David K. Bainbridge | 215e024 | 2017-09-05 23:18:24 -0700 | [diff] [blame] | 1 | // Copyright 2011 The Go Authors. All rights reserved. |
| 2 | // Use of this source code is governed by a BSD-style |
| 3 | // license that can be found in the LICENSE file. |
| 4 | |
| 5 | package xml |
| 6 | |
| 7 | import ( |
| 8 | "bufio" |
| 9 | "bytes" |
| 10 | "encoding" |
| 11 | "fmt" |
| 12 | "io" |
| 13 | "reflect" |
| 14 | "strconv" |
| 15 | "strings" |
| 16 | ) |
| 17 | |
| 18 | const ( |
| 19 | // A generic XML header suitable for use with the output of Marshal. |
| 20 | // This is not automatically added to any output of this package, |
| 21 | // it is provided as a convenience. |
| 22 | Header = `<?xml version="1.0" encoding="UTF-8"?>` + "\n" |
| 23 | ) |
| 24 | |
| 25 | // Marshal returns the XML encoding of v. |
| 26 | // |
| 27 | // Marshal handles an array or slice by marshalling each of the elements. |
| 28 | // Marshal handles a pointer by marshalling the value it points at or, if the |
| 29 | // pointer is nil, by writing nothing. Marshal handles an interface value by |
| 30 | // marshalling the value it contains or, if the interface value is nil, by |
| 31 | // writing nothing. Marshal handles all other data by writing one or more XML |
| 32 | // elements containing the data. |
| 33 | // |
| 34 | // The name for the XML elements is taken from, in order of preference: |
| 35 | // - the tag on the XMLName field, if the data is a struct |
| 36 | // - the value of the XMLName field of type xml.Name |
| 37 | // - the tag of the struct field used to obtain the data |
| 38 | // - the name of the struct field used to obtain the data |
| 39 | // - the name of the marshalled type |
| 40 | // |
| 41 | // The XML element for a struct contains marshalled elements for each of the |
| 42 | // exported fields of the struct, with these exceptions: |
| 43 | // - the XMLName field, described above, is omitted. |
| 44 | // - a field with tag "-" is omitted. |
| 45 | // - a field with tag "name,attr" becomes an attribute with |
| 46 | // the given name in the XML element. |
| 47 | // - a field with tag ",attr" becomes an attribute with the |
| 48 | // field name in the XML element. |
| 49 | // - a field with tag ",chardata" is written as character data, |
| 50 | // not as an XML element. |
| 51 | // - a field with tag ",innerxml" is written verbatim, not subject |
| 52 | // to the usual marshalling procedure. |
| 53 | // - a field with tag ",comment" is written as an XML comment, not |
| 54 | // subject to the usual marshalling procedure. It must not contain |
| 55 | // the "--" string within it. |
| 56 | // - a field with a tag including the "omitempty" option is omitted |
| 57 | // if the field value is empty. The empty values are false, 0, any |
| 58 | // nil pointer or interface value, and any array, slice, map, or |
| 59 | // string of length zero. |
| 60 | // - an anonymous struct field is handled as if the fields of its |
| 61 | // value were part of the outer struct. |
| 62 | // |
| 63 | // If a field uses a tag "a>b>c", then the element c will be nested inside |
| 64 | // parent elements a and b. Fields that appear next to each other that name |
| 65 | // the same parent will be enclosed in one XML element. |
| 66 | // |
| 67 | // See MarshalIndent for an example. |
| 68 | // |
| 69 | // Marshal will return an error if asked to marshal a channel, function, or map. |
| 70 | func Marshal(v interface{}) ([]byte, error) { |
| 71 | var b bytes.Buffer |
| 72 | if err := NewEncoder(&b).Encode(v); err != nil { |
| 73 | return nil, err |
| 74 | } |
| 75 | return b.Bytes(), nil |
| 76 | } |
| 77 | |
| 78 | // Marshaler is the interface implemented by objects that can marshal |
| 79 | // themselves into valid XML elements. |
| 80 | // |
| 81 | // MarshalXML encodes the receiver as zero or more XML elements. |
| 82 | // By convention, arrays or slices are typically encoded as a sequence |
| 83 | // of elements, one per entry. |
| 84 | // Using start as the element tag is not required, but doing so |
| 85 | // will enable Unmarshal to match the XML elements to the correct |
| 86 | // struct field. |
| 87 | // One common implementation strategy is to construct a separate |
| 88 | // value with a layout corresponding to the desired XML and then |
| 89 | // to encode it using e.EncodeElement. |
| 90 | // Another common strategy is to use repeated calls to e.EncodeToken |
| 91 | // to generate the XML output one token at a time. |
| 92 | // The sequence of encoded tokens must make up zero or more valid |
| 93 | // XML elements. |
| 94 | type Marshaler interface { |
| 95 | MarshalXML(e *Encoder, start StartElement) error |
| 96 | } |
| 97 | |
| 98 | // MarshalerAttr is the interface implemented by objects that can marshal |
| 99 | // themselves into valid XML attributes. |
| 100 | // |
| 101 | // MarshalXMLAttr returns an XML attribute with the encoded value of the receiver. |
| 102 | // Using name as the attribute name is not required, but doing so |
| 103 | // will enable Unmarshal to match the attribute to the correct |
| 104 | // struct field. |
| 105 | // If MarshalXMLAttr returns the zero attribute Attr{}, no attribute |
| 106 | // will be generated in the output. |
| 107 | // MarshalXMLAttr is used only for struct fields with the |
| 108 | // "attr" option in the field tag. |
| 109 | type MarshalerAttr interface { |
| 110 | MarshalXMLAttr(name Name) (Attr, error) |
| 111 | } |
| 112 | |
| 113 | // MarshalIndent works like Marshal, but each XML element begins on a new |
| 114 | // indented line that starts with prefix and is followed by one or more |
| 115 | // copies of indent according to the nesting depth. |
| 116 | func MarshalIndent(v interface{}, prefix, indent string) ([]byte, error) { |
