mcs/class/System.Xml.Linq/System.Xml.Linq/XElement.cs

   1 //
   2 // Authors:
   3 //   Atsushi Enomoto
   4 //
   5 // Copyright 2007 Novell (http://www.novell.com)
   6 //
   7 // Permission is hereby granted, free of charge, to any person obtaining
   8 // a copy of this software and associated documentation files (the
   9 // "Software"), to deal in the Software without restriction, including
  10 // without limitation the rights to use, copy, modify, merge, publish,
  11 // distribute, sublicense, and/or sell copies of the Software, and to
  12 // permit persons to whom the Software is furnished to do so, subject to
  13 // the following conditions:
  14 //
  15 // The above copyright notice and this permission notice shall be
  16 // included in all copies or substantial portions of the Software.
  17 //
  18 // THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
  19 // EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
  20 // MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
  21 // NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
  22 // LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
  23 // OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
  24 // WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
  25 //
  26
  27 using System;
  28 using System.Collections;
  29 using System.Collections.Generic;
  30 using System.IO;
  31 using System.Text;
  32 using System.Xml;
  33 using System.Xml.Schema;
  34 using System.Xml.Serialization;
  35
  36 namespace System.Xml.Linq
  37 {
  38         [XmlSchemaProvider (null, IsAny = true)]
  39         public class XElement : XContainer, IXmlSerializable
  40         {
  41                 static IEnumerable <XElement> emptySequence =
  42                         new List <XElement> ();
  43
  44                 public static IEnumerable <XElement> EmptySequence {
  45                         get { return emptySequence; }
  46                 }
  47
  48                 XName name;
  49                 XAttribute attr_first, attr_last;
  50                 bool explicit_is_empty = true;
  51
  52                 public XElement (XName name, object value)
  53                 {
  54                         this.name = name;
  55                         Add (value);
  56                 }
  57
  58                 public XElement (XElement source)
  59                 {
  60                         name = source.name;
  61                         Add (source.Attributes ());
  62                         Add (source.Nodes ());
  63                 }
  64
  65                 public XElement (XName name)
  66                 {
  67                         this.name = name;
  68                 }
  69
  70                 public XElement (XName name, params object [] contents)
  71                 {
  72                         this.name = name;
  73                         Add (contents);
  74                 }
  75
  76                 public XElement (XStreamingElement source)
  77                 {
  78                         this.name = source.Name;
  79                         Add (source.Contents);
  80                 }
  81
  82                 [CLSCompliant (false)]
  83                 public static explicit operator bool (XElement element)
  84                 {
  85                         if (element == null)
  86                                 throw new ArgumentNullException ("element");
  87                         return XUtil.ConvertToBoolean (element.Value);
  88                 }
  89
  90                 [CLSCompliant (false)]
  91                 public static explicit operator bool? (XElement element)
  92                 {
  93                         if (element == null)
  94                                 return null;
  95
  96                         return element.Value == null ? (bool?) null : XUtil.ConvertToBoolean (element.Value);
  97                 }
  98
  99                 [CLSCompliant (false)]
 100                 public static explicit operator DateTime (XElement element)
 101                 {
 102                         if (element == null)
 103                                 throw new ArgumentNullException ("element");
 104                         return XUtil.ToDateTime (element.Value);
 105                 }
 106
 107                 [CLSCompliant (false)]
 108                 public static explicit operator DateTime? (XElement element)
 109                 {
 110                         if (element == null)
 111                                 return null;
 112
 113                         return element.Value == null ? (DateTime?) null : XUtil.ToDateTime (element.Value);
 114                 }
 115
 116 #if !TARGET_JVM // Same as for System.Xml.XmlConvert.ToDateTimeOffset
 117
 118                 [CLSCompliant (false)]
 119                 public static explicit operator DateTimeOffset (XElement element)
 120                 {
 121                         if (element == null)
 122                                 throw new ArgumentNullException ("element");
 123                         return XmlConvert.ToDateTimeOffset (element.Value);
 124                 }
 125
 126                 [CLSCompliant (false)]
 127                 public static explicit operator DateTimeOffset? (XElement element)
 128                 {
 129                         if (element == null)
 130                                 return null;
 131
 132                         return element.Value == null ? (DateTimeOffset?) null : XmlConvert.ToDateTimeOffset (element.Value);
 133                 }
 134
 135 #endif
 136
 137                 [CLSCompliant (false)]
