di/annotation/meta.go

package annotation

import (
	"reflect"
	"strings"

	cur "git.loafle.net/commons_go/util/reflect"
)

type AnnotationFieldMeta struct {
	fieldName string
	options   anotationMetaOptions
}

type anotationMetaOptions string

func (o anotationMetaOptions) Contains(optionName string) bool {
	if len(o) == 0 {
		return false
	}
	s := string(o)
	for s != "" {
		var next string
		i := strings.Index(s, AnnotationAttributeSpliter)
		if i >= 0 {
			s, next = s[:i], s[i+1:]
		}
		if s == optionName {
			return true
		}
		s = next
	}
	return false
}

func getMetaFields(t reflect.Type) map[string]*AnnotationFieldMeta {
	fields := make(map[string]*AnnotationFieldMeta, 0)
	rt, _, _ := cur.GetTypeInfo(t)
	if reflect.Struct != rt.Kind() {
		return fields
	}

	for i := 0; i < rt.NumField(); i++ {
		f := rt.Field(i)

		if f.Anonymous {
			pFields := getMetaFields(f.Type)
			for k, v := range pFields {
				fields[k] = v
			}
		} else {
			name, metaOptions := parseAnnotationMeta(f.Tag)
			if "" == name {
				continue
			}
			fields[name] = &AnnotationFieldMeta{
				fieldName: f.Name,
				options:   metaOptions,
			}
		}
	}

	return fields
}

func parseAnnotationMeta(tag reflect.StructTag) (string, anotationMetaOptions) {
	s := strings.Trim(tag.Get(AnnotationMetaTag), " ")
	if "" == s {
		return "", ""
	}

	if idx := strings.Index(s, AnnotationAttributeSpliter); idx != -1 {
		return s[:idx], anotationMetaOptions(s[idx+1:])
	}

	return s, anotationMetaOptions("")
}

func setMetaAttributes(def *AnnotationDefinition, rv reflect.Value, attributes map[string]string) {
	for k, v := range attributes {
		meta := def.fields[k]

		f := rv.FieldByName(meta.fieldName)

		f.Set(reflect.ValueOf(v))
	}
}