// 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 (
"bufio"
"bytes"
"encoding"
"fmt"
"io"
"reflect"
"strconv"
"strings"
)
const (
// Header is a generic XML header suitable for use with the output of Marshal.
// This is not automatically added to any output of this package,
// it is provided as a convenience.
Header = `<?xml version="1.0" encoding="UTF-8"?>` + "\n"
)
// Marshal returns the XML encoding of v.
//
// Marshal handles an array or slice by marshaling each of the elements.
// Marshal handles a pointer by marshaling the value it points at or, if the
// pointer is nil, by writing nothing. Marshal handles an interface value by
// marshaling the value it contains or, if the interface value is nil, by
// writing nothing. Marshal handles all other data by writing one or more XML
// elements containing the data.
//
// The name for the XML elements is taken from, in order of preference:
// - the tag on the XMLName field, if the data is a struct
// - the value of the XMLName field of type Name
// - the tag of the struct field used to obtain the data
// - the name of the struct field used to obtain the data
// - the name of the marshaled type
//
// The XML element for a struct contains marshaled elements for each of the
// exported fields of the struct, with these exceptions:
// - the XMLName field, described above, is omitted.
// - a field with tag "-" is omitted.
// - a field with tag "name,attr" becomes an attribute with
// the given name in the XML element.
// - a field with tag ",attr" becomes an attribute with the
// field name in the XML element.
// - a field with tag ",chardata" is written as character data,
// not as an XML element.
// - a field with tag ",cdata" is written as character data
// wrapped in one or more <![CDATA[ ... ]]> tags, not as an XML element.
// - a field with tag ",innerxml" is written verbatim, not subject
// to the usual marshaling procedure.
// - a field with tag ",comment" is written as an XML comment, not
// subject to the usual marshaling procedure. It must not contain
// the "--" string within it.
// - a field with a tag including the "omitempty" option is omitted
// if the field value is empty. The empty values are false, 0, any
// nil pointer or interface value, and any array, slice, map, or
// string of length zero.
// - an anonymous struct field is handled as if the fields of its
// value were part of the outer struct.
// - a field implementing Marshaler is written by calling its MarshalXML
// method.
// - a field implementing encoding.TextMarshaler is written by encoding the
// result of its MarshalText method as text.
//
// If a field uses a tag "a>b>c", then the element c will be nested inside
// parent elements a and b. Fields that appear next to each other that name
// the same parent will be enclosed in one XML element.
//
// If the XML name for a struct field is defined by both the field tag and the
// struct's XMLName field, the names must match.
//
// See MarshalIndent for an example.
//
// Marshal will return an error if asked to marshal a channel, function, or map.
func Marshal(v interface{}) ([]byte, error) {
var b bytes.Buffer
if err := NewEncoder(&b).Encode(v); err != nil {
return nil, err
}
return b.Bytes(), nil
}
// Marshaler is the interface implemented by objects that can marshal
// themselves into valid XML elements.
//
// MarshalXML encodes the receiver as zero or more XML elements.
// By convention, arrays or slices are typically encoded as a sequence
// of elements, one per entry.
// Using start as the element tag is not required, but doing so
// will enable Unmarshal to match the XML elements to the correct
// struct field.
// One common implementation strategy is to construct a separate
// value with a layout corresponding to the desired XML and then
// to encode it using e.EncodeElement.
// Another common strategy is to use repeated calls to e.EncodeToken
// to generate the XML output one token at a time.
// The sequence of encoded tokens must make up zero or more valid
// XML elements.
type Marshaler interface {
MarshalXML(e *Encoder, start StartElement) error
}
// MarshalerAttr is the interface implemented by objects that can marshal
// themselves into valid XML attributes.
//
// MarshalXMLAttr returns an XML attribute with the encoded value of the receiver.
// Using name as the attribute name is not required, but doing so
// will enable Unmarshal to match the attribute to the correct
// struct field.
