khtml/dom/dom_element.h

   1 /*
   2  * This file is part of the DOM implementation for KDE.
   3  *
   4  * Copyright 1999 Lars Knoll (knoll@kde.org)
   5  *
   6  * This library is free software; you can redistribute it and/or
   7  * modify it under the terms of the GNU Library General Public
   8  * License as published by the Free Software Foundation; either
   9  * version 2 of the License, or (at your option) any later version.
  10  *
  11  * This library is distributed in the hope that it will be useful,
  12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  14  * Library General Public License for more details.
  15  *
  16  * You should have received a copy of the GNU Library General Public License
  17  * along with this library; see the file COPYING.LIB.  If not, write to
  18  * the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
  19  * Boston, MA 02110-1301, USA.
  20  *
  21  * This file includes excerpts from the Document Object Model (DOM)
  22  * Level 1 Specification (Recommendation)
  23  * http://www.w3.org/TR/REC-DOM-Level-1/
  24  * Copyright © World Wide Web Consortium , (Massachusetts Institute of
  25  * Technology , Institut National de Recherche en Informatique et en
  26  * Automatique , Keio University ). All Rights Reserved.
  27  *
  28  */
  29 #ifndef _DOM_ELEMENT_h_
  30 #define _DOM_ELEMENT_h_
  31
  32 #include <khtml_export.h>
  33 #include <dom/dom_node.h>
  34 #include <dom/css_value.h>
  35
  36 namespace DOM {
  37
  38 class DOMString;
  39 class AttrImpl;
  40 class Element;
  41 class ElementImpl;
  42 class NamedAttrMapImpl;
  43 class DocumentImpl;
  44
  45 /**
  46  * The \c Attr interface represents an attribute in an
  47  * \c Element object. Typically the allowable values for
  48  * the attribute are defined in a document type definition.
  49  *
  50  *  \c Attr objects inherit the \c Node
  51  * interface, but since they are not actually child nodes of the
  52  * element they describe, the DOM does not consider them part of the
  53  * document tree. Thus, the \c Node attributes
  54  * \c parentNode , \c previousSibling , and
  55  * \c nextSibling have a null value for \c Attr
  56  * objects. The DOM takes the view that attributes are properties of
  57  * elements rather than having a separate identity from the elements
  58  * they are associated with; this should make it more efficient to
  59  * implement such features as default attributes associated with all
  60  * elements of a given type. Furthermore, \c Attr nodes
  61  * may not be immediate children of a \c DocumentFragment
  62  * . However, they can be associated with \c Element nodes
  63  * contained within a \c DocumentFragment . In short,
  64  * users and implementors of the DOM need to be aware that \c Attr
  65  * nodes have some things in common with other objects
  66  * inheriting the \c Node interface, but they also are
  67  * quite distinct.
  68  *
  69  *  The attribute's effective value is determined as follows: if this
  70  * attribute has been explicitly assigned any value, that value is the
  71  * attribute's effective value; otherwise, if there is a declaration
  72  * for this attribute, and that declaration includes a default value,
  73  * then that default value is the attribute's effective value;
  74  * otherwise, the attribute does not exist on this element in the
  75  * structure model until it has been explicitly added. Note that the
  76  * \c nodeValue attribute on the \c Attr
  77  * instance can also be used to retrieve the string version of the
  78  * attribute's value(s).
  79  *
  80  *  In XML, where the value of an attribute can contain entity
  81  * references, the child nodes of the \c Attr node provide
  82  * a representation in which entity references are not expanded. These
  83  * child nodes may be either \c Text or
  84  * \c EntityReference nodes. Because the attribute type may be
  85  * unknown, there are no tokenized attribute values.
  86  *
  87  */
  88 class KHTML_EXPORT Attr : public Node
  89 {
  90     friend class Element;
  91     friend class Document;
  92     friend class DocumentImpl;
  93     friend class HTMLDocument;
  94     friend class ElementImpl;
  95     friend class NamedAttrMapImpl;
  96     friend class AttrImpl;
  97
  98 public:
  99     Attr();
 100     Attr(const Node &other) : Node()
 101         {(*this)=other;}
 102     Attr(const Attr &other);
 103
 104     Attr & operator = (const Node &other);
 105     Attr & operator = (const Attr &other);
 106
 107     ~Attr();
 108
 109     /**
 110      * Returns the name of this attribute.
