dynamic: add CallStructFieldsMethod for map struct field call

Signed-off-by: c9s <yoanlin93@gmail.com>

pkg/bbgo/exit.go

@@ -1,10 +1,9 @@
 package bbgo
 
 import (
-	"reflect"
+	"github.com/pkg/errors"
 
 	"github.com/c9s/bbgo/pkg/dynamic"
-	"github.com/c9s/bbgo/pkg/types"
 )
 
 type ExitMethod struct {
@@ -16,34 +15,29 @@ type ExitMethod struct {
 }
 
 func (m *ExitMethod) Subscribe(session *ExchangeSession) {
-	// TODO: pull out this implementation as a simple function to reflect.go
-	rv := reflect.ValueOf(m)
-	rt := reflect.TypeOf(m)
-
-	rv = rv.Elem()
-	rt = rt.Elem()
-	infType := reflect.TypeOf((*types.Subscriber)(nil)).Elem()
-
-	argValues := dynamic.ToReflectValues(session)
-	for i := 0; i < rt.NumField(); i++ {
-		fieldType := rt.Field(i)
-		if fieldType.Type.Implements(infType) {
-			method := rv.Field(i).MethodByName("Subscribe")
-			method.Call(argValues)
-		}
+	if err := dynamic.CallStructFieldsMethod(m, "Subscribe", session); err != nil {
+		panic(errors.Wrap(err, "dynamic call failed"))
 	}
 }
 
 func (m *ExitMethod) Bind(session *ExchangeSession, orderExecutor *GeneralOrderExecutor) {
 	if m.ProtectiveStopLoss != nil {
 		m.ProtectiveStopLoss.Bind(session, orderExecutor)
-	} else if m.RoiStopLoss != nil {
+	}
+
+	if m.RoiStopLoss != nil {
 		m.RoiStopLoss.Bind(session, orderExecutor)
-	} else if m.RoiTakeProfit != nil {
+	}
+
+	if m.RoiTakeProfit != nil {
 		m.RoiTakeProfit.Bind(session, orderExecutor)
-	} else if m.LowerShadowTakeProfit != nil {
+	}
+
+	if m.LowerShadowTakeProfit != nil {
 		m.LowerShadowTakeProfit.Bind(session, orderExecutor)
-	} else if m.CumulatedVolumeTakeProfit != nil {
+	}
+
+	if m.CumulatedVolumeTakeProfit != nil {
 		m.CumulatedVolumeTakeProfit.Bind(session, orderExecutor)
 	}
 }

pkg/dynamic/call.go

@@ -0,0 +1,41 @@
+package dynamic
+
+import (
+	"errors"
+	"reflect"
+)
+
+// CallStructFieldsMethod iterates field from the given struct object
+// check if the field object implements the interface, if it's implemented, then we call a specific method
+func CallStructFieldsMethod(m interface{}, method string, args ...interface{}) error {
+	rv := reflect.ValueOf(m)
+	rt := reflect.TypeOf(m)
+
+	if rt.Kind() != reflect.Ptr {
+		return errors.New("the given object needs to be a pointer")
+	}
+
+	rv = rv.Elem()
+	rt = rt.Elem()
+
+	if rt.Kind() != reflect.Struct {
+		return errors.New("the given object needs to be struct")
+	}
+
+	argValues := ToReflectValues(args...)
+	for i := 0; i < rt.NumField(); i++ {
+		fieldType := rt.Field(i)
+
+		// skip non-exported fields
+		if !fieldType.IsExported() {
+			continue
+		}
+
+		if _, ok := fieldType.Type.MethodByName(method); ok {
+			refMethod := rv.Field(i).MethodByName(method)
+			refMethod.Call(argValues)
+		}
+	}
+
+	return nil
+}

pkg/dynamic/call_test.go

@@ -0,0 +1,29 @@
+package dynamic
+
+import (
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+)
+
+type callTest struct {
+	ChildCall1 *childCall1
+	ChildCall2 *childCall2
+}
+
+type childCall1 struct{}
+
+func (c *childCall1) Subscribe(a int) {}
+
+type childCall2 struct{}
+
+func (c *childCall2) Subscribe(a int) {}
+
+func TestCallStructFieldsMethod(t *testing.T) {
+	c := &callTest{
+		ChildCall1: &childCall1{},
+		ChildCall2: &childCall2{},
+	}
+	err := CallStructFieldsMethod(c, "Subscribe", 10)
+	assert.NoError(t, err)
+}

pkg/types/subscribe.go

@@ -1,5 +0,0 @@
-package types
-
-type Subscriber interface {
-	Subscribe()
-}