// xmlSeqToMapParser - load a 'clean' XML doc into a map[string]interface{} directly.
// Add #seq tag value for each element decoded - to be used for Encoding later.
func xmlSeqToMapParser(skey string, a []xml.Attr, p *xml.Decoder, r bool) (map[string]interface{}, error) {
// NOTE: all attributes and sub-elements parsed into 'na', 'na' is returned as value for 'skey' in 'n'.
var n, na map[string]interface{}
var seq int // for including seq num when decoding
// Allocate maps and load attributes, if any.
// NOTE: on entry from NewMapXml(), etc., skey=="", and we fall through
// to get StartElement then recurse with skey==xml.StartElement.Name.Local
// where we begin allocating map[string]interface{} values 'n' and 'na'.
if skey != "" {
// 'n' only needs one slot - save call to runtime•hashGrow()
// 'na' we don't know
n = make(map[string]interface{}, 1)
na = make(map[string]interface{})
if len(a) > 0 {
// xml.Attr is decoded into: map["#attr"]map[<attr_label>]interface{}
// where interface{} is map[string]interface{}{"#text":<attr_val>, "#seq":<attr_seq>}
aa := make(map[string]interface{}, len(a))
for i, v := range a {
if len(v.Name.Space) > 0 {
aa[v.Name.Space+`:`+v.Name.Local] = map[string]interface{}{"#text": cast(v.Value, r), "#seq": i}
} else {
aa[v.Name.Local] = map[string]interface{}{"#text": cast(v.Value, r), "#seq": i}
}
}
na["#attr"] = aa
}
}
for {
t, err := p.RawToken()
if err != nil {
if err != io.EOF {
return nil, errors.New("xml.Decoder.Token() - " + err.Error())
}
return nil, err
}
switch t.(type) {
case xml.StartElement:
tt := t.(xml.StartElement)
// First call to xmlSeqToMapParser() doesn't pass xml.StartElement - the map key.
// So when the loop is first entered, the first token is the root tag along
// with any attributes, which we process here.
//
// Subsequent calls to xmlSeqToMapParser() will pass in tag+attributes for
// processing before getting the next token which is the element value,
// which is done above.
if skey == "" {
if len(tt.Name.Space) > 0 {
return xmlSeqToMapParser(tt.Name.Space+`:`+tt.Name.Local, tt.Attr, p, r)
} else {
return xmlSeqToMapParser(tt.Name.Local, tt.Attr, p, r)
}
}
// If not initializing the map, parse the element.
// len(nn) == 1, necessarily - it is just an 'n'.
var nn map[string]interface{}
if len(tt.Name.Space) > 0 {
nn, err = xmlSeqToMapParser(tt.Name.Space+`:`+tt.Name.Local, tt.Attr, p, r)
} else {
nn, err = xmlSeqToMapParser(tt.Name.Local, tt.Attr, p, r)
}
if err != nil {
return nil, err
}
// The nn map[string]interface{} value is a na[nn_key] value.
// We need to see if nn_key already exists - means we're parsing a list.
// This may require converting na[nn_key] value into []interface{} type.
// First, extract the key:val for the map - it's a singleton.
var key string
var val interface{}
for key, val = range nn {
break
}
// add "#seq" k:v pair -
// Sequence number included even in list elements - this should allow us
// to properly resequence even something goofy like:
// <list>item 1</list>
// <subelement>item 2</subelement>
// <list>item 3</list>
// where all the "list" subelements are decoded into an array.
switch val.(type) {
case map[string]interface{}:
val.(map[string]interface{})["#seq"] = seq
seq++
case interface{}: // a non-nil simple element: string, float64, bool
v := map[string]interface{}{"#text": val, "#seq": seq}
seq++
val = v
}
// 'na' holding sub-elements of n.
// See if 'key' already exists.
// If 'key' exists, then this is a list, if not just add key:val to na.
if v, ok := na[key]; ok {
var a []interface{}
switch v.(type) {
case []interface{}:
a = v.([]interface{})
default: // anything else - note: v.(type) != nil
a = []interface{}{v}
}
a = append(a, val)
na[key] = a
} else {
na[key] = val // save it as a singleton
}
case xml.EndElement:
if skey != "" {
tt := t.(xml.EndElement)
var name string
if len(tt.Name.Space) > 0 {
name = tt.Name.Space + `:` + tt.Name.Local
} else {
name = tt.Name.Local
}
if skey != name {
return nil, fmt.Errorf("element %s not properly terminated, got %s at #%d",
skey, name, p.InputOffset())
}
}
// len(n) > 0 if this is a simple element w/o xml.Attrs - see xml.CharData case.
if len(n) == 0 {
// If len(na)==0 we have an empty element == "";
// it has no xml.Attr nor xml.CharData.
// Empty element content will be map["etag"]map["#text"]""
// after #seq injection - map["etag"]map["#seq"]seq - after return.
if len(na) > 0 {
n[skey] = na
} else {
n[skey] = "" // empty element
}
}
return n, nil
case xml.CharData:
// clean up possible noise
tt := strings.Trim(string(t.(xml.CharData)), "\t\r\b\n ")
if skey == "" {
// per Adrian (http://www.adrianlungu.com/) catch stray text
// in decoder stream -
// https://github.com/clbanning/mxj/pull/14#issuecomment-182816374
// NOTE: CharSetReader must be set to non-UTF-8 CharSet or you'll get
// a p.Token() decoding error when the BOM is UTF-16 or UTF-32.
continue
}
if len(tt) > 0 {
// every simple element is a #text and has #seq associated with it
na["#text"] = cast(tt, r)
na["#seq"] = seq
seq++
}
case xml.Comment:
if n == nil { // no root 'key'
n = map[string]interface{}{"#comment": string(t.(xml.Comment))}
return n, NoRoot
}
cm := make(map[string]interface{}, 2)
cm["#text"] = string(t.(xml.Comment))
cm["#seq"] = seq
seq++
na["#comment"] = cm
case xml.Directive:
if n == nil { // no root 'key'
n = map[string]interface{}{"#directive": string(t.(xml.Directive))}
return n, NoRoot
}
dm := make(map[string]interface{}, 2)
dm["#text"] = string(t.(xml.Directive))
dm["#seq"] = seq
seq++
na["#directive"] = dm
case xml.ProcInst:
if n == nil {
na = map[string]interface{}{"#target": t.(xml.ProcInst).Target, "#inst": string(t.(xml.ProcInst).Inst)}
n = map[string]interface{}{"#procinst": na}
return n, NoRoot
}
pm := make(map[string]interface{}, 3)
pm["#target"] = t.(xml.ProcInst).Target
pm["#inst"] = string(t.(xml.ProcInst).Inst)
pm["#seq"] = seq
seq++
na["#procinst"] = pm
default:
// noop - shouldn't ever get here, now, since we handle all token types
}
}
}