 111      *
 112      */
 113     DOMString name() const;
 114
 115     /**
 116      * If this attribute was explicitly given a value in the original
 117      * document, this is \c true ; otherwise, it is
 118      * \c false . Note that the implementation is in charge of
 119      * this attribute, not the user. If the user changes the value of
 120      * the attribute (even if it ends up having the same value as the
 121      * default value) then the \c specified flag is
 122      * automatically flipped to \c true . To re-specify
 123      * the attribute as the default value from the DTD, the user must
 124      * delete the attribute. The implementation will then make a new
 125      * attribute available with \c specified set to
 126      * \c false and the default value (if one exists).
 127      *
 128      *  In summary:
 129      *  \li If the attribute has an assigned
 130      * value in the document then \c specified is
 131      * \c true , and the value is the assigned value.
 132      *
 133      *  \li If the attribute has no assigned value in the
 134      * document and has a default value in the DTD, then
 135      * \c specified is \c false , and the value is
 136      * the default value in the DTD.
 137      *
 138      *  \li If the attribute has no assigned value in the
 139      * document and has a value of #IMPLIED in the DTD, then the
 140      * attribute does not appear in the structure model of the
 141      * document.
 142      *
 143      *
 144      *
 145      */
 146     bool specified() const;
 147
 148     /**
 149      * On retrieval, the value of the attribute is returned as a
 150      * string. Character and general entity references are replaced
 151      * with their values.
 152      *
 153      *  On setting, this creates a \c Text node with the
 154      * unparsed contents of the string.
 155      *
 156      */
 157     DOMString value() const;
 158
 159     /**
 160      * see value
 161      */
 162     void setValue( const DOMString & );
 163
 164     /**
 165      * Introduced in DOM Level 2
 166      *
 167      * The Element node this attribute is attached to or null if this attribute
 168      * is not in use.
 169      */
 170     Element ownerElement() const;
 171
 172 protected:
 173
 174     Attr( AttrImpl *_impl );
 175 };
 176
 177 class NodeList;
 178 class Attr;
 179 class DOMString;
 180
 181 /**
 182  * By far the vast majority of objects (apart from text) that authors
 183  * encounter when traversing a document are \c Element
 184  * nodes. Assume the following XML document: &lt;elementExample
 185  * id=&quot;demo&quot;&gt; &lt;subelement1/&gt;
 186  * &lt;subelement2&gt;&lt;subsubelement/&gt;&lt;/subelement2&gt;
 187  * &lt;/elementExample&gt;
 188  *
 189  *  When represented using DOM, the top node is an \c Element
 190  * node for &quot;elementExample&quot;, which contains two
 191  * child \c Element nodes, one for &quot;subelement1&quot;
 192  * and one for &quot;subelement2&quot;. &quot;subelement1&quot;
 193  * contains no child nodes.
 194  *
 195  *  Elements may have attributes associated with them; since the
 196  * \c Element interface inherits from \c Node
 197  * , the generic \c Node interface method
 198  * \c getAttributes may be used to retrieve the set of all
 199  * attributes for an element. There are methods on the \c Element
 200  * interface to retrieve either an \c Attr object
 201  * by name or an attribute value by name. In XML, where an attribute
 202  * value may contain entity references, an \c Attr object
 203  * should be retrieved to examine the possibly fairly complex sub-tree
 204  * representing the attribute value. On the other hand, in HTML, where
 205  * all attributes have simple string values, methods to directly
 206  * access an attribute value can safely be used as a convenience.
