geodata 0.3.0-nullsafety.0

A geospatial client reading OGC API and other geospatial data sources.

Geospatial - geodata

A geospatial client reading OGC API and other data sources for Dart and Flutter mobile developers.

Currently the package has a partial (and still quite limited) support for OGC API Features services with functions to read metadata and feature items.

This package is at the alpha-stage, breaking changes are possible.

This is a Dart code package named geodata under the geospatial repository. The package supports Dart null-safety.

Installing

The package is designed null-safety in mind and requires SDK from beta channel:

environment:
  sdk: '>=2.12.0-0 <3.0.0'

More information about how to switch to the latest beta release of Dart or Flutter SDKs is available in the official null-safety migration guide. Please consult it first about null-safety.

Dependencies defined in the pubspec.yaml when using the package:

dependencies:
  geodata: ^0.3.0-nullsafety.0  

Please note that following dependencies used by geodata are not yet migrated to null-safety or null-safety version is not depended from the geodata package:

• http
• http_parser

Usage

An example how to setup an API client and a provider for OGC API Features service.

Imports:

import 'package:geodata/geodata.dart';

Setting up an API client and a feature provider:

// Create an API client accessing HTTP endpoints.
final client = HttpApiClient.endpoints([
  Endpoint.url(baseURL),
]);

// Create a feature provider for OGC API Features (OAPIF).
final provider = FeatureProviderOAPIF.client(client);

Now it's possible to access metadata (the provider implementation calls a landing page or '/', '/conformance' and '/collections' resources under a base URL and combines all metadata fetched):

// Read metadata 
final meta = await provider.meta();

// do something with meta data accessed

Fetching items (or features of a OGC API Features service) as paged sets:

// Get feature resource for a collection by id
final resource = await provider.collection(collectionId);

// fetch feature items as paged results with max 10 features on one query
final items1 = await resource.itemsPaged(limit: 10);

// do something with feature items fetched

// check for next set (of max 10 features) and fetch it too if available
if (items1.hasNext) {
  final items2 = await items1.next();

  // do something with feature items fetched
}

Please see full example code for more details.

Authors

This project is authored by Navibyte.

License

This project is licensed under the "BSD-3-Clause"-style license.

Please see the LICENSE.