491 lines
15 KiB
Go
491 lines
15 KiB
Go
// Copyright 2014 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 dav
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// The XML encoding is covered by Section 14.
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// http://www.webdav.org/specs/rfc4918.html#xml.element.definitions
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import (
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"bytes"
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"errors"
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"fmt"
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"io"
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"net/http"
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// As of https://go-review.googlesource.com/#/c/12772/ which was submitted
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// in July 2015, this package uses an internal fork of the standard
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// library's encoding/xml package, due to changes in the way namespaces
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// were encoded. Such changes were introduced in the Go 1.5 cycle, but were
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// rolled back in response to https://github.com/golang/go/issues/11841
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//
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// However, this package's exported API, specifically the Property and
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// DeadPropsHolder types, need to refer to the standard library's version
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// of the xml.Name type, as code that imports this package cannot refer to
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// the internal version.
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//
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// This file therefore imports both the internal and external versions, as
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// ixml and xml, and converts between them.
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//
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// In the long term, this package should use the standard library's version
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// only, and the internal fork deleted, once
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// https://github.com/golang/go/issues/13400 is resolved.
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"tank/rest/dav/xml"
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)
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// http://www.webdav.org/specs/rfc4918.html#status.code.extensions.to.http11
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const (
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StatusMulti = 207
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StatusUnprocessableEntity = 422
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StatusLocked = 423
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StatusFailedDependency = 424
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StatusInsufficientStorage = 507
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)
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func StatusText(code int) string {
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switch code {
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case StatusMulti:
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return "Multi-Status"
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case StatusUnprocessableEntity:
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return "Unprocessable Entity"
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case StatusLocked:
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return "Locked"
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case StatusFailedDependency:
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return "Failed Dependency"
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case StatusInsufficientStorage:
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return "Insufficient Storage"
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}
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return http.StatusText(code)
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}
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var (
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errInvalidPropfind = errors.New("webdav: invalid propfind")
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errInvalidResponse = errors.New("webdav: invalid response")
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)
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// http://www.webdav.org/specs/rfc4918.html#ELEMENT_lockinfo
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type LockInfo struct {
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XMLName xml.Name `xml:"lockinfo"`
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Exclusive *struct{} `xml:"lockscope>exclusive"`
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Shared *struct{} `xml:"lockscope>shared"`
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Write *struct{} `xml:"locktype>write"`
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Owner Owner `xml:"owner"`
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}
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// http://www.webdav.org/specs/rfc4918.html#ELEMENT_owner
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type Owner struct {
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InnerXML string `xml:",innerxml"`
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}
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//这是一个带字节计数器的Reader，可以知道总共读取了多少个字节。
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type CountingReader struct {
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n int
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reader io.Reader
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}
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func (c *CountingReader) Read(p []byte) (int, error) {
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n, err := c.reader.Read(p)
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c.n += n
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return n, err
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}
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func escape(s string) string {
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for i := 0; i < len(s); i++ {
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switch s[i] {
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case '"', '&', '\'', '<', '>':
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b := bytes.NewBuffer(nil)
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xml.EscapeText(b, []byte(s))
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return b.String()
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}
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}
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return s
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}
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// Next returns the next token, if any, in the XML stream of d.
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// RFC 4918 requires to ignore comments, processing instructions
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// and directives.
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// http://www.webdav.org/specs/rfc4918.html#property_values
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// http://www.webdav.org/specs/rfc4918.html#xml-extensibility
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func next(d *xml.Decoder) (xml.Token, error) {
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for {
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t, err := d.Token()
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if err != nil {
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return t, err
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}
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switch t.(type) {
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case xml.Comment, xml.Directive, xml.ProcInst:
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continue
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default:
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return t, nil
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}
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}
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}
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// http://www.webdav.org/specs/rfc4918.html#ELEMENT_prop (for propfind)
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type PropfindProps []xml.Name
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// UnmarshalXML appends the property names enclosed within start to pn.
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//
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// It returns an error if start does not contain any properties or if
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// properties contain values. Character data between properties is ignored.