 207  *
 208  */
 209 class KHTML_EXPORT Element : public Node
 210 {
 211     friend class Document;
 212     friend class HTMLDocument;
 213 //    friend class AttrImpl;
 214     friend class Attr;
 215
 216 public:
 217     Element();
 218     Element(const Node &other) : Node()
 219         {(*this)=other;}
 220     Element(const Element &other);
 221
 222     Element & operator = (const Node &other);
 223     Element & operator = (const Element &other);
 224
 225     ~Element();
 226
 227     /**
 228      * The name of the element. For example, in: &lt;elementExample
 229      * id=&quot;demo&quot;&gt; ... &lt;/elementExample&gt; ,
 230      * \c tagName has the value \c &quot;elementExample&quot;
 231      * . Note that this is case-preserving in XML, as are all
 232      * of the operations of the DOM. The HTML DOM returns the
 233      * \c tagName of an HTML element in the canonical uppercase
 234      * form, regardless of the case in the source HTML document.
 235      *
 236      */
 237     DOMString tagName() const;
 238
 239     /**
 240      * Retrieves an attribute value by name.
 241      *
 242      * @param name The name of the attribute to retrieve.
 243      *
 244      * @return The \c Attr value as a string, or the empty
 245      * string if that attribute does not have a specified or default
 246      * value.
 247      *
 248      */
 249     DOMString getAttribute ( const DOMString &name );
 250
 251     /**
 252      * Adds a new attribute. If an attribute with that name is already
 253      * present in the element, its value is changed to be that of the
 254      * value parameter. This value is a simple string, it is not
 255      * parsed as it is being set. So any markup (such as syntax to be
 256      * recognized as an entity reference) is treated as literal text,
 257      * and needs to be appropriately escaped by the implementation
 258      * when it is written out. In order to assign an attribute value
 259      * that contains entity references, the user must create an
 260      * \c Attr node plus any \c Text and
 261      * \c EntityReference nodes, build the appropriate subtree,
 262      * and use \c setAttributeNode to assign it as the
 263      * value of an attribute.
 264      *
 265      * @param name The name of the attribute to create or alter.
 266      *
 267      * @param value Value to set in string form.
 268      *
 269      * @return
 270      *
 271      * @exception DOMException
 272      * INVALID_CHARACTER_ERR: Raised if the specified name contains an
 273      * invalid character.
 274      *
 275      *  NO_MODIFICATION_ALLOWED_ERR: Raised if this node is readonly.
 276      *
 277      */
 278     void setAttribute ( const DOMString &name, const DOMString &value );
 279
 280     /**
 281      * Removes an attribute by name. If the removed attribute has a
 282      * default value it is immediately replaced.
 283      *
 284      * @param name The name of the attribute to remove.
 285      *
 286      * @return
 287      *
 288      * @exception DOMException
 289      * NO_MODIFICATION_ALLOWED_ERR: Raised if this node is readonly.
 290      *
 291      */
 292     void removeAttribute ( const DOMString &name );
 293
 294     /**
 295      * Retrieves an \c Attr node by name.
 296      *
 297      * @param name The name of the attribute to retrieve.
 298      *
 299      * @return The \c Attr node with the specified
 300      * attribute name or \c null if there is no such
 301      * attribute.
 302      *
 303      */
 304     Attr getAttributeNode ( const DOMString &name );
 305
 306     /**
 307      * Adds a new attribute. If an attribute with that name is already
 308      * present in the element, it is replaced by the new one.
 309      *
 310      * @param newAttr The \c Attr node to add to the
 311      * attribute list.
 312      *
 313      * @return If the \c newAttr attribute replaces an
 314      * existing attribute with the same name, the previously existing
 315      * \c Attr node is returned, otherwise \c null
 316      * is returned.
 317      *
 318      * @exception DOMException
 319      * WRONG_DOCUMENT_ERR: Raised if \c newAttr was
 320      * created from a different document than the one that created the
 321      * element.
 322      *
 323      *  NO_MODIFICATION_ALLOWED_ERR: Raised if this node is readonly.
 324      *
 325      *  INUSE_ATTRIBUTE_ERR: Raised if \c newAttr is
 326      * already an attribute of another \c Element object.
 327      * The DOM user must explicitly clone \c Attr nodes to
 328      * re-use them in other elements.
