Roadmap 2025 - Analyze and refine main goals for Hakunapi as an OGC API Features Server

[teezip]

This is not a dedicated enhancement issue but a more generic analysis and plan for future improvements.

The current state

https://github.com/nlsfi/hakunapi

Current main goals are stated in the readme:

A server implementation of OGC API Features

• OGC API - Features - Part 1: Core
• OGC API - Features - Part 2: Coordinate Reference Systems by Reference
• OGC API - Features - Part 3: Filtering and Common Query Language (CQL2)

Focus on:

• Simple features backed by a PostGIS database
• High performance (achieved with streaming and by reducing the amount of garbage created)

Latest major releases and feature releases

• 1.5.0
  • Support for OGC API Features Part 3 and CQL2 1.0.0
  • source-gpkg v0.1
• 1.5.2
  • Add configuration option to support output of 3D geometries for configured srids only. This leaves room for improvement, though. Also using new compound crs 10774 along 2D crs 3067 in NLS of Finland specific services requires code hacks.

Format support

• Data stores
  • PostgreSQL / PostGIS​
  • GeoPackage​
  • Experiments, not published​
    • Custom file based system (“Hakunapi snapshot”)
• Output writers
  • GeoJSON​
  • HTML​
  • GeoPackage​
  • CSV (WKT)​
  • Other formats, not fully supported​
    • GML (3.1.1/WFS 1.1.0)​
    • ElasticSearch Bulk API JSON​
    • Jackson Smile (GeoJSON)
    • JSON-FG

What is current JSON-FG status? It was discussed and partially (?) implemented and closed on release 1.5.0:

• Analyze use cases and implementation choices for supporting OGC Features and Geometries JSON #26
• Initial implementation for JSONFG output format #73
• Support multiple floating point formatter configurations for JSONFG geometry and place output - with side effects #89

JSON-FG status

• standard: still some issues open, but "almost final"
• Hakunapi: initial implementations was included in 1.5.0, but need still analysis / corrections according to standard

Other notes

• Hakunapi has *paging strategy" option that allows implementing paging using next links (as the default implementation in Hakunapi and the standard) or offset parameters

Roadmap 2025

TODO (this shall be edited on the meeting 27th March 2025)

New dockerized demo service

• New dockerized demo service - inspire-addresses #138

Documentation improvements

• at least this : Improve main readme page with details about supported OGC API standards and list of modules #137

#133

• next steps as mentioned on the issue: copying by templates

Version 1.6.0 see milestone

• target date: June 2025 or August 2025???
• main goals:
  • vertical and compound coordinate system support and consistent configuration
  • OGC API Features standard enhancements
  • other smaller issues from the list of open issues
• Support for compound CRSs or use service defined (in configuration) vertical reference system when no applicable compound CRS is available  #132
• initial analysis also about this: enhancements on the current schemas endpoints and preparing for OGC API - Features - Part 5: Schemas (see links below)

Version 1.7.0

• target date: XXX 2025???
• main goals (draft, depending how these standards evolve and get finalized):
  • Part 5 / Schemas?
  • JSON-FG enhancements?
• Support for publishing programmable application schemas of feature objects and codelists provided by OGC API Features service #70

Future standard support enhancement candidates

OGC API Features development

See OGC resources

• status of OGC API Features
• projects for each standard part

According to status page following parts are currently at public review stage (checked 26th March 2025)

• Part 4: Create, Replace, Update and Delete v1.0.0
  • Issues: Todo 0, In progress 3, to be drafted 3, review in progress 0, reviewer approved 0, done 35
• Part 5: Schemas v1.0
  • Issues: Todo 1, In progress 2, to be drafted 5, review in progress 0, reviewer approved 0, done 19

The OGC Features API SWG has provided draft standard documention on github repo (checked 26th March 2025):

• OGC API - Features - Part 4: Create, Replace, Update and Delete
  • The draft is complete and in the Public Comment Period.
• OGC API - Features - Part 5: Schemas
  • The draft is complete and in the Public Comment Period.

There is currently no any acute use cases in NLS of Finland for the Part 4.

The part 5 is mentioned and discussed also in the Hakunapi issue #70 (Support for publishing programmable application schemas of feature objects and codelists provided by OGC API Features service) and in the pull request #122 (output format fixes for schema). Enhanced support for the part 5 might also advance goals in NLS of Finland for renewing the documentation site for APIs and geospatial data technical information.

Other future parts have interesting features but maybe not relevant for the Hakunapi development in 2025.