Pick a default set of media types for @EnableHypermediaSupport

[gregturn]

Instead of manually requiring setting the types field when using this annotation, let's select a default set of media types, whether that's simply HAL to match what is done historically, or whether it's to enable all support media types.

Or perhaps we can it be a little more sophisticated and have an HypermediaType type that says to activate all discovered media types dynamically.

[odrotbohm]

I remember having a discussion with @wilkinsona about this. The challenge here is to make things reasonably but at the same time to be careful that we don't necessarily change user's APIs just because we decide to add support for a new media type as that might be surprising.

We also have to make up our minds on how explicitly activating media type support contributed via an extension plays into this.

[gregturn]

Is go for at least these options (if it’s not too complicated):

• LEGACY - activates HAL and nothing else
• SUPPORTED - activates all of the supported but not 3rd party
• SCANNED - activates all 3rd party types
• SUPPORTED_AND_SCANNED - everything

The names are up for grabs but these seem like the most logical groupings to me. If we also need something for HAL + HAL_FORMS I also wouldn’t object.

[gregturn]

Spring Boot simply has @EnableHypermediaSupport(HAL), which defaults to HAL. Check out #1060, and its ability to allow users to simply use @EnableHypermediaSupport, and have ALL registered hypermedia supports enabled.

[gregturn]

Closing this out in favor of letting #1060 support a "null" or "empty" configuration, where it will NOT enable any of our pre-built hypermedia types, and instead simply fall back to whatever custom ones the user has designed.