Strongly typed params - deserialization

[EwenQuim]

Is your feature request related to a problem? Please describe.

When refactoring an old app, I found that using loosely coupled syntax defined in #174 make it easy to use a parameter in the controller and forget to declare it in the route registration.

Current situation

fuego.Get(s, "/test", myController,
		defaultOptions,
		option.Query("name", "description"), 
		option.Header("Accept", "coucou"),
		option.Middleware(middleware1),
		option.Description("coucou"),
		option.Middleware(mdlw, middleware2), // the middlewares will be applied in the order `middleware1`, `mdlw`, `middleware2`
                myReusableOption,
	)

func myController(c fuego.ContextNoBody) (string, error) {
    return c.QueryParam("name"), nil // if making a typo or using a non-declared param, it will just raise a runtime warning in the logs
}

I still think that variadic route options are good:

• having warnings at runtime is OK when creating new routes and iterating
• variadic route options are not only about parameters, they are also about tags, description...
• It looks like Go handlers and so it's easy to onboard newcormers

I'm just suggesting a new way to declare & deserialize params.

Describe the solution you'd like

Create a type netHttpContextWithParams[T any] that embeds netHttpContext with a single additional method Params() T.

Params() T deserialize the HTTP request's Headers, Query parameters and Cookie in a statically typed struct like

type ParamsIn struct {
  Authorization string `header:"Authorization"`
  Token string `cookie:"Token"`
  Limit *int `query:"limit"` // optional
  BookID string `query:"bookID"` // required
}

Draft

func (c netHttpContextWithParams[T any]) Params() T {
    var t T

    // Deserialize headers
    for ... { //iterate on struct fields that are headers with reflection and `field.Tag.Lookup("header")`
    }

    // Deserialize query params
    ...

    return t
}

Later, users will be able to use this syntax:

fuego.Get(s, "/test", myController,
		defaultOptions,
		// option.Query("name", "description"), // Will be declared through the controller signature. NOT this issue!
		// option.Header("Accept", "coucou"), // Will be declared through the controller signature. NOT this issue!
		option.Middleware(middleware1),
		option.Description("coucou"),
		option.Middleware(mdlw, middleware2), // the middlewares will be applied in the order `middleware1`, `mdlw`, `middleware2`
                myReusableOption,
	)

type ParamsIn struct {
  Authorization string `header:"Authorization"`
  Token string `cookie:"Token"`
  Limit *int `query:"limit"` // optional
  BookID string `query:"bookID"` // required
}

func (c *fuego.Context[Body, ParamsIn, ParamsOut]) (string, error) {
  return c.Params().Authorization, nil
}

But for the moment, we just want the new method. We'll plug it in another issue.

Please use spec defined in #119

[KinmatTech]

Can I take this from here?

[bruhhgnik]

Hey I'm agnik, i have some experience in Go, I would love to take on this issue.
I'll follow the spec from #119 and maintain backwards compatibility. Happy to provide more technical details if needed.
Looking forward for a heads up!

[EwenQuim]

Hi @bruhhgnik, you can take this issue!

[bruhhgnik]

Hi @bruhhgnik, you can take this issue!

Hey @EwenQuim Thanks for assigning me the issue, hoping on to it real quick

[EwenQuim]

Hi @bruhhgnik , any news on this?

[bruhhgnik]

Hi @bruhhgnik , any news on this?

Hey, im almost done, i can make the PR by tomorrow EOD

[EwenQuim]

It's not an easy one, don't hesitate to show us a draft early because there might be many coms incoming ;)

[bruhhgnik]

It's not an easy one, don't hesitate to show us a draft early because there might be many coms incoming ;)

Sure! on it