added function in openapi3.operation

ctx.go

@@ -326,3 +326,9 @@ func body[B any](c netHttpContext[B]) (B, error) {
 
 	return body, err
 }
+
+type ContextWithBodyAndParams[Body any, ParamsIn any, ParamsOut any] interface {
+	ContextWithBody[Body]
+	Params() (ParamsIn, error)
+	SetParams(ParamsOut) error
+}

documentation/docs/guides/controllers.md

@@ -19,6 +19,54 @@
 Used when the request has a body.
 Fuego will automatically parse the body and validate it using the input struct.
 
+_🚧 Below contains incoming syntax, not available currently_
+
+```go
+func(c fuego.ContextWithBodyAndParams[MyInput,ParamsIn,ParamsOut]) (MyResponse, error)
+```
+
+This controller is used to declare params with strong static typing.
+
+```go
+type CreateUserRequest struct {
+    Name string `json:"name"`
+    Email string `json:"email"`
+}
+
+type UserParams struct {
+    Limit *int    `query:"limit"`
+    Group *string `header:"X-User-Group"`
+}
+
+type UserResponseParams struct {
+    CustomHeader string `header:"X-Rate-Limit"`
+    SessionToken string `cookie:"session_token"`
+}
+
+func CreateUserController(
+    c fuego.ContextWithBodyAndParams[CreateUserRequest, UserParams, UserResponseParams]
+) (User, error) {
+    params, err := c.Params()
+    if err != nil {
+        return User{}, err
+    }
+    body, err := c.Body()
+    if err != nil {
+        return User{}, err
+    }
+    user, err := createUser(body, *params.Limit, *params.Group)
+    if err != nil {
+        return User{}, err
+    }
+    c.SetHeader("X-Rate-Limit", "100")
+    c.SetCookie(http.Cookie{
+        Name:  "session_token",
+        Value: generateSessionToken(),
+    })
+    return user, nil
+}
+```
+
 ### Returning HTML
 
 ```go

openapi.go

@@ -1,6 +1,7 @@
 package fuego
 
 import (
+	"errors"
 	"fmt"
 	"log/slog"
 	"net/http"
@@ -252,6 +253,50 @@ func RegisterOpenAPIOperation[T, B any](openapi *OpenAPI, route Route[T, B]) (*o
 	return route.Operation, nil
 }
 
+type RouteWithParams[Params any, ResponseBody any, RequestBody any] struct {
+	Route[ResponseBody, RequestBody]
+}
+
+func NewRouteWithParams[Params, ResponseBody, RequestBody any](method, path string, handler any, e *Engine, options ...func(*BaseRoute)) RouteWithParams[Params, ResponseBody, RequestBody] {
+	return RouteWithParams[Params, ResponseBody, RequestBody]{
+		Route: NewRoute[ResponseBody, RequestBody](method, path, handler, e, options...),
+	}
+}
+
+// RegisterParams registers the parameters of a given type to an OpenAPI operation.
+// It inspects the fields of the provided struct, looking for "header" tags, and creates
+// OpenAPI parameters for each tagged field.
+func (route *RouteWithParams[Params, ResponseBody, RequestBody]) RegisterParams() error {
+	if route.Operation == nil {
+		route.Operation = openapi3.NewOperation()
+	}
+	params := *new(Params)
+	typeOfParams := reflect.TypeOf(params)
+	if typeOfParams == nil {
+		return errors.New("params cannot be nil")
+	}
+	if typeOfParams.Kind() == reflect.Ptr {
+		typeOfParams = typeOfParams.Elem()
+	}
+
+	if typeOfParams.Kind() == reflect.Struct {
+		for i := range typeOfParams.NumField() {
+			field := typeOfParams.Field(i)
+			if headerKey, ok := field.Tag.Lookup("header"); ok {
+				OptionHeader(headerKey, "string")(&route.BaseRoute)
+			}
+			if queryKey, ok := field.Tag.Lookup("query"); ok {
+				OptionQuery(queryKey, "string")(&route.BaseRoute)
+			}
+			if cookieKey, ok := field.Tag.Lookup("cookie"); ok {
+				OptionCookie(cookieKey, "string")(&route.BaseRoute)
+			}
+		}
+	}
+
+	return nil
+}
+
 func newRequestBody[RequestBody any](tag SchemaTag, consumes []string) *openapi3.RequestBody {
 	content := openapi3.NewContentWithSchemaRef(&tag.SchemaRef, consumes)
 	return openapi3.NewRequestBody().

parameter_registration_test.go

@@ -0,0 +1,65 @@
+package fuego
+
+import (
+	"net/http"
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
+)
+
+func Test_RegisterOpenAPIOperation(t *testing.T) {
+	handler := func(w http.ResponseWriter, r *http.Request) {}
+	s := NewServer()
+
+	t.Run("Nil operation handling", func(t *testing.T) {
+		route := NewRouteWithParams[struct{}, struct{}, struct{}](
+			http.MethodGet,
+			"/test",
+			handler,
+			s.Engine,
+		)
+		route.Operation = nil
+		err := route.RegisterParams()
+		require.NoError(t, err)
+		assert.NotNil(t, route.Operation)
+	})
+
+	t.Run("Register with params", func(t *testing.T) {
+		route := NewRouteWithParams[struct {
+			QueryParam  string `query:"queryParam"`
+			HeaderParam string `header:"headerParam"`
+		}, struct{}, struct{}](
+			http.MethodGet,
+			"/some/path/{pathParam}",
+			handler,
+			s.Engine,
+		)
+		err := route.RegisterParams()
+		require.NoError(t, err)
+		operation := route.Operation
+		assert.NotNil(t, operation)
+		assert.Len(t, operation.Parameters, 2)
+
+		queryParam := operation.Parameters.GetByInAndName("query", "queryParam")
+		assert.NotNil(t, queryParam)
+		assert.Equal(t, "queryParam", queryParam.Name)
+
+		headerParam := operation.Parameters.GetByInAndName("header", "headerParam")
+		assert.NotNil(t, headerParam)
+		assert.Equal(t, "headerParam", headerParam.Name)
+	})
+
+	t.Run("RegisterParams should not with interfaces", func(t *testing.T) {
+		route := NewRouteWithParams[any, struct{}, struct{}](
+			http.MethodGet,
+			"/no-interfaces",
+			handler,
+			s.Engine,
+			OptionDefaultStatusCode(201),
+		)
+
+		err := route.RegisterParams()
+		require.Error(t, err)
+	})
+}