mirror of
https://github.com/miniflux/v2.git
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1224 lines
35 KiB
Go
1224 lines
35 KiB
Go
// Copyright 2011 The Go Authors. All rights reserved.
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// Use of this source code is governed by a BSD-style
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// license that can be found in the LICENSE file.
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package xml
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import (
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"bufio"
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"bytes"
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"encoding"
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"fmt"
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"io"
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"reflect"
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"strconv"
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"strings"
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)
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const (
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// A generic XML header suitable for use with the output of Marshal.
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// This is not automatically added to any output of this package,
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// it is provided as a convenience.
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Header = `<?xml version="1.0" encoding="UTF-8"?>` + "\n"
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)
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// Marshal returns the XML encoding of v.
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//
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// Marshal handles an array or slice by marshalling each of the elements.
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// Marshal handles a pointer by marshalling the value it points at or, if the
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// pointer is nil, by writing nothing. Marshal handles an interface value by
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// marshalling the value it contains or, if the interface value is nil, by
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// writing nothing. Marshal handles all other data by writing one or more XML
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// elements containing the data.
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//
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// The name for the XML elements is taken from, in order of preference:
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// - the tag on the XMLName field, if the data is a struct
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// - the value of the XMLName field of type xml.Name
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// - the tag of the struct field used to obtain the data
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// - the name of the struct field used to obtain the data
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// - the name of the marshalled type
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//
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// The XML element for a struct contains marshalled elements for each of the
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// exported fields of the struct, with these exceptions:
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// - the XMLName field, described above, is omitted.
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// - a field with tag "-" is omitted.
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// - a field with tag "name,attr" becomes an attribute with
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// the given name in the XML element.
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// - a field with tag ",attr" becomes an attribute with the
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// field name in the XML element.
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// - a field with tag ",chardata" is written as character data,
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// not as an XML element.
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// - a field with tag ",innerxml" is written verbatim, not subject
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// to the usual marshalling procedure.
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// - a field with tag ",comment" is written as an XML comment, not
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// subject to the usual marshalling procedure. It must not contain
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// the "--" string within it.
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// - a field with a tag including the "omitempty" option is omitted
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// if the field value is empty. The empty values are false, 0, any
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// nil pointer or interface value, and any array, slice, map, or
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// string of length zero.
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// - an anonymous struct field is handled as if the fields of its
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// value were part of the outer struct.
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//
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// If a field uses a tag "a>b>c", then the element c will be nested inside
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// parent elements a and b. Fields that appear next to each other that name
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// the same parent will be enclosed in one XML element.
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//
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// See MarshalIndent for an example.
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//
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// Marshal will return an error if asked to marshal a channel, function, or map.
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func Marshal(v interface{}) ([]byte, error) {
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var b bytes.Buffer
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if err := NewEncoder(&b).Encode(v); err != nil {
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return nil, err
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}
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return b.Bytes(), nil
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}
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// Marshaler is the interface implemented by objects that can marshal
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// themselves into valid XML elements.
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//
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// MarshalXML encodes the receiver as zero or more XML elements.
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// By convention, arrays or slices are typically encoded as a sequence
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// of elements, one per entry.
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// Using start as the element tag is not required, but doing so
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// will enable Unmarshal to match the XML elements to the correct
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// struct field.
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// One common implementation strategy is to construct a separate
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// value with a layout corresponding to the desired XML and then
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// to encode it using e.EncodeElement.
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// Another common strategy is to use repeated calls to e.EncodeToken
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// to generate the XML output one token at a time.
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// The sequence of encoded tokens must make up zero or more valid
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// XML elements.
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type Marshaler interface {
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MarshalXML(e *Encoder, start StartElement) error
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}
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// MarshalerAttr is the interface implemented by objects that can marshal
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// themselves into valid XML attributes.
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//
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// MarshalXMLAttr returns an XML attribute with the encoded value of the receiver.
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// Using name as the attribute name is not required, but doing so
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// will enable Unmarshal to match the attribute to the correct
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// struct field.
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// If MarshalXMLAttr returns the zero attribute Attr{}, no attribute
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// will be generated in the output.
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// MarshalXMLAttr is used only for struct fields with the
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// "attr" option in the field tag.
