Whether you’re just beginning with Leaflet or you’ve been around when Leaflet 0.7 was the current release, this collection of more than sixty Leaflet examples is a valuable resource for anyone. There are basic examples like setting up a Leaflet map or adding a marker, solutions to more complex problems like fitting bounds with padding, and advanced concepts such as overlaying images or searching across layers.

A new release of the web-mapping library OpenLayers is out. v6.15 includes, among other things, performance improvements, enhanced styling options for symbols, and bug fixes.

mbtiles-s3-server is a new Python library, developed by Michal Charemza, which reads vector geo-data from an MBTiles file stored in S3 and serves it as vector tiles. The library leverages range requests to query an SQLite database in S3.

Very much in line with advancements in file-based, cloud-optimised data storage we’ve been seeing in the last couple of years.

Google Maps Introduces Data-Driven Styling, the Cumbersome and Inaccurate Way to Make a Map

The Google Maps API was never an obvious choice for building advanced cartographic data products. It was always something local businesses use to put a map on their website showing where their shops are located.

Google Maps has now introduced data-driven styling, addressing a new audience outside local businesses. Data-driven styling of Google-maintained administrative boundaries that is. Google maintains and provides a data set of boundaries at varying administrative levels and allows developers to join their thematic data to create choropleth maps.

Looking at the documentation, linking your own data to Google’s boundaries dataset isn’t straightforward. To match the records from your dataset to the features from Google’s boundary dataset, you need to find the corresponding place ID from the Region Lookup API. If you have a hundred records, you need to do a hundred location lookups via the API before your map can be fully rendered. Unless you’re already keeping Google’s place ID in your data, which we all do, don’t we?

What’s the point of this approach is over loading and styling a GeoJSON layer, which has been supported by the Google Maps API before? Sure, you don’t have to maintain an administrative-boundaries dataset. But if the geometry and thematic data come from different sources, can we be sure that both represent the same underlying geographic area. Does this number of Covid cases aggregated by council assume precisely the same boundaries Google provides? We can’t know for sure, and the resulting maps might be unintentional lies.

And obvious use cases for maps based on administrative boundaries include election data, demographic information, or the number of COVID cases within a council. The people producing such data sets will likely maintain or have access to official and accurate boundary data sets. They have no reason to use Google Maps.

Google Maps data-driven styling isn’t a well-designed API of a product that solves a real problem. It’s a marketing stunt.

Mapbox GL JS 2.9.0 Adds Globe Projection

Mapbox GL JS’ latest release (v2.9.0) adds a new globe projection, which enables presenting web maps in a way that allows viewers to interact with geographic data much like you would interact with a physical globe.

A globe rendered with Mapboc GL JS, showing Africa in the center.
Background tiles: © Mapbox. Map data: © OpenStreetMap contributors.

From the release notes:

This new projection displays the map as a 3d globe and can be enabled by either passing projection: globe to the map constructor or by calling map.setProjection('globe'). All layers are supported by globe except for Custom Layers and Sky.

The globe projection is a continuation from custom projections, which were introduced a couple of months ago and, for the first time, allowed creating interactive web maps using projections other than Web Mercator. While custom projections were ideal to present data restricted to countries or continents and without the hefty distortions that come with Web Mercator, the globe projection allows to do the same but on a global scale; ideal to present global data sets like visualisations of climate change.

Update: Mapbox has published a blog post with very nice-looking examples: A new way to experience the world.