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func (pn *PropfindProps) UnmarshalXML(d *xml.Decoder, start xml.StartElement) error {
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for {
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t, err := next(d)
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if err != nil {
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return err
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}
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switch t.(type) {
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case xml.EndElement:
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if len(*pn) == 0 {
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return fmt.Errorf("%s must not be empty", start.Name.Local)
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}
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return nil
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case xml.StartElement:
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name := t.(xml.StartElement).Name
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t, err = next(d)
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if err != nil {
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return err
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}
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if _, ok := t.(xml.EndElement); !ok {
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return fmt.Errorf("unexpected token %T", t)
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}
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*pn = append(*pn, xml.Name(name))
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}
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}
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}
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// http://www.webdav.org/specs/rfc4918.html#ELEMENT_propfind
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// <!ELEMENT propfind ( propname | (allprop, include?) | prop ) >
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type Propfind struct {
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XMLName xml.Name `xml:"DAV: propfind"`
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Allprop *struct{} `xml:"DAV: allprop"`
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Propname *struct{} `xml:"DAV: propname"`
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Prop PropfindProps `xml:"DAV: prop"`
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Include PropfindProps `xml:"DAV: include"`
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}
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//从request中读出需要的属性。比如：getcontentlength 大小 creationdate 创建时间
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func ReadPropfind(reader io.Reader) (propfind Propfind, status int, err error) {
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c := CountingReader{reader: reader}
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if err = xml.NewDecoder(&c).Decode(&propfind); err != nil {
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if err == io.EOF {
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if c.n == 0 {
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// An empty body means to propfind allprop.
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// http://www.webdav.org/specs/rfc4918.html#METHOD_PROPFIND
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return Propfind{Allprop: new(struct{})}, 0, nil
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}
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err = errInvalidPropfind
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}
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return Propfind{}, http.StatusBadRequest, err
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}
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if propfind.Allprop == nil && propfind.Include != nil {
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return Propfind{}, http.StatusBadRequest, errInvalidPropfind
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}
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if propfind.Allprop != nil && (propfind.Prop != nil || propfind.Propname != nil) {
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return Propfind{}, http.StatusBadRequest, errInvalidPropfind
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}
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if propfind.Prop != nil && propfind.Propname != nil {
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return Propfind{}, http.StatusBadRequest, errInvalidPropfind
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}
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if propfind.Propname == nil && propfind.Allprop == nil && propfind.Prop == nil {
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return Propfind{}, http.StatusBadRequest, errInvalidPropfind
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}
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return propfind, 0, nil
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}
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// Property represents a single DAV resource property as defined in RFC 4918.
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// See http://www.webdav.org/specs/rfc4918.html#data.model.for.resource.properties
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type Property struct {
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// XMLName is the fully qualified name that identifies this property.
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XMLName xml.Name
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// Lang is an optional xml:lang attribute.
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Lang string `xml:"xml:lang,attr,omitempty"`
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// InnerXML contains the XML representation of the property value.
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// See http://www.webdav.org/specs/rfc4918.html#property_values
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//
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// Property values of complex type or mixed-content must have fully
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// expanded XML namespaces or be self-contained with according
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// XML namespace declarations. They must not rely on any XML
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// namespace declarations within the scope of the XML document,
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// even including the DAV: namespace.
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InnerXML []byte `xml:",innerxml"`
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}
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// ixmlProperty is the same as the Property type except it holds an xml.Name
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// instead of an xml.Name.
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type IxmlProperty struct {
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XMLName xml.Name
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Lang string `xml:"xml:lang,attr,omitempty"`
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InnerXML []byte `xml:",innerxml"`
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}
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// http://www.webdav.org/specs/rfc4918.html#ELEMENT_error
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// See MultiStatusWriter for the "D:" namespace prefix.
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type XmlError struct {
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XMLName xml.Name `xml:"D:error"`
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InnerXML []byte `xml:",innerxml"`
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}
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// http://www.webdav.org/specs/rfc4918.html#ELEMENT_propstat
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// See MultiStatusWriter for the "D:" namespace prefix.
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type SubPropstat struct {
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Prop []Property `xml:"D:prop>_ignored_"`
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Status string `xml:"D:status"`
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Error *XmlError `xml:"D:error"`
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ResponseDescription string `xml:"D:responsedescription,omitempty"`
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}
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// ixmlPropstat is the same as the propstat type except it holds an xml.Name
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// instead of an xml.Name.
