diff -r 000000000000 -r e35f40988205 xml/xmldomandxpath/inc/xmlenginedom/xmlengelement.h --- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/xml/xmldomandxpath/inc/xmlenginedom/xmlengelement.h Thu Dec 17 09:29:21 2009 +0200 @@ -0,0 +1,1057 @@ +/* +* Copyright (c) 2008 Nokia Corporation and/or its subsidiary(-ies). +* All rights reserved. +* This component and the accompanying materials are made available +* under the terms of "Eclipse Public License v1.0" +* which accompanies this distribution, and is available +* at the URL "http://www.eclipse.org/legal/epl-v10.html". +* +* Initial Contributors: +* Nokia Corporation - initial contribution. +* +* Contributors: +* +* Description: +* +*/ + +/** @file +@publishedAll +@released +*/ +#ifndef XMLENGELEMENT_H +#define XMLENGELEMENT_H + +#include +#include + +template class RXmlEngNodeList; + + +/** +This class represents an XML element in the DOM tree. + +Namespace handling: + +The namespace of a XML element is an URI that in pair with the local part of +the element's name consistute the @c expanded-name of the element. It is said +that "the element is of NNN namespace". + +XML elements are shown as belonging to a specific namespace by using prefixes +that previously were bound to some namespace URIs. The scope of a prefix is the +element, where it was declared and all its child (sub-)elements. + +Namespace declaration is created by using a special @c xmlns:{prefix-name} +attribute (which is not really considered as an attribute in DOM): +@code + ... +OR + ... + ... +@endcode + +The latter two examples are equivalent and show the use of @c default namespace. + +Implementation notes: +- Elements having no namespace are either presented with a NULL + TXmlEngNamespace node or a TXmlEngNamespace node that has NULL (KNullDesC8) + prefix and namespace URI set to "" (an empty descriptor). The former is + used by default on all nodes, whereas the latter is for cases when some node + contains undeclaration of the default namespace: + @code + .. + @endcode + +- The prefix of the default attribute is NULL (KNullDesC8), not an "" (empty + descriptor). An empty descriptor which corresponds to + @code + ... + @endcode + (it does not contradict XML spec, but you are strongly advised against using + this) + +- Prefix "xml" is reserved by XML Namespace spec for special purposes; it is + implicitly bound to XML's namespace "http://www.w3.org/XML/1998/namespace" + and no one is allowed to use this prefix except as with spec-defined + elements and attributes or to rebind this prefix to other namespaces + +- Namespace URI may be "" (an empty descriptor) only for default namespace. In + other words, "" namespace URI may not be bound to non-NULL prefix. + + Declaration of "" (an empty descriptor) namespace with NULL (KNullDesC8) + prefix results in: + @code + ... + @endcode + which undeclares any existing (in some parent element) default namespace + for the scope of element 'a': element, its attributes and all child nodes + of DOM tree. Note, that such "undeclaration" will be added only if neccessary. + +- Unneccessary namespace declaration are ignored. Attemps to add namespace binding + using same namespace URI and prefix if such binding already exists in the scope + will have no effect. + +- IMPORTANT! Attributes DO NOT HAVE default namespaces. If an attribute has no + prefix, its namespace is undeclared even if there is some default namespaces for + the scope of the element, which contains the attribute. + +So, it is wrong to write something like this: +@code + ... +@endcode +and assume that the attr belongs to namespace pointed to with @c ns_uri. + +HINTS: +- Use namespace declaration nodes as much as possible (but watch out for prefix collisions). +- Add most referred to namespace declarations (AddNamespaceDeclarationL(uri,pref)) after + any other namespace declarations in a element -- they will be found faster in + namespace lookups. + +For more informarion on NULL and NULL nodes: +@see TXmlEngNode +@see KNullDesC8 +*/ +class TXmlEngElement : public TXmlEngNode +{ + public: + /** Default constructor */ + inline TXmlEngElement(); + + /** + Constructor + @param aInternal element pointer + */ + inline TXmlEngElement(void* aInternal); + + /* + Extensions to the DOM Level 3 Core methods + */ + + /** + Retrieves a list of the attribute nodes of an element + + Upon return, aList is initialized and is ready for use with HasNext() and + Next() methods: + + @code + ... + TXmlEngElement root = doc.DocumentElement(); + RXmlEngNodeList attlist; + root.GetAttributes(attlist); + while (attlist.HasNext()) + processAttribute(attlist.Next()); + ... + attlist.Close(); + @endcode + + If there are no attributes the list will be empty. + + @param aList An attribute list to initialize + */ + IMPORT_C void GetAttributes(RXmlEngNodeList& aList) const; + + /** + Retrieves