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.Nodes ());
  62                 }
  63
  64                 public XElement (XName name)
  65                 {
  66                         this.name = name;
  67                 }
  68
  69                 public XElement (XName name, params object [] contents)
  70                 {
  71                         this.name = name;
  72                         Add (contents);
  73                 }
  74
  75                 [MonoTODO ("finish")]
  76                 public XElement (XStreamingElement source)
  77                 {
  78                         this.name = source.Name;
  79                 }
  80
  81                 public static explicit operator bool (XElement element)
  82                 {
  83                         if (element == null)
  84                                 throw new ArgumentNullException ("element");
  85                         return XmlConvert.ToBoolean (element.Value);
  86                 }
  87
  88                 public static explicit operator bool? (XElement element)
  89                 {
  90                         if (element == null)
  91                                 return null;
  92
  93                         return element.Value == null ? (bool?) null : XmlConvert.ToBoolean (element.Value);
  94                 }
  95
  96                 public static explicit operator DateTime (XElement element)
  97                 {
  98                         if (element == null)
  99                                 throw new ArgumentNullException ("element");
 100                         return XmlConvert.ToDateTime (element.Value, XmlDateTimeSerializationMode.RoundtripKind);
 101                 }
 102
 103                 public static explicit operator DateTime? (XElement element)
 104                 {
 105                         if (element == null)
 106                                 return null;
 107
 108                         return element.Value == null ? (DateTime?) null : XmlConvert.ToDateTime (element.Value, XmlDateTimeSerializationMode.RoundtripKind);
 109                 }
 110
 111                 public static explicit operator decimal (XElement element)
 112                 {
 113                         if (element == null)
 114                                 throw new ArgumentNullException ("element");
 115                         return XmlConvert.ToDecimal (element.Value);
 116                 }
 117
 118                 public static explicit operator decimal? (XElement element)
 119                 {
 120                         if (element == null)
 121                                 return null;
 122
 123                         return element.Value == null ? (decimal?) null : XmlConvert.ToDecimal (element.Value);
 124                 }
 125
 126                 public static explicit operator double (XElement element)
 127                 {
 128                         if (element == null)
 129                                 throw new ArgumentNullException ("element");
 130                         return XmlConvert.ToDouble (element.Value);
 131                 }
 132
 133                 public static explicit operator double? (XElement element)
 134                 {
 135                         if (element == null)
 136                                 return null;
 137
 138                         return element.Value == null ? (double?) null : XmlConvert.ToDouble (element.Value);
 139                 }
 140
 141                 public static explicit operator float (XElement element)
 142                 {
 143                         if (element == null)
 144                                 throw new ArgumentNullException ("element");
 145                         return XmlConvert.ToSingle (element.Value);
 146                 }
 147
 148                 public static explicit operator float? (XElement element)
 149                 {
 150                         if (element == null)
 151                                 return null;
 152
 153                         return element.Value == null ? (float?) null : XmlConvert.ToSingle (element.Value);
 154                 }
 155
 156                 public static explicit operator Guid (XElement element)
 157                 {
 158                         if (element == null)
 159                                 throw new ArgumentNullException ("element");
 160                         return XmlConvert.ToGuid (element.Value);
 161                 }
 162
 163                 public static explicit operator Guid? (XElement element)
 164                 {
 165                         if (element == null)
 166                                 return null;
 167
 168                         return element.Value == null ? (Guid?) null : XmlConvert.ToGuid (element.Value);
 169                 }
 170
 171                 public static explicit operator int (XElement element)
 172                 {
 173                         if (element == null)
 174                                 throw new ArgumentNullException ("element");
 175                         return XmlConvert.ToInt32 (element.Value);
 176                 }
 177
 178                 public static explicit operator int? (XElement element)
 179                 {
 180                         if (element == null)
 181                                 return null;
 182
 183                         return element.Value == null ? (int?) null : XmlConvert.ToInt32 (element.Value);
 184                 }
 185
 186                 public static explicit operator long (XElement element)
 187                 {
 188                         if (element == null)
 189                                 throw new ArgumentNullException ("element");
 190                         return XmlConvert.ToInt64 (element.Value);
 191                 }
 192
 193                 public static explicit operator long? (XElement element)
 194                 {
 195                         if (element == null)
 196                                 return null;
 197
 198                         return element.Value == null ? (long?) null : XmlConvert.ToInt64 (element.Value);
 199                 }
 200
 201                 [CLSCompliant (false)]
