+++ /dev/null
-// 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 (
- // 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 marshalling each of the elements.
-// Marshal handles a pointer by marshalling the value it points at or, if the
-// pointer is nil, by writing nothing. Marshal handles an interface value by
-// marshalling 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 xml.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 marshalled type
-//
-// The XML element for a struct contains marshalled 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 ",innerxml" is written verbatim, not subject
-// to the usual marshalling procedure.
-// - a field with tag ",comment" is written as an XML comment, not
-// subject to the usual marshalling 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.
-//
-// 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.
-//
-// 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("?>")
- endDirective = []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.
-//
-// When encoding a StartElement holding an XML namespace prefix
-// declaration for a prefix that is not already declared, contained
-// elements (including the StartElement itself) will use the declared
-// prefix when encoding names with matching namespace URIs.
-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
- defaultNS string
- attrNS map[string]string // map prefix -> name space
- attrPrefix map[string]string // map name space -> prefix
- prefixes []printerPrefix
- tags []Name
-}
-
-// printerPrefix holds a namespace undo record.
-// When an element is popped, the prefix record
-// is set back to the recorded URL. The empty
-// prefix records the URL for the default name space.
-//
-// The start of an element is recorded with an element
-// that has mark=true.
-type printerPrefix struct {
- prefix string
- url string
- mark bool
-}
-
-func (p *printer) prefixForNS(url string, isAttr bool) string {
- // 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 "xml"
- }
- if !isAttr && url == p.defaultNS {
- // We can use the default name space.
- return ""
- }
- return p.attrPrefix[url]
-}
-
-// defineNS pushes any namespace definition found in the given attribute.
-// If ignoreNonEmptyDefault is true, an xmlns="nonempty"
-// attribute will be ignored.
-func (p *printer) defineNS(attr Attr, ignoreNonEmptyDefault bool) error {
- var prefix string
- if attr.Name.Local == "xmlns" {
- if attr.Name.Space != "" && attr.Name.Space != "xml" && attr.Name.Space != xmlURL {
- return fmt.Errorf("xml: cannot redefine xmlns attribute prefix")
- }
- } else if attr.Name.Space == "xmlns" && attr.Name.Local != "" {
- prefix = attr.Name.Local
- if attr.Value == "" {
- // Technically, an empty XML namespace is allowed for an attribute.
- // From http://www.w3.org/TR/xml-names11/#scoping-defaulting:
- //
- // The attribute value in a namespace declaration for a prefix may be
- // empty. This has the effect, within the scope of the declaration, of removing
- // any association of the prefix with a namespace name.
- //
- // However our namespace prefixes here are used only as hints. There's
- // no need to respect the removal of a namespace prefix, so we ignore it.
- return nil
- }
- } else {
- // Ignore: it's not a namespace definition
- return nil
- }
- if prefix == "" {
- if attr.Value == p.defaultNS {
- // No need for redefinition.
- return nil
- }
- if attr.Value != "" && ignoreNonEmptyDefault {
- // We have an xmlns="..." value but
- // it can't define a name space in this context,
- // probably because the element has an empty
- // name space. In this case, we just ignore
- // the name space declaration.
- return nil
- }
- } else if _, ok := p.attrPrefix[attr.Value]; ok {
- // There's already a prefix for the given name space,
- // so use that. This prevents us from
- // having two prefixes for the same name space
- // so attrNS and attrPrefix can remain bijective.
- return nil
- }
- p.pushPrefix(prefix, attr.Value)
- return nil
-}
-
-// createNSPrefix creates a name space prefix attribute
-// to use for the given name space, defining a new prefix
-// if necessary.
-// If isAttr is true, the prefix is to be created for an attribute
-// prefix, which means that the default name space cannot
-// be used.
-func (p *printer) createNSPrefix(url string, isAttr bool) {
- if _, ok := p.attrPrefix[url]; ok {
- // We already have a prefix for the given URL.
- return
- }
- switch {
- case !isAttr && url == p.defaultNS:
- // We can use the default name space.
- return
- case url == "":
- // The only way we can encode names in the empty
- // name space is by using the default name space,
- // so we must use that.
- if p.defaultNS != "" {
- // The default namespace is non-empty, so we
- // need to set it to empty.
- p.pushPrefix("", "")
- }
- return
- case url == xmlURL:
- return
- }
- // TODO If the URL is an existing prefix, we could
- // use it as is. That would enable the
- // marshaling of elements that had been unmarshaled
- // and with a name space prefix that was not found.
- // although technically it would be incorrect.
-
- // 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.pushPrefix(prefix, url)
-}
-
-// writeNamespaces writes xmlns attributes for all the
-// namespace prefixes that have been defined in
-// the current element.
