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                 public XElement (XStreamingElement source)
  76                 {
  77                         this.name = source.Name;
  78                         Add (source.Contents);
  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.ProhibitDtd = false;
 360                         s.IgnoreWhitespace = (options & LoadOptions.PreserveWhitespace) == 0;
 361                         using (XmlReader r = XmlReader.Create (uri, s)) {
 362                                 return LoadCore (r, options);
 363                         }
 364                 }
 365
 366                 public static XElement Load (TextReader tr)
 367                 {
 368                         return Load (tr, LoadOptions.None);
 369                 }
 370
 371                 public static XElement Load (TextReader tr, LoadOptions options)
 372                 {
 373                         XmlReaderSettings s = new XmlReaderSettings ();
 374                         s.ProhibitDtd = false;
 375                         s.IgnoreWhitespace = (options & LoadOptions.PreserveWhitespace) == 0;
 376                         using (XmlReader r = XmlReader.Create (tr, s)) {
 377                                 return LoadCore (r, options);
 378                         }
 379                 }
 380
 381                 public static XElement Load (XmlReader reader)
 382                 {
 383                         return Load (reader, LoadOptions.None);
 384                 }
 385
 386                 public static XElement Load (XmlReader reader, LoadOptions options)
 387                 {
 388                         XmlReaderSettings s = reader.Settings.Clone ();
 389                         s.ProhibitDtd = false;
 390                         s.IgnoreWhitespace = (options & LoadOptions.PreserveWhitespace) == 0;
 391                         using (XmlReader r = XmlReader.Create (reader, s)) {
 392                                 return LoadCore (r, options);
 393                         }
 394                 }
 395
 396                 static XElement LoadCore (XmlReader r, LoadOptions options)
 397                 {
 398                         r.MoveToContent ();
 399                         if (r.NodeType != XmlNodeType.Element)
 400                                 throw new InvalidOperationException ("The XmlReader must be positioned at an element");
 401                         XName name = XName.Get (r.LocalName, r.NamespaceURI);
 402                         XElement e = new XElement (name);
 403                         e.FillLineInfoAndBaseUri (r, options);
 404
 405                         if (r.MoveToFirstAttribute ()) {
 406                                 do {
 407                                         // not sure how current Orcas behavior makes sense here though ...
 408                                         if (r.LocalName == "xmlns" && r.NamespaceURI == XNamespace.Xmlns.NamespaceName)
 409                                                 e.SetAttributeValue (XNamespace.None.GetName ("xmlns"), r.Value);
 410                                         else
 411                                                 e.SetAttributeValue (XName.Get (r.LocalName, r.NamespaceURI), r.Value);
 412                                         e.LastAttribute.FillLineInfoAndBaseUri (r, options);
 413                                 } while (r.MoveToNextAttribute ());
 414                                 r.MoveToElement ();
 415                         }
 416                         if (!r.IsEmptyElement) {
 417                                 r.Read ();
 418                                 e.ReadContentFrom (r, options);
 419                                 r.ReadEndElement ();
 420                                 e.explicit_is_empty = false;
 421                         } else {
 422                                 e.explicit_is_empty = true;
 423                                 r.Read ();
 424                         }
 425                         return e;
 426                 }
 427
 428                 public static XElement Parse (string s)
 429                 {
 430                         return Parse (s, LoadOptions.None);
 431                 }
 432
 433                 public static XElement Parse (string s, LoadOptions options)
 434                 {
 435                         return Load (new StringReader (s), options);
 436                 }
 437
 438                 public void RemoveAll ()
 439                 {
 440                         RemoveAttributes ();
 441                         RemoveNodes ();
 442                 }
 443
 444                 public void RemoveAttributes ()
 445                 {
 446                         while (attr_first != null)
 447                                 attr_last.Remove ();
 448                 }
 449
 450                 public void Save (string filename)
 451                 {
 452                         Save (filename, SaveOptions.None);
 453                 }
 454
 455                 public void Save (string filename, SaveOptions options)
 456                 {
 457                         XmlWriterSettings s = new XmlWriterSettings ();
 458                         s.Indent = options != SaveOptions.DisableFormatting;
 459                         using (XmlWriter w = XmlWriter.Create (filename, s)) {
 460                                 Save (w);
 461                         }
 462                 }
 463
 464                 public void Save (TextWriter tw)
 465                 {
 466                         Save (tw, SaveOptions.None);
 467                 }
 468
 469                 public void Save (TextWriter tw, SaveOptions options)
 470                 {
 471                         XmlWriterSettings s = new XmlWriterSettings ();
 472                         s.Indent = options != SaveOptions.DisableFormatting;
 473                         using (XmlWriter w = XmlWriter.Create (tw, s)) {
 474                                 Save (w);
 475                         }
 476                 }
 477
 478                 public void Save (XmlWriter w)
 479                 {
 480                         WriteTo (w);
 481                 }
 482
 483                 public IEnumerable <XElement> AncestorsAndSelf ()
 484                 {
 485                         return GetAncestorList (null, true);
 486                 }
 487
 488                 public IEnumerable <XElement> AncestorsAndSelf (XName name)
 489                 {
 490                         return GetAncestorList (name, true);
 491                 }
 492
 493                 public IEnumerable <XElement> DescendantsAndSelf ()
 494                 {
 495                         List <XElement> list = new List <XElement> ();
 496                         list.Add (this);
 497                         list.AddRange (Descendants ());
 498                         return list;
 499                 }
 500
 501                 public IEnumerable <XElement> DescendantsAndSelf (XName name)
 502                 {
 503                         List <XElement> list = new List <XElement> ();
 504                         if (name == this.name)
 505                                 list.Add (this);
 506                         list.AddRange (Descendants (name));
