vCloud API clients implement a RESTful workflow, making HTTP requests to the server and retrieving the information they need from the server’s responses.
REST, an acronym for Representational State Transfer, describes an architectural style characteristic of programs that use the Hypertext Transfer Protocol (HTTP) to exchange serialized representations of objects between a client and a server. In the vCloud API, these representations are XML documents.
In a RESTful workflow, representations of objects are passed back and forth between a client and a server with the explicit assumption that neither party need know anything about an object other than what is presented in a single request or response. The URLs at which these documents are available often persist beyond the lifetime of the request or response that includes them. The other content of the documents is nominally valid until the expiration date noted in the HTTP Expires header.
Application programs written to a REST API use HTTP requests that are often executed by a script or other higher-level language to make remote procedure calls that create, retrieve, update, or delete objects that the API defines. In the vCloud REST API, these objects are defined by a collection of XML schemas. The operations themselves are HTTP requests, and so are generic to all HTTP clients.
To write a RESTful client application, you must understand only the HTTP protocol and the semantics of XML, the transfer format that the vCloud API uses. To use the vCloud API effectively in such a client, you need to know only a few things:
You can find that information in this Guide, and in the vCloud API Schema Reference. See About the Schema Reference.
All RESTful workflows follow a common pattern.
These operations can repeat, in this order, for as long as necessary.