API Configuration

This implementation supports automatic API generation from metadata descriptions. To generate the API, you must:

Create an ASP.NET Core WebAPI project.
Install the necessary NuGet packages.
Register providers in the ConfigureServices method. For example, to publish data from PostgreSQL, add the PostGis provider:
```
services.AddOgcApiPostGisProvider();
```
Register OpenAPI and configure the API:
```
services.AddOgcApi("ogcapi.json");
```

Add controllers in the ConfigureServices method:

services.AddControllers().AddOgcApiControllers();

This implementation uses attribute routing. All API endpoints will be accessible via the /api/ogc path.

API configuration can be done using a configuration file named ogcsettings.json, which has the following structure:

Options example

{
  "LandingPage": {
    "Title": "OGC API Implementation",
    "Description": "The implementation of the OGC API family of standards that being developed to make it easy for anyone to provide geospatial data to the web",
    "Version": "1.0",
    "ContactName": "OGC API",
    "ContactUrl": "https://www.example.com/",
    "ApiDocumentPage": "/api/ogc/index.html",
    "ApiDescriptionPage": "/api/ogc/swagger.json"
  },
  "Collections": {
    "Items": [
      {
        "Id": "Test",
        "Title": "Test collection",
        "Features": {
          "Crs": [
            "http://www.opengis.net/def/crs/OGC/1.3/CRS84",
            "http://www.opengis.net/def/crs/EPSG/0/3857"
          ],
          "StorageCrs": "http://www.opengis.net/def/crs/EPSG/0/3857",
          "Storage": {
            "Type": "PostGis",
            "ConnectionString": "Host=localhost;User Id=postgre;Password=myStrongP@ssword;Database=Tests;Port=5432;Timeout=50;",
            "Schema": "test",
            "Table": "test_table",
            "GeometryColumn": "geom",
            "GeometrySrid": 3857,
            "GeometryDataType": "geometry",
            "GeometryGeoJsonType": "MultiPolygon",
            "IdentifierColumn": "id",
            "Properties": [
              "name",
              "region"
            ]
          }
        },
        "Tiles": {
          "Crs": "http://www.opengis.net/def/crs/EPSG/0/3857",
          "Storage": {
            "Type": "MbTiles",
            "FileName": "TilesData\\data.mbtiles"
          }
        }
      }
    ]
  }
}

The Landing page element provides links to:

the API definition (Swagger documentation and JSON description pages)
the Conformance declaration (path /conformance, link relation conformance), and
the Collections (path /collections, link relation data).

The Conformance declaration states the conformance classes from standards or community specifications identified by a URI that the API conforms to.

In the landing page options, you must specify:

Title
Description
Version - API version
ContactName - name of the data owner or API developer
ContactUrl - URL to the data owner or API developer site
ApiDocumentPage - URL to the API definition (Swagger or custom HTML page with API description)
ApiDescriptionPage - URL to the API documentation (OpenAPI JSON)

In collection options, you must specify:

Id - unique identifier of the collection
Title
Features options that dependents on the data provider
Tiles options that dependents on the data provider

Collection can be:

features only. All data will be published as GeoJson objects
tiles only. Collection in this case will be published as MapBox Vector Tiles
hybrid: features + tiles. That means that API consumer can use tiles API for fast data queries and features API to get precise objects coordinates or modify objects

Tiles and features providers for one collection can be different. For example, you can create collection that publishes features from the database, but the tiles can be taken from mbtiles file.