a list of child elements of an element. + + Upon return, aList is initialized and is ready for use with HasNext() and + Next() methods. + + Note: This returns a list of the child element nodes only. + + There is no affect if the element attributes are empty. + + @param aList A child list to initialize + */ + IMPORT_C void GetChildElements(RXmlEngNodeList& aList) const; + + /** + Creates a new attribute node outside of any namespace (i.e. it has no + prefix), sets the attribute's value and links it as the last attribute of + the current element. + + Note: + - No checks are made that an attribute with the same name exists. + Use this method only on newly created elements! + Otherwise, use TXmlEngElement::SetAttributeL() + - Attributes do not inherit default namespace of its element + (http://w3.org/TR/REC-xml-names/#defaulting) + - The attribute's value is the second argument in all AddNewAttributeL() methods + + When adding the first attribute, use TXmlEngNode::SetAsFirstSibling() on the attribute: + @code + TXmlEngElement el = ... ; // get some element + el.AddNewAttributeL("version","0.1").SetAsFirstSibling(); + @endcode + + Copies are taken of descripters passed in. + + @see SetAsLastSibling() + @see MoveBeforeSibling(TXmlEngNode) + @see MoveAfterSibling(TXmlEngNode) + * + @param aName A local name of the attribute + @param aValue Value to set for new attribute or KNullDesC8 + @return The created attribute + @leave KXmlEngErrNullNode The node is NULL + @leave KXmlEngErrWrongUseOfAPI aName is empty + @leave - One of the system-wide error codes + */ + IMPORT_C TXmlEngAttr AddNewAttributeL(const TDesC8& aName, const TDesC8& aValue); + + /** + Creates a new attribute node and adds it to the element. + + The provided namespace declaration is used to set the attribute's namespace. + + Note: If aNsDef is not defined in some of the attribute's ascendants + (including this element), then the ReconcileNamespacesL() method must be + called on this element later. + + Copies are taken of descripters passed in. + + @param aName The local name of attribute + @param aValue Value to set for new attribute or KNullDesC8 + @param aNsDef Namespace to add to the attribute + @return The created attribute + @leave KXmlEngErrNullNode The node is NULL + @leave KXmlEngErrWrongUseOfAPI aName is empty + @leave - One of the system-wide error codes + */ + IMPORT_C TXmlEngAttr AddNewAttributeL(const TDesC8& aName, + const TDesC8& aValue, + const TXmlEngNamespace aNsDef); + + /** + Creates a new attribute for the element. A namespace declaration for the + attribute namespace is also created. + + Note: Namespace declarations are reused if possible (no redundant ones are + created) + + Copies are taken of descripters passed in. + + @param aName The local name of attribute + @param aValue Value to set for the new attribute or an empty string + @param aNsUri Namespace URI + @param aPrefix Namespace prefix + @return The created attribute + @leave KXmlEngErrNullNode The node is NULL + @leave KXmlEngErrWrongUseOfAPI aName is empty + @leave - One of the system-wide error codes + */ + IMPORT_C TXmlEngAttr AddNewAttributeL(const TDesC8& aName, + const TDesC8& aValue, + const TDesC8& aNsUri, + const TDesC8& aPrefix); + + /** + Creates a new attribute node using the namespace of its parent element + (this element), sets the attribute's value and links it as the last + attribute of the element + + For more hints how to use it @see AddNewAttributeL(const TDesC8&,const TDesC8&) + + Note: + - No checks are made that an attribute with the same name exists + - if the namespace of the parent element is default (i.e. bound prefix is KNullDesC8), + then a temporary prefix will be used and bound to the same namespace URI as the element + (It is due to the fact that default namespaces do not spread on unprefixed attributes, + see http://w3.org/TR/REC-xml-names/#defaulting) + + Copies are taken of descripters passed in. + @see KNullDesC8 + + @param aName Local name of attribute + @param aValue Value to set for the new attribute or empty. + @return The created attribute + @leave KXmlEngErrNullNode The node is NULL + @leave KXmlEngErrWrongUseOfAPI aName is empty + @leave - One of the system-wide error codes + */ + inline TXmlEngAttr AddNewAttributeSameNsL(const TDesC8& aName, const TDesC8& aValue); + + /** + Creates a new attribute using the namespace which is bound to the specified prefix + + Use this mothod only for construction of new parts of DOM tree where + you know for sure that the prefix is bound in the given scope. + @code + TXmlEngElement el = parent.AddNewAttributeUsePrefixL("property","ObjName","rdf"); + el.AddNewAttributeUsePrefixL("type", "xs:integer", "rdf"); + @endcode + + Otherwise, you should check that the prefix is bound like this example shows: + @code + TXmlEngNamespace boundNS = TXmlEngNamespace::LookupByPrefix(thisElement, prefix); + if (boundNS.NotNull()){ + thisElement.AddNewAttributeUsePrefixL("name", value, prefix); + } + @endcode + + Note: Use AddNewAttributeNsL(name,value,nsDefNode) as much as you can, + because it is the most efficient way to create namespaced DOM elements (no + additional lookups for namespace declarations are required). + + @code + // If namespace with given URI is not in the scope, then it will be declared + // and bound to "data" prefix. + TXmlEngNamespace nsDef = elem.FindOrCreateNsDefL("http://../Data", "data"); + elem.AddNewAttributeL("location", "...", nsDef); + elem.AddNewElementL("child", nsDef).AddNewAttributeL("attr","...value..."); + // the result is + ... + + + + ... + // + @endcode + + Copies are taken of descripters passed in. + + @param aLocalName The local name of the attribute + @param aValue Value to set for the new attribute or empty string. + @param aPrefix Namespace prefix for the new attribute + @return The created attribute + @leave KXmlEngErrNullNode The node is NULL + @leave KXmlEngErrWrongUseOfAPI aLocalName is empty + @leave KErrNoMemory The namespace is not found and the URI is not + http://www.w3.org/XML/1998/namespace; or there is a memory allocation error + @leave - One of the system-wide error codes + */ + IMPORT_C TXmlEngAttr AddNewAttributeUsePrefixL(const TDesC8& aLocalName, + const TDesC8& aValue, + const TDesC8& aPrefix); + + /** + Creates new attributes using the namespace in scope, which has the specified URI + + Almost the same as AddNewAttributeUsePrefixL() but does lookup by namespace URI + + @see AddNewAttributeUsePrefixL(const TDesC8&,const TDesC8&,const TDesC8&) + + Copies are taken of descripters passed in. + @see KNullDesC8 + + @param aLocalName The local name of the attribute + @param aValue Value to set for new attribute or empty string. + @param aNsUri Namespace URI for new attribute + @return NULL attribute if namespace declaration is not found OR newly added + to the end of attribute list attribute of this element. + @leave KXmlEngErrNullNode The node is NULL + @leave KXmlEngErrWrongUseOfAPI aLocalName is empty + @leave - One of the system-wide error codes + */ + IMPORT_C TXmlEngAttr AddNewAttributeWithNsL(const TDesC8& aLocalName, + const TDesC8& aValue, + const TDesC8& aNsUri); + + /** + Adds attribute to element that will be used as Xml:Id. Does not check if + an attribute with the same name exists. + + Note: Call RXmlEngDocument.RegisterXmlIdL(aName,aNsUri) first to register + existed id's in the document. If the ids are not registered the ID will + not be added to the element. + + Copies are taken of descripters passed in. + + @param aLocalName Name of the attribute + @param aValue Value of the attribute + @param aNs Namespace of the attribute + @return Attribute if created. Null attribute if Xml:Id exists + @leave KXmlEngErrWrongUseOfAPI Element is NULL or attribute doesn't exist + @leave - One of the system-wide error codes + */ + IMPORT_C TXmlEngAttr AddXmlIdL(const TDesC8& aLocalName, + const TDesC8& aValue, + TXmlEngNamespace aNs = TXmlEngNamespace()); + + /** + Adds a child element with no namespace. This results in adding an element + with aName and no prefix. + + This method is the best for creation of non-namespace based documents + or document fragments, where no default namespace declared. + + It may be used also as a method for adding elements from the default + namespace, BUT namespace will be assigned ONLY after serialization of the + current document and parsing it back into a DOM tree!! If you need the new + element to inherit the default namespace use: + + @code + ... + TXmlEngNamespace defns = element.DefaultNamespace(); + TXmlEngElement newEl = element.AddNewElementL("Name",defns); + ... + @endcode + + It is not recommended that you use an undefined namespace with libxml. + If an undefined namespace for the element is truly required, then DO NOT + USE this method if there is a default namespace in the scope! + @see AddNamespaceDeclarationL + + Copies are taken of descripters passed in. + + @param aName The name of the element + @return The created element + @leave KXmlEngErrNullNode Element is NULL + @leave KXmlEngErrWrongUseOfAPI Name is not specified + @leave - One of the system-wide error codes + */ + IMPORT_C TXmlEngElement AddNewElementL(const TDesC8& aName); + + /** + Creates a new child element with the provided name and namespace + declaration and adds it as the last child of its parent. + + Copies are taken of descripters passed in. + + @param aLocalName The name of the element + @param aNsDecl The namespace declaration that must be retrieved from + one of the ascendant nodes of the new elements (and its prefix + should not be remapped to another namespace URI for the scope + of the new element) + @return Created element