Merge pull request #2 from jaksonlin/develop

add search by tag

interpreter/err.go

@@ -16,6 +16,7 @@ const (
 	FieldTypeNotMatchAST               = "field type %s is not of ast collection node type"
 	KVKindNotMatch                     = "expect %s as key but value is not :%#v"
 	FieldNotValid                      = "field not valid %s"
+	FieldNotFound                      = "field with tag %s not found"
 )
 
 var (
@@ -84,3 +85,7 @@ func NewErrorInternalMapKeyValueKindNotMatch(kind string, value interface{}) err
 func NewErrorFieldNotValid(field string) error {
 	return fmt.Errorf(FieldNotValid, field)
 }
+
+func NewErrorFieldNotFound(field string) error {
+	return fmt.Errorf(FieldNotFound, field)
+}

interpreter/unmarshallResolver.go

@@ -40,9 +40,9 @@ func (resolver *unmarshallResolver) resolveSliceDependency(dependentResolver *un
 	return nil
 }
 func (resolver *unmarshallResolver) resolveStructDependency(dependentResolver *unmarshallResolver) error {
-	field := resolver.ptrToActualValue.Elem().FieldByName(dependentResolver.objectKey)
-	if !field.IsValid() || !field.CanSet() {
-		return NewErrFieldCannotSetOrNotfound(dependentResolver.objectKey)
+	field, err := resolver.getFieldByTag(resolver.ptrToActualValue.Elem(), dependentResolver.objectKey)
+	if err != nil {
+		return err
 	}
 
 	dependentValue := dependentResolver.restoreValue()

interpreter/unmarshaller.go

@@ -22,6 +22,26 @@ func (resolver *unmarshallResolver) processKVKeyNode(node ast.JsonStringValueNod
 	return key, nil
 }
 
+func (resolver *unmarshallResolver) getFieldByTag(obj reflect.Value, objKey string) (reflect.Value, error) {
+
+	for i := 0; i < obj.NumField(); i++ {
+		field := obj.Type().Field(i)
+		if fieldTag := field.Tag.Get("json"); fieldTag == objKey {
+			fieldInfo := obj.Field(i)
+			if !fieldInfo.IsValid() || !fieldInfo.CanSet() {
+				return reflect.Value{}, NewErrorFieldNotValid(objKey)
+			}
+			return fieldInfo, nil
+		}
+	}
+	// fall back to field by name
+	fieldInfo := obj.FieldByName(objKey)
+	if !fieldInfo.IsValid() || !fieldInfo.CanSet() {
+		return reflect.Value{}, NewErrorFieldNotValid(objKey)
+	}
+	return fieldInfo, nil
+}
+
 // create resolver to resolving the things in kv's value
 func (resolver *unmarshallResolver) processKVValueNode(key string, valueNode ast.JsonNode) (*unmarshallResolver, error) {
 	// create child resolver by data type
@@ -34,9 +54,9 @@ func (resolver *unmarshallResolver) processKVValueNode(key string, valueNode ast
 
 	} else if childElementType.Kind() == reflect.Struct {
 
-		fieldInfo := resolver.ptrToActualValue.Elem().FieldByName(key) // struct field
-		if !fieldInfo.IsValid() || !fieldInfo.CanSet() {
-			return nil, NewErrorFieldNotValid(key)
+		fieldInfo, err := resolver.getFieldByTag(resolver.ptrToActualValue.Elem(), key) // struct field
+		if err != nil {
+			return nil, err
 		}
 		childElementType = fieldInfo.Type()
 

interpreter/unmarshaller_test.go

@@ -1,6 +1,7 @@
 package interpreter_test
 
 import (
+	"bytes"
 	"encoding/base64"
 	"encoding/json"
 	"fmt"
@@ -3147,3 +3148,41 @@ func TestVariable(t *testing.T) {
 		t.FailNow()
 	}
 }
+
+func TestFieldByTag(t *testing.T) {
+	type mydata struct {
+		Name1   string `json:"name"`
+		Name2   int    `json:"age"`
+		Address string
+	}
+
+	test1 := mydata{"Ann", 198, "CA Redwood shore"}
+	data, _ := json.Marshal(test1)
+
+	var checker mydata
+	_ = json.Unmarshal(data, &checker)
+
+	sm := tokenizer.NewTokenizerStateMachine()
+	err := sm.ProcessData(bytes.NewReader(data))
+	if err != nil {
+		t.Log(err)
+		t.FailNow()
+	}
+	node := sm.GetASTConstructor().GetAST()
+	var myReceiver mydata
+	err = interpreter.UnmarshallAST(node, nil, &myReceiver)
+	if err != nil {
+		t.Log(err)
+		t.FailNow()
+	}
+	if myReceiver.Name1 != "Ann" {
+		t.FailNow()
+	}
+	if myReceiver.Name2 != 198 {
+		t.FailNow()
+	}
+	if myReceiver.Address != "CA Redwood shore" {
+		t.FailNow()
+	}
+
+}