golang XML map[string]string encode/decode

StringMap

// https://stackoverflow.com/questions/30928770/marshall-map-to-xml-in-go
// https://stackoverflow.com/questions/33486725/golang-xml-unmarshal-interface-types
package main

import (
	"fmt"
	"encoding/xml"
)

// StringMap is a map[string]string.
type StringMap map[string]string

// StringMap marshals into XML.
func (s StringMap) MarshalXML(e *xml.Encoder, start xml.StartElement) error {
    tokens := []xml.Token{start}

    for key, value := range s {
        t := xml.StartElement{Name: xml.Name{"", key}}
        tokens = append(tokens, t, xml.CharData(value), xml.EndElement{t.Name})
    }

    tokens = append(tokens, xml.EndElement{start.Name})

    for _, t := range tokens {
        err := e.EncodeToken(t)
        if err != nil {
            return err
        }
    }

    // flush to ensure tokens are written
    return e.Flush()
}

func (s StringMap) UnmarshalXML(d *xml.Decoder, start xml.StartElement) error {
    for {
        t, err := d.Token()
        if err != nil {
        	return err
        }

        switch tt := t.(type) {
        case xml.StartElement:
            key := tt.Name.Local
            val := ""
            if err := d.DecodeElement(&val, &tt); err != nil {
            	return err
            }
            s[key] = val

        case xml.EndElement:
            if tt.Name == start.Name {
                return nil
            }
        }
    }

    return nil
}