// If MarshalXMLAttr returns the zero attribute Attr{}, no attribute
// will be generated in the output.
// MarshalXMLAttr is used only for struct fields with the
// "attr" option in the field tag.
type MarshalerAttr interface {
MarshalXMLAttr(name Name) (Attr, error)
}
// MarshalIndent works like Marshal, but each XML element begins on a new
// indented line that starts with prefix and is followed by one or more
// copies of indent according to the nesting depth.
func MarshalIndent(v interface{}, prefix, indent string) ([]byte, error) {
var b bytes.Buffer
enc := NewEncoder(&b)
enc.Indent(prefix, indent)
if err := enc.Encode(v); err != nil {
return nil, err
}
return b.Bytes(), nil
}
// An Encoder writes XML data to an output stream.
type Encoder struct {
p printer
}
// NewEncoder returns a new encoder that writes to w.
func NewEncoder(w io.Writer) *Encoder {
e := &Encoder{printer{Writer: bufio.NewWriter(w)}}
e.p.encoder = e
return e
}
// Indent sets the encoder to generate XML in which each element
// begins on a new indented line that starts with prefix and is followed by
// one or more copies of indent according to the nesting depth.
func (enc *Encoder) Indent(prefix, indent string) {
enc.p.prefix = prefix
enc.p.indent = indent
}
// Encode writes the XML encoding of v to the stream.
//
// See the documentation for Marshal for details about the conversion
// of Go values to XML.
//
// Encode calls Flush before returning.
func (enc *Encoder) Encode(v interface{}) error {
err := enc.p.marshalValue(reflect.ValueOf(v), nil, nil)
if err != nil {
return err
}
return enc.p.Flush()
}
// EncodeElement writes the XML encoding of v to the stream,
// using start as the outermost tag in the encoding.
//
// See the documentation for Marshal for details about the conversion
// of Go values to XML.
//
// EncodeElement calls Flush before returning.
func (enc *Encoder) EncodeElement(v interface{}, start StartElement) error {
err := enc.p.marshalValue(reflect.ValueOf(v), nil, &start)
if err != nil {
return err
}
return enc.p.Flush()
}
var (
begComment = []byte("<!--")
endComment = []byte("-->")
endProcInst = []byte("?>")
)
// EncodeToken writes the given XML token to the stream.
// It returns an error if StartElement and EndElement tokens are not properly matched.
//
// EncodeToken does not call Flush, because usually it is part of a larger operation
// such as Encode or EncodeElement (or a custom Marshaler's MarshalXML invoked
// during those), and those will call Flush when finished.
// Callers that create an Encoder and then invoke EncodeToken directly, without
// using Encode or EncodeElement, need to call Flush when finished to ensure
// that the XML is written to the underlying writer.
//
// EncodeToken allows writing a ProcInst with Target set to "xml" only as the first token
// in the stream.
func (enc *Encoder) EncodeToken(t Token) error {
p := &enc.p
switch t := t.(type) {
case StartElement:
if err := p.writeStart(&t); err != nil {
return err
}
case EndElement:
if err := p.writeEnd(t.Name); err != nil {
return err
}
case CharData:
escapeText(p, t, false)
case Comment:
if bytes.Contains(t, endComment) {
return fmt.Errorf("xml: EncodeToken of Comment containing --> marker")
}
p.WriteString("<!--")
p.Write(t)
p.WriteString("-->")
return p.cachedWriteError()
case ProcInst:
// First token to be encoded which is also a ProcInst with target of xml
// is the xml declaration. The only ProcInst where target of xml is allowed.
if t.Target == "xml" && p.Buffered() != 0 {
return fmt.Errorf("xml: EncodeToken of ProcInst xml target only valid for xml declaration, first token encoded")
}
if !isNameString(t.Target) {
return fmt.Errorf("xml: EncodeToken of ProcInst with invalid Target")
}
if bytes.Contains(t.Inst, endProcInst) {
return fmt.Errorf("xml: EncodeToken of ProcInst containing ?> marker")
}
p.WriteString("<?")