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type IxmlPropstat struct {
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Prop []IxmlProperty `xml:"D:prop>_ignored_"`
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Status string `xml:"D:status"`
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Error *XmlError `xml:"D:error"`
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ResponseDescription string `xml:"D:responsedescription,omitempty"`
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}
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// MarshalXML prepends the "D:" namespace prefix on properties in the DAV: namespace
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// before encoding. See MultiStatusWriter.
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func (ps SubPropstat) MarshalXML(e *xml.Encoder, start xml.StartElement) error {
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// Convert from a propstat to an ixmlPropstat.
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ixmlPs := IxmlPropstat{
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Prop: make([]IxmlProperty, len(ps.Prop)),
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Status: ps.Status,
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Error: ps.Error,
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ResponseDescription: ps.ResponseDescription,
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}
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for k, prop := range ps.Prop {
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ixmlPs.Prop[k] = IxmlProperty{
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XMLName: xml.Name(prop.XMLName),
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Lang: prop.Lang,
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InnerXML: prop.InnerXML,
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}
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}
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for k, prop := range ixmlPs.Prop {
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if prop.XMLName.Space == "DAV:" {
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prop.XMLName = xml.Name{Space: "", Local: "D:" + prop.XMLName.Local}
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ixmlPs.Prop[k] = prop
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}
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}
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// Distinct type to avoid infinite recursion of MarshalXML.
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type newpropstat IxmlPropstat
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return e.EncodeElement(newpropstat(ixmlPs), start)
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}
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// http://www.webdav.org/specs/rfc4918.html#ELEMENT_response
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// See MultiStatusWriter for the "D:" namespace prefix.
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type Response struct {
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XMLName xml.Name `xml:"D:response"`
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Href []string `xml:"D:href"`
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Propstat []SubPropstat `xml:"D:propstat"`
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Status string `xml:"D:status,omitempty"`
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Error *XmlError `xml:"D:error"`
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ResponseDescription string `xml:"D:responsedescription,omitempty"`
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}
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// MultistatusWriter marshals one or more Responses into a XML
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// multistatus response.
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// See http://www.webdav.org/specs/rfc4918.html#ELEMENT_multistatus
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// TODO(rsto, mpl): As a workaround, the "D:" namespace prefix, defined as
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// "DAV:" on this element, is prepended on the nested response, as well as on all
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// its nested elements. All property names in the DAV: namespace are prefixed as
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// well. This is because some versions of Mini-Redirector (on windows 7) ignore
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// elements with a default namespace (no prefixed namespace). A less intrusive fix
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// should be possible after golang.org/cl/11074. See https://golang.org/issue/11177
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type MultiStatusWriter struct {
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// ResponseDescription contains the optional responsedescription
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// of the multistatus XML element. Only the latest content before
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// close will be emitted. Empty response descriptions are not
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// written.
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ResponseDescription string
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Writer http.ResponseWriter
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Encoder *xml.Encoder
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}
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// Write validates and emits a DAV response as part of a multistatus response
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// element.
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//
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// It sets the HTTP status code of its underlying http.ResponseWriter to 207
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// (Multi-Status) and populates the Content-Type header. If r is the
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// first, valid response to be written, Write prepends the XML representation
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// of r with a multistatus tag. Callers must call close after the last response
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// has been written.
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func (this *MultiStatusWriter) Write(r *Response) error {
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switch len(r.Href) {
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case 0:
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return errInvalidResponse
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case 1:
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if len(r.Propstat) > 0 != (r.Status == "") {
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return errInvalidResponse
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}
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default:
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if len(r.Propstat) > 0 || r.Status == "" {
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return errInvalidResponse
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}
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}
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err := this.writeHeader()
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if err != nil {
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return err
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}
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return this.Encoder.Encode(r)
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}
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// writeHeader writes a XML multistatus start element on w's underlying
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// http.ResponseWriter and returns the result of the write operation.
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// After the first write attempt, writeHeader becomes a no-op.