 202                 public static explicit operator uint (XElement element)
 203                 {
 204                         if (element == null)
 205                                 throw new ArgumentNullException ("element");
 206                         return XmlConvert.ToUInt32 (element.Value);
 207                 }
 208
 209                 [CLSCompliant (false)]
 210                 public static explicit operator uint? (XElement element)
 211                 {
 212                         if (element == null)
 213                                 return null;
 214
 215                         return element.Value == null ? (uint?) null : XmlConvert.ToUInt32 (element.Value);
 216                 }
 217
 218                 [CLSCompliant (false)]
 219                 public static explicit operator ulong (XElement element)
 220                 {
 221                         if (element == null)
 222                                 throw new ArgumentNullException ("element");
 223                         return XmlConvert.ToUInt64 (element.Value);
 224                 }
 225
 226                 [CLSCompliant (false)]
 227                 public static explicit operator ulong? (XElement element)
 228                 {
 229                         if (element == null)
 230                                 return null;
 231
 232                         return element.Value == null ? (ulong?) null : XmlConvert.ToUInt64 (element.Value);
 233                 }
 234
 235                 public static explicit operator TimeSpan (XElement element)
 236                 {
 237                         if (element == null)
 238                                 throw new ArgumentNullException ("element");
 239                         return XmlConvert.ToTimeSpan (element.Value);
 240                 }
 241
 242                 public static explicit operator TimeSpan? (XElement element)
 243                 {
 244                         if (element == null)
 245                                 return null;
 246
 247                         return element.Value == null ? (TimeSpan?) null : XmlConvert.ToTimeSpan (element.Value);
 248                 }
 249
 250                 public static explicit operator string (XElement element)
 251                 {
 252                         if (element == null)
 253                                 return null;
 254
 255                         return element.Value;
 256                 }
 257
 258                 public XAttribute FirstAttribute {
 259                         get { return attr_first; }
 260                         internal set { attr_first = value; }
 261                 }
 262
 263                 public XAttribute LastAttribute {
 264                         get { return attr_last; }
 265                         internal set { attr_last = value; }
 266                 }
 267
 268                 public bool HasAttributes {
 269                         get { return attr_first != null; }
 270                 }
 271
 272                 public bool HasElements {
 273                         get {
 274                                 foreach (object o in Nodes ())
 275                                         if (o is XElement)
 276                                                 return true;
 277                                 return false;
 278                         }
 279                 }
 280
 281                 public bool IsEmpty {
 282                         get { return !Nodes ().GetEnumerator ().MoveNext () && explicit_is_empty; }
 283                         internal set { explicit_is_empty = value; }
 284                 }
 285
 286                 public XName Name {
 287                         get { return name; }
 288                         set {
 289                                 if (name == null)
 290                                         throw new ArgumentNullException ("value");
 291                                 name = value;
 292                         }
 293                 }
 294
 295                 public override XmlNodeType NodeType {
 296                         get { return XmlNodeType.Element; }
 297                 }
 298
 299                 public string Value {
 300                         get {
 301                                 StringBuilder sb = null;
 302                                 foreach (object s in Nodes ()) {
 303                                         if (sb == null)
 304                                                 sb = new StringBuilder ();
 305                                         sb.Append (s);
 306                                 }
 307                                 return sb == null ? String.Empty : sb.ToString ();
 308                         }
 309                         set {
 310                                 RemoveNodes ();
 311                                 Add (value);
 312                         }
 313                 }
 314
 315                 IEnumerable <XElement> GetAncestorList (XName name, bool getMeIn)
 316                 {
 317                         List <XElement> list = new List <XElement> ();
 318                         if (getMeIn)
 319                                 list.Add (this);
 320                         for (XElement el = Parent as XElement; el != null; el = el.Parent as XElement)
 321                                 if (name == null || el.Name == name)
 322                                         list.Add (el);
 323                         return list;
 324                 }
 325
 326                 public XAttribute Attribute (XName name)
 327                 {
 328                         foreach (XAttribute a in Attributes ())
 329                                 if (a.Name == name)
 330                                         return a;
 331                         return null;
 332                 }
 333
 334                 public IEnumerable <XAttribute> Attributes ()
 335                 {
 336                         XAttribute next;
 337                         for (XAttribute a = attr_first; a != null; a = next) {
 338                                 next = a.NextAttribute;
 339                                 yield return a;
 340                         }
 341                 }
 342
 343                 // huh?
