fix: implement parameter construction and response transfer for framework handlers

Author: sattvikc

ROADMAP.md

@@ -2,11 +2,14 @@
 
 ## Features
 
+- [ ] Configurable Swagger Spec
+- [ ] Swagger descriptions
 - [ ] Response Headers
 - [ ] Non-json responses
 - [ ] Middleware
 - [ ] Response Cookies
 - [ ] Streaming responses
+- [ ] Native handler
 
 ## Framework support
 

pkg/handler/inputParams.go

@@ -0,0 +1,27 @@
+package handler
+
+import (
+	"reflect"
+
+	"github.com/go-simpl/simplapi/pkg/context"
+	"github.com/go-simpl/simplapi/pkg/framework"
+	"github.com/go-simpl/simplapi/pkg/reflection"
+)
+
+func constructParams(req framework.FrameworkRequest, ctx *context.Context, handlerInputTypes []reflect.Type) ([]reflect.Value, error) {
+	numInputs := len(handlerInputTypes)
+	inputs := make([]reflect.Value, numInputs)
+	for i := 0; i < numInputs; i++ {
+		if handlerInputTypes[i] == reflect.TypeOf(ctx) {
+			inputs[i] = reflect.ValueOf(ctx)
+			continue
+		}
+
+		inputs[i] = reflect.New(handlerInputTypes[i]).Elem()
+		err := reflection.ComputeValuesFromRequest(req, handlerInputTypes[i], inputs[i])
+		if err != nil {
+			return nil, err
+		}
+	}
+	return inputs, nil
+}

pkg/handler/main.go

@@ -7,8 +7,6 @@ import (
 	"github.com/go-simpl/simplapi/errors"
 	"github.com/go-simpl/simplapi/pkg/context"
 	"github.com/go-simpl/simplapi/pkg/framework"
-	"github.com/go-simpl/simplapi/pkg/reflection"
-	"github.com/go-simpl/simplapi/types"
 )
 
 func WrapHandler(handler interface{}, next framework.FrameworkHandler) framework.FrameworkHandler {
@@ -30,26 +28,13 @@ func WrapHandler(handler interface{}, next framework.FrameworkHandler) framework
 		panic("handler must return an error at the last position")
 	}
 
-	createParams := func(req framework.FrameworkRequest, ctx *context.Context) ([]reflect.Value, error) {
-		numInputs := handlerType.NumIn()
-		inputs := make([]reflect.Value, numInputs)
-		for i := 0; i < numInputs; i++ {
-			if handlerType.In(i) == reflect.TypeOf(ctx) {
-				inputs[i] = reflect.ValueOf(ctx)
-				continue
-			}
-
-			inputs[i] = reflect.New(handlerType.In(i)).Elem()
-			err := reflection.PopulateValueFromTypeUsingContext(req, handlerType.In(i), inputs[i])
-			if err != nil {
-				return nil, err
-			}
-		}
-		return inputs, nil
+	handlerInputTypes := make([]reflect.Type, handlerType.NumIn())
+	for i := 0; i < handlerType.NumIn(); i++ {
+		handlerInputTypes[i] = handlerType.In(i)
 	}
 
 	return func(req framework.FrameworkRequest, res framework.FrameworkResponse, ctx *context.Context) error {
-		inputs, err := createParams(req, ctx)
+		inputs, err := constructParams(req, ctx, handlerInputTypes)
 		if err != nil {
 			if typeErr, ok := err.(errors.TypeError); ok {
 				res.SetStatusCode(http.StatusUnprocessableEntity)
@@ -68,19 +53,15 @@ func WrapHandler(handler interface{}, next framework.FrameworkHandler) framework
 		// handle response
 		for _, result := range results {
 			if !result.IsNil() {
-				// check for custom response types
-				if response, ok := result.Interface().(*types.HTMLResponse); ok {
-					res.SetStatusCode(http.StatusOK)
-					res.SetHeader("Content-Type", "text/html")
-					return res.SendString(response.HTML)
+				bodyDone, err := transferToResponse(res, result)
+				if err != nil {
+					return err
 				}
 
-				if response, ok := result.Interface().(types.APIResponse); ok {
-					res.SetStatusCode(response.GetStatusCode())
-					return res.SendJSON(result.Interface())
-				} else {
-					return res.SendJSON(result.Interface())
+				if bodyDone {
+					return nil
 				}
+
 			}
 		}
 

pkg/handler/transferToResponse.go

@@ -0,0 +1,25 @@
+package handler
+
+import (
+	"net/http"
+	"reflect"
+
+	"github.com/go-simpl/simplapi/pkg/framework"
+	"github.com/go-simpl/simplapi/types"
+)
+
+func transferToResponse(res framework.FrameworkResponse, result reflect.Value) (bool, error) {
+	// check for custom response types
+	if response, ok := result.Interface().(*types.HTMLResponse); ok {
+		res.SetStatusCode(http.StatusOK)
+		res.SetHeader("Content-Type", "text/html")
+		return true, res.SendString(response.HTML)
+	}
+
+	if response, ok := result.Interface().(types.APIResponse); ok {
+		res.SetStatusCode(response.GetStatusCode())
+		return true, res.SendJSON(result.Interface())
+	} else {
+		return true, res.SendJSON(result.Interface())
+	}
+}

pkg/reflection/reflection.go

@@ -10,7 +10,7 @@ import (
 	"github.com/go-simpl/simplapi/pkg/framework"
 )
 
-func PopulateValueFromTypeUsingContext(f framework.FrameworkRequest, pType reflect.Type, pVal reflect.Value) error {
+func ComputeValuesFromRequest(f framework.FrameworkRequest, pType reflect.Type, pVal reflect.Value) error {
 	for i := 0; i < pVal.NumField(); i++ {
 		if pType.Field(i).Tag.Get("body") == "json" {
 			b := pVal.Field(i).Addr().Interface()
@@ -52,7 +52,7 @@ func PopulateValueFromTypeUsingContext(f framework.FrameworkRequest, pType refle
 			}
 
 		} else if pType.Field(i).Type.Kind() == reflect.Struct {
-			err := PopulateValueFromTypeUsingContext(f, pType.Field(i).Type, pVal.Field(i))
+			err := ComputeValuesFromRequest(f, pType.Field(i).Type, pVal.Field(i))
 			if err != nil {
 				return err
 			}