Commit b8064cee authored by Paul Warren's avatar Paul Warren
Browse files

Branch of encoding/xml for improved QName support.

parent a45dfc56
// Copyright 2011 The Go Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
package xml
import "time"
var atomValue = &Feed{
XMLName: Name{"http://www.w3.org/2005/Atom", "feed"},
Title: "Example Feed",
Link: []Link{{Href: "http://example.org/"}},
Updated: ParseTime("2003-12-13T18:30:02Z"),
Author: Person{Name: "John Doe"},
Id: "urn:uuid:60a76c80-d399-11d9-b93C-0003939e0af6",
Entry: []Entry{
{
Title: "Atom-Powered Robots Run Amok",
Link: []Link{{Href: "http://example.org/2003/12/13/atom03"}},
Id: "urn:uuid:1225c695-cfb8-4ebb-aaaa-80da344efa6a",
Updated: ParseTime("2003-12-13T18:30:02Z"),
Summary: NewText("Some text."),
},
},
}
var atomXml = `` +
`<feed xmlns="http://www.w3.org/2005/Atom" updated="2003-12-13T18:30:02Z">` +
`<title>Example Feed</title>` +
`<id>urn:uuid:60a76c80-d399-11d9-b93C-0003939e0af6</id>` +
`<link href="http://example.org/"></link>` +
`<author><name>John Doe</name><uri></uri><email></email></author>` +
`<entry>` +
`<title>Atom-Powered Robots Run Amok</title>` +
`<id>urn:uuid:1225c695-cfb8-4ebb-aaaa-80da344efa6a</id>` +
`<link href="http://example.org/2003/12/13/atom03"></link>` +
`<updated>2003-12-13T18:30:02Z</updated>` +
`<author><name></name><uri></uri><email></email></author>` +
`<summary>Some text.</summary>` +
`</entry>` +
`</feed>`
func ParseTime(str string) time.Time {
t, err := time.Parse(time.RFC3339, str)
if err != nil {
panic(err)
}
return t
}
func NewText(text string) Text {
return Text{
Body: text,
}
}
// Copyright 2012 The Go Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
package xml_test
import (
"encoding/xml"
"fmt"
"os"
)
func ExampleMarshalIndent() {
type Address struct {
City, State string
}
type Person struct {
XMLName xml.Name `xml:"person"`
Id int `xml:"id,attr"`
FirstName string `xml:"name>first"`
LastName string `xml:"name>last"`
Age int `xml:"age"`
Height float32 `xml:"height,omitempty"`
Married bool
Address
Comment string `xml:",comment"`
}
v := &Person{Id: 13, FirstName: "John", LastName: "Doe", Age: 42}
v.Comment = " Need more details. "
v.Address = Address{"Hanga Roa", "Easter Island"}
output, err := xml.MarshalIndent(v, " ", " ")
if err != nil {
fmt.Printf("error: %v\n", err)
}
os.Stdout.Write(output)
// Output:
// <person id="13">
// <name>
// <first>John</first>
// <last>Doe</last>
// </name>
// <age>42</age>
// <Married>false</Married>
// <City>Hanga Roa</City>
// <State>Easter Island</State>
// <!-- Need more details. -->
// </person>
}
func ExampleEncoder() {
type Address struct {
City, State string
}
type Person struct {
XMLName xml.Name `xml:"person"`
Id int `xml:"id,attr"`
FirstName string `xml:"name>first"`
LastName string `xml:"name>last"`
Age int `xml:"age"`
Height float32 `xml:"height,omitempty"`
Married bool
Address
Comment string `xml:",comment"`
}
v := &Person{Id: 13, FirstName: "John", LastName: "Doe", Age: 42}
v.Comment = " Need more details. "
v.Address = Address{"Hanga Roa", "Easter Island"}
enc := xml.NewEncoder(os.Stdout)
enc.Indent(" ", " ")
if err := enc.Encode(v); err != nil {
fmt.Printf("error: %v\n", err)
}
// Output:
// <person id="13">
// <name>
// <first>John</first>
// <last>Doe</last>
// </name>
// <age>42</age>
// <Married>false</Married>
// <City>Hanga Roa</City>
// <State>Easter Island</State>
// <!-- Need more details. -->
// </person>
}
// This example demonstrates unmarshaling an XML excerpt into a value with
// some preset fields. Note that the Phone field isn't modified and that
// the XML <Company> element is ignored. Also, the Groups field is assigned
// considering the element path provided in its tag.
