Hypermedia-driven RESTful Service Composition

Representational State Transfer (REST) services are gaining momentum as a lightweight approach for the provision of services on the Web. Unlike WSDL-based services, in REST the set of operations is reduced, standardized, with well known semantics, and changes the resource's state. Few attempts have been proposed to support composition models for REST, they are mainly operation-centric and fail to acknowledge the hypermedia nature of REST, that is, clients must inspect the served resource state and choose the link to follow from there. We explore RESTful service composition as it is driven by the hypermedia net that is dynamically created while a client interacts with a server resulting in a light-weight approach. We based our proposal on a hypermedia-centric REST service description, the Resource Linking Language (ReLL) and Petri Nets as a mechanism for describing the machine-client navigation.