 138                 public static explicit operator decimal (XElement element)
 139                 {
 140                         if (element == null)
 141                                 throw new ArgumentNullException ("element");
 142                         return XmlConvert.ToDecimal (element.Value);
 143                 }
 144
 145                 [CLSCompliant (false)]
 146                 public static explicit operator decimal? (XElement element)
 147                 {
 148                         if (element == null)
 149                                 return null;
 150
 151                         return element.Value == null ? (decimal?) null : XmlConvert.ToDecimal (element.Value);
 152                 }
 153
 154                 [CLSCompliant (false)]
 155                 public static explicit operator double (XElement element)
 156                 {
 157                         if (element == null)
 158                                 throw new ArgumentNullException ("element");
 159                         return XmlConvert.ToDouble (element.Value);
 160                 }
 161
 162                 [CLSCompliant (false)]
 163                 public static explicit operator double? (XElement element)
 164                 {
 165                         if (element == null)
 166                                 return null;
 167
 168                         return element.Value == null ? (double?) null : XmlConvert.ToDouble (element.Value);
 169                 }
 170
 171                 [CLSCompliant (false)]
 172                 public static explicit operator float (XElement element)
 173                 {
 174                         if (element == null)
 175                                 throw new ArgumentNullException ("element");
 176                         return XmlConvert.ToSingle (element.Value);
 177                 }
 178
 179                 [CLSCompliant (false)]
 180                 public static explicit operator float? (XElement element)
 181                 {
 182                         if (element == null)
 183                                 return null;
 184
 185                         return element.Value == null ? (float?) null : XmlConvert.ToSingle (element.Value);
 186                 }
 187
 188                 [CLSCompliant (false)]
 189                 public static explicit operator Guid (XElement element)
 190                 {
 191                         if (element == null)
 192                                 throw new ArgumentNullException ("element");
 193                         return XmlConvert.ToGuid (element.Value);
 194                 }
 195
 196                 [CLSCompliant (false)]
 197                 public static explicit operator Guid? (XElement element)
 198                 {
 199                         if (element == null)
 200                                 return null;
 201
 202                         return element.Value == null ? (Guid?) null : XmlConvert.ToGuid (element.Value);
 203                 }
 204
 205                 [CLSCompliant (false)]
 206                 public static explicit operator int (XElement element)
 207                 {
 208                         if (element == null)
 209                                 throw new ArgumentNullException ("element");
 210                         return XmlConvert.ToInt32 (element.Value);
 211                 }
 212
 213                 [CLSCompliant (false)]
 214                 public static explicit operator int? (XElement element)
 215                 {
 216                         if (element == null)
 217                                 return null;
 218
 219                         return element.Value == null ? (int?) null : XmlConvert.ToInt32 (element.Value);
 220                 }
 221
 222                 [CLSCompliant (false)]
 223                 public static explicit operator long (XElement element)
 224                 {
 225                         if (element == null)
 226                                 throw new ArgumentNullException ("element");
 227                         return XmlConvert.ToInt64 (element.Value);
 228                 }
 229
 230                 [CLSCompliant (false)]
 231                 public static explicit operator long? (XElement element)
 232                 {
 233                         if (element == null)
 234                                 return null;
 235
 236                         return element.Value == null ? (long?) null : XmlConvert.ToInt64 (element.Value);
 237                 }
 238
 239                 [CLSCompliant (false)]
 240                 public static explicit operator uint (XElement element)
 241                 {
 242                         if (element == null)
 243                                 throw new ArgumentNullException ("element");
 244                         return XmlConvert.ToUInt32 (element.Value);
 245                 }
 246
 247                 [CLSCompliant (false)]
 248                 public static explicit operator uint? (XElement element)
 249                 {
 250                         if (element == null)
 251                                 return null;
 252
 253                         return element.Value == null ? (uint?) null : XmlConvert.ToUInt32 (element.Value);
 254                 }
 255
 256                 [CLSCompliant (false)]
 257                 public static explicit operator ulong (XElement element)
 258                 {
 259                         if (element == null)
 260                                 throw new ArgumentNullException ("element");