func ExampleUnmarshal() {
type Email struct {
Where string `xml:"where,attr"`
Addr string
}
type Address struct {
City, State string
}
type Result struct {
XMLName xml.Name `xml:"Person"`
Name string `xml:"FullName"`
Phone string
Email []Email
Groups []string `xml:"Group>Value"`
Address
}
v := Result{Name: "none", Phone: "none"}
data := `
<Person>
<FullName>Grace R. Emlin</FullName>
<Company>Example Inc.</Company>
<Email where="home">
<Addr>gre@example.com</Addr>
</Email>
<Email where='work'>
<Addr>gre@work.com</Addr>
</Email>
<Group>
<Value>Friends</Value>
<Value>Squash</Value>
</Group>
<City>Hanga Roa</City>
<State>Easter Island</State>
</Person>
`
err := xml.Unmarshal([]byte(data), &v)
if err != nil {
fmt.Printf("error: %v", err)
return
}
fmt.Printf("XMLName: %#v\n", v.XMLName)
fmt.Printf("Name: %q\n", v.Name)
fmt.Printf("Phone: %q\n", v.Phone)
fmt.Printf("Email: %v\n", v.Email)
fmt.Printf("Groups: %v\n", v.Groups)
fmt.Printf("Address: %v\n", v.Address)
// Output:
// XMLName: xml.Name{Space:"", Local:"Person"}
// Name: "Grace R. Emlin"
// Phone: "none"
// Email: [{home gre@example.com} {work gre@work.com}]
// Groups: [Friends Squash]
// Address: {Hanga Roa Easter Island}
}
This diff is collapsed.
This diff is collapsed.
This diff is collapsed.
This diff is collapsed.
// Copyright 2011 The Go Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
package xml
import (
"fmt"
"reflect"
"strings"
"sync"
)
// typeInfo holds details for the xml representation of a type.
type typeInfo struct {
xmlname *fieldInfo
fields []fieldInfo
}
// fieldInfo holds details for the xml representation of a single field.
type fieldInfo struct {
idx []int
name string
xmlns string
flags fieldFlags
parents []string
}
type fieldFlags int
const (
fElement fieldFlags = 1 << iota
fAttr
fCharData
fInnerXml
fComment
fAny
fOmitEmpty
fMode = fElement | fAttr | fCharData | fInnerXml | fComment | fAny
)
var tinfoMap = make(map[reflect.Type]*typeInfo)
var tinfoLock sync.RWMutex
var nameType = reflect.TypeOf(Name{})
// getTypeInfo returns the typeInfo structure with details necessary
// for marshalling and unmarshalling typ.
func getTypeInfo(typ reflect.Type) (*typeInfo, error) {
tinfoLock.RLock()
tinfo, ok := tinfoMap[typ]
tinfoLock.RUnlock()
if ok {
return tinfo, nil
}
tinfo = &typeInfo{}
if typ.Kind() == reflect.Struct && typ != nameType {
n := typ.NumField()
for i := 0; i < n; i++ {
f := typ.Field(i)
if f.PkgPath != "" || f.Tag.Get("xml") == "-" {
continue // Private field
}
// For embedded structs, embed its fields.
if f.Anonymous {
t := f.Type
if t.Kind() == reflect.Ptr {
t = t.Elem()
}
if t.Kind() == reflect.Struct {
inner, err := getTypeInfo(t)
if err != nil {
return nil, err
}
if tinfo.xmlname == nil {
tinfo.xmlname = inner.xmlname
}
for _, finfo := range inner.fields {
finfo.idx = append([]int{i}, finfo.idx...)
if err := addFieldInfo(typ, tinfo, &finfo); err != nil {
return nil, err
}
}
continue
}
}
finfo, err := structFieldInfo(typ, &f)
if err != nil {
return nil, err
}
if f.Name == "XMLName" {
tinfo.xmlname = finfo
continue
}
// Add the field if it doesn't conflict with other fields.