p.WriteString(t.Target)
if len(t.Inst) > 0 {
p.WriteByte(' ')
p.Write(t.Inst)
}
p.WriteString("?>")
case Directive:
if !isValidDirective(t) {
return fmt.Errorf("xml: EncodeToken of Directive containing wrong < or > markers")
}
p.WriteString("<!")
p.Write(t)
p.WriteString(">")
default:
return fmt.Errorf("xml: EncodeToken of invalid token type")
}
return p.cachedWriteError()
}
// isValidDirective reports whether dir is a valid directive text,
// meaning angle brackets are matched, ignoring comments and strings.
func isValidDirective(dir Directive) bool {
var (
depth int
inquote uint8
incomment bool
)
for i, c := range dir {
switch {
case incomment:
if c == '>' {
if n := 1 + i - len(endComment); n >= 0 && bytes.Equal(dir[n:i+1], endComment) {
incomment = false
}
}
// Just ignore anything in comment
case inquote != 0:
if c == inquote {
inquote = 0
}
// Just ignore anything within quotes
case c == '\'' || c == '"':
inquote = c
case c == '<':
if i+len(begComment) < len(dir) && bytes.Equal(dir[i:i+len(begComment)], begComment) {
incomment = true
} else {
depth++
}
case c == '>':
if depth == 0 {
return false
}
depth--
}
}
return depth == 0 && inquote == 0 && !incomment
}
// Flush flushes any buffered XML to the underlying writer.
// See the EncodeToken documentation for details about when it is necessary.
func (enc *Encoder) Flush() error {
return enc.p.Flush()
}
type printer struct {
*bufio.Writer
encoder *Encoder
seq int
indent string
prefix string
depth int
indentedIn bool
putNewline bool
attrNS map[string]string // map prefix -> name space
attrPrefix map[string]string // map name space -> prefix
prefixes []string
tags []Name
}
// createAttrPrefix finds the name space prefix attribute to use for the given name space,
// defining a new prefix if necessary. It returns the prefix.
func (p *printer) createAttrPrefix(url string) string {
if prefix := p.attrPrefix[url]; prefix != "" {
return prefix
}
// The "http://www.w3.org/XML/1998/namespace" name space is predefined as "xml"
// and must be referred to that way.
// (The "http://www.w3.org/2000/xmlns/" name space is also predefined as "xmlns",
// but users should not be trying to use that one directly - that's our job.)
if url == xmlURL {
return xmlPrefix
}
// Need to define a new name space.
if p.attrPrefix == nil {
p.attrPrefix = make(map[string]string)
p.attrNS = make(map[string]string)
}
// Pick a name. We try to use the final element of the path
// but fall back to _.
prefix := strings.TrimRight(url, "/")
if i := strings.LastIndex(prefix, "/"); i >= 0 {
prefix = prefix[i+1:]
}
if prefix == "" || !isName([]byte(prefix)) || strings.Contains(prefix, ":") {
prefix = "_"
}
if strings.HasPrefix(prefix, "xml") {
// xmlanything is reserved.
prefix = "_" + prefix
}
if p.attrNS[prefix] != "" {
// Name is taken. Find a better one.
for p.seq++; ; p.seq++ {
if id := prefix + "_" + strconv.Itoa(p.seq); p.attrNS[id] == "" {
prefix = id
break
}
}
}
p.attrPrefix[url] = prefix
p.attrNS[prefix] = url
p.WriteString(`xmlns:`)
p.WriteString(prefix)
p.WriteString(`="`)
EscapeText(p, []byte(url))
p.WriteString(`" `)
p.prefixes = append(p.prefixes, prefix)
return prefix
}
// deleteAttrPrefix removes an attribute name space prefix.