| 117 | var b bytes.Buffer |
| 118 | enc := NewEncoder(&b) |
| 119 | enc.Indent(prefix, indent) |
| 120 | if err := enc.Encode(v); err != nil { |
| 121 | return nil, err |
| 122 | } |
| 123 | return b.Bytes(), nil |
| 124 | } |
| 125 | |
| 126 | // An Encoder writes XML data to an output stream. |
| 127 | type Encoder struct { |
| 128 | p printer |
| 129 | } |
| 130 | |
| 131 | // NewEncoder returns a new encoder that writes to w. |
| 132 | func NewEncoder(w io.Writer) *Encoder { |
| 133 | e := &Encoder{printer{Writer: bufio.NewWriter(w)}} |
| 134 | e.p.encoder = e |
| 135 | return e |
| 136 | } |
| 137 | |
| 138 | // Indent sets the encoder to generate XML in which each element |
| 139 | // begins on a new indented line that starts with prefix and is followed by |
| 140 | // one or more copies of indent according to the nesting depth. |
| 141 | func (enc *Encoder) Indent(prefix, indent string) { |
| 142 | enc.p.prefix = prefix |
| 143 | enc.p.indent = indent |
| 144 | } |
| 145 | |
| 146 | // Encode writes the XML encoding of v to the stream. |
| 147 | // |
| 148 | // See the documentation for Marshal for details about the conversion |
| 149 | // of Go values to XML. |
| 150 | // |
| 151 | // Encode calls Flush before returning. |
| 152 | func (enc *Encoder) Encode(v interface{}) error { |
| 153 | err := enc.p.marshalValue(reflect.ValueOf(v), nil, nil) |
| 154 | if err != nil { |
| 155 | return err |
| 156 | } |
| 157 | return enc.p.Flush() |
| 158 | } |
| 159 | |
| 160 | // EncodeElement writes the XML encoding of v to the stream, |
| 161 | // using start as the outermost tag in the encoding. |
| 162 | // |
| 163 | // See the documentation for Marshal for details about the conversion |
| 164 | // of Go values to XML. |
| 165 | // |
| 166 | // EncodeElement calls Flush before returning. |
| 167 | func (enc *Encoder) EncodeElement(v interface{}, start StartElement) error { |
| 168 | err := enc.p.marshalValue(reflect.ValueOf(v), nil, &start) |
| 169 | if err != nil { |
| 170 | return err |
| 171 | } |
| 172 | return enc.p.Flush() |
| 173 | } |
| 174 | |
| 175 | var ( |
| 176 | begComment = []byte("<!--") |
| 177 | endComment = []byte("-->") |
| 178 | endProcInst = []byte("?>") |
| 179 | endDirective = []byte(">") |
| 180 | ) |
| 181 | |
| 182 | // EncodeToken writes the given XML token to the stream. |
| 183 | // It returns an error if StartElement and EndElement tokens are not |
| 184 | // properly matched. |
| 185 | // |
| 186 | // EncodeToken does not call Flush, because usually it is part of a |
| 187 | // larger operation such as Encode or EncodeElement (or a custom |
| 188 | // Marshaler's MarshalXML invoked during those), and those will call |
| 189 | // Flush when finished. Callers that create an Encoder and then invoke |
| 190 | // EncodeToken directly, without using Encode or EncodeElement, need to |
| 191 | // call Flush when finished to ensure that the XML is written to the |
| 192 | // underlying writer. |
| 193 | // |
| 194 | // EncodeToken allows writing a ProcInst with Target set to "xml" only |
| 195 | // as the first token in the stream. |
| 196 | // |
| 197 | // When encoding a StartElement holding an XML namespace prefix |
| 198 | // declaration for a prefix that is not already declared, contained |
| 199 | // elements (including the StartElement itself) will use the declared |
| 200 | // prefix when encoding names with matching namespace URIs. |
| 201 | func (enc *Encoder) EncodeToken(t Token) error { |
| 202 | |
| 203 | p := &enc.p |
| 204 | switch t := t.(type) { |
| 205 | case StartElement: |
| 206 | if err := p.writeStart(&t); err != nil { |
| 207 | return err |
| 208 | } |
| 209 | case EndElement: |
| 210 | if err := p.writeEnd(t.Name); err != nil { |
| 211 | return err |
| 212 | } |
| 213 | case CharData: |
| 214 | escapeText(p, t, false) |
| 215 | case Comment: |
| 216 | if bytes.Contains(t, endComment) { |
| 217 | return fmt.Errorf("xml: EncodeToken of Comment containing --> marker") |
| 218 | } |
| 219 | p.WriteString("<!--") |
| 220 | p.Write(t) |
| 221 | p.WriteString("-->") |
| 222 | return p.cachedWriteError() |
| 223 | case ProcInst: |
| 224 | // First token to be encoded which is also a ProcInst with target of xml |
| 225 | // is the xml declaration. The only ProcInst where target of xml is allowed. |
| 226 | if t.Target == "xml" && p.Buffered() != 0 { |
| 227 | return fmt.Errorf("xml: EncodeToken of ProcInst xml target only valid for xml declaration, first token encoded") |
| 228 | } |
| 229 | if !isNameString(t.Target) { |
| 230 | return fmt.Errorf("xml: EncodeToken of ProcInst with invalid Target") |
| 231 | } |
| 232 | if bytes.Contains(t.Inst, endProcInst) { |
| 233 | return fmt.Errorf("xml: EncodeToken of ProcInst containing ?> marker") |
| 234 | } |
| 235 | p.WriteString("<?") |
| 236 | p.WriteString(t.Target) |
| 237 | if len(t.Inst) > 0 { |
| 238 | p.WriteByte(' ') |
| 239 | p.Write(t.Inst) |
| 240 | } |
| 241 | p.WriteString("?>") |
| 242 | case Directive: |
| 243 | if !isValidDirective(t) { |
| 244 | return fmt.Errorf("xml: EncodeToken of Directive containing wrong < or > markers") |
| 245 | } |
| 246 | p.WriteString("<!") |
| 247 | p.Write(t) |
| 248 | p.WriteString(">") |
| 249 | default: |
| 250 | return fmt.Errorf("xml: EncodeToken of invalid token type") |
| 251 | |
| 252 | } |
| 253 | return p.cachedWriteError() |
| 254 | } |
| 255 | |
| 256 | // isValidDirective reports whether dir is a valid directive text, |
| 257 | // meaning angle brackets are matched, ignoring comments and strings. |
| 258 | func isValidDirective(dir Directive) bool { |
| 259 | var ( |
| 260 | depth int |
| 261 | inquote uint8 |
| 262 | incomment bool |
| 263 | ) |
| 264 | for i, c := range dir { |
| 265 | switch { |
| 266 | case incomment: |
