90 lines
2.1 KiB
Go
90 lines
2.1 KiB
Go
// Copyright (c) 2014 Couchbase, Inc.
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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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package mapping
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import (
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"reflect"
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"strings"
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)
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func lookupPropertyPath(data interface{}, path string) interface{} {
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pathParts := decodePath(path)
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current := data
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for _, part := range pathParts {
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current = lookupPropertyPathPart(current, part)
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if current == nil {
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break
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}
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}
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return current
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}
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func lookupPropertyPathPart(data interface{}, part string) interface{} {
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val := reflect.ValueOf(data)
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typ := val.Type()
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switch typ.Kind() {
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case reflect.Map:
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// FIXME can add support for other map keys in the future
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if typ.Key().Kind() == reflect.String {
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key := reflect.ValueOf(part)
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entry := val.MapIndex(key)
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if entry.IsValid() {
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return entry.Interface()
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}
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}
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case reflect.Struct:
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field := val.FieldByName(part)
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if field.IsValid() && field.CanInterface() {
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return field.Interface()
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}
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case reflect.Ptr:
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ptrElem := val.Elem()
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if ptrElem.IsValid() && ptrElem.CanInterface() {
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return lookupPropertyPathPart(ptrElem.Interface(), part)
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}
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}
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return nil
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}
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const pathSeparator = "."
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func decodePath(path string) []string {
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return strings.Split(path, pathSeparator)
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}
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func encodePath(pathElements []string) string {
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return strings.Join(pathElements, pathSeparator)
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}
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func mustString(data interface{}) (string, bool) {
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if data != nil {
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str, ok := data.(string)
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if ok {
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return str, true
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}
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}
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return "", false
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}
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// parseTagName extracts the field name from a struct tag
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func parseTagName(tag string) string {
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if idx := strings.Index(tag, ","); idx != -1 {
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return tag[:idx]
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}
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return tag
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}
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