func (p *printer) deleteAttrPrefix(prefix string) {
delete(p.attrPrefix, p.attrNS[prefix])
delete(p.attrNS, prefix)
}
func (p *printer) markPrefix() {
p.prefixes = append(p.prefixes, "")
}
func (p *printer) popPrefix() {
for len(p.prefixes) > 0 {
prefix := p.prefixes[len(p.prefixes)-1]
p.prefixes = p.prefixes[:len(p.prefixes)-1]
if prefix == "" {
break
}
p.deleteAttrPrefix(prefix)
}
}
var (
marshalerType = reflect.TypeOf((*Marshaler)(nil)).Elem()
marshalerAttrType = reflect.TypeOf((*MarshalerAttr)(nil)).Elem()
textMarshalerType = reflect.TypeOf((*encoding.TextMarshaler)(nil)).Elem()
)
// marshalValue writes one or more XML elements representing val.
// If val was obtained from a struct field, finfo must have its details.
func (p *printer) marshalValue(val reflect.Value, finfo *fieldInfo, startTemplate *StartElement) error {
if startTemplate != nil && startTemplate.Name.Local == "" {
return fmt.Errorf("xml: EncodeElement of StartElement with missing name")
}
if !val.IsValid() {
return nil
}
if finfo != nil && finfo.flags&fOmitEmpty != 0 && isEmptyValue(val) {
return nil
}
// Drill into interfaces and pointers.
// This can turn into an infinite loop given a cyclic chain,
// but it matches the Go 1 behavior.
for val.Kind() == reflect.Interface || val.Kind() == reflect.Ptr {
if val.IsNil() {
return nil
}
val = val.Elem()
}
kind := val.Kind()
typ := val.Type()
// Check for marshaler.
if val.CanInterface() && typ.Implements(marshalerType) {
return p.marshalInterface(val.Interface().(Marshaler), defaultStart(typ, finfo, startTemplate))
}
if val.CanAddr() {
pv := val.Addr()
if pv.CanInterface() && pv.Type().Implements(marshalerType) {
return p.marshalInterface(pv.Interface().(Marshaler), defaultStart(pv.Type(), finfo, startTemplate))
}
}
// Check for text marshaler.
if val.CanInterface() && typ.Implements(textMarshalerType) {
return p.marshalTextInterface(val.Interface().(encoding.TextMarshaler), defaultStart(typ, finfo, startTemplate))
}
if val.CanAddr() {
pv := val.Addr()
if pv.CanInterface() && pv.Type().Implements(textMarshalerType) {
return p.marshalTextInterface(pv.Interface().(encoding.TextMarshaler), defaultStart(pv.Type(), finfo, startTemplate))
}
}
// Slices and arrays iterate over the elements. They do not have an enclosing tag.
if (kind == reflect.Slice || kind == reflect.Array) && typ.Elem().Kind() != reflect.Uint8 {
for i, n := 0, val.Len(); i < n; i++ {
if err := p.marshalValue(val.Index(i), finfo, startTemplate); err != nil {
return err
}
}
return nil
}
tinfo, err := getTypeInfo(typ)
if err != nil {
return err
}
// Create start element.
// Precedence for the XML element name is:
// 0. startTemplate
// 1. XMLName field in underlying struct;
// 2. field name/tag in the struct field; and
// 3. type name
var start StartElement
if startTemplate != nil {
start.Name = startTemplate.Name
start.Attr = append(start.Attr, startTemplate.Attr...)