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type MarshalerAttr interface {
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MarshalXMLAttr(name Name) (Attr, error)
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}
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// MarshalIndent works like Marshal, but each XML element begins on a new
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// indented line that starts with prefix and is followed by one or more
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// copies of indent according to the nesting depth.
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func MarshalIndent(v interface{}, prefix, indent string) ([]byte, error) {
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var b bytes.Buffer
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enc := NewEncoder(&b)
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enc.Indent(prefix, indent)
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if err := enc.Encode(v); err != nil {
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return nil, err
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}
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return b.Bytes(), nil
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}
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// An Encoder writes XML data to an output stream.
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type Encoder struct {
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p printer
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}
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// NewEncoder returns a new encoder that writes to w.
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func NewEncoder(w io.Writer) *Encoder {
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e := &Encoder{printer{Writer: bufio.NewWriter(w)}}
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e.p.encoder = e
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return e
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}
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// Indent sets the encoder to generate XML in which each element
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// begins on a new indented line that starts with prefix and is followed by
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// one or more copies of indent according to the nesting depth.
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func (enc *Encoder) Indent(prefix, indent string) {
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enc.p.prefix = prefix
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enc.p.indent = indent
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}
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// Encode writes the XML encoding of v to the stream.
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//
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// See the documentation for Marshal for details about the conversion
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// of Go values to XML.
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//
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// Encode calls Flush before returning.
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func (enc *Encoder) Encode(v interface{}) error {
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err := enc.p.marshalValue(reflect.ValueOf(v), nil, nil)
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if err != nil {
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return err
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}
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return enc.p.Flush()
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}
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// EncodeElement writes the XML encoding of v to the stream,
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// using start as the outermost tag in the encoding.
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//
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// See the documentation for Marshal for details about the conversion
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// of Go values to XML.
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//
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// EncodeElement calls Flush before returning.
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func (enc *Encoder) EncodeElement(v interface{}, start StartElement) error {
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err := enc.p.marshalValue(reflect.ValueOf(v), nil, &start)
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if err != nil {
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return err
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}
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return enc.p.Flush()
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}
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var (
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begComment = []byte("<!--")
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endComment = []byte("-->")
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endProcInst = []byte("?>")
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endDirective = []byte(">")
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)
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// EncodeToken writes the given XML token to the stream.
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// It returns an error if StartElement and EndElement tokens are not
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// properly matched.
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//
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// EncodeToken does not call Flush, because usually it is part of a
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// larger operation such as Encode or EncodeElement (or a custom
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// Marshaler's MarshalXML invoked during those), and those will call
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// Flush when finished. Callers that create an Encoder and then invoke
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// EncodeToken directly, without using Encode or EncodeElement, need to
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// call Flush when finished to ensure that the XML is written to the
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// underlying writer.
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//
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// EncodeToken allows writing a ProcInst with Target set to "xml" only
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// as the first token in the stream.
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//
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// When encoding a StartElement holding an XML namespace prefix
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// declaration for a prefix that is not already declared, contained
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// elements (including the StartElement itself) will use the declared
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// prefix when encoding names with matching namespace URIs.
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func (enc *Encoder) EncodeToken(t Token) error {
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p := &enc.p
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switch t := t.(type) {
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case StartElement:
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if err := p.writeStart(&t); err != nil {
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return err
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}
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case EndElement:
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if err := p.writeEnd(t.Name); err != nil {
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return err
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}
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case CharData:
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escapeText(p, t, false)
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case Comment:
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if bytes.Contains(t, endComment) {
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return fmt.Errorf("xml: EncodeToken of Comment containing --> marker")
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}
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p.WriteString("<!--")
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p.Write(t)
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p.WriteString("-->")
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return p.cachedWriteError()
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case ProcInst:
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// First token to be encoded which is also a ProcInst with target of xml
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// is the xml declaration. The only ProcInst where target of xml is allowed.
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if t.Target == "xml" && p.Buffered() != 0 {
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return fmt.Errorf("xml: EncodeToken of ProcInst xml target only valid for xml declaration, first token encoded")
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}
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if !isNameString(t.Target) {
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return fmt.Errorf("xml: EncodeToken of ProcInst with invalid Target")
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}
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if bytes.Contains(t.Inst, endProcInst) {
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return fmt.Errorf("xml: EncodeToken of ProcInst containing ?> marker")
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}
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p.WriteString("<?")