 329      *
 330      */
 331     Attr setAttributeNode ( const Attr &newAttr );
 332
 333     /**
 334      * Removes the specified attribute.
 335      *
 336      * @param oldAttr The \c Attr node to remove from the
 337      * attribute list. If the removed \c Attr has a
 338      * default value it is immediately replaced.
 339      *
 340      * @return The \c Attr node that was removed.
 341      *
 342      * @exception DOMException
 343      * NO_MODIFICATION_ALLOWED_ERR: Raised if this node is readonly.
 344      *
 345      *  NOT_FOUND_ERR: Raised if \c oldAttr is not an
 346      * attribute of the element.
 347      *
 348      */
 349     Attr removeAttributeNode ( const Attr &oldAttr );
 350
 351     /**
 352      * Returns a \c NodeList of all descendant elements
 353      * with a given tag name, in the order in which they would be
 354      * encountered in a preorder traversal of the \c Element
 355      * tree.
 356      *
 357      * @param name The name of the tag to match on. The special value
 358      * "*" matches all tags.
 359      *
 360      * @return A list of matching \c Element nodes.
 361      *
 362      */
 363     NodeList getElementsByTagName ( const DOMString &name );
 364
 365     /**
 366      * Introduced in DOM Level 2
 367      * Returns a NodeList of all the descendant Elements with a given local
 368      * name and namespace URI in the order in which they are encountered in a
 369      * preorder traversal of this Element tree.
 370      *
 371      * @param namespaceURI The namespace URI of the elements to match on. The
 372      * special value "*" matches all namespaces.
 373      *
 374      * @param localName The local name of the elements to match on. The special
 375      * value "*" matches all local names.
 376      *
 377      * @return A new NodeList object containing all the matched Elements.
 378      */
 379     NodeList getElementsByTagNameNS ( const DOMString &namespaceURI,
 380                                       const DOMString &localName );
 381
 382     /**
 383      * Introduced in HTML 5.
 384      * No Exceptions.
 385      *
 386      * Returns a \c NodeList of all the \c Element 's
 387      * with a given class name in the order in which they
 388      * would be encountered in a preorder traversal of the
 389      * \c Document tree.
 390      *
 391      * @param tagname An unordered set of unique space-separated
 392      * tokens representing classes.
 393      *
 394      * @return A new \c NodeList object containing all the
 395      * matched \c Element s.
 396      *
 397      * @since 4.1
 398      */
 399     NodeList getElementsByClassName ( const DOMString &className );
 400
 401     /**
 402      * Introduced in DOM Level 2.
 403      *
 404      * No Exceptions.
 405      *
 406      * Retrieves an attribute value by local name and namespace URI. HTML-only
 407      * DOM implementations do not need to implement this method.
 408      *
 409      * @param namespaceURI The namespace URI of the attribute to retrieve.
 410      *
 411      * @param localName The local name of the attribute to retrieve.
 412      *
 413      * @return The Attr value as a string, or the empty string if that
 414      * attribute does not have a specified or default value.
 415      */
 416     DOMString getAttributeNS ( const DOMString &namespaceURI,
 417                                const DOMString &localName );
 418
 419     /**
 420      * Introduced in DOM Level 2
 421      *
 422      * Adds a new attribute. If an attribute with the same local name and
 423      * namespace URI is already present on the element, its prefix is changed
 424      * to be the prefix part of the qualifiedName, and its value is changed to
 425      * be the value parameter. This value is a simple string; it is not parsed
 426      * as it is being set. So any markup (such as syntax to be recognized as an
 427      * entity reference) is treated as literal text, and needs to be
 428      * appropriately escaped by the implementation when it is written out. In
 429      * order to assign an attribute value that contains entity references, the
 430      * user must create an Attr node plus any Text and EntityReference nodes,
 431      * build the appropriate subtree, and use setAttributeNodeNS or
 432      * setAttributeNode to assign it as the value of an attribute.
 433      *
 434      * HTML-only DOM implementations do not need to implement this method.
 435      *
 436      * @param namespaceURI The namespace URI of the attribute to create or
 437      * alter.