} else if tinfo.xmlname != nil {
xmlname := tinfo.xmlname
if xmlname.name != "" {
start.Name.Space, start.Name.Local = xmlname.xmlns, xmlname.name
} else if v, ok := xmlname.value(val).Interface().(Name); ok && v.Local != "" {
start.Name = v
}
}
if start.Name.Local == "" && finfo != nil {
start.Name.Space, start.Name.Local = finfo.xmlns, finfo.name
}
if start.Name.Local == "" {
name := typ.Name()
if name == "" {
return &UnsupportedTypeError{typ}
}
start.Name.Local = name
}
// Attributes
for i := range tinfo.fields {
finfo := &tinfo.fields[i]
if finfo.flags&fAttr == 0 {
continue
}
fv := finfo.value(val)
if finfo.flags&fOmitEmpty != 0 && isEmptyValue(fv) {
continue
}
if fv.Kind() == reflect.Interface && fv.IsNil() {
continue
}
name := Name{Space: finfo.xmlns, Local: finfo.name}
if err := p.marshalAttr(&start, name, fv); err != nil {
return err
}
}
if err := p.writeStart(&start); err != nil {
return err
}
if val.Kind() == reflect.Struct {
err = p.marshalStruct(tinfo, val)
} else {
s, b, err1 := p.marshalSimple(typ, val)
if err1 != nil {
err = err1
} else if b != nil {
EscapeText(p, b)
} else {
p.EscapeString(s)
}
}
if err != nil {
return err
}
if err := p.writeEnd(start.Name); err != nil {
return err
}
return p.cachedWriteError()
}
// marshalAttr marshals an attribute with the given name and value, adding to start.Attr.
func (p *printer) marshalAttr(start *StartElement, name Name, val reflect.Value) error {
if val.CanInterface() && val.Type().Implements(marshalerAttrType) {
attr, err := val.Interface().(MarshalerAttr).MarshalXMLAttr(name)
if err != nil {
return err
}
if attr.Name.Local != "" {
start.Attr = append(start.Attr, attr)
}
return nil
}
if val.CanAddr() {
pv := val.Addr()
if pv.CanInterface() && pv.Type().Implements(marshalerAttrType) {
attr, err := pv.Interface().(MarshalerAttr).MarshalXMLAttr(name)
if err != nil {
return err
}
if attr.Name.Local != "" {
start.Attr = append(start.Attr, attr)
}
return nil
}
}
if val.CanInterface() && val.Type().Implements(textMarshalerType) {
text, err := val.Interface().(encoding.TextMarshaler).MarshalText()
if err != nil {
return err
}
start.Attr = append(start.Attr, Attr{name, string(text)})
return nil
}
if val.CanAddr() {
pv := val.Addr()
if pv.CanInterface() && pv.Type().Implements(textMarshalerType) {
text, err := pv.Interface().(encoding.TextMarshaler).MarshalText()
if err != nil {
return err
}
start.Attr = append(start.Attr, Attr{name, string(text)})
return nil
}
}
// Dereference or skip nil pointer, interface values.
switch val.Kind() {
case reflect.Ptr, reflect.Interface:
if val.IsNil() {
return nil
}
val = val.Elem()
}
// Walk slices.
if val.Kind() == reflect.Slice && val.Type().Elem().Kind() != reflect.Uint8 {
n := val.Len()
for i := 0; i < n; i++ {
if err := p.marshalAttr(start, name, val.Index(i)); err != nil {
return err
}
}
return nil
}
if val.Type() == attrType {
start.Attr = append(start.Attr, val.Interface().(Attr))
return nil
}
s, b, err := p.marshalSimple(val.Type(), val)
if err != nil {
return err
}
if b != nil {
s = string(b)
}
start.Attr = append(start.Attr, Attr{name, s})
return nil
}
// defaultStart returns the default start element to use,
// given the reflect type, field info, and start template.
func defaultStart(typ reflect.Type, finfo *fieldInfo, startTemplate *StartElement) StartElement {
var start StartElement
// Precedence for the XML element name is as above,
// except that we do not look inside structs for the first field.
if startTemplate != nil {
start.Name = startTemplate.Name
start.Attr = append(start.Attr, startTemplate.Attr...)
