Declarative schema from configuration file

[ZeLonewolf]

Fixes #18

This PR provides the ability for a user to specify an arbitrary vector schema via a configuration file. Configuration is via a YML file which specifies the contents of the configured layers. Documentation for the schema definition format is provided in planetiler-custommap/README.md.

The schema language allows for the following features:

• Ability to define layers and features within layers based on tag filters
• Ability to specify attributes as a function of tags
• Ability to specify feature zoom levels as a function of tagging or feature area
• Ability to specify data sources in a configuration file

A collection of unit tests are provided, as well as a sample schema intended to support OWG vector tile exploration under openstreetmap/operations#565

A typical invocation looks something like:

(java/docker launch) generate-custom --schema=schema_file.yml --download --area=rhode-island

This PR does not include handling for line merging, which needs a deeper investigation to deal with attributes that have minimum zooms greater than the overall feature minimum zoom, which would allow certain linestring features to merge only at certain lower zooms.

[msbarry]

Looks good! Pushed a couple of minor changes and added #247 to track some followup tasks after this lands. I'll plan to merge a couple of other in-flight changes, put out a 0.5.0 release then land this PR.

[msbarry]

How will we specify other geometry accessors like centroid eventually? Would that be a different value for geometry? Or an additional flag so you can vary the source feature geometry type and accessor function separately?

[ZeLonewolf]

I think it would be a flag or enumeration. A centroid is still a representation of an area IMO.

[sonarcloud]

Kudos, SonarCloud Quality Gate passed!   

0 Bugs
0 Vulnerabilities
0 Security Hotspots
1 Code Smell

89.0% Coverage
0.0% Duplication

[fphilippe]

Hi everyone, I've understood that this PR is already integrated the main base code ? Do you know when a release will be compiled ?

[wipfli]

I think it is already released. Try something like the following:

mkdir data/
cd data/
wget https://raw.githubusercontent.com/onthegomap/planetiler/main/planetiler-custommap/src/main/resources/samples/shortbread.yml
cd ..
docker run -v "$(pwd)/data":/data ghcr.io/onthegomap/planetiler:latest generate-custom --schema=/data/shortbread.yml --download

[fphilippe]

Thank you @wipfli for your quick answer. I got it, but the jar file is not available in releases.