| 267 | if c == '>' { |
| 268 | if n := 1 + i - len(endComment); n >= 0 && bytes.Equal(dir[n:i+1], endComment) { |
| 269 | incomment = false |
| 270 | } |
| 271 | } |
| 272 | // Just ignore anything in comment |
| 273 | case inquote != 0: |
| 274 | if c == inquote { |
| 275 | inquote = 0 |
| 276 | } |
| 277 | // Just ignore anything within quotes |
| 278 | case c == '\'' || c == '"': |
| 279 | inquote = c |
| 280 | case c == '<': |
| 281 | if i+len(begComment) < len(dir) && bytes.Equal(dir[i:i+len(begComment)], begComment) { |
| 282 | incomment = true |
| 283 | } else { |
| 284 | depth++ |
| 285 | } |
| 286 | case c == '>': |
| 287 | if depth == 0 { |
| 288 | return false |
| 289 | } |
| 290 | depth-- |
| 291 | } |
| 292 | } |
| 293 | return depth == 0 && inquote == 0 && !incomment |
| 294 | } |
| 295 | |
| 296 | // Flush flushes any buffered XML to the underlying writer. |
| 297 | // See the EncodeToken documentation for details about when it is necessary. |
| 298 | func (enc *Encoder) Flush() error { |
| 299 | return enc.p.Flush() |
| 300 | } |
| 301 | |
| 302 | type printer struct { |
| 303 | *bufio.Writer |
| 304 | encoder *Encoder |
| 305 | seq int |
| 306 | indent string |
| 307 | prefix string |
| 308 | depth int |
| 309 | indentedIn bool |
| 310 | putNewline bool |
| 311 | defaultNS string |
| 312 | attrNS map[string]string // map prefix -> name space |
| 313 | attrPrefix map[string]string // map name space -> prefix |
| 314 | prefixes []printerPrefix |
| 315 | tags []Name |
| 316 | } |
| 317 | |
| 318 | // printerPrefix holds a namespace undo record. |
| 319 | // When an element is popped, the prefix record |
| 320 | // is set back to the recorded URL. The empty |
| 321 | // prefix records the URL for the default name space. |
| 322 | // |
| 323 | // The start of an element is recorded with an element |
| 324 | // that has mark=true. |
| 325 | type printerPrefix struct { |
| 326 | prefix string |
| 327 | url string |
| 328 | mark bool |
| 329 | } |
| 330 | |
| 331 | func (p *printer) prefixForNS(url string, isAttr bool) string { |
| 332 | // The "http://www.w3.org/XML/1998/namespace" name space is predefined as "xml" |
| 333 | // and must be referred to that way. |
| 334 | // (The "http://www.w3.org/2000/xmlns/" name space is also predefined as "xmlns", |
| 335 | // but users should not be trying to use that one directly - that's our job.) |
| 336 | if url == xmlURL { |
| 337 | return "xml" |
| 338 | } |
| 339 | if !isAttr && url == p.defaultNS { |
| 340 | // We can use the default name space. |
| 341 | return "" |
| 342 | } |
| 343 | return p.attrPrefix[url] |
| 344 | } |
| 345 | |
| 346 | // defineNS pushes any namespace definition found in the given attribute. |
| 347 | // If ignoreNonEmptyDefault is true, an xmlns="nonempty" |
| 348 | // attribute will be ignored. |
| 349 | func (p *printer) defineNS(attr Attr, ignoreNonEmptyDefault bool) error { |
| 350 | var prefix string |
| 351 | if attr.Name.Local == "xmlns" { |
| 352 | if attr.Name.Space != "" && attr.Name.Space != "xml" && attr.Name.Space != xmlURL { |
| 353 | return fmt.Errorf("xml: cannot redefine xmlns attribute prefix") |
| 354 | } |
| 355 | } else if attr.Name.Space == "xmlns" && attr.Name.Local != "" { |
| 356 | prefix = attr.Name.Local |
| 357 | if attr.Value == "" { |
| 358 | // Technically, an empty XML namespace is allowed for an attribute. |
| 359 | // From http://www.w3.org/TR/xml-names11/#scoping-defaulting: |
| 360 | // |
| 361 | // The attribute value in a namespace declaration for a prefix may be |
| 362 | // empty. This has the effect, within the scope of the declaration, of removing |
| 363 | // any association of the prefix with a namespace name. |
| 364 | // |
| 365 | // However our namespace prefixes here are used only as hints. There's |
| 366 | // no need to respect the removal of a namespace prefix, so we ignore it. |
| 367 | return nil |
| 368 | } |
| 369 | } else { |
| 370 | // Ignore: it's not a namespace definition |
| 371 | return nil |
| 372 | } |
| 373 | if prefix == "" { |
| 374 | if attr.Value == p.defaultNS { |
| 375 | // No need for redefinition. |
| 376 | return nil |
| 377 | } |
| 378 | if attr.Value != "" && ignoreNonEmptyDefault { |
| 379 | // We have an xmlns="..." value but |
| 380 | // it can't define a name space in this context, |
| 381 | // probably because the element has an empty |
| 382 | // name space. In this case, we just ignore |
| 383 | // the name space declaration. |
| 384 | return nil |
| 385 | } |
| 386 | } else if _, ok := p.attrPrefix[attr.Value]; ok { |
| 387 | // There's already a prefix for the given name space, |
| 388 | // so use that. This prevents us from |
| 389 | // having two prefixes for the same name space |
| 390 | // so attrNS and attrPrefix can remain bijective. |
| 391 | return nil |
| 392 | } |
| 393 | p.pushPrefix(prefix, attr.Value) |
| 394 | return nil |
| 395 | } |
| 396 | |
| 397 | // createNSPrefix creates a name space prefix attribute |
| 398 | // to use for the given name space, defining a new prefix |
| 399 | // if necessary. |
| 400 | // If isAttr is true, the prefix is to be created for an attribute |
| 401 | // prefix, which means that the default name space cannot |
| 402 | // be used. |
| 403 | func (p *printer) createNSPrefix(url string, isAttr bool) { |
| 404 | if _, ok := p.attrPrefix[url]; ok { |
| 405 | // We already have a prefix for the given URL. |
| 406 | return |
| 407 | } |
| 408 | switch { |
| 409 | case !isAttr && url == p.defaultNS: |
| 410 | // We can use the default name space. |
| 411 | return |
| 412 | case url == "": |
| 413 | // The only way we can encode names in the empty |
| 414 | // name space is by using the default name space, |
| 415 | // so we must use that. |
| 416 | if p.defaultNS != "" { |