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func (this *MultiStatusWriter) writeHeader() error {
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if this.Encoder != nil {
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return nil
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}
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this.Writer.Header().Add("Content-Type", "text/xml; charset=utf-8")
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this.Writer.WriteHeader(StatusMulti)
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_, err := fmt.Fprintf(this.Writer, `<?xml version="1.0" encoding="UTF-8"?>`)
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if err != nil {
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return err
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}
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this.Encoder = xml.NewEncoder(this.Writer)
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return this.Encoder.EncodeToken(xml.StartElement{
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Name: xml.Name{
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Space: "DAV:",
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Local: "multistatus",
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},
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Attr: []xml.Attr{{
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Name: xml.Name{Space: "xmlns", Local: "D"},
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Value: "DAV:",
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}},
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})
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}
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// Close completes the marshalling of the multistatus response. It returns
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// an error if the multistatus response could not be completed. If both the
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// return value and field Encoder of w are nil, then no multistatus response has
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// been written.
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func (this *MultiStatusWriter) Close() error {
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if this.Encoder == nil {
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return nil
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}
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var end []xml.Token
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if this.ResponseDescription != "" {
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name := xml.Name{Space: "DAV:", Local: "responsedescription"}
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end = append(end,
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xml.StartElement{Name: name},
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xml.CharData(this.ResponseDescription),
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xml.EndElement{Name: name},
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)
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}
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end = append(end, xml.EndElement{
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Name: xml.Name{Space: "DAV:", Local: "multistatus"},
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})
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for _, t := range end {
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err := this.Encoder.EncodeToken(t)
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if err != nil {
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return err
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}
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}
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return this.Encoder.Flush()
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}
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var xmlLangName = xml.Name{Space: "http://www.w3.org/XML/1998/namespace", Local: "lang"}
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func xmlLang(s xml.StartElement, d string) string {
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for _, attr := range s.Attr {
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if attr.Name == xmlLangName {
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return attr.Value
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}
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}
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return d
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}
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type XmlValue []byte
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func (v *XmlValue) UnmarshalXML(d *xml.Decoder, start xml.StartElement) error {
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// The XML value of a property can be arbitrary, mixed-content XML.
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// To make sure that the unmarshalled value contains all required
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// namespaces, we encode all the property value XML tokens into a
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// buffer. This forces the encoder to redeclare any used namespaces.
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var b bytes.Buffer
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e := xml.NewEncoder(&b)
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for {
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t, err := next(d)
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if err != nil {
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return err
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}
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if e, ok := t.(xml.EndElement); ok && e.Name == start.Name {
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break
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}
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if err = e.EncodeToken(t); err != nil {
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return err
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}
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}
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err := e.Flush()
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if err != nil {
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return err
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}
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*v = b.Bytes()
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return nil
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}
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// http://www.webdav.org/specs/rfc4918.html#ELEMENT_prop (for proppatch)
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type ProppatchProps []Property
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|
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// UnmarshalXML appends the property names and values enclosed within start
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// to ps.
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//
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// An xml:lang attribute that is defined either on the DAV:prop or property
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// name XML element is propagated to the property's Lang field.
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//
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// UnmarshalXML returns an error if start does not contain any properties or if
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// property values contain syntactically incorrect XML.
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func (ps *ProppatchProps) UnmarshalXML(d *xml.Decoder, start xml.StartElement) error {
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lang := xmlLang(start, "")
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for {
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t, err := next(d)
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if err != nil {
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return err
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}
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switch elem := t.(type) {
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case xml.EndElement:
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if len(*ps) == 0 {
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return fmt.Errorf("%s must not be empty", start.Name.Local)
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}
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return nil
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case xml.StartElement:
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p := Property{
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XMLName: xml.Name(t.(xml.StartElement).Name),
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Lang: xmlLang(t.(xml.StartElement), lang),
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}
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err = d.DecodeElement(((*XmlValue)(&p.InnerXML)), &elem)
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if err != nil {
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return err
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}
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*ps = append(*ps, p)
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}
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}
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}
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// http://www.webdav.org/specs/rfc4918.html#ELEMENT_set
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// http://www.webdav.org/specs/rfc4918.html#ELEMENT_remove
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type SetRemove struct {
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XMLName xml.Name
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Lang string `xml:"xml:lang,attr,omitempty"`
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Prop ProppatchProps `xml:"DAV: prop"`
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}
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// http://www.webdav.org/specs/rfc4918.html#ELEMENT_propertyupdate
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type PropertyUpdate struct {
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XMLName xml.Name `xml:"DAV: propertyupdate"`
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Lang string `xml:"xml:lang,attr,omitempty"`
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SetRemove []SetRemove `xml:",any"`
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}
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