-func (p *printer) writeNamespaces() {
- for i := len(p.prefixes) - 1; i >= 0; i-- {
- prefix := p.prefixes[i]
- if prefix.mark {
- return
- }
- p.WriteString(" ")
- if prefix.prefix == "" {
- // Default name space.
- p.WriteString(`xmlns="`)
- } else {
- p.WriteString("xmlns:")
- p.WriteString(prefix.prefix)
- p.WriteString(`="`)
- }
- EscapeText(p, []byte(p.nsForPrefix(prefix.prefix)))
- p.WriteString(`"`)
- }
-}
-
-// pushPrefix pushes a new prefix on the prefix stack
-// without checking to see if it is already defined.
-func (p *printer) pushPrefix(prefix, url string) {
- p.prefixes = append(p.prefixes, printerPrefix{
- prefix: prefix,
- url: p.nsForPrefix(prefix),
- })
- p.setAttrPrefix(prefix, url)
-}
-
-// nsForPrefix returns the name space for the given
-// prefix. Note that this is not valid for the
-// empty attribute prefix, which always has an empty
-// name space.
-func (p *printer) nsForPrefix(prefix string) string {
- if prefix == "" {
- return p.defaultNS
- }
- return p.attrNS[prefix]
-}
-
-// markPrefix marks the start of an element on the prefix
-// stack.
-func (p *printer) markPrefix() {
- p.prefixes = append(p.prefixes, printerPrefix{
- mark: true,
- })
-}
-
-// popPrefix pops all defined prefixes for the current
-// element.
-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.mark {
- break
- }
- p.setAttrPrefix(prefix.prefix, prefix.url)
- }
-}
-
-// setAttrPrefix sets an attribute name space prefix.
-// If url is empty, the attribute is removed.
-// If prefix is empty, the default name space is set.
-func (p *printer) setAttrPrefix(prefix, url string) {
- if prefix == "" {
- p.defaultNS = url
- return
- }
- if url == "" {
- delete(p.attrPrefix, p.attrNS[prefix])
- delete(p.attrNS, prefix)
- return
- }
- if p.attrPrefix == nil {
- // Need to define a new name space.
- p.attrPrefix = make(map[string]string)
- p.attrNS = make(map[string]string)
- }
- // Remove any old prefix value. This is OK because we maintain a
- // strict one-to-one mapping between prefix and URL (see
- // defineNS)
- delete(p.attrPrefix, p.attrNS[prefix])
- p.attrPrefix[url] = prefix
- p.attrNS[prefix] = url
-}
-
-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), p.defaultStart(typ, finfo, startTemplate))
- }
- if val.CanAddr() {
- pv := val.Addr()
- if pv.CanInterface() && pv.Type().Implements(marshalerType) {
- return p.marshalInterface(pv.Interface().(Marshaler), p.defaultStart(pv.Type(), finfo, startTemplate))
- }
- }
-
- // Check for text marshaler.
- if val.CanInterface() && typ.Implements(textMarshalerType) {
- return p.marshalTextInterface(val.Interface().(encoding.TextMarshaler), p.defaultStart(typ, finfo, startTemplate))
- }
- if val.CanAddr() {
- pv := val.Addr()
- if pv.CanInterface() && pv.Type().Implements(textMarshalerType) {
- return p.marshalTextInterface(pv.Interface().(encoding.TextMarshaler), p.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
-
- // explicitNS records whether the element's name space has been
- // explicitly set (for example an XMLName field).
- explicitNS := false
-
- if startTemplate != nil {
- start.Name = startTemplate.Name
- explicitNS = true
- 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
- }
- explicitNS = true
- }
- if start.Name.Local == "" && finfo != nil {
- start.Name.Local = finfo.name
- if finfo.xmlns != "" {
- start.Name.Space = finfo.xmlns
- explicitNS = true
- }
- }
- if start.Name.Local == "" {
- name := typ.Name()
- if name == "" {
- return &UnsupportedTypeError{typ}
- }
- start.Name.Local = name
- }
-
- // defaultNS records the default name space as set by a xmlns="..."
- // attribute. We don't set p.defaultNS because we want to let
- // the attribute writing code (in p.defineNS) be solely responsible
- // for maintaining that.
- defaultNS := p.defaultNS
-
- // Attributes
- for i := range tinfo.fields {
- finfo := &tinfo.fields[i]
- if finfo.flags&fAttr == 0 {
- continue
- }
- attr, err := p.fieldAttr(finfo, val)
- if err != nil {
- return err
- }
- if attr.Name.Local == "" {
- continue
- }
- start.Attr = append(start.Attr, attr)
- if attr.Name.Space == "" && attr.Name.Local == "xmlns" {
- defaultNS = attr.Value
- }
- }
- if !explicitNS {
- // Historic behavior: elements use the default name space
- // they are contained in by default.