 507                         return list;
 508                 }
 509
 510                 public IEnumerable <XNode> DescendantNodesAndSelf ()
 511                 {
 512                         yield return this;
 513                         foreach (XNode node in DescendantNodes ())
 514                                 yield return node;
 515                 }
 516
 517                 public void SetAttributeValue (XName name, object value)
 518                 {
 519                         XAttribute a = Attribute (name);
 520                         if (value == null) {
 521                                 if (a != null)
 522                                         a.Remove ();
 523                         } else {
 524                                 if (a == null) {
 525                                         a = new XAttribute (name, value);
 526                                         a.SetOwner (this);
 527                                         if (attr_first == null) {
 528                                                 attr_first = a;
 529                                                 attr_last = a;
 530                                         } else {
 531                                                 attr_last.NextAttribute = a;
 532                                                 a.PreviousAttribute = attr_last;
 533                                                 attr_last = a;
 534                                         }
 535                                 }
 536                                 else
 537                                         a.Value = XUtil.ToString (value);
 538                         }
 539                 }
 540
 541                 public override void WriteTo (XmlWriter w)
 542                 {
 543                         w.WriteStartElement (name.LocalName, name.Namespace.NamespaceName);
 544
 545                         foreach (XAttribute a in Attributes ()) {
 546                                 if (a.IsNamespaceDeclaration) {
 547                                         if (a.Name.Namespace == XNamespace.Xmlns)
 548                                                 w.WriteAttributeString ("xmlns", a.Name.LocalName, XNamespace.Xmlns.NamespaceName, a.Value);
 549                                         else
 550                                                 w.WriteAttributeString ("xmlns", a.Value);
 551                                 }
 552                                 else
 553                                         w.WriteAttributeString (a.Name.LocalName, a.Name.Namespace.NamespaceName, a.Value);
 554                         }
 555
 556                         foreach (XNode node in Nodes ())
 557                                 node.WriteTo (w);
 558
 559                         if (explicit_is_empty)
 560                                 w.WriteEndElement ();
 561                         else
 562                                 w.WriteFullEndElement ();
 563                 }
 564
 565                 public XNamespace GetDefaultNamespace ()
 566                 {
 567                         for (XElement el = this; el != null; el = el.Parent)
 568                                 foreach (XAttribute a in el.Attributes ())
 569                                         if (a.IsNamespaceDeclaration && a.Name.Namespace == XNamespace.None)
 570                                                 return XNamespace.Get (a.Value);
 571                         return XNamespace.None; // nothing is declared.
 572                 }
 573
 574                 public XNamespace GetNamespaceOfPrefix (string prefix)
 575                 {
 576                         for (XElement el = this; el != null; el = el.Parent)
 577                                 foreach (XAttribute a in el.Attributes ())
 578                                         if (a.IsNamespaceDeclaration && a.Name.LocalName == prefix)
 579                                                 return XNamespace.Get (a.Value);
 580                         return XNamespace.None; // nothing is declared.
 581                 }
 582
 583                 public string GetPrefixOfNamespace (XNamespace ns)
 584                 {
 585                         foreach (string prefix in GetPrefixOfNamespaceCore (ns))
 586                                 if (GetNamespaceOfPrefix (prefix) == ns)
 587                                         return prefix;
 588                         return null; // nothing is declared
 589                 }
 590
 591                 IEnumerable<string> GetPrefixOfNamespaceCore (XNamespace ns)
 592                 {
 593                         for (XElement el = this; el != null; el = el.Parent)
 594                                 foreach (XAttribute a in el.Attributes ())
 595                                         if (a.IsNamespaceDeclaration && a.Value == ns.NamespaceName)
 596                                                 yield return a.Name.Namespace == XNamespace.None ? String.Empty : a.Name.LocalName;
 597                 }
 598
 599                 public void ReplaceAll (object item)
 600                 {
 601                         RemoveNodes ();
 602                         Add (item);
 603                 }
 604
 605                 public void ReplaceAll (params object [] items)
 606                 {
 607                         RemoveNodes ();
 608                         Add (items);
 609                 }
 610
 611                 public void ReplaceAttributes (object item)
 612                 {
 613                         RemoveAttributes ();
 614                         Add (item);
 615                 }
 616
 617                 public void ReplaceAttributes (params object [] items)
 618                 {
 619                         RemoveAttributes ();
 620                         Add (items);
 621                 }
 622
 623                 public void SetElementValue (XName name, object value)
 624                 {
 625                         XElement el = new XElement (name, value);
 626                         RemoveNodes ();
 627                         Add (el);
 628                 }
 629
 630                 public void SetValue (object value)
 631                 {
 632                         RemoveNodes ();
 633                         foreach (XNode n in XUtil.ToNodes (value))
 634                                 Add (n);
 635                 }
 636
 637                 internal override void OnAdded (XNode node, bool addFirst)
 638                 {
 639                         if (node is XDocument || node is XDocumentType)
 640                                 throw new ArgumentException (String.Format ("A node of type {0} cannot be added as a content", node.GetType ()));
 641                 }
 642
 643                 void IXmlSerializable.WriteXml (XmlWriter writer)
 644                 {
 645                         Save (writer);
 646                 }
 647
 648                 void IXmlSerializable.ReadXml (XmlReader reader)
 649                 {
 650                         ReadContentFrom (reader, LoadOptions.None);
 651                 }
 652
 653                 XmlSchema IXmlSerializable.GetSchema ()
 654                 {
 655                         return null;
 656                 }
 657         }
 658 }