 261                         return XmlConvert.ToUInt64 (element.Value);
 262                 }
 263
 264                 [CLSCompliant (false)]
 265                 public static explicit operator ulong? (XElement element)
 266                 {
 267                         if (element == null)
 268                                 return null;
 269
 270                         return element.Value == null ? (ulong?) null : XmlConvert.ToUInt64 (element.Value);
 271                 }
 272
 273                 [CLSCompliant (false)]
 274                 public static explicit operator TimeSpan (XElement element)
 275                 {
 276                         if (element == null)
 277                                 throw new ArgumentNullException ("element");
 278                         return XmlConvert.ToTimeSpan (element.Value);
 279                 }
 280
 281                 [CLSCompliant (false)]
 282                 public static explicit operator TimeSpan? (XElement element)
 283                 {
 284                         if (element == null)
 285                                 return null;
 286
 287                         return element.Value == null ? (TimeSpan?) null : XmlConvert.ToTimeSpan (element.Value);
 288                 }
 289
 290                 [CLSCompliant (false)]
 291                 public static explicit operator string (XElement element)
 292                 {
 293                         if (element == null)
 294                                 return null;
 295
 296                         return element.Value;
 297                 }
 298
 299                 public XAttribute FirstAttribute {
 300                         get { return attr_first; }
 301                         internal set { attr_first = value; }
 302                 }
 303
 304                 public XAttribute LastAttribute {
 305                         get { return attr_last; }
 306                         internal set { attr_last = value; }
 307                 }
 308
 309                 public bool HasAttributes {
 310                         get { return attr_first != null; }
 311                 }
 312
 313                 public bool HasElements {
 314                         get {
 315                                 foreach (object o in Nodes ())
 316                                         if (o is XElement)
 317                                                 return true;
 318                                 return false;
 319                         }
 320                 }
 321
 322                 public bool IsEmpty {
 323                         get { return !Nodes ().GetEnumerator ().MoveNext () && explicit_is_empty; }
 324                         internal set { explicit_is_empty = value; }
 325                 }
 326
 327                 public XName Name {
 328                         get { return name; }
 329                         set {
 330                                 if (name == null)
 331                                         throw new ArgumentNullException ("value");
 332                                 name = value;
 333                         }
 334                 }
 335
 336                 public override XmlNodeType NodeType {
 337                         get { return XmlNodeType.Element; }
 338                 }
 339
 340                 public string Value {
 341                         get {
 342                                 StringBuilder sb = null;
 343                                 foreach (XNode n in Nodes ()) {
 344                                         if (sb == null)
 345                                                 sb = new StringBuilder ();
 346                                         if (n is XText)
 347                                                 sb.Append (((XText) n).Value);
 348                                         else if (n is XElement)
 349                                                 sb.Append (((XElement) n).Value);
 350                                 }
 351                                 return sb == null ? String.Empty : sb.ToString ();
 352                         }
 353                         set {
 354                                 RemoveNodes ();
 355                                 Add (value);
 356                         }
 357                 }
 358
 359                 IEnumerable <XElement> GetAncestorList (XName name, bool getMeIn)
 360                 {
 361                         List <XElement> list = new List <XElement> ();
 362                         if (getMeIn)
 363                                 list.Add (this);
 364                         for (XElement el = Parent as XElement; el != null; el = el.Parent as XElement)
 365                                 if (name == null || el.Name == name)
 366                                         list.Add (el);
 367                         return list;
 368                 }
 369
 370                 public XAttribute Attribute (XName name)
 371                 {
 372                         foreach (XAttribute a in Attributes ())
 373                                 if (a.Name == name)
 374                                         return a;
 375                         return null;
 376                 }
 377
 378                 public IEnumerable <XAttribute> Attributes ()
 379                 {
 380                         XAttribute next;
 381                         for (XAttribute a = attr_first; a != null; a = next) {
 382                                 next = a.NextAttribute;
 383                                 yield return a;
 384                         }
 385                 }
 386
 387                 // huh?
