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Diffstat (limited to '')
-rw-r--r-- | src/encoding/xml/marshal.go | 1062 |
1 files changed, 1062 insertions, 0 deletions
diff --git a/src/encoding/xml/marshal.go b/src/encoding/xml/marshal.go new file mode 100644 index 0000000..7792ac7 --- /dev/null +++ b/src/encoding/xml/marshal.go @@ -0,0 +1,1062 @@ +// 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 any) ([]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 any, 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 any) 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 any, 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 = "_" + } + // xmlanything is reserved and any variant of it regardless of + // case should be matched, so: + // (('X'|'x') ('M'|'m') ('L'|'l')) + // See Section 2.3 of https://www.w3.org/TR/REC-xml/ + if len(prefix) >= 3 && strings.EqualFold(prefix[:3], "xml") { + 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.Pointer { + 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 { + fv := xmlname.value(val, dontInitNilPointers) + if v, ok := fv.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 i := strings.IndexByte(name, '['); i >= 0 { + // Truncate generic instantiation name. See issue 48318. + name = name[:i] + } + 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, dontInitNilPointers) + + if finfo.flags&fOmitEmpty != 0 && (!fv.IsValid() || 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.Pointer, 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.Pointer { + 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, dontInitNilPointers) + if !vf.IsValid() { + // The field is behind an anonymous struct field that's + // nil. Skip it. + continue + } + + 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.Pointer && 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.Pointer: + return v.IsNil() + } + return false +} |