} else if finfo != nil && finfo.name != "" {
start.Name.Local = finfo.name
start.Name.Space = finfo.xmlns
} else if typ.Name() != "" {
start.Name.Local = typ.Name()
} else {
// Must be a pointer to a named type,
// since it has the Marshaler methods.
start.Name.Local = typ.Elem().Name()
}
return start
}
// marshalInterface marshals a Marshaler interface value.
func (p *printer) marshalInterface(val Marshaler, start StartElement) error {
// Push a marker onto the tag stack so that MarshalXML
// cannot close the XML tags that it did not open.
p.tags = append(p.tags, Name{})
n := len(p.tags)
err := val.MarshalXML(p.encoder, start)
if err != nil {
return err
}
// Make sure MarshalXML closed all its tags. p.tags[n-1] is the mark.
if len(p.tags) > n {
return fmt.Errorf("xml: %s.MarshalXML wrote invalid XML: <%s> not closed", receiverType(val), p.tags[len(p.tags)-1].Local)
}
p.tags = p.tags[:n-1]
return nil
}
// marshalTextInterface marshals a TextMarshaler interface value.
func (p *printer) marshalTextInterface(val encoding.TextMarshaler, start StartElement) error {
if err := p.writeStart(&start); err != nil {
return err
}
text, err := val.MarshalText()
if err != nil {
return err
}
EscapeText(p, text)
return p.writeEnd(start.Name)
}
// writeStart writes the given start element.
func (p *printer) writeStart(start *StartElement) error {
if start.Name.Local == "" {
return fmt.Errorf("xml: start tag with no name")
}
p.tags = append(p.tags, start.Name)
p.markPrefix()
p.writeIndent(1)
p.WriteByte('<')
p.WriteString(start.Name.Local)
if start.Name.Space != "" {
p.WriteString(` xmlns="`)
p.EscapeString(start.Name.Space)
p.WriteByte('"')
}
// Attributes
for _, attr := range start.Attr {
name := attr.Name
if name.Local == "" {
continue
}
p.WriteByte(' ')
if name.Space != "" {
p.WriteString(p.createAttrPrefix(name.Space))
p.WriteByte(':')
}
p.WriteString(name.Local)
p.WriteString(`="`)
p.EscapeString(attr.Value)
p.WriteByte('"')
}
p.WriteByte('>')
return nil
}
func (p *printer) writeEnd(name Name) error {
if name.Local == "" {
return fmt.Errorf("xml: end tag with no name")
}
if len(p.tags) == 0 || p.tags[len(p.tags)-1].Local == "" {
return fmt.Errorf("xml: end tag </%s> without start tag", name.Local)
}
if top := p.tags[len(p.tags)-1]; top != name {
if top.Local != name.Local {
return fmt.Errorf("xml: end tag </%s> does not match start tag <%s>", name.Local, top.Local)
}
return fmt.Errorf("xml: end tag </%s> in namespace %s does not match start tag <%s> in namespace %s", name.Local, name.Space, top.Local, top.Space)
}
p.tags = p.tags[:len(p.tags)-1]
p.writeIndent(-1)
p.WriteByte('<')
p.WriteByte('/')
p.WriteString(name.Local)
p.WriteByte('>')
p.popPrefix()
return nil
}
func (p *printer) marshalSimple(typ reflect.Type, val reflect.Value) (string, []byte, error) {
switch val.Kind() {
case reflect.Int, reflect.Int8, reflect.Int16, reflect.Int32, reflect.Int64:
return strconv.FormatInt(val.Int(), 10), nil, nil
case reflect.Uint, reflect.Uint8, reflect.Uint16, reflect.Uint32, reflect.Uint64, reflect.Uintptr:
return strconv.FormatUint(val.Uint(), 10), nil, nil
case reflect.Float32, reflect.Float64:
return strconv.FormatFloat(val.Float(), 'g', -1, val.Type().Bits()), nil, nil
case reflect.String:
return val.String(), nil, nil
case reflect.Bool:
return strconv.FormatBool(val.Bool()), nil, nil
case reflect.Array:
if typ.Elem().Kind() != reflect.Uint8 {
break
}
// [...]byte
var bytes []byte
if val.CanAddr() {
bytes = val.Slice(0, val.Len()).Bytes()
} else {
bytes = make([]byte, val.Len())
reflect.Copy(reflect.ValueOf(bytes), val)
}
return "", bytes, nil
case reflect.Slice:
if typ.Elem().Kind() != reflect.Uint8 {
break
}
// []byte
return "", val.Bytes(), nil
}
return "", nil, &UnsupportedTypeError{typ}
}
var ddBytes = []byte("--")
// indirect drills into interfaces and pointers, returning the pointed-at value.