 388                 public IEnumerable <XAttribute> Attributes (XName name)
 389                 {
 390                         foreach (XAttribute a in Attributes ())
 391                                 if (a.Name == name)
 392                                         yield return a;
 393                 }
 394
 395                 static void DefineDefaultSettings (XmlReaderSettings settings, LoadOptions options)
 396                 {
 397 #if NET_2_1 && !MONOTOUCH
 398                         // 2.1 has a DtdProcessing property which defaults to DtdProcessing.Prohibit
 399                         settings.DtdProcessing = DtdProcessing.Parse;
 400 #else
 401                         settings.ProhibitDtd = false;
 402 #endif
 403
 404                         settings.IgnoreWhitespace = (options & LoadOptions.PreserveWhitespace) == 0;
 405                 }
 406
 407                 static XmlReaderSettings CreateDefaultSettings (LoadOptions options)
 408                 {
 409                         var settings = new XmlReaderSettings ();
 410                         DefineDefaultSettings (settings, options);
 411                         return settings;
 412                 }
 413
 414                 public static XElement Load (string uri)
 415                 {
 416                         return Load (uri, LoadOptions.None);
 417                 }
 418
 419                 public static XElement Load (string uri, LoadOptions options)
 420                 {
 421                         XmlReaderSettings s = CreateDefaultSettings (options);
 422
 423                         using (XmlReader r = XmlReader.Create (uri, s)) {
 424                                 return LoadCore (r, options);
 425                         }
 426                 }
 427
 428                 public static XElement Load (TextReader tr)
 429                 {
 430                         return Load (tr, LoadOptions.None);
 431                 }
 432
 433                 public static XElement Load (TextReader tr, LoadOptions options)
 434                 {
 435                         XmlReaderSettings s = CreateDefaultSettings (options);
 436
 437                         using (XmlReader r = XmlReader.Create (tr, s)) {
 438                                 return LoadCore (r, options);
 439                         }
 440                 }
 441
 442                 public static XElement Load (XmlReader reader)
 443                 {
 444                         return Load (reader, LoadOptions.None);
 445                 }
 446
 447                 public static XElement Load (XmlReader reader, LoadOptions options)
 448                 {
 449                         XmlReaderSettings s = reader.Settings != null ? reader.Settings.Clone () : new XmlReaderSettings ();
 450                         DefineDefaultSettings (s, options);
 451
 452                         using (XmlReader r = XmlReader.Create (reader, s)) {
 453                                 return LoadCore (r, options);
 454                         }
 455                 }
 456
 457                 internal static XElement LoadCore (XmlReader r, LoadOptions options)
 458                 {
 459                         r.MoveToContent ();
 460                         if (r.NodeType != XmlNodeType.Element)
 461                                 throw new InvalidOperationException ("The XmlReader must be positioned at an element");
 462                         XName name = XName.Get (r.LocalName, r.NamespaceURI);
 463                         XElement e = new XElement (name);
 464                         e.FillLineInfoAndBaseUri (r, options);
 465
 466                         if (r.MoveToFirstAttribute ()) {
 467                                 do {
 468                                         // not sure how current Orcas behavior makes sense here though ...