| 417 | // The default namespace is non-empty, so we |
| 418 | // need to set it to empty. |
| 419 | p.pushPrefix("", "") |
| 420 | } |
| 421 | return |
| 422 | case url == xmlURL: |
| 423 | return |
| 424 | } |
| 425 | // TODO If the URL is an existing prefix, we could |
| 426 | // use it as is. That would enable the |
| 427 | // marshaling of elements that had been unmarshaled |
| 428 | // and with a name space prefix that was not found. |
| 429 | // although technically it would be incorrect. |
| 430 | |
| 431 | // Pick a name. We try to use the final element of the path |
| 432 | // but fall back to _. |
| 433 | prefix := strings.TrimRight(url, "/") |
| 434 | if i := strings.LastIndex(prefix, "/"); i >= 0 { |
| 435 | prefix = prefix[i+1:] |
| 436 | } |
| 437 | if prefix == "" || !isName([]byte(prefix)) || strings.Contains(prefix, ":") { |
| 438 | prefix = "_" |
| 439 | } |
| 440 | if strings.HasPrefix(prefix, "xml") { |
| 441 | // xmlanything is reserved. |
| 442 | prefix = "_" + prefix |
| 443 | } |
| 444 | if p.attrNS[prefix] != "" { |
| 445 | // Name is taken. Find a better one. |
| 446 | for p.seq++; ; p.seq++ { |
| 447 | if id := prefix + "_" + strconv.Itoa(p.seq); p.attrNS[id] == "" { |
| 448 | prefix = id |
| 449 | break |
| 450 | } |
| 451 | } |
| 452 | } |
| 453 | |
| 454 | p.pushPrefix(prefix, url) |
| 455 | } |
| 456 | |
| 457 | // writeNamespaces writes xmlns attributes for all the |
| 458 | // namespace prefixes that have been defined in |
| 459 | // the current element. |
| 460 | func (p *printer) writeNamespaces() { |
| 461 | for i := len(p.prefixes) - 1; i >= 0; i-- { |
| 462 | prefix := p.prefixes[i] |
| 463 | if prefix.mark { |
| 464 | return |
| 465 | } |
| 466 | p.WriteString(" ") |
| 467 | if prefix.prefix == "" { |
| 468 | // Default name space. |
| 469 | p.WriteString(`xmlns="`) |
| 470 | } else { |
| 471 | p.WriteString("xmlns:") |
| 472 | p.WriteString(prefix.prefix) |
| 473 | p.WriteString(`="`) |
| 474 | } |
| 475 | EscapeText(p, []byte(p.nsForPrefix(prefix.prefix))) |
| 476 | p.WriteString(`"`) |
| 477 | } |
| 478 | } |
| 479 | |
| 480 | // pushPrefix pushes a new prefix on the prefix stack |
| 481 | // without checking to see if it is already defined. |
| 482 | func (p *printer) pushPrefix(prefix, url string) { |
| 483 | p.prefixes = append(p.prefixes, printerPrefix{ |
| 484 | prefix: prefix, |
| 485 | url: p.nsForPrefix(prefix), |
| 486 | }) |
| 487 | p.setAttrPrefix(prefix, url) |
| 488 | } |
| 489 | |
| 490 | // nsForPrefix returns the name space for the given |
| 491 | // prefix. Note that this is not valid for the |
| 492 | // empty attribute prefix, which always has an empty |
| 493 | // name space. |
| 494 | func (p *printer) nsForPrefix(prefix string) string { |
| 495 | if prefix == "" { |
| 496 | return p.defaultNS |
| 497 | } |
| 498 | return p.attrNS[prefix] |
| 499 | } |
| 500 | |
| 501 | // markPrefix marks the start of an element on the prefix |
| 502 | // stack. |
| 503 | func (p *printer) markPrefix() { |
| 504 | p.prefixes = append(p.prefixes, printerPrefix{ |
| 505 | mark: true, |
| 506 | }) |
| 507 | } |
| 508 | |
| 509 | // popPrefix pops all defined prefixes for the current |
| 510 | // element. |
| 511 | func (p *printer) popPrefix() { |
| 512 | for len(p.prefixes) > 0 { |
| 513 | prefix := p.prefixes[len(p.prefixes)-1] |
| 514 | p.prefixes = p.prefixes[:len(p.prefixes)-1] |
| 515 | if prefix.mark { |
| 516 | break |
| 517 | } |
| 518 | p.setAttrPrefix(prefix.prefix, prefix.url) |
| 519 | } |
| 520 | } |
| 521 | |
| 522 | // setAttrPrefix sets an attribute name space prefix. |
| 523 | // If url is empty, the attribute is removed. |
| 524 | // If prefix is empty, the default name space is set. |
| 525 | func (p *printer) setAttrPrefix(prefix, url string) { |
| 526 | if prefix == "" { |
| 527 | p.defaultNS = url |
| 528 | return |
| 529 | } |
| 530 | if url == "" { |
| 531 | delete(p.attrPrefix, p.attrNS[prefix]) |
| 532 | delete(p.attrNS, prefix) |
| 533 | return |
| 534 | } |
| 535 | if p.attrPrefix == nil { |
| 536 | // Need to define a new name space. |
| 537 | p.attrPrefix = make(map[string]string) |
| 538 | p.attrNS = make(map[string]string) |
| 539 | } |
| 540 | // Remove any old prefix value. This is OK because we maintain a |
| 541 | // strict one-to-one mapping between prefix and URL (see |
| 542 | // defineNS) |
| 543 | delete(p.attrPrefix, p.attrNS[prefix]) |
| 544 | p.attrPrefix[url] = prefix |
| 545 | p.attrNS[prefix] = url |
| 546 | } |
| 547 | |
| 548 | var ( |
| 549 | marshalerType = reflect.TypeOf((*Marshaler)(nil)).Elem() |
| 550 | marshalerAttrType = reflect.TypeOf((*MarshalerAttr)(nil)).Elem() |
| 551 | textMarshalerType = reflect.TypeOf((*encoding.TextMarshaler)(nil)).Elem() |
| 552 | ) |
| 553 | |
| 554 | // marshalValue writes one or more XML elements representing val. |
| 555 | // If val was obtained from a struct field, finfo must have its details. |
| 556 | func (p *printer) marshalValue(val reflect.Value, finfo *fieldInfo, startTemplate *StartElement) error { |
| 557 | if startTemplate != nil && startTemplate.Name.Local == "" { |
| 558 | return fmt.Errorf("xml: EncodeElement of StartElement with missing name") |
| 559 | } |
| 560 | |
| 561 | if !val.IsValid() { |
| 562 | return nil |
| 563 | } |
| 564 | if finfo != nil && finfo.flags&fOmitEmpty != 0 && isEmptyValue(val) { |
| 565 | return nil |
| 566 | } |
| 567 | |
| 568 | // Drill into interfaces and pointers. |
| 569 | // This can turn into an infinite loop given a cyclic chain, |
| 570 | // but it matches the Go 1 behavior. |
| 571 | for val.Kind() == reflect.Interface || val.Kind() == reflect.Ptr { |
| 572 | if val.IsNil() { |
| 573 | return nil |
| 574 | } |
| 575 | val = val.Elem() |
| 576 | } |
| 577 | |
| 578 | kind := val.Kind() |