 344                 public IEnumerable <XAttribute> Attributes (XName name)
 345                 {
 346                         foreach (XAttribute a in Attributes ())
 347                                 if (a.Name == name)
 348                                         yield return a;
 349                 }
 350
 351                 public static XElement Load (string uri)
 352                 {
 353                         return Load (uri, LoadOptions.None);
 354                 }
 355
 356                 public static XElement Load (string uri, LoadOptions options)
 357                 {
 358                         XmlReaderSettings s = new XmlReaderSettings ();
 359                         s.IgnoreWhitespace = (options & LoadOptions.PreserveWhitespace) == 0;
 360                         using (XmlReader r = XmlReader.Create (uri, s)) {
 361                                 return LoadCore (r, options);
 362                         }
 363                 }
 364
 365                 public static XElement Load (TextReader tr)
 366                 {
 367                         return Load (tr, LoadOptions.None);
 368                 }
 369
 370                 public static XElement Load (TextReader tr, LoadOptions options)
 371                 {
 372                         XmlReaderSettings s = new XmlReaderSettings ();
 373                         s.IgnoreWhitespace = (options & LoadOptions.PreserveWhitespace) == 0;
 374                         using (XmlReader r = XmlReader.Create (tr, s)) {
 375                                 return LoadCore (r, options);
 376                         }
 377                 }
 378
 379                 public static XElement Load (XmlReader reader)
 380                 {
 381                         return Load (reader, LoadOptions.None);
 382                 }
 383
 384                 public static XElement Load (XmlReader reader, LoadOptions options)
 385                 {
 386                         XmlReaderSettings s = reader.Settings.Clone ();
 387                         s.IgnoreWhitespace = (options & LoadOptions.PreserveWhitespace) == 0;
 388                         using (XmlReader r = XmlReader.Create (reader, s)) {
 389                                 return LoadCore (r, options);
 390                         }
 391                 }
 392
 393                 static XElement LoadCore (XmlReader r, LoadOptions options)
 394                 {
 395                         r.MoveToContent ();
 396                         if (r.NodeType != XmlNodeType.Element)
 397                                 throw new InvalidOperationException ("The XmlReader must be positioned at an element");
 398                         XName name = XName.Get (r.LocalName, r.NamespaceURI);
 399                         XElement e = new XElement (name);
 400                         e.FillLineInfoAndBaseUri (r, options);
 401
 402                         if (r.MoveToFirstAttribute ()) {
 403                                 do {
 404                                         // not sure how current Orcas behavior makes sense here though ...
 405                                         if (r.LocalName == "xmlns" && r.NamespaceURI == XNamespace.Xmlns.NamespaceName)
 406                                                 e.SetAttributeValue (XNamespace.None.GetName ("xmlns"), r.Value);
 407                                         else
 408                                                 e.SetAttributeValue (XName.Get (r.LocalName, r.NamespaceURI), r.Value);
 409                                         e.LastAttribute.FillLineInfoAndBaseUri (r, options);
 410                                 } while (r.MoveToNextAttribute ());
 411                                 r.MoveToElement ();
 412                         }
 413                         if (!r.IsEmptyElement) {
 414                                 r.Read ();
 415                                 e.ReadContentFrom (r, options);
 416                                 r.ReadEndElement ();
 417                                 e.explicit_is_empty = false;
 418                         } else {
 419                                 e.explicit_is_empty = true;
 420                                 r.Read ();
 421                         }
 422                         return e;
 423                 }
 424
 425                 public static XElement Parse (string s)
 426                 {
 427                         return Parse (s, LoadOptions.None);
 428                 }
 429
 430                 public static XElement Parse (string s, LoadOptions options)
 431                 {
 432                         return Load (new StringReader (s), options);
 433                 }
 434
 435                 public void RemoveAll ()
 436                 {
 437                         RemoveAttributes ();
 438                         RemoveNodes ();
 439                 }
 440
 441                 public void RemoveAttributes ()
 442                 {
 443                         while (attr_first != null)
 444                                 attr_last.Remove ();
 445                 }
 446
 447                 public void Save (string filename)
 448                 {
 449                         Save (filename, SaveOptions.None);
 450                 }
 451
 452                 public void Save (string filename, SaveOptions options)
 453                 {
 454                         XmlWriterSettings s = new XmlWriterSettings ();
 455                         if ((options & SaveOptions.DisableFormatting) != 0) {
 456                                 // hacky!
