QUESTION: Can HATEOAS in REST be considered a valid proposition when it is self-evidently internally contradictory : If an interface is said to not be RESTful (according to Fielding), when a Client cannot utilize the in-band data (URI's) from the Response Hypertext (Hypermedia) without reference to an external (out-of-band) document, and therefore tightly coupling Client and Server according to Fielding, how can we do anything but fail Roy Fielding's prima facie assertion?
It seems to me that Fielding's exposition makes HATEOAS and REST an internally contradictory proposition that cannot be fulfilled with the current technology - unless someone knows how to it without referring to out-of-band data?
(EDIT) I suspect no-one is reading/has read Fielding's rant, so here's the most relevant piece:
"A REST API should be entered with no prior knowledge beyond the initial URI (bookmark) and set of standardized media types that are appropriate for the intended audience (i.e., expected to be understood by any client that might use the API). From that point on, all application state transitions must be driven by client selection of server-provided choices that are present in the received representations or implied by the user’s manipulation of those representations. The transitions may be determined (or limited by) the client’s knowledge of media types and resource communication mechanisms, both of which may be improved on-the-fly (e.g., code-on-demand). [Failure here implies that out-of-band information is driving interaction instead of hypertext.]"
We all keep asserting that we must have out-of-band knowledge of the URI's available methods beyond the initial data stream. Note how Fielding very stridently tells us that this is failure. Yet, it's how we're all dong it, me included. But Fielding screams No back at us.
(EDIT: because no-one's reading ithe explanation).