Contributors
Contributors are an important concept of the xdi2-messaging and xdi2-transport components. They are used as an extensibility mechanism to provide additional XDI graph functionality on top of a messaging target. Unlike interceptors, they typically cover only a part of the addressing space of an XDI endpoint, or in other words, a subgraph of the local graph that is exposed at that XDI endpoint. For example, this can be used to fetch certain data from an external data source rather than from a local store.
Unlike messaging targets and interceptors, whose functionality is typically the same or very similar across an entire local graph, contributors are more specialized and apply only to a certain part of the local graph, e.g. a single entity or attribute, or a context in which a user's data from an external data source is modeled. When implementing a contributor it usually makes sense to also create an XDI dictionary, which may either serve a merely descriptive purpose, or may be actively used by the contributor for mapping purposes.
Contributors may be nested, i.e. just like a contributor can override a messaging target, a child contributor can override its parent contributor.
- xdi2.messaging.target.contributor.Contributor: Contributor interface.
This work is licensed under a Creative Commons Attribution 4.0 International License.
