Connectivity Framework Annex D: Assessment Template: HTTP
D. 6.4 Functional Viewpoint D. 6.4.1 Core Framework Layer Functions
Data Resource Model
( Section 4.1.1)
ID & Addressing( Section 4.1.2)
Data Type System( Section 4.1.3)
Data Resource Lifecycle( CRUD)( Section 4.1.4)
State Management( Section 4.1.5)
Publish-Subscribe( Section 4.1.6)
Request-Reply( Section 4.1.7)
Discovery( Section 4.1.8)
Exception Handling( Section 4.1.9)
Does it provide a data resource model? Summarize the salient aspects.
Yes, HTTP provides a data resource model. A data object is represented via an HTTP resource, formatted as a uniform resource identifier( URI) path string that is meaningful in context of the server. HTTP defines a core set of methods, GET, POST, PUT, DELETE that can be applied to the resources on a server. Resource representation returned by a server is hypertext that provides the context and links to other resources. To drive the application state, application architects will define the hypertext and the resource organization.
Does it provide a way to identifying and addressing data objects? Summarize the identification and addressing scheme.
Yes, the HTTP resource URI path string provides a way of identifying and addressing a data object within a server. The server itself is addressed as a network IP address and port number. The result of combing the URI with the network endpoint is a Uniform Resource Locator( URL), expressed as http:// or https://( when TLS is used for security). Does it provide a data type system? Summarize the salient aspects.
No, HTTP does not provide a data type system.
Does it provide a means of managing a data object’ s lifecycle? Summarize the salient aspects.
Yes, it provides HTTP a means for managing data object lifecycles. A client can use the POST or the PUT method to create a data object; the GET method to retrieve the data object’ s representation; the PUT method to update a data object’ s representation; and the DELETE method to delete its representation. The server controls which methods are applicable on a data object, via the response for each operation.
Does it provide a means to manage the recent history of data objects? Summarize the salient aspects.
HTTP provides cache-mechanisms for proxies and clients to maintain responses of previous requests. These responses may contain the representations of the resources. The HTTP specification defines mechanisms for determining the freshness of the caches and provides rules for access control and applicability of a cached response.
Does it provide a means to publish and subscribe the state of data objects? Summarize the salient aspects.
No, HTTP does not provide a means to publish and subscribe to the state of data objects. Does it provide a means to request the state of data objects? Summarize the salient aspects.
Yes, HTTPS provides a means to request the state of data objects. This is the fundamental means of communicating using HTTP. Does it provide a means to discover the data objects? Summarize the salient aspects.
Yes, data objects can be discovered via the embedded resource links in the hypertext.
Does it provide a means to handle exceptions when quality of service or connectivity violations happen? Summarize the salient aspects.
HTTP does not assume that connection will be continuously available. It supports request timeout error code, when a server does not receive a complete request within the time it was prepared to wait. When service on a resource is unavailable, a server can inform the client to retry after a certain amount of time.
IIC: PUB: G5: V1.0: PB: 20170228- 97-