- start.Name.Space = defaultNS
- }
- // Historic behaviour: an element that's in a namespace sets
- // the default namespace for all elements contained within it.
- start.setDefaultNamespace()
-
- 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()
-}
-
-// fieldAttr returns the attribute of the given field.
-// If the returned attribute has an empty Name.Local,
-// it should not be used.
-// The given value holds the value containing the field.
-func (p *printer) fieldAttr(finfo *fieldInfo, val reflect.Value) (Attr, error) {
- fv := finfo.value(val)
- name := Name{Space: finfo.xmlns, Local: finfo.name}
- if finfo.flags&fOmitEmpty != 0 && isEmptyValue(fv) {
- return Attr{}, nil
- }
- if fv.Kind() == reflect.Interface && fv.IsNil() {
- return Attr{}, nil
- }
- if fv.CanInterface() && fv.Type().Implements(marshalerAttrType) {
- attr, err := fv.Interface().(MarshalerAttr).MarshalXMLAttr(name)
- return attr, err
- }
- if fv.CanAddr() {
- pv := fv.Addr()
- if pv.CanInterface() && pv.Type().Implements(marshalerAttrType) {
- attr, err := pv.Interface().(MarshalerAttr).MarshalXMLAttr(name)
- return attr, err
- }
- }
- if fv.CanInterface() && fv.Type().Implements(textMarshalerType) {
- text, err := fv.Interface().(encoding.TextMarshaler).MarshalText()
- if err != nil {
- return Attr{}, err
- }
- return Attr{name, string(text)}, nil
- }
- if fv.CanAddr() {
- pv := fv.Addr()
- if pv.CanInterface() && pv.Type().Implements(textMarshalerType) {
- text, err := pv.Interface().(encoding.TextMarshaler).MarshalText()
- if err != nil {
- return Attr{}, err
- }
- return Attr{name, string(text)}, nil
- }
- }
- // Dereference or skip nil pointer, interface values.
- switch fv.Kind() {
- case reflect.Ptr, reflect.Interface:
- if fv.IsNil() {
- return Attr{}, nil
- }
- fv = fv.Elem()
- }
- s, b, err := p.marshalSimple(fv.Type(), fv)
- if err != nil {
- return Attr{}, err
- }
- if b != nil {
- s = string(b)
- }
- return Attr{name, s}, nil
-}
-
-// defaultStart returns the default start element to use,
-// given the reflect type, field info, and start template.
-func (p *printer) 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()
- }
- // Historic behaviour: elements use the name space of
- // the element they are contained in by default.
- if start.Name.Space == "" {
- start.Name.Space = p.defaultNS
- }
- start.setDefaultNamespace()
- 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()
- // Define any name spaces explicitly declared in the attributes.
- // We do this as a separate pass so that explicitly declared prefixes
- // will take precedence over implicitly declared prefixes
- // regardless of the order of the attributes.
- ignoreNonEmptyDefault := start.Name.Space == ""
- for _, attr := range start.Attr {
- if err := p.defineNS(attr, ignoreNonEmptyDefault); err != nil {
- return err
- }
- }
- // Define any new name spaces implied by the attributes.
- for _, attr := range start.Attr {
- name := attr.Name
- // From http://www.w3.org/TR/xml-names11/#defaulting
- // "Default namespace declarations do not apply directly
- // to attribute names; the interpretation of unprefixed
- // attributes is determined by the element on which they
- // appear."
- // This means we don't need to create a new namespace
- // when an attribute name space is empty.
- if name.Space != "" && !name.isNamespace() {
- p.createNSPrefix(name.Space, true)
- }
- }
- p.createNSPrefix(start.Name.Space, false)
-
- p.writeIndent(1)
- p.WriteByte('<')
- p.writeName(start.Name, false)
- p.writeNamespaces()
- for _, attr := range start.Attr {
- name := attr.Name
- if name.Local == "" || name.isNamespace() {
- // Namespaces have already been written by writeNamespaces above.
- continue
- }
- p.WriteByte(' ')
- p.writeName(name, true)
- p.WriteString(`="`)
- p.EscapeString(attr.Value)
- p.WriteByte('"')
- }
- p.WriteByte('>')
- return nil
-}
-
-// writeName writes the given name. It assumes
-// that p.createNSPrefix(name) has already been called.
