| // Copyright 2017 Google Inc. All Rights Reserved. |
| // |
| // Licensed under the Apache License, Version 2.0 (the "License"); |
| // you may not use this file except in compliance with the License. |
| // You may obtain a copy of the License at |
| // |
| // http://www.apache.org/licenses/LICENSE-2.0 |
| // |
| // Unless required by applicable law or agreed to in writing, software |
| // distributed under the License is distributed on an "AS IS" BASIS, |
| // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| // See the License for the specific language governing permissions and |
| // limitations under the License. |
| |
| package jsonwriter |
| |
| import ( |
| "bytes" |
| "errors" |
| "fmt" |
| "strings" |
| |
| "gopkg.in/yaml.v2" |
| ) |
| |
| const indentation = " " |
| |
| // basic escaping, will need to be improved or replaced |
| func escape(s string) string { |
| s = strings.Replace(s, "\n", "\\n", -1) |
| s = strings.Replace(s, "\"", "\\\"", -1) |
| return s |
| } |
| |
| type writer struct { |
| b bytes.Buffer |
| } |
| |
| func (w *writer) bytes() []byte { |
| return w.b.Bytes() |
| } |
| |
| func (w *writer) writeString(s string) { |
| w.b.Write([]byte(s)) |
| } |
| |
| func (w *writer) writeMap(info interface{}, indent string) { |
| w.writeString("{\n") |
| innerIndent := indent + indentation |
| switch pairs := info.(type) { |
| case yaml.MapSlice: |
| for i, pair := range pairs { |
| // first print the key |
| w.writeString(fmt.Sprintf("%s\"%+v\": ", innerIndent, pair.Key)) |
| // then the value |
| switch value := pair.Value.(type) { |
| case string: |
| w.writeString("\"") |
| w.writeString(escape(value)) |
| w.writeString("\"") |
| case bool: |
| if value { |
| w.writeString("true") |
| } else { |
| w.writeString("false") |
| } |
| case []interface{}: |
| w.writeArray(value, innerIndent) |
| case yaml.MapSlice: |
| w.writeMap(value, innerIndent) |
| case int: |
| w.writeString(fmt.Sprintf("%d", value)) |
| case int64: |
| w.writeString(fmt.Sprintf("%d", value)) |
| case []string: |
| w.writeStringArray(value, innerIndent) |
| case float64: |
| w.writeString(fmt.Sprintf("%f", value)) |
| case []yaml.MapSlice: |
| w.writeMapSliceArray(value, innerIndent) |
| default: |
| w.writeString(fmt.Sprintf("???MapItem(%+v, %T)", value, value)) |
| } |
| if i < len(pairs)-1 { |
| w.writeString(",") |
| } |
| w.writeString("\n") |
| } |
| default: |
| // t is some other type that we didn't name. |
| } |
| w.writeString(indent) |
| w.writeString("}") |
| } |
| |
| func (w *writer) writeArray(array []interface{}, indent string) { |
| w.writeString("[\n") |
| innerIndent := indent + indentation |
| for i, item := range array { |
| w.writeString(innerIndent) |
| switch item := item.(type) { |
| case string: |
| w.writeString("\"") |
| w.writeString(item) |
| w.writeString("\"") |
| case bool: |
| if item { |
| w.writeString("true") |
| } else { |
| w.writeString("false") |
| } |
| case yaml.MapSlice: |
| w.writeMap(item, innerIndent) |
| default: |
| w.writeString(fmt.Sprintf("???ArrayItem(%+v)", item)) |
| } |
| if i < len(array)-1 { |
| w.writeString(",") |
| } |
| w.writeString("\n") |
| } |
| w.writeString(indent) |
| w.writeString("]") |
| } |
| |
| func (w *writer) writeStringArray(array []string, indent string) { |
| w.writeString("[\n") |
| innerIndent := indent + indentation |
| for i, item := range array { |
| w.writeString(innerIndent) |
| w.writeString("\"") |
| w.writeString(escape(item)) |
| w.writeString("\"") |
| if i < len(array)-1 { |
| w.writeString(",") |
| } |
| w.writeString("\n") |
| } |
| w.writeString(indent) |
| w.writeString("]") |
| } |
| |
| func (w *writer) writeMapSliceArray(array []yaml.MapSlice, indent string) { |
| w.writeString("[\n") |
| innerIndent := indent + indentation |
| for i, item := range array { |
| w.writeString(innerIndent) |
| w.writeMap(item, innerIndent) |
| if i < len(array)-1 { |
| w.writeString(",") |
| } |
| w.writeString("\n") |
| } |
| w.writeString(indent) |
| w.writeString("]") |
| } |
| |
| // Marshal writes a yaml.MapSlice as JSON |
| func Marshal(in interface{}) (out []byte, err error) { |
| var w writer |
| m, ok := in.(yaml.MapSlice) |
| if !ok { |
| return nil, errors.New("invalid type passed to Marshal") |
| } |
| w.writeMap(m, "") |
| w.writeString("\n") |
| return w.bytes(), err |
| } |