node + @leave KXmlEngErrNullNode Element is NULL + @leave KXmlEngErrWrongUseOfAPI Name is not specified + @leave - One of the system-wide error codes + */ + IMPORT_C TXmlEngElement AddNewElementL(const TDesC8& aLocalName, TXmlEngNamespace aNsDecl); + + /** + Creates a new child element with provided the name, prefix and namespace + URI and adds it as the last child of its parent. + + The new namespace declaration will be attached to the parent (this) element + and used as the namespace for newly created child element. If such a + binding already exists (same prefix is bound to same URI), it will be + reused. If the prefix is already bound to some other namespace URI, it will + be rebound by the new namespace declaration node. + + Copies are taken of descripters passed in. + + @param aLocalName Name of the element + @param aNsUri URI of the element's namespace + @param aPrefix Prefix of the element + @return The created element node + @leave KXmlEngErrNullNode Element is NULL + @leave KXmlEngErrWrongUseOfAPI Name or URI or prefix is not specified + @leave - One of the system-wide error codes + */ + IMPORT_C TXmlEngElement AddNewElementL(const TDesC8& aLocalName, + const TDesC8& aNsUri, + const TDesC8& aPrefix); + + /** + Creates a child element with the same namespace (and prefix if present) as + the parent element and adds it as the last child of its parent. + + Copies are taken of descripters passed in. + + @param aLocalName The element's name + @return The created element + @leave KXmlEngErrNullNode Element is NULL + @leave KXmlEngErrWrongUseOfAPI Name is not specified + @leave - One of the system-wide error codes + */ + IMPORT_C TXmlEngElement AddNewElementSameNsL(const TDesC8& aLocalName); + + /** + Performs a lookup for the namespace declaration for the specified prefix + and adds a new child element with the found namespace as the last child of + its parent. + + @pre The prefix is bound + + Copies are taken of descripters passed in. + + @param aLocalName The element's name + @param aPrefix The prefix to use for the search + @return The created element + @leave KXmlEngErrNullNode Element is NULL + @leave KXmlEngErrWrongUseOfAPI Name is not specified + @leave KErrNoMemory The namespace is not found and the prefix is not "xml" + (i.e http://www.w3.org/XML/1998/namespace); or there is a memory allocation + error. + @leave - One of the system-wide error codes + */ + IMPORT_C TXmlEngElement AddNewElementUsePrefixL(const TDesC8& aLocalName, const TDesC8& aPrefix); + + /** + Performs a lookup for the namespace declaration for the specified namespace + URI and adds a new child element with the found namespace. The new element + is added as the last child of this element. + + Copies are taken of descripters passed in. + + @pre A namespace with the given URI has been declared + + @param aLocalName The element's name + @param aNsUri The namespace of the element + @return The created element + @leave KXmlEngErrNullNode Element is NULL + @leave KXmlEngErrWrongUseOfAPI Name is not specified + @leave KErrNoMemory The namespace is not found and the URI is not http://www.w3.org/XML/1998/namespace + or there is a memory allocation error + @leave - One of the system-wide error codes + */ + IMPORT_C TXmlEngElement AddNewElementWithNsL(const TDesC8& aLocalName, const TDesC8& aNsUri); + + /** + Creates a new child element. If there is no a prefix binding for the new + element's namespace, a namespace decaration is created with a generated + prefix at the specified element. + + The location of the namespace declaration may be controlled with + aNsDeclTarget: + + @code + el.AddNewElementAutoPrefixL(tagName,uri,KNullDesC8); // declare on the new element + el.AddNewElementAutoPrefixL(tagName,uri,el); // declare on the parent element + el.AddNewElementAutoPrefixL(tagName,uri,doc.DocumentElement()); // declare on the root element + ... + @endcode + + Note: The farther namespace declaration up in the document tree, the + longer the namespace declaration lookups take. + + Copies are taken of descripters passed in. + + @param aLocalName Name of the element to create + @param aNsUri Namespace URI of the new element + @param aNsDeclTarget The element where the namespace declaraton should be placed. + @return The created element + @leave KXmlEngErrNullNode Element is NULL + @leave KXmlEngErrWrongUseOfAPI Name or URI is not specified + @leave - One of the system-wide error codes + */ + IMPORT_C TXmlEngElement AddNewElementAutoPrefixL(const TDesC8& aLocalName, + const TDesC8& aNsUri, + TXmlEngElement aNsDeclTarget); + + /** + Gets element content. This method may be used in most cases when the element + has only simple text content (without entity references embedded). If the + element's contents is mixed (other types of nodes present), only the contents + of the first child node is returned (if it is a TXmlEngTextNode node). + + For getting the contents of an element that has contents containing entity + references, WholeTextValueCopyL() should be used. + + @see TXmlEngNode::WholeTextContentsCopyL() + + @return The simple text contents of the element or NULL if there is no text. + */ + IMPORT_C TPtrC8 Text() const; + + /** + Adds text as a child of the element to the end of the list of children. + + Note: There may be several TXmlEngTextNode and TXmlEngEntityReference + nodes added, depending on the aString value. For example, if the curernt + node has text and attributes, a text node and attribute nodes will + be added. + + Copies are taken of descripters passed in. + + @param aString Text to be added as the element's content. + @leave KXmlEngErrNullNode Element is NULL + @leave - One of the system-wide error codes + */ + IMPORT_C void AddTextL(const TDesC8& aString); + + /** + Sets text contents for the element. Any child nodes are removed. + This function is the same as TXmlEngNode::SetValueL(TDesC8&) + + @see TXmlEngNode::SetValueL(TDesC8&) + + @param aString Text to be set as element's content. + @leave KXmlEngErrNullNode Element is NULL + @leave - One of the system-wide error codes + */ + IMPORT_C void SetTextL(const TDesC8& aString); + + /** + Sets the text content of the element from an escaped string. + @see TXmlEngAttr::SetEscapedValueL(TDesC8&) + + @param aEscapedString New value + @leave KXmlEngErrNullNode Element is NULL + @leave - One of the system-wide error codes + */ + IMPORT_C void SetEscapedTextL(const TDesC8& aEscapedString); + + /** + Sets the new element value exactly as presented in the string. Predefined + entities are not converted into the characters they represent. Any child + nodes are removed. + + @see TXmlEngAttr::SetValueNoEncL(const TDesC8& aNewValue); + + @param aNotEncString New string value + @leave KXmlEngErrNullNode Element is NULL + @leave - One of the system-wide error codes + */ + IMPORT_C void SetTextNoEncL(const TDesC8& aNotEncString); + + /** + Appends a new text node with the value exactly as presented in the string. + Predefined entities are not converted into the characters they represent. + Existing child nodes are not removed. + + @see TXmlEngAttr::SetValueNoEncL(const TDesC8& aNewValue); + + Copies are taken of descripters passed in. + + @param aNotEncString Appended string value + @leave KXmlEngErrNullNode Element is NULL + @leave - One of the system-wide error codes + */ + IMPORT_C void AppendTextNoEncL(const TDesC8& aNotEncString); + + /** + Adds a namespace declaration to the current element: a binding of prefix to namespace URI. + + If the same namespace declaration exists (same prefix and URI), a redundant + namespace declaration will not be created. + + Both KNullDesC8 or an empty descriptor may be used for "UNDEFINED URI" + and "NO PREFIX" values of arguments. Please refer to the class + documentation for more specific information. + @see TXmlEngElement + @see KNullDesC8 + + Note: Undeclaring of default namespace (xmlns="") is supported by + the SetNoDefaultNamespace() method. + @see SetNoDefaulNamespace() + + Note: Adding a namespace declaration that rebinds the prefix mapping (or + default namespace) used by nodes lower in the tree may damage the document + tree because references to namespace declarations are not updated. + However, after serialization, the document will have the desired structure. + Use this method with care! + + Copies are taken of descripters passed in. + + @param aNsUri Namespace URI, KNullDesC8 or an empty descriptor. + @param aPrefix Namespace prefix, KNullDesC8 or an empty descriptor. + @return The namespace that was created or found or a NULL namespace if the + namespace is being undeclared. + @leave KXmlEngErrNullNode Element is NULL + @leave KXmlEngErrWrongUseOfAPI URI or prefix is not specified + @leave - One of the system-wide error codes + */ + IMPORT_C TXmlEngNamespace AddNamespaceDeclarationL(const TDesC8& aNsUri, const TDesC8& aPrefix); + + /** + Adds a default namespace declaration. + +1 + This achieves the same result as with AddNamespaceDeclarationL(aNsUri, + KNullDesC8), but additionally the element's namespace is modified (if it has no + prefix and there were no default namespace declaration in the scope) to the + new default one. + + Copies are taken of descripters passed in. + @see KNullDesC8 + + @param aNsUri Namespace URI; KNullDesC8 and empty descriptor are allowed to represent UNDEFINED NAMSPACE + @return The created namespace declaration (NULL for UNDEFINED NAMESPACE) + @leave KXmlEngErrNullNode Element is NULL + @leave KXmlEngErrWrongUseOfAPI URI is not specified + @leave - One of the system-wide error codes + */ + IMPORT_C TXmlEngNamespace SetDefaultNamespaceL(const TDesC8& aNsUri); + + /** + Undeclares any default namespace for this element