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p.WriteString(t.Target)
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if len(t.Inst) > 0 {
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p.WriteByte(' ')
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p.Write(t.Inst)
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}
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p.WriteString("?>")
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case Directive:
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if !isValidDirective(t) {
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return fmt.Errorf("xml: EncodeToken of Directive containing wrong < or > markers")
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}
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p.WriteString("<!")
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p.Write(t)
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p.WriteString(">")
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default:
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return fmt.Errorf("xml: EncodeToken of invalid token type")
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}
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return p.cachedWriteError()
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}
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// isValidDirective reports whether dir is a valid directive text,
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// meaning angle brackets are matched, ignoring comments and strings.
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func isValidDirective(dir Directive) bool {
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var (
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depth int
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inquote uint8
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incomment bool
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)
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for i, c := range dir {
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switch {
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case incomment:
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if c == '>' {
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if n := 1 + i - len(endComment); n >= 0 && bytes.Equal(dir[n:i+1], endComment) {
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incomment = false
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}
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}
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// Just ignore anything in comment
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case inquote != 0:
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if c == inquote {
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inquote = 0
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}
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// Just ignore anything within quotes
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case c == '\'' || c == '"':
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inquote = c
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case c == '<':
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if i+len(begComment) < len(dir) && bytes.Equal(dir[i:i+len(begComment)], begComment) {
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incomment = true
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} else {
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depth++
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}
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case c == '>':
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if depth == 0 {
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return false
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}
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depth--
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}
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}
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return depth == 0 && inquote == 0 && !incomment
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}
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// Flush flushes any buffered XML to the underlying writer.
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// See the EncodeToken documentation for details about when it is necessary.
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func (enc *Encoder) Flush() error {
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return enc.p.Flush()
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}
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type printer struct {
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*bufio.Writer
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encoder *Encoder
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seq int
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indent string
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prefix string
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depth int
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indentedIn bool
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putNewline bool
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defaultNS string
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attrNS map[string]string // map prefix -> name space
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attrPrefix map[string]string // map name space -> prefix
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prefixes []printerPrefix
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tags []Name
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}
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// printerPrefix holds a namespace undo record.
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// When an element is popped, the prefix record
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// is set back to the recorded URL. The empty
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// prefix records the URL for the default name space.
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//
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// The start of an element is recorded with an element
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// that has mark=true.
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type printerPrefix struct {
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prefix string
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url string
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mark bool
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}
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func (p *printer) prefixForNS(url string, isAttr bool) string {
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// The "http://www.w3.org/XML/1998/namespace" name space is predefined as "xml"
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// and must be referred to that way.
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// (The "http://www.w3.org/2000/xmlns/" name space is also predefined as "xmlns",
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// but users should not be trying to use that one directly - that's our job.)
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if url == xmlURL {
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return "xml"
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}
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if !isAttr && url == p.defaultNS {
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// We can use the default name space.
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return ""
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}
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return p.attrPrefix[url]
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}
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// defineNS pushes any namespace definition found in the given attribute.
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// If ignoreNonEmptyDefault is true, an xmlns="nonempty"
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// attribute will be ignored.
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func (p *printer) defineNS(attr Attr, ignoreNonEmptyDefault bool) error {
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var prefix string
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if attr.Name.Local == "xmlns" {
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if attr.Name.Space != "" && attr.Name.Space != "xml" && attr.Name.Space != xmlURL {
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return fmt.Errorf("xml: cannot redefine xmlns attribute prefix")
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}
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} else if attr.Name.Space == "xmlns" && attr.Name.Local != "" {
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prefix = attr.Name.Local
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if attr.Value == "" {
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// Technically, an empty XML namespace is allowed for an attribute.
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// From http://www.w3.org/TR/xml-names11/#scoping-defaulting:
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//
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// The attribute value in a namespace declaration for a prefix may be
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// empty. This has the effect, within the scope of the declaration, of removing
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// any association of the prefix with a namespace name.
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//
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// However our namespace prefixes here are used only as hints. There's
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// no need to respect the removal of a namespace prefix, so we ignore it.
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return nil
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}
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} else {
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// Ignore: it's not a namespace definition
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return nil
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}
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if prefix == "" {
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if attr.Value == p.defaultNS {
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// No need for redefinition.
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return nil
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}
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if attr.Value != "" && ignoreNonEmptyDefault {
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// We have an xmlns="..." value but
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// it can't define a name space in this context,
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// probably because the element has an empty
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// name space. In this case, we just ignore
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// the name space declaration.
