Developing with Web API
Discovery and access
Figure 9 shows the main Web API’s objects and their behavior in a typical application:
DAB: It is the Web API entry point. This object represents a VH discovery and access broker which is capable to access heterogeneous data sources in a homogeneous way. During the creation phase, it is associated to a specific VH instance. It provides discovery capabilities to find relevant datasets provided by the VH.
ResultSet: An object provided as a result of a DAB discovery operation. It represents a set of datasets matching the DAB discovery constraints.
Paginator: An object associated to the ResultSet which allows to retrieve results as subsets (pages). It helps handling results avoiding long and unmanageable lists.
Page: An object representing a subset of a ResultSet.
GINode: An object representing a geoinformation resource (typically a dataset) which is a single result of the discovery operation and part of a Page.
The main concepts represented as objects in the Web API
The discover method of the DAB object, allows to retrieve a ResultSet object, containing all the GINode objects satisfying the query contraints which are specified as a JSON object passed to the discovery call. The access to the GINode objects is mediated by a Paginator object linked with the ResultSet, which allows to access limited sets of GINodes as Pages. The GINode content can be accessed as a layer of different types.
The full Web API documentation available online provides a detailed description of objects, properties, and methods including examples and live demos.
The endpoint for the DAB object configuration for accessing the pan-European Virtual Hub is:
Web API documentation
The full documentation of the VH Web API is available at http://api.eurogeoss-broker.eu/docs/index.html