and its descendants. + + If there is already a default namespace, a @c xmlns="" namespace + declaration is added. Otherwise, nothing happens, since elements with no + prefix in such scope are automaticaly considered outside of any namespace. + + The side effect of this method is that the namespace of the current element + may change from the previous default namespace to a NULL TXmlEngNamespace, + which is considered an absence of namespace. + + If the element has a prefix (i.e. not having default namespace), then the + only effect for the element is undeclaration of existing default namespace. + + If the element is in the scope of another @c xmlns="" undeclaration, no + action is taken. + + Note: Use AddNamespaceDeclarationL(KNullDesC8,KNullDesC8) to force the creation of a @c + xmlns="" declaration within the scope of another such declaration + (otherwise unneccessary/duplicate declarations are not created). + + Note: This method should be called on elements before adding children, + because default namespace undeclaration is not spread into its subtree and + descendants' default namespaces are not reset to NULL. This should be taken + into account if later some processing on the subtree occurs. However, + after serialization and deserialization, undeclared default namespace will + affect whole element's subtree correctly. + + @see KNullDesC8 + + @leave KXmlEngErrNullNode Element is NULL + @leave - One of the system-wide error codes + */ + IMPORT_C void SetNoDefaultNamespaceL(); + + /** + Finds the namespace declaration that has a specific prefix in the list of parents for + this element. + + If no prefix is specified (an empty descriptor or KNullDesC8) then it is + considered to be a "NO PREFIX" search. Therefore, if the namespace + declaration for "no prefix" is searched, then the default namespace is + returned. + + Copies are taken of descripters passed in. + @see KNullDesC8 + + @param aPrefix Namespace prefix. + @return The namespace, which may be NULL if prefix is not found; NULL result for "no prefix" means that default namespace is undefined. + @leave - One of the system-wide error codes + */ + IMPORT_C TXmlEngNamespace LookupNamespaceByPrefixL(const TDesC8& aPrefix) const; + + /** + Finds a namespace declaration that has a specific namespace URI in the + scope for the given node. + + KNullDesC8 value of aUri is equivalent to an empty descriptor and means + "UNDEFINED NAMESPACE". + For such URI's a NULL namespace handle is always returned even if there is + a namespace undeclaration, which has an empty descriptor URI (and KNullDesC8 + prefix). + + Hint: Use the returned instance of TXmlEngNamespace as the aNsDef argument + to an element's methods that create new child elements and attributes. The + same TXmlEngNamespace may be used on deeper descentants of the reference + element (and doing this way will generally increase performance of DOM tree + construction). However, if namespace bindings are not controlled for the + element's children and the prefix (which is bound to the search namespace) + is rebound to some other namespace URI, then reusing the namespace may lead + to unwanted result. + + Note: At the moment it is possible to retrieve namespace declaration nodes + whose prefixes were rebound. Be careful when using returned + TXmlEngNamespace objects for creation of new elements. + + Copies are taken of descripters passed in. + + @param aUri Namespace URI, for which the namespace declaration is searched + @return The namespace declaration that binds the given namespace URI to a + prefix or sets it as a default namespace + @leave - One of the system-wide error codes + */ + IMPORT_C TXmlEngNamespace LookupNamespaceByUriL(const TDesC8& aUri) const; + + /** + Retrieves the implicitly declared XML infoset binding of the 'xml' prefix + to XML's namespace URI: "http://www.w3.org/XML/1998/namespace" + + The result should be used for creating attributes beloging to the XML namespace + (xml:lang, xml:space, xml:id , etc.) + + DO NOT USE the methods LookupNamespaceByUriL(const TDesC8&) and + LookupNamespaceByPrefixL(const TDesC8&) (with the arguments + "http://www.w3.org/XML/1998/namespace" and "xml" respectively) for + retrieving the namespace node, since in the case of a memory allocation + fault, a NULL result is returned (and breaks your program silently) + + Note: Normally the 'xml' prefix is bound to the XML namespace URI in the + document node, BUT if this element is not a part of the document tree yet, + the requested namespace declaration WILL BE ADDED to the current node. + This is the reason why the method may fail in OOM conditions. + + @return The namespace matching the prefix binding + {xml,"http://www.w3.org/XML/1998/namespace"} in the current document + @leave KErrNoMemory The element is NULL or there was a memory allocation error + @leave - One of the system-wide error codes + */ + IMPORT_C TXmlEngNamespace TheXMLNamespaceL() const; + + /** + Get the default namespace for the element. + + A NULL TXmlEngNamespace means that an element with no prefix + has no namespace associated with it because no default namespace was declared or + the default namespace was undeclared with @c xmlns="" + + This function is equivalent to LookupNamespaceByPrefixL(KNullDesC8). + @see KNullDesC8 + + @return The default namespace in the scope of the element + @leave - One of the system-wide error codes + */ + inline TXmlEngNamespace DefaultNamespaceL() const; + + /** + Performs a search for the namespace in the scope of the element. This + method will create new namespace declaration on the element if such + namespace is not found. + + Note: Be sure not to use the result of this method for non-descendants of + the element or in situations when prefix overlapping might occur. + @see TXmlEngAttr + @see TXmlEngNamespace + Please read the documentation for this class: + @see TXmlEngElement + + Copies are taken of descripters passed in. + + @param aNsUri Namespace to search for + @param aPrefix Prefix to use for the new namespace declaration (if it is to be created) + @return The namespace found or created + @leave KXmlEngErrNullNode Element is NULL + @leave KXmlEngErrWrongUseOfAPI URI is not specified + @leave - One of the system-wide error codes + + @see LookupNamespacebyUriL + */ + IMPORT_C TXmlEngNamespace FindOrCreateNsDeclL(const TDesC8& aNsUri, const TDesC8& aPrefix); + + /** + Performs a search on the element and its ascendants for any namespace + declaration with a given URI. Creates a new namespace declaration with a + (unique) prefix if the search was not successful. + @see AddNamespaceDeclarationL + + Copies are taken of descripters passed in. + + @param aNsUri Namespace to search for + @return The namespace found or created + @leave KXmlEngErrNullNode Element is NULL + @leave KXmlEngErrWrongUseOfAPI URI is not specified + @leave - One of the system-wide error codes + */ + IMPORT_C TXmlEngNamespace FindOrCreateNsDeclL(const TDesC8& aNsUri); + + /** + Checks whether a prefix has been bound in this element (not in one of its ascendants) + + Use this method for preventing prefix-name collision in a element node + + Copies are taken of descripters passed in. + + @param aPrefix Namespace prefix + @return ETrue if there is already a namespace declaration that uses aPrefix on this element + @leave - One of the system-wide error codes + */ + IMPORT_C TBool HasNsDeclarationForPrefixL(const TDesC8& aPrefix) const; + + /** + Copies the element with its attributes, but not child nodes + + If the context is preserved (preserveNsContent), then all namespace + declarations that are in the element are writen to the tag. + + @param preserveNsContext Whether the namespace context should be preserved + @return The copied element + @leave KXmlEngErrNullNode The element is NULL + @leave - One of the system-wide error codes + */ + IMPORT_C TXmlEngElement ElementCopyNoChildrenL(TBool preserveNsContext) const; + + /** + Specialized version of TXmlEngNode::CopyL() + @return Deep copy of the element. + @leave KXmlEngErrNullNode The element is NULL + @leave - One of the system-wide error codes + */ + inline TXmlEngElement CopyL() const; + + /** Resets element's content: all child nodes are removed */ + IMPORT_C void RemoveChildren(); + + /** Resets element's attributes */ + IMPORT_C void RemoveAttributes(); + + /** + Resets all namespace declarations made in the element + + Note: There can be references to these namespace declarations elsewhere! + Use ReconcileNamespacesL() to fix that. + */ + IMPORT_C void RemoveNamespaceDeclarations(); + + /** + Removes all element contents: child nodes, attributes and namespace declarations + + @see RemoveChildren() + @see RemoveAttributes() + @see RemoveNamespaceDeclarations(); + */ + inline void ClearElement(); + + /** + Copies attributes from another element. It may be a very convenient method + for initializing element with a set of predefined attributes. + + Note: Namespaces of the this element may need to be reconciled if the + copied attributes belong to any namespace that is not declared on some + ascendant of this node. @see ReconcileNamespacesL() + + @param aSrc Source element + @leave KXmlEngErrNullNode The element is NULL + @leave - One of the system-wide error codes + */ + IMPORT_C void CopyAttributesL(TXmlEngElement aSrc); + + /** + Recursively copies the children (and all of it's associated information) + from another element. Elements are appended to the current element's + children list. + + Note: Namespaces of this element may need to be reconciled after copy + operation + @see ReconcileNamespacesL() + + @param aSrc Source element + @leave KXmlEngErrNullNode The element is NULL + @leave KXmlEngWrongUseOfAPI The source element is NULL + @leave - One of the system-wide error codes + */ + IMPORT_C void CopyChildrenL(TXmlEngElement aSrc); + + /** + Removes the child element with the given name and namespace URI (if it exists). + Memory allocated for the element is freed. + + @param aLocalName Child element name + @param aNamespaceUri Child element namespace + @leave KXmlEngErrNullNode The element is NULL + @leave - One of the system-wide error codes + */ + IMPORT_C void RemoveChildElementsL(const TDesC8& aLocalName,const TDesC8& aNamespaceUri); + + /** + Renames the element with the given name, namespace URI, and namespace prefix. + + @param aLocalName The new element name + @param aNamespaceUri The new namespace URI + @param aPrefix The new namespace prefix + @leave - One of the system-wide error codes + */ + IMPORT_C void RenameElementL(const TDesC8& aLocalName, const TDesC8& aNamespaceUri, const TDesC8& aPrefix); + + /* + DOM Level 3 Core methods + + Most methods of DOM spec operate with fully-qualified names (QNames) + of elements and attributes. It is different in this API - all methods + instead accept prefix and localName parts of QName. + */ + + /** + Returns the value of the attribute with the given name and namespace URI. + + @param aLocalName Local name of the attribute + @param aNamespaceUri Namespace URI of the attribute, or the default namespace if not specified. + @return The attribute value (for as long as the attribute exists) or + NULL if not found. + @leave - One of the system-wide error codes + */ + IMPORT_C TPtrC8 AttributeValueL(const TDesC8& aLocalName, + const TDesC8& aNamespaceUri = KNullDesC8) const; + + /** + Initializes list of child elements with matching names and namespace URIs. + + Note: This method does not list all descendants of the element, only child elements + @see KNullDesC8 + + @param aList Node list to be created + @param aLocalName Element name + @param aNamespaceUri if specified it sets the Namespace URI, default is KNullDesC8 (no namespace set). + @leave - One of the system-wide error codes + */ + IMPORT_C void GetElementsByTagNameL(RXmlEngNodeList& aList, + const TDesC8& aLocalName, + const TDesC8& aNamespaceUri = KNullDesC8) const; + + /** + Sets the value of the given attribute. The attribute is created if there + is no such attribute yet. + + Note: If prefix is not KNullDesC8 (or an empty descriptor), + then the namespace URI may not be empty see + http://www.w3.org/TR/REC-xml-names/#ns-decl (Definition #3) + + Copies are taken of descripters passed in. + @see KNullDesC8 + + @param aLocalName Attribute name + @param aValue Attribute value + @param aNamespaceUri Namespace URI - default is KNullDesC8 + @param aPrefix Namespace prefix - default is KNullDesC8 + @leave KXmlEngErrNullNode The element is NULL + @leave KXmlEngErrWrongUseOfAPI Attribute name not specified + @leave - One of the system-wide error codes + */ + IMPORT_C void SetAttributeL(const TDesC8& aLocalName, + const TDesC8& aValue, + const TDesC8& aNamespaceUri = KNullDesC8, + const TDesC8& aPrefix = KNullDesC8); + + /** + Removes the attribute with the given name and namespace URI (if it exists). + Memory allocated for the attribute is freed. + + @see KNullDesC8 + + @param aLocalName Name of the attribute + @param aNamespaceUri Attribute namespace URI, default is KNullDesC8 + @leave - One of the system-wide error codes + */ + IMPORT_C void RemoveAttributeL(const TDesC8& aLocalName, + const TDesC8& aNamespaceUri = KNullDesC8); + + /** + Retrieves an attribute node with a specific namespace by its name. + + @see KNullDesC8 + + @param aLocalName Name of the attribute + @param aNamespaceUri Attribute namespace URI, default is KNullDesC8 + @return Attribute node with matching namespace URI and name, NULL if not found. + @leave - One of the system-wide error codes + */ + IMPORT_C TXmlEngAttr AttributeNodeL(const TDesC8& aLocalName, + const TDesC8& aNamespaceUri = KNullDesC8) const; + + /** + Check if the element has an attribute with given parameters. + + This function is the same as AttributeNodeL(uri,name).NotNull(). + + @see KNullDesC8 + + @param aLocalName Name of attribute + @param aNamespaceUri Namespace uri, default is KNullDesC8. + @return ETrue if the element holds an attribute with such namespace URI and name. + @leave - One of the system-wide error codes + */ + inline TBool HasAttributeL(const TDesC8& aLocalName, + const TDesC8& aNamespaceUri = KNullDesC8) const; + + /** + Adds an attribute to this element. If an attribute of the same name + exists, it will be destroyed. + + @param aNewAttr The new attribute + @leave KXmlEngErrNullNode The element or attribute is NULL + @leave - One of the system-wide error codes + */ + IMPORT_C void SetAttributeNodeL(TXmlEngAttr aNewAttr); +}; + + +#include + +#endif /* XMLENGELEMENT_H */ +