97 lines
2.2 KiB
Go
97 lines
2.2 KiB
Go
/*
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* Copyright (c) 2020 Alex aka mailoman <alex@webz.asia>
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*
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* Licensed under the Apache License, Version 2.0 (the "License");
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* you may not use this file except in compliance with the License.
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* You may obtain a copy of the License at
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*
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* http://www.apache.org/licenses/LICENSE-2.0
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*
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* Unless required by applicable law or agreed to in writing, software
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* distributed under the License is distributed on an "AS IS" BASIS,
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* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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* See the License for the specific language governing permissions and
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* limitations under the License.
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*
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* @author Alex aka mailoman <alex@webz.asia>
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* @copyright Copyright (c) 2020 Alex aka mailoman <alex@webz.asia>
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* @since 14.01.2020
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*
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*/
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package fields
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import (
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"log"
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"reflect"
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"strings"
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)
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//Convert copies field values from one struct to another based on tags setup
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func Сonvert(from interface{}, kind string, to interface{}) {
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if nil == from {
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log.Print("nil value is not supported")
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return
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}
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v := reflect.ValueOf(from)
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vt := reflect.ValueOf(to)
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t := v.Type()
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if t.Kind() != reflect.Struct {
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log.Printf("type %s is not supported", t.Kind())
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return
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}
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if vt.Kind() == reflect.Ptr {
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vt = reflect.ValueOf(to).Elem()
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}
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for i := 0; i < t.NumField(); i++ {
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f := t.Field(i)
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// skip unexported fields. from godoc:
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// PkgPath is the package path that qualifies a lower case (unexported)
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// field name. It is empty for upper case (exported) field names.
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if f.PkgPath != "" {
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continue
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}
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fv := v.Field(i)
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found, omit, omitempty := readTag(f, kind)
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// skip if tag "omit" set.
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if omit {
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continue
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}
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// skip empty values when "omitempty" set.
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if omitempty && fv.String() == "" {
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continue
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}
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if found {
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ft := vt.FieldByName(f.Name)
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ft.Set(fv)
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}
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}
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}
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func readTag(f reflect.StructField, kind string) (bool, bool, bool) {
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val, ok := f.Tag.Lookup(ConvertTagName())
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if !ok {
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return false, false, false
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}
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opts := strings.Split(val, ",")
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return indexOf(opts, kind) > -1, indexOf(opts, OmitTagName()) > -1, indexOf(opts, OmitEmptyTagName()) > -1
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}
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func indexOf(a []string, x string) int {
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for i, n := range a {
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if x == n {
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return i
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}
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}
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return -1
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}
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