 469                                         if (r.LocalName == "xmlns" && r.NamespaceURI == XNamespace.Xmlns.NamespaceName)
 470                                                 e.SetAttributeValue (XNamespace.None.GetName ("xmlns"), r.Value);
 471                                         else
 472                                                 e.SetAttributeValue (XName.Get (r.LocalName, r.NamespaceURI), r.Value);
 473                                         e.LastAttribute.FillLineInfoAndBaseUri (r, options);
 474                                 } while (r.MoveToNextAttribute ());
 475                                 r.MoveToElement ();
 476                         }
 477                         if (!r.IsEmptyElement) {
 478                                 r.Read ();
 479                                 e.ReadContentFrom (r, options);
 480                                 r.ReadEndElement ();
 481                                 e.explicit_is_empty = false;
 482                         } else {
 483                                 e.explicit_is_empty = true;
 484                                 r.Read ();
 485                         }
 486                         return e;
 487                 }
 488
 489                 public static XElement Parse (string s)
 490                 {
 491                         return Parse (s, LoadOptions.None);
 492                 }
 493
 494                 public static XElement Parse (string s, LoadOptions options)
 495                 {
 496                         return Load (new StringReader (s), options);
 497                 }
 498
 499                 public void RemoveAll ()
 500                 {
 501                         RemoveAttributes ();
 502                         RemoveNodes ();
 503                 }
 504
 505                 public void RemoveAttributes ()
 506                 {
 507                         while (attr_first != null)
 508                                 attr_last.Remove ();
 509                 }
 510
 511                 public void Save (string filename)
 512                 {
 513                         Save (filename, SaveOptions.None);
 514                 }
 515
 516                 public void Save (string filename, SaveOptions options)
 517                 {
 518                         XmlWriterSettings s = new XmlWriterSettings ();
 519
 520                         if ((options & SaveOptions.DisableFormatting) == SaveOptions.None)
 521                                 s.Indent = true;
 522 #if NET_4_0
 523                         if ((options & SaveOptions.OmitDuplicateNamespaces) == SaveOptions.OmitDuplicateNamespaces)
 524                                 s.NamespaceHandling |= NamespaceHandling.OmitDuplicates;
 525 #endif
 526                         using (XmlWriter w = XmlWriter.Create (filename, s)) {
 527                                 Save (w);
 528                         }
 529                 }
 530
 531                 public void Save (TextWriter tw)
 532                 {
 533                         Save (tw, SaveOptions.None);
 534                 }
 535
 536                 public void Save (TextWriter tw, SaveOptions options)
 537                 {
 538                         XmlWriterSettings s = new XmlWriterSettings ();
 539
 540                         if ((options & SaveOptions.DisableFormatting) == SaveOptions.None)
 541                                 s.Indent = true;
 542 #if NET_4_0
 543                         if ((options & SaveOptions.OmitDuplicateNamespaces) == SaveOptions.OmitDuplicateNamespaces)
 544                                 s.NamespaceHandling |= NamespaceHandling.OmitDuplicates;
 545 #endif
 546                         using (XmlWriter w = XmlWriter.Create (tw, s)) {
 547                                 Save (w);
 548                         }
 549                 }
 550
 551                 public void Save (XmlWriter w)
 552                 {
 553                         WriteTo (w);
 554                 }
 555
 556 #if NET_4_0
 557                 public void Save (Stream stream)
 558                 {
 559                         Save (stream, SaveOptions.None);
 560                 }
 561
 562                 public void Save (Stream stream, SaveOptions options)
 563                 {
 564                         XmlWriterSettings s = new XmlWriterSettings ();
 565                         if ((options & SaveOptions.DisableFormatting) == SaveOptions.None)
 566                                 s.Indent = true;
 567                         if ((options & SaveOptions.OmitDuplicateNamespaces) == SaveOptions.OmitDuplicateNamespaces)
 568                                 s.NamespaceHandling |= NamespaceHandling.OmitDuplicates;
 569
 570                         using (var writer = XmlWriter.Create (stream, s)){
 571                                 Save (writer);
 572                         }
 573                 }
 574 #endif
 575                 public IEnumerable <XElement> AncestorsAndSelf ()
 576                 {
 577                         return GetAncestorList (null, true);
 578                 }
 579
 580                 public IEnumerable <XElement> AncestorsAndSelf (XName name)
 581                 {