if err := addFieldInfo(typ, tinfo, finfo); err != nil {
return nil, err
}
}
}
tinfoLock.Lock()
tinfoMap[typ] = tinfo
tinfoLock.Unlock()
return tinfo, nil
}
// structFieldInfo builds and returns a fieldInfo for f.
func structFieldInfo(typ reflect.Type, f *reflect.StructField) (*fieldInfo, error) {
finfo := &fieldInfo{idx: f.Index}
// Split the tag from the xml namespace if necessary.
tag := f.Tag.Get("xml")
if i := strings.Index(tag, " "); i >= 0 {
finfo.xmlns, tag = tag[:i], tag[i+1:]
}
// Parse flags.
tokens := strings.Split(tag, ",")
if len(tokens) == 1 {
finfo.flags = fElement
} else {
tag = tokens[0]
for _, flag := range tokens[1:] {
switch flag {
case "attr":
finfo.flags |= fAttr
case "chardata":
finfo.flags |= fCharData
case "innerxml":
finfo.flags |= fInnerXml
case "comment":
finfo.flags |= fComment
case "any":
finfo.flags |= fAny
case "omitempty":
finfo.flags |= fOmitEmpty
}
}
// Validate the flags used.
valid := true
switch mode := finfo.flags & fMode; mode {
case 0:
finfo.flags |= fElement
case fAttr, fCharData, fInnerXml, fComment, fAny:
if f.Name == "XMLName" || tag != "" && mode != fAttr {
valid = false
}
default:
// This will also catch multiple modes in a single field.
valid = false
}
if finfo.flags&fMode == fAny {
finfo.flags |= fElement
}
if finfo.flags&fOmitEmpty != 0 && finfo.flags&(fElement|fAttr) == 0 {
valid = false
}
if !valid {
return nil, fmt.Errorf("xml: invalid tag in field %s of type %s: %q",
f.Name, typ, f.Tag.Get("xml"))
}
}
// Use of xmlns without a name is not allowed.
if finfo.xmlns != "" && tag == "" {
return nil, fmt.Errorf("xml: namespace without name in field %s of type %s: %q",
f.Name, typ, f.Tag.Get("xml"))
}
if f.Name == "XMLName" {
// The XMLName field records the XML element name. Don't
// process it as usual because its name should default to
// empty rather than to the field name.
finfo.name = tag
return finfo, nil
}
if tag == "" {
// If the name part of the tag is completely empty, get
// default from XMLName of underlying struct if feasible,
// or field name otherwise.
if xmlname := lookupXMLName(f.Type); xmlname != nil {
finfo.xmlns, finfo.name = xmlname.xmlns, xmlname.name
} else {
finfo.name = f.Name
}
return finfo, nil
}
// Prepare field name and parents.
parents := strings.Split(tag, ">")
if parents[0] == "" {
parents[0] = f.Name
}
if parents[len(parents)-1] == "" {
return nil, fmt.Errorf("xml: trailing '>' in field %s of type %s", f.Name, typ)
}
finfo.name = parents[len(parents)-1]
if len(parents) > 1 {
if (finfo.flags & fElement) == 0 {
return nil, fmt.Errorf("xml: %s chain not valid with %s flag", tag, strings.Join(tokens[1:], ","))
}
finfo.parents = parents[:len(parents)-1]
}
// If the field type has an XMLName field, the names must match
// so that the behavior of both marshalling and unmarshalling
// is straightforward and unambiguous.
if finfo.flags&fElement != 0 {
ftyp := f.Type
xmlname := lookupXMLName(ftyp)
if xmlname != nil && xmlname.name != finfo.name {
return nil, fmt.Errorf("xml: name %q in tag of %s.%s conflicts with name %q in %s.XMLName",
finfo.name, typ, f.Name, xmlname.name, ftyp)
}
}
return finfo, nil
}
// lookupXMLName returns the fieldInfo for typ's XMLName field
// in case it exists and has a valid xml field tag, otherwise
// it returns nil.
func lookupXMLName(typ reflect.Type) (xmlname *fieldInfo) {
for typ.Kind() == reflect.Ptr {
typ = typ.Elem()
}
if typ.Kind() != reflect.Struct {
return nil
}
for i, n := 0, typ.NumField(); i < n; i++ {
f := typ.Field(i)
if f.Name != "XMLName" {
continue
}
finfo, err := structFieldInfo(typ, &f)
if finfo.name != "" && err == nil {
return finfo
}
// Also consider errors as a non-existent field tag
// and let getTypeInfo itself report the error.
break
}
return nil
}
func min(a, b int) int {
if a <= b {
return a
}
return b
}
// addFieldInfo adds finfo to tinfo.fields if there are no
// conflicts, or if conflicts arise from previous fields that were
// obtained from deeper embedded structures than finfo. In the latter
// case, the conflicting entries are dropped.