// If it encounters a nil interface or pointer, indirect returns that nil value.
// This can turn into an infinite loop given a cyclic chain,
// but it matches the Go 1 behavior.
func indirect(vf reflect.Value) reflect.Value {
for vf.Kind() == reflect.Interface || vf.Kind() == reflect.Ptr {
if vf.IsNil() {
return vf
}
vf = vf.Elem()
}
return vf
}
func (p *printer) marshalStruct(tinfo *typeInfo, val reflect.Value) error {
s := parentStack{p: p}
for i := range tinfo.fields {
finfo := &tinfo.fields[i]
if finfo.flags&fAttr != 0 {
continue
}
vf := finfo.value(val)
switch finfo.flags & fMode {
case fCDATA, fCharData:
emit := EscapeText
if finfo.flags&fMode == fCDATA {
emit = emitCDATA
}
if err := s.trim(finfo.parents); err != nil {
return err
}
if vf.CanInterface() && vf.Type().Implements(textMarshalerType) {
data, err := vf.Interface().(encoding.TextMarshaler).MarshalText()
if err != nil {
return err
}
if err := emit(p, data); err != nil {
return err
}
continue
}
if vf.CanAddr() {
pv := vf.Addr()
if pv.CanInterface() && pv.Type().Implements(textMarshalerType) {
data, err := pv.Interface().(encoding.TextMarshaler).MarshalText()
if err != nil {
return err
}
if err := emit(p, data); err != nil {
return err
}
continue
}
}
var scratch [64]byte
vf = indirect(vf)
switch vf.Kind() {
case reflect.Int, reflect.Int8, reflect.Int16, reflect.Int32, reflect.Int64:
if err := emit(p, strconv.AppendInt(scratch[:0], vf.Int(), 10)); err != nil {
return err
}
case reflect.Uint, reflect.Uint8, reflect.Uint16, reflect.Uint32, reflect.Uint64, reflect.Uintptr:
if err := emit(p, strconv.AppendUint(scratch[:0], vf.Uint(), 10)); err != nil {
return err
}
case reflect.Float32, reflect.Float64:
if err := emit(p, strconv.AppendFloat(scratch[:0], vf.Float(), 'g', -1, vf.Type().Bits())); err != nil {
return err
}
case reflect.Bool:
if err := emit(p, strconv.AppendBool(scratch[:0], vf.Bool())); err != nil {
return err
}
case reflect.String:
if err := emit(p, []byte(vf.String())); err != nil {
return err
}
case reflect.Slice:
if elem, ok := vf.Interface().([]byte); ok {
if err := emit(p, elem); err != nil {
return err
}
}
}
continue
case fComment:
if err := s.trim(finfo.parents); err != nil {
return err
}
vf = indirect(vf)
k := vf.Kind()
if !(k == reflect.String || k == reflect.Slice && vf.Type().Elem().Kind() == reflect.Uint8) {
return fmt.Errorf("xml: bad type for comment field of %s", val.Type())
}
if vf.Len() == 0 {
continue
}
p.writeIndent(0)
p.WriteString("<!--")
dashDash := false
dashLast := false
switch k {
case reflect.String:
s := vf.String()
dashDash = strings.Contains(s, "--")
dashLast = s[len(s)-1] == '-'
if !dashDash {
p.WriteString(s)
}
case reflect.Slice:
b := vf.Bytes()
dashDash = bytes.Contains(b, ddBytes)
dashLast = b[len(b)-1] == '-'
if !dashDash {
p.Write(b)
}
default:
panic("can't happen")
}
if dashDash {
return fmt.Errorf(`xml: comments must not contain "--"`)
}
if dashLast {