 582                         return GetAncestorList (name, true);
 583                 }
 584
 585                 public IEnumerable <XElement> DescendantsAndSelf ()
 586                 {
 587                         List <XElement> list = new List <XElement> ();
 588                         list.Add (this);
 589                         list.AddRange (Descendants ());
 590                         return list;
 591                 }
 592
 593                 public IEnumerable <XElement> DescendantsAndSelf (XName name)
 594                 {
 595                         List <XElement> list = new List <XElement> ();
 596                         if (name == this.name)
 597                                 list.Add (this);
 598                         list.AddRange (Descendants (name));
 599                         return list;
 600                 }
 601
 602                 public IEnumerable <XNode> DescendantNodesAndSelf ()
 603                 {
 604                         yield return this;
 605                         foreach (XNode node in DescendantNodes ())
 606                                 yield return node;
 607                 }
 608
 609                 public void SetAttributeValue (XName name, object value)
 610                 {
 611                         XAttribute a = Attribute (name);
 612                         if (value == null) {
 613                                 if (a != null)
 614                                         a.Remove ();
 615                         } else {
 616                                 if (a == null) {
 617                                         SetAttributeObject (new XAttribute (name, value));
 618                                 }
 619                                 else
 620                                         a.Value = XUtil.ToString (value);
 621                         }
 622                 }
 623
 624                 void SetAttributeObject (XAttribute a)
 625                 {
 626                         a = (XAttribute) XUtil.GetDetachedObject (a);
 627                         a.SetOwner (this);
 628                         if (attr_first == null) {
 629                                 attr_first = a;
 630                                 attr_last = a;
 631                         } else {
 632                                 attr_last.NextAttribute = a;
 633                                 a.PreviousAttribute = attr_last;
 634                                 attr_last = a;
 635                         }
 636                 }
 637
 638                 public override void WriteTo (XmlWriter w)
 639                 {
 640                         // some people expect the same prefix output as in input,
 641                         // in the loss of performance... see bug #466423.
 642                         string prefix = name.NamespaceName.Length > 0 ? w.LookupPrefix (name.Namespace.NamespaceName) : String.Empty;
 643                         foreach (XAttribute a in Attributes ()) {
 644                                 if (a.IsNamespaceDeclaration && a.Value == name.Namespace.NamespaceName) {
 645                                         if (a.Name.Namespace == XNamespace.Xmlns)
 646                                                 prefix = a.Name.LocalName;
 647                                         // otherwise xmlns="..."
 648                                         break;
 649                                 }
 650                         }
 651
 652                         w.WriteStartElement (prefix, name.LocalName, name.Namespace.NamespaceName);
 653
 654                         foreach (XAttribute a in Attributes ()) {
 655                                 if (a.IsNamespaceDeclaration) {
 656                                         if (a.Name.Namespace == XNamespace.Xmlns)
 657                                                 w.WriteAttributeString ("xmlns", a.Name.LocalName, XNamespace.Xmlns.NamespaceName, a.Value);
 658                                         else
 659                                                 w.WriteAttributeString ("xmlns", a.Value);
 660                                 }
 661                                 else
 662                                         w.WriteAttributeString (a.Name.LocalName, a.Name.Namespace.NamespaceName, a.Value);
 663                         }
 664
 665                         foreach (XNode node in Nodes ())
 666                                 node.WriteTo (w);
 667
 668                         if (explicit_is_empty)
 669                                 w.WriteEndElement ();
 670                         else
 671                                 w.WriteFullEndElement ();
 672                 }
 673
 674                 public XNamespace GetDefaultNamespace ()
 675                 {
 676                         for (XElement el = this; el != null; el = el.Parent)
 677                                 foreach (XAttribute a in el.Attributes ())
 678                                         if (a.IsNamespaceDeclaration && a.Name.Namespace == XNamespace.None)
 679                                                 return XNamespace.Get (a.Value);
 680                         return XNamespace.None; // nothing is declared.