| 579 | typ := val.Type() |
| 580 | |
| 581 | // Check for marshaler. |
| 582 | if val.CanInterface() && typ.Implements(marshalerType) { |
| 583 | return p.marshalInterface(val.Interface().(Marshaler), p.defaultStart(typ, finfo, startTemplate)) |
| 584 | } |
| 585 | if val.CanAddr() { |
| 586 | pv := val.Addr() |
| 587 | if pv.CanInterface() && pv.Type().Implements(marshalerType) { |
| 588 | return p.marshalInterface(pv.Interface().(Marshaler), p.defaultStart(pv.Type(), finfo, startTemplate)) |
| 589 | } |
| 590 | } |
| 591 | |
| 592 | // Check for text marshaler. |
| 593 | if val.CanInterface() && typ.Implements(textMarshalerType) { |
| 594 | return p.marshalTextInterface(val.Interface().(encoding.TextMarshaler), p.defaultStart(typ, finfo, startTemplate)) |
| 595 | } |
| 596 | if val.CanAddr() { |
| 597 | pv := val.Addr() |
| 598 | if pv.CanInterface() && pv.Type().Implements(textMarshalerType) { |
| 599 | return p.marshalTextInterface(pv.Interface().(encoding.TextMarshaler), p.defaultStart(pv.Type(), finfo, startTemplate)) |
| 600 | } |
| 601 | } |
| 602 | |
| 603 | // Slices and arrays iterate over the elements. They do not have an enclosing tag. |
| 604 | if (kind == reflect.Slice || kind == reflect.Array) && typ.Elem().Kind() != reflect.Uint8 { |
| 605 | for i, n := 0, val.Len(); i < n; i++ { |
| 606 | if err := p.marshalValue(val.Index(i), finfo, startTemplate); err != nil { |
| 607 | return err |
| 608 | } |
| 609 | } |
| 610 | return nil |
| 611 | } |
| 612 | |
| 613 | tinfo, err := getTypeInfo(typ) |
| 614 | if err != nil { |
| 615 | return err |
| 616 | } |
| 617 | |
| 618 | // Create start element. |
| 619 | // Precedence for the XML element name is: |
| 620 | // 0. startTemplate |
| 621 | // 1. XMLName field in underlying struct; |
| 622 | // 2. field name/tag in the struct field; and |
| 623 | // 3. type name |
| 624 | var start StartElement |
| 625 | |
| 626 | // explicitNS records whether the element's name space has been |
| 627 | // explicitly set (for example an XMLName field). |
| 628 | explicitNS := false |
| 629 | |
| 630 | if startTemplate != nil { |
| 631 | start.Name = startTemplate.Name |
| 632 | explicitNS = true |
| 633 | start.Attr = append(start.Attr, startTemplate.Attr...) |
| 634 | } else if tinfo.xmlname != nil { |
| 635 | xmlname := tinfo.xmlname |
| 636 | if xmlname.name != "" { |
| 637 | start.Name.Space, start.Name.Local = xmlname.xmlns, xmlname.name |
| 638 | } else if v, ok := xmlname.value(val).Interface().(Name); ok && v.Local != "" { |
| 639 | start.Name = v |
| 640 | } |
| 641 | explicitNS = true |
| 642 | } |
| 643 | if start.Name.Local == "" && finfo != nil { |
| 644 | start.Name.Local = finfo.name |
| 645 | if finfo.xmlns != "" { |
| 646 | start.Name.Space = finfo.xmlns |
| 647 | explicitNS = true |
| 648 | } |
| 649 | } |
| 650 | if start.Name.Local == "" { |
| 651 | name := typ.Name() |
| 652 | if name == "" { |
| 653 | return &UnsupportedTypeError{typ} |
| 654 | } |
| 655 | start.Name.Local = name |
| 656 | } |
| 657 | |
| 658 | // defaultNS records the default name space as set by a xmlns="..." |
| 659 | // attribute. We don't set p.defaultNS because we want to let |
| 660 | // the attribute writing code (in p.defineNS) be solely responsible |
| 661 | // for maintaining that. |
| 662 | defaultNS := p.defaultNS |
| 663 | |
| 664 | // Attributes |
| 665 | for i := range tinfo.fields { |
| 666 | finfo := &tinfo.fields[i] |
| 667 | if finfo.flags&fAttr == 0 { |
| 668 | continue |
| 669 | } |
| 670 | attr, err := p.fieldAttr(finfo, val) |
| 671 | if err != nil { |
| 672 | return err |
| 673 | } |
| 674 | if attr.Name.Local == "" { |
| 675 | continue |
| 676 | } |
| 677 | start.Attr = append(start.Attr, attr) |
| 678 | if attr.Name.Space == "" && attr.Name.Local == "xmlns" { |
| 679 | defaultNS = attr.Value |
| 680 | } |
| 681 | } |
| 682 | if !explicitNS { |
| 683 | // Historic behavior: elements use the default name space |
| 684 | // they are contained in by default. |
| 685 | start.Name.Space = defaultNS |
| 686 | } |
| 687 | // Historic behaviour: an element that's in a namespace sets |
| 688 | // the default namespace for all elements contained within it. |
| 689 | start.setDefaultNamespace() |
| 690 | |
| 691 | if err := p.writeStart(&start); err != nil { |
| 692 | return err |
| 693 | } |
| 694 | |
| 695 | if val.Kind() == reflect.Struct { |
| 696 | err = p.marshalStruct(tinfo, val) |
| 697 | } else { |
| 698 | s, b, err1 := p.marshalSimple(typ, val) |
| 699 | if err1 != nil { |
| 700 | err = err1 |
| 701 | } else if b != nil { |
| 702 | EscapeText(p, b) |
| 703 | } else { |
| 704 | p.EscapeString(s) |
| 705 | } |
| 706 | } |
| 707 | if err != nil { |
| 708 | return err |
| 709 | } |
| 710 | |
| 711 | if err := p.writeEnd(start.Name); err != nil { |
| 712 | return err |
| 713 | } |
| 714 | |
| 715 | return p.cachedWriteError() |
| 716 | } |
| 717 | |
| 718 | // fieldAttr returns the attribute of the given field. |
| 719 | // If the returned attribute has an empty Name.Local, |
| 720 | // it should not be used. |
| 721 | // The given value holds the value containing the field. |
| 722 | func (p *printer) fieldAttr(finfo *fieldInfo, val reflect.Value) (Attr, error) { |
| 723 | fv := finfo.value(val) |
| 724 | name := Name{Space: finfo.xmlns, Local: finfo.name} |
| 725 | if finfo.flags&fOmitEmpty != 0 && isEmptyValue(fv) { |
| 726 | return Attr{}, nil |
| 727 | } |
| 728 | if fv.Kind() == reflect.Interface && fv.IsNil() { |
| 729 | return Attr{}, nil |
| 730 | } |
| 731 | if fv.CanInterface() && fv.Type().Implements(marshalerAttrType) { |
| 732 | attr, err := fv.Interface().(MarshalerAttr).MarshalXMLAttr(name) |
| 733 | return attr, err |
| 734 | } |
| 735 | if fv.CanAddr() { |
| 736 | pv := fv.Addr() |