// "--->" is invalid grammar. Make it "- -->"
p.WriteByte(' ')
}
p.WriteString("-->")
continue
case fInnerXml:
vf = indirect(vf)
iface := vf.Interface()
switch raw := iface.(type) {
case []byte:
p.Write(raw)
continue
case string:
p.WriteString(raw)
continue
}
case fElement, fElement | fAny:
if err := s.trim(finfo.parents); err != nil {
return err
}
if len(finfo.parents) > len(s.stack) {
if vf.Kind() != reflect.Ptr && vf.Kind() != reflect.Interface || !vf.IsNil() {
if err := s.push(finfo.parents[len(s.stack):]); err != nil {
return err
}
}
}
}
if err := p.marshalValue(vf, finfo, nil); err != nil {
return err
}
}
s.trim(nil)
return p.cachedWriteError()
}
// return the bufio Writer's cached write error
func (p *printer) cachedWriteError() error {
_, err := p.Write(nil)
return err
}
func (p *printer) writeIndent(depthDelta int) {
if len(p.prefix) == 0 && len(p.indent) == 0 {
return
}
if depthDelta < 0 {
p.depth--
if p.indentedIn {
p.indentedIn = false
return
}
p.indentedIn = false
}
if p.putNewline {
p.WriteByte('\n')
} else {
p.putNewline = true
}
if len(p.prefix) > 0 {
p.WriteString(p.prefix)
}
if len(p.indent) > 0 {
for i := 0; i < p.depth; i++ {
p.WriteString(p.indent)
}
}
if depthDelta > 0 {
p.depth++
p.indentedIn = true
}
}
type parentStack struct {
p *printer
stack []string
}
// trim updates the XML context to match the longest common prefix of the stack
// and the given parents. A closing tag will be written for every parent
// popped. Passing a zero slice or nil will close all the elements.
func (s *parentStack) trim(parents []string) error {
split := 0
for ; split < len(parents) && split < len(s.stack); split++ {
if parents[split] != s.stack[split] {
break
}
}
for i := len(s.stack) - 1; i >= split; i-- {
if err := s.p.writeEnd(Name{Local: s.stack[i]}); err != nil {
return err
}
}
s.stack = s.stack[:split]
return nil
}
// push adds parent elements to the stack and writes open tags.
func (s *parentStack) push(parents []string) error {
for i := 0; i < len(parents); i++ {
if err := s.p.writeStart(&StartElement{Name: Name{Local: parents[i]}}); err != nil {
return err
}
}
s.stack = append(s.stack, parents...)
return nil
}
// UnsupportedTypeError is returned when Marshal encounters a type
// that cannot be converted into XML.
type UnsupportedTypeError struct {
Type reflect.Type
}
func (e *UnsupportedTypeError) Error() string {
return "xml: unsupported type: " + e.Type.String()
}
func isEmptyValue(v reflect.Value) bool {
switch v.Kind() {
case reflect.Array, reflect.Map, reflect.Slice, reflect.String:
return v.Len() == 0
case reflect.Bool:
return !v.Bool()
case reflect.Int, reflect.Int8, reflect.Int16, reflect.Int32, reflect.Int64:
return v.Int() == 0
case reflect.Uint, reflect.Uint8, reflect.Uint16, reflect.Uint32, reflect.Uint64, reflect.Uintptr:
return v.Uint() == 0
case reflect.Float32, reflect.Float64:
return v.Float() == 0
case reflect.Interface, reflect.Ptr:
return v.IsNil()
}
return false
}