An Introduction to OGC API - Features¶

Introduction¶

OGC API - Features is a multi-part standard that offers the capability to create, modify, and query spatial data on the Web and specifies requirements and recommendations for APIs that want to follow a standard way of sharing feature data. The Core part of the standard is called OGC API - Features - Part 1: Core. The Core part of the specification describes the mandatory capabilities that every implementing service has to support and is restricted to read-access to spatial data. Additional capabilities that address specific needs will be specified in additional parts. Envisaged future capabilities include, for example, support for creating and modifying data, more complex data models, richer queries, and additional coordinate reference systems.

Note

This tutorial module is not intended to be a replacement to the actual OGC API - Features - Part 1: Core standard. The tutorial intentionally focuses on a subset of capabilities in order to get the student started with using the standard. Please refer to the OGC API - Features - Part 1: Core standard for additional detail.

Background¶

History

While in draft form and prior to February 2019, OGC API - Features - Part 1: Core was referred to as WFS3.0.

Versions

OGC API - Features - Part 1: Core version 1.0.0 is the current latest version

Test Suite

Test suites are available for:

OGC API - Features

Implementations

Implementations can be found on the Compliance Database here <http://www.opengeospatial.org/resource/products/byspec>

Usage¶

OGC API - Features - Part 1: Core specifies discovery and query operations that are implemented using the HTTP GET method. Support for additional methods (in particular POST, PUT, DELETE, PATCH) will be specified in additional parts. Government agencies, private organisations and academic institutes use this standard to publish vector geospatial datasets in a way that makes it easier for receiving organisations to compile new maps or conduct analysis on the supplied data.

The standard provides a standard interface for requesting vector geospatial data consisting of geographic features and their properties. The benefit of this is that client applications can request source data from multiple implementations of the API, and then render the data for display or process the data further as part of a workflow. The standard enables the data to be accessed consistently with other data. Feature properties encoded using common data types such as text strings, date and time can also be accessed consistently.

Relation to other OGC Standards¶

OGC Web Feature Service Interface Standard (WFS): The WFS standard is more appropriate when working with client applications that only support classic OGC Web Services. Note as well that WFS adopts the Geography Markup Language (GML) as a default data format. In contrast, OGC API - Features includes recommendations to support HTML and GeoJSON as encodings, where practical. Implementations of OGC API - Features may also optionally support GML.

Overview of Resources¶

OGC API - Features - Part 1: Core defines the resources listed in the following table.

Overview of OGC API - Features resources¶
Resource	Path	Purpose
Landing page	/	This is the top-level resource, which serves as an entry point.
Conformance declaration	/conformance	This resource presents information about the functionality that is implemented by the server.
API definition	/api	This resource provides metadata about the API itself. Note use of /api on the server is optional and the API definition may be hosted on completely separate server
Feature collections	/collections	This resource lists the feature collections that are offered through the API.
Feature collection	/collections/{collectionId}	This resource describes the feature collection identified in the path.
Features	/collections/{collectionId}/items	This resource presents the features that are contained in the collection.
Feature	/collections/{collectionId}/items/{featureId}	This resource presents the feature that is identified in the path

Example¶

This demonstration server publishes vector geospatial data through an interface that conforms to OGC API - Features.

An example request that can be used to retrieve data from the Vegetation surface feature collection is https://services.interactive-instruments.de/t15/daraa/collections/VegetationSrf/items?f=html

Note that the response to the request is HTML in this case.

Alternatively, the same data can be retrieved in GeoJSON format, through the request https://services.interactive-instruments.de/t15/daraa/collections/VegetationSrf/items?f=json

A client application can then retrieve the GeoJSON document and display or process it.