| 737 | if pv.CanInterface() && pv.Type().Implements(marshalerAttrType) { |
| 738 | attr, err := pv.Interface().(MarshalerAttr).MarshalXMLAttr(name) |
| 739 | return attr, err |
| 740 | } |
| 741 | } |
| 742 | if fv.CanInterface() && fv.Type().Implements(textMarshalerType) { |
| 743 | text, err := fv.Interface().(encoding.TextMarshaler).MarshalText() |
| 744 | if err != nil { |
| 745 | return Attr{}, err |
| 746 | } |
| 747 | return Attr{name, string(text)}, nil |
| 748 | } |
| 749 | if fv.CanAddr() { |
| 750 | pv := fv.Addr() |
| 751 | if pv.CanInterface() && pv.Type().Implements(textMarshalerType) { |
| 752 | text, err := pv.Interface().(encoding.TextMarshaler).MarshalText() |
| 753 | if err != nil { |
| 754 | return Attr{}, err |
| 755 | } |
| 756 | return Attr{name, string(text)}, nil |
| 757 | } |
| 758 | } |
| 759 | // Dereference or skip nil pointer, interface values. |
| 760 | switch fv.Kind() { |
| 761 | case reflect.Ptr, reflect.Interface: |
| 762 | if fv.IsNil() { |
| 763 | return Attr{}, nil |
| 764 | } |
| 765 | fv = fv.Elem() |
| 766 | } |
| 767 | s, b, err := p.marshalSimple(fv.Type(), fv) |
| 768 | if err != nil { |
| 769 | return Attr{}, err |
| 770 | } |
| 771 | if b != nil { |
| 772 | s = string(b) |
| 773 | } |
| 774 | return Attr{name, s}, nil |
| 775 | } |
| 776 | |
| 777 | // defaultStart returns the default start element to use, |
| 778 | // given the reflect type, field info, and start template. |
| 779 | func (p *printer) defaultStart(typ reflect.Type, finfo *fieldInfo, startTemplate *StartElement) StartElement { |
| 780 | var start StartElement |
| 781 | // Precedence for the XML element name is as above, |
| 782 | // except that we do not look inside structs for the first field. |
| 783 | if startTemplate != nil { |
| 784 | start.Name = startTemplate.Name |
| 785 | start.Attr = append(start.Attr, startTemplate.Attr...) |
| 786 | } else if finfo != nil && finfo.name != "" { |
| 787 | start.Name.Local = finfo.name |
| 788 | start.Name.Space = finfo.xmlns |
| 789 | } else if typ.Name() != "" { |
| 790 | start.Name.Local = typ.Name() |
| 791 | } else { |
| 792 | // Must be a pointer to a named type, |
| 793 | // since it has the Marshaler methods. |
| 794 | start.Name.Local = typ.Elem().Name() |
| 795 | } |
| 796 | // Historic behaviour: elements use the name space of |
| 797 | // the element they are contained in by default. |
| 798 | if start.Name.Space == "" { |
| 799 | start.Name.Space = p.defaultNS |
| 800 | } |
| 801 | start.setDefaultNamespace() |
| 802 | return start |
| 803 | } |
| 804 | |
| 805 | // marshalInterface marshals a Marshaler interface value. |
| 806 | func (p *printer) marshalInterface(val Marshaler, start StartElement) error { |
| 807 | // Push a marker onto the tag stack so that MarshalXML |
| 808 | // cannot close the XML tags that it did not open. |
| 809 | p.tags = append(p.tags, Name{}) |
| 810 | n := len(p.tags) |
| 811 | |
| 812 | err := val.MarshalXML(p.encoder, start) |
| 813 | if err != nil { |
| 814 | return err |
| 815 | } |
| 816 | |
| 817 | // Make sure MarshalXML closed all its tags. p.tags[n-1] is the mark. |
| 818 | if len(p.tags) > n { |
| 819 | return fmt.Errorf("xml: %s.MarshalXML wrote invalid XML: <%s> not closed", receiverType(val), p.tags[len(p.tags)-1].Local) |
| 820 | } |
| 821 | p.tags = p.tags[:n-1] |
| 822 | return nil |
| 823 | } |
| 824 | |
| 825 | // marshalTextInterface marshals a TextMarshaler interface value. |
| 826 | func (p *printer) marshalTextInterface(val encoding.TextMarshaler, start StartElement) error { |
| 827 | if err := p.writeStart(&start); err != nil { |
| 828 | return err |
| 829 | } |
| 830 | text, err := val.MarshalText() |
| 831 | if err != nil { |
| 832 | return err |
| 833 | } |
| 834 | EscapeText(p, text) |
| 835 | return p.writeEnd(start.Name) |
| 836 | } |
| 837 | |
| 838 | // writeStart writes the given start element. |
| 839 | func (p *printer) writeStart(start *StartElement) error { |
| 840 | if start.Name.Local == "" { |
| 841 | return fmt.Errorf("xml: start tag with no name") |
| 842 | } |
| 843 | |
| 844 | p.tags = append(p.tags, start.Name) |
| 845 | p.markPrefix() |
| 846 | // Define any name spaces explicitly declared in the attributes. |
| 847 | // We do this as a separate pass so that explicitly declared prefixes |
| 848 | // will take precedence over implicitly declared prefixes |
| 849 | // regardless of the order of the attributes. |
| 850 | ignoreNonEmptyDefault := start.Name.Space == "" |
| 851 | for _, attr := range start.Attr { |
| 852 | if err := p.defineNS(attr, ignoreNonEmptyDefault); err != nil { |
| 853 | return err |
| 854 | } |
| 855 | } |
| 856 | // Define any new name spaces implied by the attributes. |
| 857 | for _, attr := range start.Attr { |
| 858 | name := attr.Name |
| 859 | // From http://www.w3.org/TR/xml-names11/#defaulting |
| 860 | // "Default namespace declarations do not apply directly |
| 861 | // to attribute names; the interpretation of unprefixed |
| 862 | // attributes is determined by the element on which they |
| 863 | // appear." |
| 864 | // This means we don't need to create a new namespace |
| 865 | // when an attribute name space is empty. |
| 866 | if name.Space != "" && !name.isNamespace() { |
| 867 | p.createNSPrefix(name.Space, true) |
| 868 | } |
| 869 | } |
| 870 | p.createNSPrefix(start.Name.Space, false) |
| 871 | |
| 872 | p.writeIndent(1) |
| 873 | p.WriteByte('<') |
| 874 | p.writeName(start.Name, false) |
| 875 | p.writeNamespaces() |
| 876 | for _, attr := range start.Attr { |
| 877 | name := attr.Name |
| 878 | if name.Local == "" || name.isNamespace() { |
| 879 | // Namespaces have already been written by writeNamespaces above. |
| 880 | continue |
| 881 | } |
| 882 | p.WriteByte(' ') |
| 883 | p.writeName(name, true) |