 438      *
 439      * @param qualifiedName The qualified name of the attribute to create or
 440      * alter.
 441      *
 442      * @param value The value to set in string form.
 443      *
 444      * @exception DOMException
 445      * INVALID_CHARACTER_ERR: Raised if the specified qualified name contains
 446      * an illegal character.
 447      *
 448      * NO_MODIFICATION_ALLOWED_ERR: Raised if this node is readonly.
 449      *
 450      * NAMESPACE_ERR: Raised if the qualifiedName is malformed, if the
 451      * qualifiedName has a prefix and the namespaceURI is null, if the
 452      * qualifiedName has a prefix that is "xml" and the namespaceURI is
 453      * different from "http://www.w3.org/XML/1998/namespace", or if the
 454      * qualifiedName is "xmlns" and the namespaceURI is different from
 455      * "http://www.w3.org/2000/xmlns/".
 456      */
 457     void setAttributeNS ( const DOMString &namespaceURI,
 458                           const DOMString &qualifiedName,
 459                           const DOMString &value );
 460
 461     /**
 462      * Introduced in DOM Level 2
 463      *
 464      * Removes an attribute by local name and namespace URI. If the removed
 465      * attribute has a default value it is immediately replaced. The replacing
 466      * attribute has the same namespace URI and local name, as well as the
 467      * original prefix.
 468      *
 469      * HTML-only DOM implementations do not need to implement this method.
 470      *
 471      * @param namespaceURI The namespace URI of the attribute to remove.
 472      *
 473      * @param localName The local name of the attribute to remove.
 474      *
 475      * @exception DOMException
 476      * NO_MODIFICATION_ALLOWED_ERR: Raised if this node is readonly.
 477      */
 478     void removeAttributeNS ( const DOMString &namespaceURI,
 479                              const DOMString &localName );
 480
 481     /**
 482      * Introduced in DOM Level 2
 483      *
 484      * Retrieves an Attr node by local name and namespace URI. HTML-only DOM
 485      * implementations do not need to implement this method.
 486      *
 487      * @param namespaceURI The namespace URI of the attribute to retrieve.
 488      *
 489      * @param localName The local name of the attribute to retrieve.
 490      *
 491      * @return The Attr node with the specified attribute local name and
 492      * namespace URI or null if there is no such attribute.
 493      */
 494     Attr getAttributeNodeNS ( const DOMString &namespaceURI,
 495                               const DOMString &localName );
 496
 497     /**
 498      * Introduced in DOM Level 2
 499      *
 500      * Adds a new attribute. If an attribute with that local name and that
 501      * namespace URI is already present in the element, it is replaced by the
 502      * new one.
 503      *
 504      * HTML-only DOM implementations do not need to implement this method.
 505      *
 506      * @param newAttr The Attr node to add to the attribute list.
 507      *
 508      * @return If the newAttr attribute replaces an existing attribute with the
 509      * same local name and namespace URI, the replaced Attr node is returned,
 510      * otherwise null is returned.
 511      *
 512      * @exception DOMException
 513      * WRONG_DOCUMENT_ERR: Raised if newAttr was created from a different
 514      * document than the one that created the element.
 515      *
 516      * NO_MODIFICATION_ALLOWED_ERR: Raised if this node is readonly.
 517      *
 518      * INUSE_ATTRIBUTE_ERR: Raised if newAttr is already an attribute of
 519      * another Element object. The DOM user must explicitly clone Attr nodes to
 520      * re-use them in other elements.
 521      */
 522     Attr setAttributeNodeNS ( const Attr &newAttr );
 523
 524     /**
 525      * Returns true when an attribute with a given name is specified on this
 526      * element or has a default value, false otherwise.
 527      * Introduced in DOM Level 2.
 528      *
 529      * @param name The name of the attribute to look for.
 530      *
 531      * @return true if an attribute with the given name is specified on this
 532      * element or has a default value, false otherwise.
 533      */
 534     bool hasAttribute( const DOMString& name );
 535
 536     /**
 537      * Introduced in DOM Level 2
 538      *
 539      * Returns true when an attribute with a given local name and namespace URI
 540      * is specified on this element or has a default value, false otherwise.
