/
roster.go
255 lines (218 loc) · 5.76 KB
/
roster.go
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// Copyright 2018 The Mellium Contributors.
// Use of this source code is governed by the BSD 2-clause
// license that can be found in the LICENSE file.
// Package roster implements contact list functionality.
package roster
import (
"context"
"encoding/xml"
"io"
"mellium.im/xmlstream"
"mellium.im/xmpp"
"mellium.im/xmpp/jid"
"mellium.im/xmpp/stanza"
)
// Namespaces used by this package provided as a convenience.
const (
NS = "jabber:iq:roster"
)
// Iter is an iterator over roster items.
type Iter struct {
r xmlstream.TokenReadCloser
d *xml.Decoder
err error
item Item
next *xml.StartElement
}
func (i *Iter) setNext() {
i.next = nil
t, err := i.d.Token()
if err != nil {
i.err = err
return
}
start, ok := t.(xml.StartElement)
// If we're done with the items and get the roster payload end element (or
// anything else), call it done.
if !ok {
return
}
// TODO: check the name of the payload to make sure the server is behaving
// correctly.
i.next = &start
}
// Returns true if there are more items to decode.
func (i *Iter) Next() bool {
if i.err != nil || i.next == nil {
return false
}
// If this is a start element, decode the item.
item := Item{}
err := i.d.DecodeElement(&item, i.next)
if err != nil {
i.err = err
return false
}
i.item = item
ret := i.err == nil && i.next != nil
i.setNext()
return ret
}
// Returns the current roster item.
func (i *Iter) Item() Item {
return i.item
}
// Returns the last error encountered by the iterator (if any).
func (i *Iter) Err() error {
return i.err
}
// Close indicates that we are finished with the given roster.
// Calling it multiple times has no effect.
func (i *Iter) Close() error {
i.next = nil
return i.r.Close()
}
// Fetch requests the roster and returns an iterator over all roster items
// (blocking until a response is received).
//
// The iterator must be closed before anything else is done on the session or it
// will become invalid.
// Any errors encountered while creating the iter are deferred until the iter is
// used.
func Fetch(ctx context.Context, s *xmpp.Session) *Iter {
return FetchIQ(ctx, stanza.IQ{}, s)
}
// FetchIQ is like Fetch but it allows you to customize the IQ.
func FetchIQ(ctx context.Context, iq stanza.IQ, s *xmpp.Session) *Iter {
rosterIQ := IQ{IQ: iq}
r, err := s.Send(ctx, rosterIQ.TokenReader())
if err != nil {
return &Iter{err: err}
}
d := xml.NewTokenDecoder(r)
// Pop the start IQ token.
_, err = d.Token()
if err != nil {
return &Iter{err: err}
}
// Pop the roster wrapper token.
_, err = d.Token()
if err != nil {
return &Iter{err: err}
}
// Return the iterator which will parse the rest of the payload incrementally.
iter := &Iter{
r: r,
d: d,
}
iter.setNext()
return iter
}
// IQ represents a user roster request or response.
// The zero value is a valid query for the roster.
type IQ struct {
stanza.IQ
Query struct {
Ver string `xml:"version,attr,omitempty"`
Item []Item `xml:"item"`
} `xml:"jabber:iq:roster query"`
}
type itemMarshaler struct {
items []Item
cur xml.TokenReader
}
func (m itemMarshaler) Token() (xml.Token, error) {
if len(m.items) == 0 {
return nil, io.EOF
}
if m.cur == nil {
var item Item
item, m.items = m.items[0], m.items[1:]
m.cur = item.TokenReader()
}
tok, err := m.cur.Token()
if err != nil && err != io.EOF {
return tok, err
}
if tok == nil {
m.cur = nil
return m.Token()
}
return tok, nil
}
// TokenReader returns a stream of XML tokens that match the IQ.
func (iq IQ) TokenReader() xml.TokenReader {
attrs := []xml.Attr{}
if iq.Query.Ver != "" {
attrs = append(attrs, xml.Attr{Name: xml.Name{Local: "version"}, Value: iq.Query.Ver})
}
if iq.IQ.Type != stanza.GetIQ {
iq.IQ.Type = stanza.GetIQ
}
return stanza.WrapIQ(&iq.IQ, xmlstream.Wrap(
itemMarshaler{items: iq.Query.Item},
xml.StartElement{Name: xml.Name{Local: "query", Space: NS}, Attr: attrs},
))
}
// WriteXML satisfies the xmlstream.WriterTo interface.
// It is like MarshalXML except it writes tokens to w.
func (iq IQ) WriteXML(w xmlstream.TokenWriter) (n int, err error) {
return xmlstream.Copy(w, iq.TokenReader())
}
// MarshalXML satisfies the xml.Marshaler interface.
func (iq IQ) MarshalXML(e *xml.Encoder, _ xml.StartElement) error {
_, err := iq.WriteXML(e)
if err != nil {
return err
}
return e.Flush()
}
// Item represents a contact in the roster.
type Item struct {
JID jid.JID `xml:"jid,attr,omitempty"`
Name string `xml:"name,attr,omitempty"`
Subscription string `xml:"subscription,attr,omitempty"`
Group string `xml:"group,omitempty"`
}
// TokenReader satisfies the xmlstream.Marshaler interface.
func (item Item) TokenReader() xml.TokenReader {
var group xml.TokenReader
if item.Group != "" {
group = xmlstream.Wrap(
xmlstream.Token(xml.CharData(item.Group)),
xml.StartElement{
Name: xml.Name{Local: "group"},
},
)
}
attrs := []xml.Attr{}
if j := item.JID.String(); j != "" {
attrs = append(attrs, xml.Attr{Name: xml.Name{Local: "jid"}, Value: j})
}
if item.Name != "" {
attrs = append(attrs, xml.Attr{Name: xml.Name{Local: "name"}, Value: item.Name})
}
if item.Subscription != "" {
attrs = append(attrs, xml.Attr{Name: xml.Name{Local: "subscription"}, Value: item.Subscription})
}
return xmlstream.Wrap(
group,
xml.StartElement{
Name: xml.Name{Local: "item"},
Attr: attrs,
},
)
}
// WriteXML satisfies the xmlstream.WriterTo interface.
// It is like MarshalXML except it writes tokens to w.
func (item Item) WriteXML(w xmlstream.TokenWriter) (n int, err error) {
return xmlstream.Copy(w, item.TokenReader())
}
// MarshalXML satisfies the xml.Marshaler interface.
func (item Item) MarshalXML(e *xml.Encoder, _ xml.StartElement) error {
_, err := item.WriteXML(e)
if err != nil {
return err
}
return e.Flush()
}