baize/tag/assign/tag.go

package assign

import (
	"git.sxidc.com/go-framework/baize/infrastructure/logger"
	"git.sxidc.com/go-tools/utils/reflectutils"
	"git.sxidc.com/go-tools/utils/strutils"
	"git.sxidc.com/service-supports/fserr"
	"reflect"
	"strings"
	"time"
)

const (
	assignDefaultStringSliceSeparator = "::"
	assignTagPartSeparator            = ";"
	assignTagPartKeyValueSeparator    = ":"
)

const (
	assignTagKey     = "assign"
	assignIgnore     = "-"
	assignToField    = "toField"
	assignParseTime  = "parseTime"
	assignFormatTime = "formatTime"
	assignJoinWith   = "joinWith"
	assignSplitWith  = "splitWith"
	assignTrim       = "trim"
	assignTrimPrefix = "trimPrefix"
	assignTrimSuffix = "trimSuffix"
)

type Tag struct {
	ToField    string
	ParseTime  string
	FormatTime string
	JoinWith   string
	SplitWith  string
	Trim       string
	TrimPrefix string
	TrimSuffix string
}

func parseTag(fromElemValue reflect.Value, toElemValue *reflect.Value, onParsedFieldTagFunc OnParsedFieldTagCallback) error {
	for i := 0; i < fromElemValue.NumField(); i++ {
		fromField := fromElemValue.Type().Field(i)
		fromFieldValue := fromElemValue.Field(i)

		// 无效值
		if !fromFieldValue.IsValid() {
			continue
		}

		if fromFieldValue.Kind() == reflect.Pointer && fromFieldValue.IsNil() {
			fromFieldValue.Set(reflect.New(fromField.Type.Elem()))
		}

		fromFieldElemValue := reflectutils.PointerValueElem(fromFieldValue)

		tagStr := fromField.Tag.Get(assignTagKey)

		// 结构类型的字段上没有添加Tag, 先尝试直接按照字段赋值
		if strutils.IsStringEmpty(tagStr) && fromFieldElemValue.Kind() == reflect.Struct &&
			!reflectutils.IsValueTime(fromFieldElemValue) {
			err := parseTag(fromFieldElemValue, toElemValue, onParsedFieldTagFunc)
			if err != nil {
				return err
			}

			continue
		}

		tag, err := parseFieldTag(fromField, tagStr)
		if err != nil {
			return err
		}

		if tag == nil {
			continue
		}

		toFieldValue := toElemValue.FieldByName(tag.ToField)

		// 不存在对应的字段
		if !toFieldValue.IsValid() {
			continue
		}

		toFieldElemValue := toFieldValue
		if toFieldValue.Kind() == reflect.Pointer {
			if !toFieldValue.IsValid() {
				continue
			}

			if !toFieldValue.CanSet() {
				continue
			}

			// 空值针，初始化
			if toFieldValue.IsNil() {
				toFieldValue.Set(reflect.New(toFieldValue.Type().Elem()))
			}

			toFieldElemValue = toFieldValue.Elem()
		}

		err = onParsedFieldTagFunc(fromField.Name, fromFieldElemValue, toFieldElemValue, tag)
		if err != nil {
			return err
		}
	}

	return nil
}

func parseFieldTag(field reflect.StructField, tagStr string) (*Tag, error) {
	if tagStr == assignIgnore {
		return nil, nil
	}

	tag := &Tag{
		ToField:    field.Name,
		ParseTime:  time.DateTime,
		FormatTime: time.DateTime,
		JoinWith:   assignDefaultStringSliceSeparator,
		SplitWith:  assignDefaultStringSliceSeparator,
		Trim:       "",
		TrimPrefix: "",
		TrimSuffix: "",
	}

	if strutils.IsStringEmpty(tagStr) {
		return tag, nil
	}

	assignParts := strings.Split(tagStr, assignTagPartSeparator)
	if assignParts != nil || len(assignParts) != 0 {
		for _, assignPart := range assignParts {
			assignPartKeyValue := strings.SplitN(strings.TrimSpace(assignPart), assignTagPartKeyValueSeparator, 2)
			if assignPartKeyValue != nil && len(assignPartKeyValue) == 2 && strutils.IsStringNotEmpty(assignPartKeyValue[1]) {
				assignPartKeyValue[1] = strings.Trim(assignPartKeyValue[1], "'")
			}

			switch assignPartKeyValue[0] {
			case assignToField:
				tag.ToField = assignPartKeyValue[1]
			case assignParseTime:
				tag.ParseTime = assignPartKeyValue[1]
			case assignFormatTime:
				tag.FormatTime = assignPartKeyValue[1]
			case assignJoinWith:
				if strutils.IsStringEmpty(assignPartKeyValue[1]) {
					return nil, fserr.New(assignJoinWith + "没有赋值分隔符")
				}

				tag.JoinWith = assignPartKeyValue[1]
			case assignSplitWith:
				if strutils.IsStringEmpty(assignPartKeyValue[1]) {
					return nil, fserr.New(assignSplitWith + "没有赋值分隔符")
				}

				tag.SplitWith = assignPartKeyValue[1]
			case assignTrim:
				tag.Trim = assignPartKeyValue[1]
			case assignTrimPrefix:
				tag.TrimPrefix = assignPartKeyValue[1]
			case assignTrimSuffix:
				tag.TrimSuffix = assignPartKeyValue[1]
			default:
				err := fserr.New(assignTagKey + "不支持的tag: " + assignPartKeyValue[0])
				logger.GetInstance().Error(err)
				continue
			}
		}
	}

	return tag, nil
}