 541      * HTML-only DOM implementations do not need to implement this method.
 542      *
 543      * @param namespaceURI The namespace URI of the attribute to look for.
 544      *
 545      * @param localName The local name of the attribute to look for.
 546      *
 547      * @return true if an attribute with the given local name and namespace URI
 548      * is specified or has a default value on this element, false otherwise.
 549      */
 550     bool hasAttributeNS ( const DOMString &namespaceURI,
 551                           const DOMString &localName );
 552
 553     /**
 554      * Introduced in DOM Level 2
 555      * This method is from the CSSStyleDeclaration interface
 556      *
 557      * The style attribute
 558      */
 559     CSSStyleDeclaration style (  );
 560
 561     /**
 562      * Introduced in  DOM level 3
 563      * This method is part of the ElementTraversal interface
 564      *
 565      *  The first child node which is of nodeType ELEMENT_NODE.
 566      *
 567      */
 568     Element firstElementChild ( ) const;
 569
 570     /**
 571      * Introduced in  DOM level 3
 572      * This method is part of the ElementTraversal interface
 573      *
 574      *  @return The last child node of that element which is of nodeType ELEMENT_NODE.
 575      *
 576      */
 577     Element lastElementChild ( ) const;
 578
 579     /**
 580      * Introduced in  DOM level 3
 581      * This method is part of the ElementTraversal interface
 582      *
 583      *  @return  The sibling node of that element which most immediately precedes that element in document order,
 584      *           and which is of nodeType ELEMENT_NODE
 585      *
 586      */
 587     Element previousElementSibling ( ) const;
 588
 589     /**
 590      * Introduced in  DOM level 3
 591      * This method is part of the ElementTraversal interface
 592      *
 593      *  @return  The sibling node of that element which most immediately follows that element in document order,
 594      *           and which is of nodeType ELEMENT_NODE
 595      *
 596      */
 597     Element nextElementSibling ( ) const;
 598
 599     /**
 600      * Introduced in  DOM level 3
 601      * This method is part of the ElementTraversal interface
 602      *
 603      *  @return The current number of child nodes of that element which are of nodeType ELEMENT_NODE
 604      *
 605      */
 606     unsigned long childElementCount ( ) const;
 607
 608     /**
 609      * not part of the official DOM
 610      *
 611      * This method will always reflect the editability setting of this
 612      * element as specified by a direct or indirect (that means, inherited)
 613      * assignment to contentEditable or the respective CSS rule, even if
 614      * design mode is active.
 615      *
 616      * @return whether this element is editable.
 617      * @see setContentEditable
 618      */
 619     bool contentEditable() const;
 620
 621     /**
 622      * not part of the official DOM
 623      *
 624      * This element can be made editable by setting its contentEditable
 625      * property to @p true. The setting will be inherited to its children
 626      * as well.
 627      *
 628      * Setting or clearing contentEditable when design mode is active will
 629      * take no effect. However, its status will still be propagated to all
 630      * child elements.
 631      *
 632      * @param enabled @p true to make this element editable, @p false
 633      * otherwise.
 634      * @see DOM::Document::designMode
 635      */
 636     void setContentEditable(bool enabled);
 637
 638     /**
 639      * @internal
 640      * not part of the DOM
 641      */
 642     bool isHTMLElement() const;
 643
 644     /**
 645      * KHTML extension to DOM
 646      * This method returns the associated form element.
 647      * returns null if this element is not a form-like element
 648      * or if this elment is not in the scope of a form element.
 649      */
 650     Element form() const;
 651
 652     static bool khtmlValidAttrName(const DOMString &name);
 653     static bool khtmlValidPrefix(const DOMString &name);
 654     static bool khtmlValidQualifiedName(const DOMString &name);
 655
 656     static bool khtmlMalformedQualifiedName(const DOMString &name);
 657     static bool khtmlMalformedPrefix(const DOMString &name);
 658 protected:
 659     Element(ElementImpl *_impl);
 660 };
 661
 662 } //namespace
 663 #endif