support gob encoding/decoding of/to Maps

doc.go

@@ -14,6 +14,7 @@ Related Packages:
 	checkxml: github.com/clbanning/checkxml provides functions for validating XML data.
 
 Notes:
+	2018.03.29: mv.Gob/NewMapGob support gob encoding/decoding of Maps.
 	2018.03.26: Added mxj/x2j-wrapper sub-package for migrating from legacy x2j package.
 	2017.02.22: LeafNode paths can use ".N" syntax rather than "[N]" for list member indexing.
 	2017.02.21: github.com/clbanning/checkxml provides functions for validating XML data.

gob.go

@@ -0,0 +1,35 @@
+// gob.go - Encode/Decode a Map into a gob object.
+
+package mxj
+
+import (
+	"bytes"
+	"encoding/gob"
+)
+
+// NewMapGob returns a Map value for a gob object that has been
+// encoded from a map[string]interface{} (or compatible type) value.
+// It is intended to provide symmetric handling of Maps that have
+// been encoded using mv.Gob.
+func NewMapGob(gobj []byte) (Map, error) {
+	m := make(map[string]interface{}, 0)
+	if len(gobj) == 0 {
+		return m, nil
+	}
+	r := bytes.NewReader(gobj)
+	dec := gob.NewDecoder(r)
+	if err := dec.Decode(&m); err != nil {
+		return m, err
+	}
+	return m, nil
+}
+
+// Gob returns a gob-encoded value for the Map 'mv'.
+func (mv Map) Gob() ([]byte, error) {
+	var buf bytes.Buffer
+	enc := gob.NewEncoder(&buf)
+	if err := enc.Encode(map[string]interface{}(mv)); err != nil {
+		return nil, err
+	}
+	return buf.Bytes(), nil
+}

gob_test.go

@@ -0,0 +1,50 @@
+package mxj
+
+import (
+	"bytes"
+	"encoding/gob"
+	"fmt"
+	"testing"
+)
+
+var gobData = map[string]interface{}{
+	"one":   1,
+	"two":   2.0001,
+	"three": "tres",
+	"four":  []int{1, 2, 3, 4},
+	"five":  map[string]interface{}{"hi": "there"}}
+
+func TestGobHeader(t *testing.T) {
+	fmt.Println("\n----------------  gob_test.go ...")
+}
+
+func TestNewMapGob(t *testing.T) {
+	var buf bytes.Buffer
+	gob.Register(gobData)
+	enc := gob.NewEncoder(&buf)
+	if err := enc.Encode(gobData); err != nil {
+		t.Fatal("enc.Encode err:", err.Error())
+	}
+	// decode 'buf' into a Map - map[string]interface{}
+	m, err := NewMapGob(buf.Bytes())
+	if err != nil {
+		t.Fatal("NewMapGob err:", err.Error())
+	}
+	fmt.Printf("m: %v\n", m)
+}
+
+func TestMapGob(t *testing.T) {
+	mv := Map(gobData)
+	g, err := mv.Gob()
+	if err != nil {
+		t.Fatal("m.Gob err:", err.Error())
+	}
+	// decode 'g' into a map[string]interface{}
+	m := make(map[string]interface{})
+	r := bytes.NewReader(g)
+	dec := gob.NewDecoder(r)
+	if err := dec.Decode(&m); err != nil {
+		t.Fatal("dec.Decode err:", err.Error())
+	}
+	fmt.Printf("m: %v\n", m)
+}

readme.md

@@ -21,6 +21,7 @@ For over a year I've wanted to refactor the XML-to-map[string]interface{} decode
 
 <h4>Notices</h4>
 
+	2018.03.29: mv.Gob/NewMapGob support gob encoding/decoding of Maps.
 	2018.03.26: Added mxj/x2j-wrapper sub-package for migrating from legacy x2j package.
 	2017.02.22: LeafNode paths can use ".N" syntax rather than "[N]" for list member indexing.
 	2017.02.10: SetFieldSeparator changes field separator for args in UpdateValuesForPath, ValuesFor... methods.