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 displays a marker at the averaged center of the dataset's bounding boxes. When the marker is clicked, the bounding boxes will be displayed.
• 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.