-func (p *printer) writeName(name Name, isAttr bool) {
- if prefix := p.prefixForNS(name.Space, isAttr); prefix != "" {
- p.WriteString(prefix)
- p.WriteByte(':')
- }
- p.WriteString(name.Local)
-}
-
-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.writeName(name, false)
- 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("--")
-
-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)
-
- // Dereference or skip nil pointer, interface values.
- switch vf.Kind() {
- case reflect.Ptr, reflect.Interface:
- if !vf.IsNil() {
- vf = vf.Elem()
- }
- }
-
- switch finfo.flags & fMode {
- case fCharData:
- if err := s.setParents(&noField, reflect.Value{}); err != nil {
- return err
- }
- if vf.CanInterface() && vf.Type().Implements(textMarshalerType) {
- data, err := vf.Interface().(encoding.TextMarshaler).MarshalText()
- if err != nil {
- return err
- }
- Escape(p, data)
- 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
- }
- Escape(p, data)
- continue
- }
- }
- var scratch [64]byte
- switch vf.Kind() {
- case reflect.Int, reflect.Int8, reflect.Int16, reflect.Int32, reflect.Int64:
- Escape(p, strconv.AppendInt(scratch[:0], vf.Int(), 10))
- case reflect.Uint, reflect.Uint8, reflect.Uint16, reflect.Uint32, reflect.Uint64, reflect.Uintptr:
- Escape(p, strconv.AppendUint(scratch[:0], vf.Uint(), 10))
- case reflect.Float32, reflect.Float64:
- Escape(p, strconv.AppendFloat(scratch[:0], vf.Float(), 'g', -1, vf.Type().Bits()))
- case reflect.Bool:
- Escape(p, strconv.AppendBool(scratch[:0], vf.Bool()))
- case reflect.String:
- if err := EscapeText(p, []byte(vf.String())); err != nil {
- return err
- }
- case reflect.Slice:
- if elem, ok := vf.Interface().([]byte); ok {
- if err := EscapeText(p, elem); err != nil {
- return err
- }
- }
- }
- continue
-
- case fComment:
- if err := s.setParents(&noField, reflect.Value{}); err != nil {
- return err
- }
- 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.Index(s, "--") >= 0
- dashLast = s[len(s)-1] == '-'
- if !dashDash {
- p.WriteString(s)
- }
- case reflect.Slice:
- b := vf.Bytes()
- dashDash = bytes.Index(b, ddBytes) >= 0
- 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:
- 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.setParents(finfo, vf); err != nil {
- return err
- }
- }
- if err := p.marshalValue(vf, finfo, nil); err != nil {
- return err
- }
- }
- if err := s.setParents(&noField, reflect.Value{}); err != nil {
- return err
- }
- return p.cachedWriteError()
-}
-
-var noField fieldInfo
-
-// 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
- xmlns string
- parents []string
-}
-
-// setParents sets the stack of current parents to those found in finfo.
-// It only writes the start elements if vf holds a non-nil value.
-// If finfo is &noField, it pops all elements.
-func (s *parentStack) setParents(finfo *fieldInfo, vf reflect.Value) error {
- xmlns := s.p.defaultNS
- if finfo.xmlns != "" {
- xmlns = finfo.xmlns
- }
- commonParents := 0
- if xmlns == s.xmlns {
- for ; commonParents < len(finfo.parents) && commonParents < len(s.parents); commonParents++ {
- if finfo.parents[commonParents] != s.parents[commonParents] {
- break
- }
- }
- }
- // Pop off any parents that aren't in common with the previous field.
- for i := len(s.parents) - 1; i >= commonParents; i-- {
- if err := s.p.writeEnd(Name{
- Space: s.xmlns,
- Local: s.parents[i],
- }); err != nil {
- return err
- }
- }
- s.parents = finfo.parents
- s.xmlns = xmlns
- if commonParents >= len(s.parents) {
- // No new elements to push.
- return nil
- }
- if (vf.Kind() == reflect.Ptr || vf.Kind() == reflect.Interface) && vf.IsNil() {
- // The element is nil, so no need for the start elements.
- s.parents = s.parents[:commonParents]
- return nil
- }
- // Push any new parents required.
- for _, name := range s.parents[commonParents:] {
- start := &StartElement{
- Name: Name{
- Space: s.xmlns,
- Local: name,
- },
- }
- // Set the default name space for parent elements
- // to match what we do with other elements.
- if s.xmlns != s.p.defaultNS {
- start.setDefaultNamespace()
- }
- if err := s.p.writeStart(start); err != nil {
- return err
- }
- }
- return nil
-}
-
-// A MarshalXMLError 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
-}
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