 457                                 s.Indent = true;
 458                                 s.IndentChars = String.Empty;
 459                                 s.NewLineChars = String.Empty;
 460                         }
 461                         using (XmlWriter w = XmlWriter.Create (filename)) {
 462                                 Save (w);
 463                         }
 464                 }
 465
 466                 public void Save (TextWriter tw)
 467                 {
 468                         Save (tw, SaveOptions.None);
 469                 }
 470
 471                 public void Save (TextWriter tw, SaveOptions options)
 472                 {
 473                         XmlWriterSettings s = new XmlWriterSettings ();
 474                         if ((options & SaveOptions.DisableFormatting) != 0) {
 475                                 // hacky!
 476                                 s.Indent = true;
 477                                 s.IndentChars = String.Empty;
 478                                 s.NewLineChars = String.Empty;
 479                         }
 480                         using (XmlWriter w = XmlWriter.Create (tw)) {
 481                                 Save (w);
 482                         }
 483                 }
 484
 485                 public void Save (XmlWriter w)
 486                 {
 487                         WriteTo (w);
 488                 }
 489
 490                 public IEnumerable <XElement> AncestorsAndSelf ()
 491                 {
 492                         return GetAncestorList (null, true);
 493                 }
 494
 495                 public IEnumerable <XElement> AncestorsAndSelf (XName name)
 496                 {
 497                         return GetAncestorList (name, true);
 498                 }
 499
 500                 public IEnumerable <XElement> DescendantsAndSelf ()
 501                 {
 502                         List <XElement> list = new List <XElement> ();
 503                         list.Add (this);
 504                         list.AddRange (Descendants ());
 505                         return list;
 506                 }
 507
 508                 public IEnumerable <XElement> DescendantsAndSelf (XName name)
 509                 {
 510                         List <XElement> list = new List <XElement> ();
 511                         if (name == this.name)
 512                                 list.Add (this);
 513                         list.AddRange (Descendants (name));
 514                         return list;
 515                 }
 516
 517                 public IEnumerable <XNode> DescendantNodesAndSelf ()
 518                 {
 519                         yield return this;
 520                         foreach (XNode node in DescendantNodes ())
 521                                 yield return node;
 522                 }
 523
 524                 public void SetAttributeValue (XName name, object value)
 525                 {
 526                         XAttribute a = Attribute (name);
 527                         if (value == null) {
 528                                 if (a != null)
 529                                         a.Remove ();
 530                         } else {
 531                                 if (a == null) {
 532                                         a = new XAttribute (name, value);
 533                                         a.SetOwner (this);
 534                                         if (attr_first == null) {
 535                                                 attr_first = a;
 536                                                 attr_last = a;
 537                                         } else {
 538                                                 attr_last.NextAttribute = a;
 539                                                 a.PreviousAttribute = attr_last;
 540                                                 attr_last = a;
 541                                         }
 542                                 }
 543                                 else
 544                                         a.Value = XUtil.ToString (value);
 545                         }
 546                 }
 547
 548                 public override void WriteTo (XmlWriter w)
 549                 {
 550                         w.WriteStartElement (name.LocalName, name.Namespace.NamespaceName);
 551
 552                         foreach (XAttribute a in Attributes ()) {
 553                                 if (a.IsNamespaceDeclaration) {
 554                                         if (a.Name.Namespace == XNamespace.Xmlns)
 555                                                 w.WriteAttributeString ("xmlns", a.Name.LocalName, XNamespace.Xmlns.NamespaceName, a.Value);
 556                                         else
 557                                                 w.WriteAttributeString ("xmlns", a.Value);
 558                                 }
 559                                 else
 560                                         w.WriteAttributeString (a.Name.LocalName, a.Name.Namespace.NamespaceName, a.Value);
 561                         }
 562
 563                         foreach (XNode node in Nodes ())
 564                                 node.WriteTo (w);
 565
 566                         if (explicit_is_empty)
 567                                 w.WriteEndElement ();
 568                         else
 569                                 w.WriteFullEndElement ();
 570                 }
 571
 572                 public XNamespace GetDefaultNamespace ()
 573                 {
 574                         for (XElement el = this; el != null; el = el.Parent)
 575                                 foreach (XAttribute a in el.Attributes ())
 576                                         if (a.IsNamespaceDeclaration && a.Name.Namespace == XNamespace.None)
 577                                                 return XNamespace.Get (a.Value);
 578                         return XNamespace.None; // nothing is declared.
