Add support HtmxResponse that isn't a direct return type

[checketts]

I've working with JTE as my templating engine recently and been very impressed. The templates are statically compiled and work very well with this library.

However there is an advanced use case where the Gradle or maven plugin generates an interface that represents your templates, complete with parameters.

To leverage these templates I'm returning a JteModel in my controller methods, that isn't compatible with this library. I would like to propose a few solutions.

1- Support subclassing HtmxResponse. I might be able to leverage that so my JteModel provides the right data.
2- Support making HtmxResponse an injectable parameter, similar to how you can set the response code when injecting HttpServletResponse.
3- Support a 'provider' approach for HtmxResponse. This means my response can implement an interface and provide an HtmxResponse, allowing the builder to remain the same but making the return type more flexible.

I'll start on a PR for option 3. But I'm interested in feedback on any and all of these options.

[checketts]

Reporting back: Option 3 won't work. Spring selects only one handler. That also means that option 1 won't work.

Perhaps option 2 will work.

[checketts]

@wimdeblauwe How do you feel about PR #128 ?

It is working really well for me in my 3 projects that I've migrated to JTE

[wimdeblauwe]

Hi @checketts, sorry I forgot about this. If you can just add some documentation, we can merge it and I will create a new release for you.

[checketts]

I just pulled this into a project and it is working great!

[xhaggi]

To leverage these templates I'm returning a JteModel in my controller methods, that isn't compatible with this library. I would like to propose a few solutions.

@checketts Do you have a special implementation in your projects to handle JteModel as return type?

[checketts]

@xhaggi Yes. I'll try to upload a sample project (and hopefully push upstream into the JTE Spring module)