packer-cn/vendor/github.com/ChrisTrenkamp/goxpath/marshal.go

106 lines
1.9 KiB
Go

package goxpath
import (
"bytes"
"encoding/xml"
"io"
"github.com/ChrisTrenkamp/goxpath/tree"
)
//Marshal prints the result tree, r, in XML form to w.
func Marshal(n tree.Node, w io.Writer) error {
return marshal(n, w)
}
//MarshalStr is like Marhal, but returns a string.
func MarshalStr(n tree.Node) (string, error) {
ret := bytes.NewBufferString("")
err := marshal(n, ret)
return ret.String(), err
}
func marshal(n tree.Node, w io.Writer) error {
e := xml.NewEncoder(w)
err := encTok(n, e)
if err != nil {
return err
}
return e.Flush()
}
func encTok(n tree.Node, e *xml.Encoder) error {
switch n.GetNodeType() {
case tree.NtAttr:
return encAttr(n.GetToken().(xml.Attr), e)
case tree.NtElem:
return encEle(n.(tree.Elem), e)
case tree.NtNs:
return encNS(n.GetToken().(xml.Attr), e)
case tree.NtRoot:
for _, i := range n.(tree.Elem).GetChildren() {
err := encTok(i, e)
if err != nil {
return err
}
}
return nil
}
//case tree.NtChd, tree.NtComm, tree.NtPi:
return e.EncodeToken(n.GetToken())
}
func encAttr(a xml.Attr, e *xml.Encoder) error {
str := a.Name.Local + `="` + a.Value + `"`
if a.Name.Space != "" {
str += ` xmlns="` + a.Name.Space + `"`
}
pi := xml.ProcInst{
Target: "attribute",
Inst: ([]byte)(str),
}
return e.EncodeToken(pi)
}
func encNS(ns xml.Attr, e *xml.Encoder) error {
pi := xml.ProcInst{
Target: "namespace",
Inst: ([]byte)(ns.Value),
}
return e.EncodeToken(pi)
}
func encEle(n tree.Elem, e *xml.Encoder) error {
ele := xml.StartElement{
Name: n.GetToken().(xml.StartElement).Name,
}
attrs := n.GetAttrs()
ele.Attr = make([]xml.Attr, len(attrs))
for i := range attrs {
ele.Attr[i] = attrs[i].GetToken().(xml.Attr)
}
err := e.EncodeToken(ele)
if err != nil {
return err
}
if x, ok := n.(tree.Elem); ok {
for _, i := range x.GetChildren() {
err := encTok(i, e)
if err != nil {
return err
}
}
}
return e.EncodeToken(ele.End())
}