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return nil
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}
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} else if _, ok := p.attrPrefix[attr.Value]; ok {
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// There's already a prefix for the given name space,
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// so use that. This prevents us from
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// having two prefixes for the same name space
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// so attrNS and attrPrefix can remain bijective.
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return nil
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}
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p.pushPrefix(prefix, attr.Value)
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return nil
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}
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// createNSPrefix creates a name space prefix attribute
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// to use for the given name space, defining a new prefix
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// if necessary.
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// If isAttr is true, the prefix is to be created for an attribute
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// prefix, which means that the default name space cannot
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// be used.
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func (p *printer) createNSPrefix(url string, isAttr bool) {
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if _, ok := p.attrPrefix[url]; ok {
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// We already have a prefix for the given URL.
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return
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}
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switch {
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case !isAttr && url == p.defaultNS:
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// We can use the default name space.
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return
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case url == "":
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// The only way we can encode names in the empty
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// name space is by using the default name space,
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// so we must use that.
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if p.defaultNS != "" {
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// The default namespace is non-empty, so we
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// need to set it to empty.
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p.pushPrefix("", "")
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}
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return
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case url == xmlURL:
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return
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}
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// TODO If the URL is an existing prefix, we could
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// use it as is. That would enable the
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// marshaling of elements that had been unmarshaled
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// and with a name space prefix that was not found.
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// although technically it would be incorrect.
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// Pick a name. We try to use the final element of the path
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// but fall back to _.
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prefix := strings.TrimRight(url, "/")
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if i := strings.LastIndex(prefix, "/"); i >= 0 {
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prefix = prefix[i+1:]
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}
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if prefix == "" || !isName([]byte(prefix)) || strings.Contains(prefix, ":") {
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prefix = "_"
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}
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if strings.HasPrefix(prefix, "xml") {
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// xmlanything is reserved.
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prefix = "_" + prefix
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}
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if p.attrNS[prefix] != "" {
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// Name is taken. Find a better one.
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for p.seq++; ; p.seq++ {
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if id := prefix + "_" + strconv.Itoa(p.seq); p.attrNS[id] == "" {
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prefix = id
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break
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}
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}
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}
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p.pushPrefix(prefix, url)
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}
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// writeNamespaces writes xmlns attributes for all the
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// namespace prefixes that have been defined in
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// the current element.
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func (p *printer) writeNamespaces() {
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for i := len(p.prefixes) - 1; i >= 0; i-- {
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prefix := p.prefixes[i]
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if prefix.mark {
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return
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}
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p.WriteString(" ")
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if prefix.prefix == "" {
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// Default name space.
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p.WriteString(`xmlns="`)
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} else {
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p.WriteString("xmlns:")
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p.WriteString(prefix.prefix)
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p.WriteString(`="`)
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}
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EscapeText(p, []byte(p.nsForPrefix(prefix.prefix)))
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p.WriteString(`"`)
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}
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}
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// pushPrefix pushes a new prefix on the prefix stack
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// without checking to see if it is already defined.
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func (p *printer) pushPrefix(prefix, url string) {
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p.prefixes = append(p.prefixes, printerPrefix{
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prefix: prefix,
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url: p.nsForPrefix(prefix),
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})
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p.setAttrPrefix(prefix, url)
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}
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// nsForPrefix returns the name space for the given
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// prefix. Note that this is not valid for the
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// empty attribute prefix, which always has an empty
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// name space.
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func (p *printer) nsForPrefix(prefix string) string {
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if prefix == "" {
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return p.defaultNS
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}
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return p.attrNS[prefix]
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}
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// markPrefix marks the start of an element on the prefix
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// stack.
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func (p *printer) markPrefix() {
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p.prefixes = append(p.prefixes, printerPrefix{
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mark: true,
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})
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}
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// popPrefix pops all defined prefixes for the current
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// element.
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func (p *printer) popPrefix() {
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for len(p.prefixes) > 0 {
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prefix := p.prefixes[len(p.prefixes)-1]
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p.prefixes = p.prefixes[:len(p.prefixes)-1]
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if prefix.mark {
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break
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}
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p.setAttrPrefix(prefix.prefix, prefix.url)
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}
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}
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|
|
|
// 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
|
|
}
|