 579                 }
 580
 581                 public XNamespace GetNamespaceOfPrefix (string prefix)
 582                 {
 583                         for (XElement el = this; el != null; el = el.Parent)
 584                                 foreach (XAttribute a in el.Attributes ())
 585                                         if (a.IsNamespaceDeclaration && a.Name.LocalName == prefix)
 586                                                 return XNamespace.Get (a.Value);
 587                         return XNamespace.None; // nothing is declared.
 588                 }
 589
 590                 public string GetPrefixOfNamespace (XNamespace ns)
 591                 {
 592                         foreach (string prefix in GetPrefixOfNamespaceCore (ns))
 593                                 if (GetNamespaceOfPrefix (prefix) == ns)
 594                                         return prefix;
 595                         return null; // nothing is declared
 596                 }
 597
 598                 IEnumerable<string> GetPrefixOfNamespaceCore (XNamespace ns)
 599                 {
 600                         for (XElement el = this; el != null; el = el.Parent)
 601                                 foreach (XAttribute a in el.Attributes ())
 602                                         if (a.IsNamespaceDeclaration && a.Value == ns.NamespaceName)
 603                                                 yield return a.Name.Namespace == XNamespace.None ? String.Empty : a.Name.LocalName;
 604                 }
 605
 606                 public void ReplaceAll (object item)
 607                 {
 608                         RemoveNodes ();
 609                         Add (item);
 610                 }
 611
 612                 public void ReplaceAll (params object [] items)
 613                 {
 614                         RemoveNodes ();
 615                         Add (items);
 616                 }
 617
 618                 public void ReplaceAttributes (object item)
 619                 {
 620                         RemoveAttributes ();
 621                         Add (item);
 622                 }
 623
 624                 public void ReplaceAttributes (params object [] items)
 625                 {
 626                         RemoveAttributes ();
 627                         Add (items);
 628                 }
 629
 630                 public void SetElementValue (XName name, object value)
 631                 {
 632                         XElement el = new XElement (name, value);
 633                         RemoveNodes ();
 634                         Add (el);
 635                 }
 636
 637                 public void SetValue (object value)
 638                 {
 639                         XNode n = XUtil.ToNode (value);
 640                         RemoveNodes ();
 641                         Add (n);
 642                 }
 643
 644                 internal override void OnAdded (XNode node, bool addFirst)
 645                 {
 646                         if (node is XDocument || node is XDocumentType)
 647                                 throw new ArgumentException (String.Format ("A node of type {0} cannot be added as a content", node.GetType ()));
 648                 }
 649
 650                 void IXmlSerializable.WriteXml (XmlWriter writer)
 651                 {
 652                         Save (writer);
 653                 }
 654
 655                 void IXmlSerializable.ReadXml (XmlReader reader)
 656                 {
 657                         ReadContentFrom (reader, LoadOptions.None);
 658                 }
 659
 660                 XmlSchema IXmlSerializable.GetSchema ()
 661                 {
 662                         return null;
 663                 }
 664         }
 665 }