go-xmpp/stanza/iq.go
rcorniere 8798ff6fc1 - Changed IQ stanzas to pointer semantics
- Fixed commands from v 0.4.0 and tests
- Added primitive Result Sets support (XEP-0059)
2020-01-31 11:48:03 +01:00

193 lines
3.9 KiB
Go

package stanza
import (
"encoding/xml"
"errors"
"strings"
"github.com/google/uuid"
)
/*
TODO support ability to put Raw payload inside IQ
*/
// ============================================================================
// IQ Packet
// IQ implements RFC 6120 - A.5 Client Namespace (a part)
type IQ struct { // Info/Query
XMLName xml.Name `xml:"iq"`
// MUST have a ID
Attrs
// We can only have one payload on IQ:
// "An IQ stanza of type "get" or "set" MUST contain exactly one
// child element, which specifies the semantics of the particular
// request."
Payload IQPayload `xml:",omitempty"`
Error *Err `xml:"error,omitempty"`
// Any is used to decode unknown payload as a generic structure
Any *Node `xml:",any"`
}
type IQPayload interface {
Namespace() string
GetSet() *ResultSet
}
func NewIQ(a Attrs) (*IQ, error) {
if a.Id == "" {
if id, err := uuid.NewRandom(); err == nil {
a.Id = id.String()
}
}
iq := IQ{
XMLName: xml.Name{Local: "iq"},
Attrs: a,
}
if iq.Type.IsEmpty() {
return nil, IqTypeUnset
}
return &iq, nil
}
func (iq *IQ) MakeError(xerror Err) *IQ {
from := iq.From
to := iq.To
iq.Type = "error"
iq.From = to
iq.To = from
iq.Error = &xerror
return iq
}
func (*IQ) Name() string {
return "iq"
}
// NoOp to implement BiDirIteratorElt
func (*IQ) NoOp() {
}
type iqDecoder struct{}
var iq iqDecoder
func (iqDecoder) decode(p *xml.Decoder, se xml.StartElement) (*IQ, error) {
var packet IQ
err := p.DecodeElement(&packet, &se)
return &packet, err
}
// UnmarshalXML implements custom parsing for IQs
func (iq *IQ) UnmarshalXML(d *xml.Decoder, start xml.StartElement) error {
iq.XMLName = start.Name
// Extract IQ attributes
for _, attr := range start.Attr {
if attr.Name.Local == "id" {
iq.Id = attr.Value
}
if attr.Name.Local == "type" {
iq.Type = StanzaType(attr.Value)
}
if attr.Name.Local == "to" {
iq.To = attr.Value
}
if attr.Name.Local == "from" {
iq.From = attr.Value
}
}
// decode inner elements
for {
t, err := d.Token()
if err != nil {
return err
}
switch tt := t.(type) {
case xml.StartElement:
if tt.Name.Local == "error" {
var xmppError Err
err = d.DecodeElement(&xmppError, &tt)
if err != nil {
return err
}
iq.Error = &xmppError
continue
}
if iqExt := TypeRegistry.GetIQExtension(tt.Name); iqExt != nil {
// Decode payload extension
err = d.DecodeElement(iqExt, &tt)
if err != nil {
return err
}
iq.Payload = iqExt
continue
}
// TODO: If unknown decode as generic node
node := new(Node)
err = d.DecodeElement(node, &tt)
if err != nil {
return err
}
iq.Any = node
case xml.EndElement:
if tt == start.End() {
return nil
}
}
}
}
var (
IqTypeUnset = errors.New("iq type is not set but is mandatory")
IqIDUnset = errors.New("iq stanza ID is not set but is mandatory")
IqSGetNoPl = errors.New("iq is of type get or set but has no payload")
IqResNoPl = errors.New("iq is of type result but has no payload")
IqErrNoErrPl = errors.New("iq is of type error but has no error payload")
)
// IsValid checks if the IQ is valid. If not, return an error with the reason as a message
// Following RFC-3920 for IQs
func (iq *IQ) IsValid() (bool, error) {
// ID is required
if len(strings.TrimSpace(iq.Id)) == 0 {
return false, IqIDUnset
}
// Type is required
if iq.Type.IsEmpty() {
return false, IqTypeUnset
}
// Type get and set must contain one and only one child element that specifies the semantics
if iq.Type == IQTypeGet || iq.Type == IQTypeSet {
if iq.Payload == nil && iq.Any == nil {
return false, IqSGetNoPl
}
}
// A result must include zero or one child element
if iq.Type == IQTypeResult {
if iq.Payload != nil && iq.Any != nil {
return false, IqResNoPl
}
}
//Error type must contain an "error" child element
if iq.Type == IQTypeError {
if iq.Error == nil {
return false, IqErrNoErrPl
}
}
return true, nil
}