 681                 }
 682
 683                 public XNamespace GetNamespaceOfPrefix (string prefix)
 684                 {
 685                         for (XElement el = this; el != null; el = el.Parent)
 686                                 foreach (XAttribute a in el.Attributes ())
 687                                         if (a.IsNamespaceDeclaration && (prefix.Length == 0 && a.Name.LocalName == "xmlns" || a.Name.LocalName == prefix))
 688                                                 return XNamespace.Get (a.Value);
 689                         return XNamespace.None; // nothing is declared.
 690                 }
 691
 692                 public string GetPrefixOfNamespace (XNamespace ns)
 693                 {
 694                         foreach (string prefix in GetPrefixOfNamespaceCore (ns))
 695                                 if (GetNamespaceOfPrefix (prefix) == ns)
 696                                         return prefix;
 697                         return null; // nothing is declared
 698                 }
 699
 700                 IEnumerable<string> GetPrefixOfNamespaceCore (XNamespace ns)
 701                 {
 702                         for (XElement el = this; el != null; el = el.Parent)
 703                                 foreach (XAttribute a in el.Attributes ())
 704                                         if (a.IsNamespaceDeclaration && a.Value == ns.NamespaceName)
 705                                                 yield return a.Name.Namespace == XNamespace.None ? String.Empty : a.Name.LocalName;
 706                 }
 707
 708                 public void ReplaceAll (object item)
 709                 {
 710                         RemoveNodes ();
 711                         Add (item);
 712                 }
 713
 714                 public void ReplaceAll (params object [] items)
 715                 {
 716                         RemoveNodes ();
 717                         Add (items);
 718                 }
 719
 720                 public void ReplaceAttributes (object item)
 721                 {
 722                         RemoveAttributes ();
 723                         Add (item);
 724                 }
 725
 726                 public void ReplaceAttributes (params object [] items)
 727                 {
 728                         RemoveAttributes ();
 729                         Add (items);
 730                 }
 731
 732                 public void SetElementValue (XName name, object value)
 733                 {
 734                         XElement el = new XElement (name, value);
 735                         RemoveNodes ();
 736                         Add (el);
 737                 }
 738
 739                 public void SetValue (object value)
 740                 {
 741                         if (value == null)
 742                                 throw new ArgumentNullException ("value");
 743                         if (value is XAttribute || value is XDocument || value is XDeclaration || value is XDocumentType)
 744                                 throw new ArgumentException (String.Format ("Node type {0} is not allowed as element value", value.GetType ()));
 745                         RemoveNodes ();
 746                         foreach (object o in XUtil.ExpandArray (value))
 747                                 Add (o);
 748                 }
 749
 750                 internal override bool OnAddingObject (object o, bool rejectAttribute, XNode refNode, bool addFirst)
 751                 {
 752                         if (o is XDocument || o is XDocumentType || o is XDeclaration || (rejectAttribute && o is XAttribute))
 753                                 throw new ArgumentException (String.Format ("A node of type {0} cannot be added as a content", o.GetType ()));
 754
 755                         XAttribute a = o as XAttribute;
 756                         if (a != null) {
 757                                 foreach (XAttribute ia in Attributes ())
 758                                         if (a.Name == ia.Name)
 759                                                 throw new InvalidOperationException (String.Format ("Duplicate attribute: {0}", a.Name));
 760                                 SetAttributeObject (a);
 761                                 return true;
 762                         }
 763                         else if (o is string && refNode is XText) {
 764                                 ((XText) refNode).Value += o as string;
 765                                 return true;
 766                         }
 767                         else
 768                                 return false;
 769                 }
 770
 771                 void IXmlSerializable.WriteXml (XmlWriter writer)
 772                 {
 773                         Save (writer);
 774                 }
 775
 776                 void IXmlSerializable.ReadXml (XmlReader reader)
 777                 {
 778                         ReadContentFrom (reader, LoadOptions.None);
 779                 }
 780
 781                 XmlSchema IXmlSerializable.GetSchema ()
 782                 {
 783                         return null;
 784                 }
 785         }
 786 }