provide an alterntive xml writer that leverage go xml writer for comp…

…arison

nodeutil/xml_wtr2.go

@@ -0,0 +1,191 @@
+package nodeutil
+
+import (
+	"context"
+	"encoding/xml"
+	"errors"
+	"fmt"
+	"strconv"
+
+	"github.com/freeconf/yang/fc"
+	"github.com/freeconf/yang/meta"
+	"github.com/freeconf/yang/node"
+	"github.com/freeconf/yang/val"
+)
+
+type XMLWtr2 struct {
+	XMLName   xml.Name
+	ns        string `xml:"-"`
+	EnumAsIds bool   `xml:"-"`
+	Content   string `xml:",innerxml"`
+	Elem      []*XMLWtr2
+}
+
+func XmlName(d meta.Definition) xml.Name {
+	return xml.Name{
+		Local: d.Ident(),
+		Space: meta.OriginalModule(d).Namespace(),
+	}
+}
+
+// WriteXMLDoc includes the xml of the selection root
+func WriteXMLDoc(s *node.Selection) (string, error) {
+	ns := meta.OriginalModule(s.Meta()).Namespace()
+	w := XMLWtr2{
+		XMLName: xml.Name{
+			Local: s.Meta().Ident(),
+			Space: ns,
+		},
+		ns: meta.OriginalModule(s.Meta()).Namespace(),
+	}
+	if err := s.UpsertInto(&w); err != nil {
+		return "", err
+	}
+	buf, err := xml.Marshal(&w)
+	if err != nil {
+		return "", err
+	}
+	return string(buf), nil
+}
+
+// WriteXMLFrag does not include the selection root
+func WriteXMLFrag(s *node.Selection) (string, error) {
+	var w XMLWtr2
+	if err := s.UpsertInto(&w); err != nil {
+		return "", err
+	}
+	if len(w.Elem) == 0 {
+		return "", errors.New("no content to xml doc")
+	}
+	if len(w.Elem) > 1 {
+		return "", fmt.Errorf("%d elements found and expected one. consider using WriteXMLDoc", len(w.Elem))
+	}
+	buf, err := xml.Marshal(&w.Elem[0])
+	if err != nil {
+		return "", err
+	}
+	return string(buf), nil
+}
+
+func (x *XMLWtr2) Child(r node.ChildRequest) (node.Node, error) {
+	if r.New {
+		if meta.IsList(r.Meta) {
+			return x, nil
+		}
+		c := x.new(r.Meta)
+		x.Elem = append(x.Elem, c)
+		return c, nil
+	}
+	return nil, nil
+}
+
+func (x *XMLWtr2) new(m meta.Definition) *XMLWtr2 {
+	w := XMLWtr2{
+		EnumAsIds: x.EnumAsIds,
+		ns:        meta.OriginalModule(m).Namespace(),
+	}
+	if w.ns != x.ns {
+		w.XMLName = xml.Name{
+			Local: m.Ident(),
+			Space: w.ns,
+		}
+	} else {
+		w.XMLName = xml.Name{
+			Local: m.Ident(),
+		}
+	}
+	return &w
+}
+
+func (x *XMLWtr2) Next(r node.ListRequest) (node.Node, []val.Value, error) {
+	if r.New {
+		c := x.new(r.Meta)
+		x.Elem = append(x.Elem, c)
+		return c, r.Key, nil
+	}
+	return nil, nil, nil
+}
+
+func (x *XMLWtr2) Field(r node.FieldRequest, hnd *node.ValueHandle) error {
+	var err error
+	if r.Write {
+		if hnd.Val.Format().IsList() {
+			val.ForEach(hnd.Val, func(_ int, v val.Value) {
+				if ferr := x.writeFieldElement(r.Meta, v); ferr != nil {
+					err = ferr
+				}
+			})
+
+		} else {
+			err = x.writeFieldElement(r.Meta, hnd.Val)
+		}
+	}
+	return err
+}
+
+func (x *XMLWtr2) writeFieldElement(m meta.Definition, v val.Value) error {
+	c := x.new(m)
+	switch v.Format() {
+	case val.FmtIdentityRef:
+		id := v.String()
+		leafMod := meta.OriginalModule(m)
+		bases := m.(meta.HasType).Type().Base()
+		idty := meta.FindIdentity(bases, id)
+		if idty == nil {
+			return fmt.Errorf("could not find ident '%s'", id)
+		}
+		idtyMod := meta.RootModule(idty)
+		if idtyMod != leafMod {
+			c.Content = fmt.Sprintf("%s:%s", idtyMod.Ident(), id)
+		} else {
+			c.Content = id
+		}
+	case val.FmtEnum:
+		if x.EnumAsIds {
+			c.Content = strconv.Itoa(v.(val.Enum).Id)
+		} else {
+			c.Content = v.String()
+		}
+	case val.FmtDecimal64:
+		f := v.Value().(float64)
+		c.Content = strconv.FormatFloat(f, 'f', -1, 64)
+	default:
+		//case val.FmtString, val.FmtBinary, val.FmtAny:
+		c.Content = v.String()
+	}
+	x.Elem = append(x.Elem, c)
+	return nil
+}
+
+// Begin Stubs
+
+func (x *XMLWtr2) Choose(sel *node.Selection, choice *meta.Choice) (*meta.ChoiceCase, error) {
+	return nil, fc.NotImplementedError
+}
+
+func (x *XMLWtr2) BeginEdit(r node.NodeRequest) error {
+	return nil
+}
+
+func (x *XMLWtr2) EndEdit(r node.NodeRequest) error {
+	return nil
+}
+
+func (x *XMLWtr2) Action(r node.ActionRequest) (node.Node, error) {
+	return nil, fc.NotImplementedError
+}
+
+func (x *XMLWtr2) Notify(r node.NotifyRequest) (node.NotifyCloser, error) {
+	return nil, fc.NotImplementedError
+}
+
+func (x *XMLWtr2) Peek(sel *node.Selection, consumer interface{}) interface{} {
+	return x
+}
+
+func (x *XMLWtr2) Context(sel *node.Selection) context.Context {
+	return sel.Context
+}
+
+func (x *XMLWtr2) Release(sel *node.Selection) {
+}