// A conflict occurs when the path (parent + name) to a field is
// itself a prefix of another path, or when two paths match exactly.
// It is okay for field paths to share a common, shorter prefix.
func addFieldInfo(typ reflect.Type, tinfo *typeInfo, newf *fieldInfo) error {
var conflicts []int
Loop:
// First, figure all conflicts. Most working code will have none.
for i := range tinfo.fields {
oldf := &tinfo.fields[i]
if oldf.flags&fMode != newf.flags&fMode {
continue
}
if oldf.xmlns != "" && newf.xmlns != "" && oldf.xmlns != newf.xmlns {
continue
}
minl := min(len(newf.parents), len(oldf.parents))
for p := 0; p < minl; p++ {
if oldf.parents[p] != newf.parents[p] {
continue Loop
}
}
if len(oldf.parents) > len(newf.parents) {
if oldf.parents[len(newf.parents)] == newf.name {
conflicts = append(conflicts, i)
}
} else if len(oldf.parents) < len(newf.parents) {
if newf.parents[len(oldf.parents)] == oldf.name {
conflicts = append(conflicts, i)
}
} else {
if newf.name == oldf.name {
conflicts = append(conflicts, i)
}
}
}
// Without conflicts, add the new field and return.
if conflicts == nil {
tinfo.fields = append(tinfo.fields, *newf)
return nil
}
// If any conflict is shallower, ignore the new field.
// This matches the Go field resolution on embedding.
for _, i := range conflicts {
if len(tinfo.fields[i].idx) < len(newf.idx) {
return nil
}
}
// Otherwise, if any of them is at the same depth level, it's an error.
for _, i := range conflicts {
oldf := &tinfo.fields[i]
if len(oldf.idx) == len(newf.idx) {
f1 := typ.FieldByIndex(oldf.idx)
f2 := typ.FieldByIndex(newf.idx)
return &TagPathError{typ, f1.Name, f1.Tag.Get("xml"), f2.Name, f2.Tag.Get("xml")}
}
}
// Otherwise, the new field is shallower, and thus takes precedence,
// so drop the conflicting fields from tinfo and append the new one.
for c := len(conflicts) - 1; c >= 0; c-- {
i := conflicts[c]
copy(tinfo.fields[i:], tinfo.fields[i+1:])
tinfo.fields = tinfo.fields[:len(tinfo.fields)-1]
}
tinfo.fields = append(tinfo.fields, *newf)
return nil
}
// A TagPathError represents an error in the unmarshalling process
// caused by the use of field tags with conflicting paths.
type TagPathError struct {
Struct reflect.Type
Field1, Tag1 string
Field2, Tag2 string
}
func (e *TagPathError) Error() string {
return fmt.Sprintf("%s field %q with tag %q conflicts with field %q with tag %q", e.Struct, e.Field1, e.Tag1, e.Field2, e.Tag2)
}
// value returns v's field value corresponding to finfo.
// It's equivalent to v.FieldByIndex(finfo.idx), but initializes
// and dereferences pointers as necessary.
func (finfo *fieldInfo) value(v reflect.Value) reflect.Value {
for i, x := range finfo.idx {
if i > 0 {
t := v.Type()
if t.Kind() == reflect.Ptr && t.Elem().Kind() == reflect.Struct {
if v.IsNil() {
v.Set(reflect.New(v.Type().Elem()))
}
v = v.Elem()
}
}
v = v.Field(x)
}
return v
}
This diff is collapsed.
This diff is collapsed.
Markdown is supported
0% or .
You are about to add 0 people to the discussion. Proceed with caution.
Finish editing this message first!
Please register or to comment