3. The Conceptual Framework
3.1. Features and properties
GML is an XML encoding for geographic features. In order to correctly interpret a GML document it is necessary to understand the conceptual model that underlies GML, which is described in the OGC Abstract Specification.
3.1.1. Object Model
A geographic feature is essentially a named list of properties. Some or all of these properties may be geospatial, describing the position and shape of the feature. Each feature has a type, which is equivalent to a class in object modeling terminology, such that the class-definition prescribes the named properties that a particular feature of that type is required to have. So a Road might be defined to have a name, a surface-construction, a destination, ...
Get Mobile Location Services: The Definitive Guide now with the O’Reilly learning platform.
O’Reilly members experience books, live events, courses curated by job role, and more from O’Reilly and nearly 200 top publishers.