| 884 | p.WriteString(`="`) |
| 885 | p.EscapeString(attr.Value) |
| 886 | p.WriteByte('"') |
| 887 | } |
| 888 | p.WriteByte('>') |
| 889 | return nil |
| 890 | } |
| 891 | |
| 892 | // writeName writes the given name. It assumes |
| 893 | // that p.createNSPrefix(name) has already been called. |
| 894 | func (p *printer) writeName(name Name, isAttr bool) { |
| 895 | if prefix := p.prefixForNS(name.Space, isAttr); prefix != "" { |
| 896 | p.WriteString(prefix) |
| 897 | p.WriteByte(':') |
| 898 | } |
| 899 | p.WriteString(name.Local) |
| 900 | } |
| 901 | |
| 902 | func (p *printer) writeEnd(name Name) error { |
| 903 | if name.Local == "" { |
| 904 | return fmt.Errorf("xml: end tag with no name") |
| 905 | } |
| 906 | if len(p.tags) == 0 || p.tags[len(p.tags)-1].Local == "" { |
| 907 | return fmt.Errorf("xml: end tag </%s> without start tag", name.Local) |
| 908 | } |
| 909 | if top := p.tags[len(p.tags)-1]; top != name { |
| 910 | if top.Local != name.Local { |
| 911 | return fmt.Errorf("xml: end tag </%s> does not match start tag <%s>", name.Local, top.Local) |
| 912 | } |
| 913 | 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) |
| 914 | } |
| 915 | p.tags = p.tags[:len(p.tags)-1] |
| 916 | |
| 917 | p.writeIndent(-1) |
| 918 | p.WriteByte('<') |
| 919 | p.WriteByte('/') |
| 920 | p.writeName(name, false) |
| 921 | p.WriteByte('>') |
| 922 | p.popPrefix() |
| 923 | return nil |
| 924 | } |
| 925 | |
| 926 | func (p *printer) marshalSimple(typ reflect.Type, val reflect.Value) (string, []byte, error) { |
| 927 | switch val.Kind() { |
| 928 | case reflect.Int, reflect.Int8, reflect.Int16, reflect.Int32, reflect.Int64: |
| 929 | return strconv.FormatInt(val.Int(), 10), nil, nil |
| 930 | case reflect.Uint, reflect.Uint8, reflect.Uint16, reflect.Uint32, reflect.Uint64, reflect.Uintptr: |
| 931 | return strconv.FormatUint(val.Uint(), 10), nil, nil |
| 932 | case reflect.Float32, reflect.Float64: |
| 933 | return strconv.FormatFloat(val.Float(), 'g', -1, val.Type().Bits()), nil, nil |
| 934 | case reflect.String: |
| 935 | return val.String(), nil, nil |
| 936 | case reflect.Bool: |
| 937 | return strconv.FormatBool(val.Bool()), nil, nil |
| 938 | case reflect.Array: |
| 939 | if typ.Elem().Kind() != reflect.Uint8 { |
| 940 | break |
| 941 | } |
| 942 | // [...]byte |
| 943 | var bytes []byte |
| 944 | if val.CanAddr() { |
| 945 | bytes = val.Slice(0, val.Len()).Bytes() |
| 946 | } else { |
| 947 | bytes = make([]byte, val.Len()) |
| 948 | reflect.Copy(reflect.ValueOf(bytes), val) |
| 949 | } |
| 950 | return "", bytes, nil |
| 951 | case reflect.Slice: |
| 952 | if typ.Elem().Kind() != reflect.Uint8 { |
| 953 | break |
| 954 | } |
| 955 | // []byte |
| 956 | return "", val.Bytes(), nil |
| 957 | } |
| 958 | return "", nil, &UnsupportedTypeError{typ} |
| 959 | } |
| 960 | |
| 961 | var ddBytes = []byte("--") |
| 962 | |
| 963 | func (p *printer) marshalStruct(tinfo *typeInfo, val reflect.Value) error { |
| 964 | s := parentStack{p: p} |
| 965 | for i := range tinfo.fields { |
| 966 | finfo := &tinfo.fields[i] |
| 967 | if finfo.flags&fAttr != 0 { |
| 968 | continue |
| 969 | } |
| 970 | vf := finfo.value(val) |
| 971 | |
| 972 | // Dereference or skip nil pointer, interface values. |
| 973 | switch vf.Kind() { |
| 974 | case reflect.Ptr, reflect.Interface: |
| 975 | if !vf.IsNil() { |
| 976 | vf = vf.Elem() |
| 977 | } |
| 978 | } |
| 979 | |
| 980 | switch finfo.flags & fMode { |
| 981 | case fCharData: |
| 982 | if err := s.setParents(&noField, reflect.Value{}); err != nil { |
| 983 | return err |
| 984 | } |
| 985 | if vf.CanInterface() && vf.Type().Implements(textMarshalerType) { |
| 986 | data, err := vf.Interface().(encoding.TextMarshaler).MarshalText() |
| 987 | if err != nil { |
| 988 | return err |
| 989 | } |
| 990 | Escape(p, data) |
| 991 | continue |
| 992 | } |
| 993 | if vf.CanAddr() { |
| 994 | pv := vf.Addr() |
| 995 | if pv.CanInterface() && pv.Type().Implements(textMarshalerType) { |
| 996 | data, err := pv.Interface().(encoding.TextMarshaler).MarshalText() |
| 997 | if err != nil { |
| 998 | return err |
| 999 | } |
| 1000 | Escape(p, data) |
| 1001 | continue |
| 1002 | } |
| 1003 | } |
| 1004 | var scratch [64]byte |
| 1005 | switch vf.Kind() { |
| 1006 | case reflect.Int, reflect.Int8, reflect.Int16, reflect.Int32, reflect.Int64: |
| 1007 | Escape(p, strconv.AppendInt(scratch[:0], vf.Int(), 10)) |
| 1008 | case reflect.Uint, reflect.Uint8, reflect.Uint16, reflect.Uint32, reflect.Uint64, reflect.Uintptr: |
| 1009 | Escape(p, strconv.AppendUint(scratch[:0], vf.Uint(), 10)) |
| 1010 | case reflect.Float32, reflect.Float64: |
| 1011 | Escape(p, strconv.AppendFloat(scratch[:0], vf.Float(), 'g', -1, vf.Type().Bits())) |
| 1012 | case reflect.Bool: |
| 1013 | Escape(p, strconv.AppendBool(scratch[:0], vf.Bool())) |
| 1014 | case reflect.String: |
| 1015 | if err := EscapeText(p, []byte(vf.String())); err != nil { |
| 1016 | return err |
| 1017 | } |
| 1018 | case reflect.Slice: |
| 1019 | if elem, ok := vf.Interface().([]byte); ok { |
| 1020 | if err := EscapeText(p, elem); err != nil { |
| 1021 | return err |
| 1022 | } |
| 1023 | } |
| 1024 | } |
| 1025 | continue |
| 1026 | |
| 1027 | case fComment: |
| 1028 | if err := s.setParents(&noField, reflect.Value{}); err != nil { |
| 1029 | return err |
| 1030 | } |
| 1031 | k := vf.Kind() |
| 1032 | if !(k == reflect.String || k == reflect.Slice && vf.Type().Elem().Kind() == reflect.Uint8) { |
| 1033 | return fmt.Errorf("xml: bad type for comment field of %s", val.Type()) |
| 1034 | } |
| 1035 | if vf.Len() == 0 { |
| 1036 | continue |
| 1037 | } |
| 1038 | p.writeIndent(0) |
| 1039 | p.WriteString("<!--") |
| 1040 | dashDash := false |
| 1041 | dashLast := false |
| 1042 | switch k { |
| 1043 | case reflect.String: |
