them.

Does this PR introduce a user interface change? If mockups are available, please link/include them here:

Yes. The map was entirely based on the design of the previously-mentioned PoC.

Is there a release notes or changelog update needed for this change?:

Yes

[julian-schneider]

Screenshot:

[coveralls]

coverage: 98.063% (+0.2%) from 97.861% — julian-schneider:feat/search-results-map into IQSS:develop

[PaulBoon]

@julian-schneider Great work!
If you want to look at the performance you could have look at the stress tests that I did some time ago; you could probably reuse the test data generating Python code and possibly the Jmeter tests.
https://github.com/DANS-KNAW/dataverse-dataset-geomap-view/tree/main/examples/testdata/stresstests

[qqmyers]

FWIW: Using ?query_entities=false in the Dataverse API is a factor or 10x faster, so unless you needed the added info, I'd definitely add it.