add Form support (IntroResponse + FromRequest)

[GlenDC]

Akin to the Json support it can be nice to develop and implement Form.
It would be used to:

• be able to decode Form from the request (which is either in the payload, or it is in the query, depending on the Http Method and Content-Type header)
• be able to return a Form response payload.

You can find inspiration here: https://docs.rs/axum/latest/src/axum/form.rs.html#73. Also look at how implement Json vs how Axum does it, to see on the differences you need to pay attention to.

Deliverables:

• Struct can be created in a file form.rs at https://github.com/plabayo/rama/tree/main/src/http/response, documented, tested, a doctest and support for IntoResponse
• FromRequest support can be added in https://github.com/plabayo/rama/blob/main/src/http/service/web/endpoint/extract/body.rs
• an integration example can be added as http_service_form in https://github.com/plabayo/rama/tree/main/examples which serves a form and also accepts a filled in form. Very minimal web service but just to show it all

Low prio item, not on any roadmap for now. But a great easy one for someone of the community to pick up if they look for something to ge started.

[devanbenz]

Could I take this one on? Saw your folks CFC in this week in rust :)

[GlenDC]

It is all yours @devanbenz. Welcome and thank you for your time and effort.

If you need guidance, have input, questions or anything else, feel free to ask/share here, by mail or discord. Whatever you prefer.

[devanbenz]

@GlenDC could you assign this to me so I can tag my PR with it and it shows up in my github page easily? :) Thank you!

[GlenDC]

Resolved by @devanbenz in #136.

[GlenDC]

@devanbenz I added some improvements on top of your great work, as it was stuff I only realised after I already merged it in, you can find the diff at 7ab08ad, summary;

• also accept query Form data (Get request only)
• ensure we parse body form data only when it is not a Get request (e.g. but it is a Post)
• support an html approach as well in that same example
• add an actual tracing subscriber (as otherwise your tracing layer will not output anything)
• while I was at it also make it graceful, just for good practise

Your curl XPOST example didn't work as curl by default (at least on MacOS) uses multipart encoding, which is not something urlencoding can handle (as it is a very different beast). Added a new issue for that one, non-prio: #139

Feel free to pick that one up, or anything else, or nothing. All up to you.

Thank you once again for the contribution @devanbenz , have a nice day and hope to see you around.