| 1044 | s := vf.String() |
| 1045 | dashDash = strings.Index(s, "--") >= 0 |
| 1046 | dashLast = s[len(s)-1] == '-' |
| 1047 | if !dashDash { |
| 1048 | p.WriteString(s) |
| 1049 | } |
| 1050 | case reflect.Slice: |
| 1051 | b := vf.Bytes() |
| 1052 | dashDash = bytes.Index(b, ddBytes) >= 0 |
| 1053 | dashLast = b[len(b)-1] == '-' |
| 1054 | if !dashDash { |
| 1055 | p.Write(b) |
| 1056 | } |
| 1057 | default: |
| 1058 | panic("can't happen") |
| 1059 | } |
| 1060 | if dashDash { |
| 1061 | return fmt.Errorf(`xml: comments must not contain "--"`) |
| 1062 | } |
| 1063 | if dashLast { |
| 1064 | // "--->" is invalid grammar. Make it "- -->" |
| 1065 | p.WriteByte(' ') |
| 1066 | } |
| 1067 | p.WriteString("-->") |
| 1068 | continue |
| 1069 | |
| 1070 | case fInnerXml: |
| 1071 | iface := vf.Interface() |
| 1072 | switch raw := iface.(type) { |
| 1073 | case []byte: |
| 1074 | p.Write(raw) |
| 1075 | continue |
| 1076 | case string: |
| 1077 | p.WriteString(raw) |
| 1078 | continue |
| 1079 | } |
| 1080 | |
| 1081 | case fElement, fElement | fAny: |
| 1082 | if err := s.setParents(finfo, vf); err != nil { |
| 1083 | return err |
| 1084 | } |
| 1085 | } |
| 1086 | if err := p.marshalValue(vf, finfo, nil); err != nil { |
| 1087 | return err |
| 1088 | } |
| 1089 | } |
| 1090 | if err := s.setParents(&noField, reflect.Value{}); err != nil { |
| 1091 | return err |
| 1092 | } |
| 1093 | return p.cachedWriteError() |
| 1094 | } |
| 1095 | |
| 1096 | var noField fieldInfo |
| 1097 | |
| 1098 | // return the bufio Writer's cached write error |
| 1099 | func (p *printer) cachedWriteError() error { |
| 1100 | _, err := p.Write(nil) |
| 1101 | return err |
| 1102 | } |
| 1103 | |
| 1104 | func (p *printer) writeIndent(depthDelta int) { |
| 1105 | if len(p.prefix) == 0 && len(p.indent) == 0 { |
| 1106 | return |
| 1107 | } |
| 1108 | if depthDelta < 0 { |
| 1109 | p.depth-- |
| 1110 | if p.indentedIn { |
| 1111 | p.indentedIn = false |
| 1112 | return |
| 1113 | } |
| 1114 | p.indentedIn = false |
| 1115 | } |
| 1116 | if p.putNewline { |
| 1117 | p.WriteByte('\n') |
| 1118 | } else { |
| 1119 | p.putNewline = true |
| 1120 | } |
| 1121 | if len(p.prefix) > 0 { |
| 1122 | p.WriteString(p.prefix) |
| 1123 | } |
| 1124 | if len(p.indent) > 0 { |
| 1125 | for i := 0; i < p.depth; i++ { |
| 1126 | p.WriteString(p.indent) |
| 1127 | } |
| 1128 | } |
| 1129 | if depthDelta > 0 { |
| 1130 | p.depth++ |
| 1131 | p.indentedIn = true |
| 1132 | } |
| 1133 | } |
| 1134 | |
| 1135 | type parentStack struct { |
| 1136 | p *printer |
| 1137 | xmlns string |
| 1138 | parents []string |
| 1139 | } |
| 1140 | |
| 1141 | // setParents sets the stack of current parents to those found in finfo. |
| 1142 | // It only writes the start elements if vf holds a non-nil value. |
| 1143 | // If finfo is &noField, it pops all elements. |
| 1144 | func (s *parentStack) setParents(finfo *fieldInfo, vf reflect.Value) error { |
| 1145 | xmlns := s.p.defaultNS |
| 1146 | if finfo.xmlns != "" { |
| 1147 | xmlns = finfo.xmlns |
| 1148 | } |
| 1149 | commonParents := 0 |
| 1150 | if xmlns == s.xmlns { |
| 1151 | for ; commonParents < len(finfo.parents) && commonParents < len(s.parents); commonParents++ { |
| 1152 | if finfo.parents[commonParents] != s.parents[commonParents] { |
| 1153 | break |
| 1154 | } |
| 1155 | } |
| 1156 | } |
| 1157 | // Pop off any parents that aren't in common with the previous field. |
| 1158 | for i := len(s.parents) - 1; i >= commonParents; i-- { |
| 1159 | if err := s.p.writeEnd(Name{ |
| 1160 | Space: s.xmlns, |
| 1161 | Local: s.parents[i], |
| 1162 | }); err != nil { |
| 1163 | return err |
| 1164 | } |
| 1165 | } |
| 1166 | s.parents = finfo.parents |
| 1167 | s.xmlns = xmlns |
| 1168 | if commonParents >= len(s.parents) { |
| 1169 | // No new elements to push. |
| 1170 | return nil |
| 1171 | } |
| 1172 | if (vf.Kind() == reflect.Ptr || vf.Kind() == reflect.Interface) && vf.IsNil() { |
| 1173 | // The element is nil, so no need for the start elements. |
| 1174 | s.parents = s.parents[:commonParents] |
| 1175 | return nil |
| 1176 | } |
| 1177 | // Push any new parents required. |
| 1178 | for _, name := range s.parents[commonParents:] { |
| 1179 | start := &StartElement{ |
| 1180 | Name: Name{ |
| 1181 | Space: s.xmlns, |
| 1182 | Local: name, |
| 1183 | }, |
| 1184 | } |
| 1185 | // Set the default name space for parent elements |
| 1186 | // to match what we do with other elements. |
| 1187 | if s.xmlns != s.p.defaultNS { |
| 1188 | start.setDefaultNamespace() |
| 1189 | } |
| 1190 | if err := s.p.writeStart(start); err != nil { |
| 1191 | return err |
| 1192 | } |
| 1193 | } |
| 1194 | return nil |
| 1195 | } |
| 1196 | |
| 1197 | // A MarshalXMLError is returned when Marshal encounters a type |
| 1198 | // that cannot be converted into XML. |
| 1199 | type UnsupportedTypeError struct { |
| 1200 | Type reflect.Type |
| 1201 | } |
| 1202 | |
| 1203 | func (e *UnsupportedTypeError) Error() string { |
| 1204 | return "xml: unsupported type: " + e.Type.String() |
| 1205 | } |
| 1206 | |
| 1207 | func isEmptyValue(v reflect.Value) bool { |
| 1208 | switch v.Kind() { |
| 1209 | case reflect.Array, reflect.Map, reflect.Slice, reflect.String: |
| 1210 | return v.Len() == 0 |
| 1211 | case reflect.Bool: |
| 1212 | return !v.Bool() |
| 1213 | case reflect.Int, reflect.Int8, reflect.Int16, reflect.Int32, reflect.Int64: |
| 1214 | return v.Int() == 0 |
| 1215 | case reflect.Uint, reflect.Uint8, reflect.Uint16, reflect.Uint32, reflect.Uint64, reflect.Uintptr: |
| 1216 | return v.Uint() == 0 |
| 1217 | case reflect.Float32, reflect.Float64: |
| 1218 | return v.Float() == 0 |
| 1219 | case reflect.Interface, reflect.Ptr: |
| 1220 | return v.IsNil() |
| 1221 | } |
| 1222 | return false |
| 1223 | } |