TXmlEngElement Class Reference

Default constructor

Constructor

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 also: TXmlEngElement KNullDesC8

Note: Undeclaring of default namespace (xmlns="") is supported by the SetNoDefaultNamespace() method.

See also: 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.

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.

        TXmlEngElement el = ... ; // get some element
        el.AddNewAttributeL("version","0.1").SetAsFirstSibling();

Copies are taken of descripters passed in.

See also: SetAsLastSibling() MoveBeforeSibling(TXmlEngNode) MoveAfterSibling(TXmlEngNode)

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KXmlEngErrNullNode The node is NULL

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KXmlEngErrWrongUseOfAPI aName is empty

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• One of the system-wide error codes

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.

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.

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 also: AddNewAttributeL(const TDesC8&,const TDesC8&)

Copies are taken of descripters passed in.

See also: KNullDesC8

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KXmlEngErrNullNode The node is NULL

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KXmlEngErrWrongUseOfAPI aName is empty

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• One of the system-wide error codes

Creates a new attribute using the namespace which is bound to the specified prefix

        TXmlEngElement el = parent.AddNewAttributeUsePrefixL("property","ObjName","rdf");
        el.AddNewAttributeUsePrefixL("type", "xs:integer", "rdf");

        TXmlEngNamespace boundNS = TXmlEngNamespace::LookupByPrefix(thisElement, prefix);
        if (boundNS.NotNull()){
            thisElement.AddNewAttributeUsePrefixL("name", value, prefix);
        }

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).

        // 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
            ...
         <elem xmlns:data="http://../Data" data:location="...">
            <data:child attr="...value..."/>
         </elem>
            ...
        //

Copies are taken of descripters passed in.

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 also: AddNewAttributeUsePrefixL(const TDesC8&,const TDesC8&,const TDesC8&)

Copies are taken of descripters passed in.

See also: KNullDesC8

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KXmlEngErrNullNode The node is NULL

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KXmlEngErrWrongUseOfAPI aLocalName is empty

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• One of the system-wide error codes

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:

        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
       ...

Note: The farther namespace declaration up in the document tree, the longer the namespace declaration lookups take.

Copies are taken of descripters passed in.

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:

       ...
       TXmlEngNamespace defns = element.DefaultNamespace();
       TXmlEngElement newEl = element.AddNewElementL("Name",defns);
       ...

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 also: AddNamespaceDeclarationL

Copies are taken of descripters passed in.

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.

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.

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.

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.

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.

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.

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.

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 also: TXmlEngAttr::SetValueNoEncL(const TDesC8& aNewValue);

Copies are taken of descripters passed in.

Retrieves an attribute node with a specific namespace by its name.

See also: KNullDesC8

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• One of the system-wide error codes

Returns the value of the attribute with the given name and namespace URI.

Removes all element contents: child nodes, attributes and namespace declarations

See also: RemoveChildren() RemoveAttributes() RemoveNamespaceDeclarations();

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 also: ReconcileNamespacesL()

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KXmlEngErrNullNode The element is NULL

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• One of the system-wide error codes

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 also: ReconcileNamespacesL()

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KXmlEngErrNullNode The element is NULL

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KXmlEngWrongUseOfAPI The source element is NULL

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• One of the system-wide error codes

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 xmlns=""

This function is equivalent to LookupNamespaceByPrefixL(KNullDesC8).

See also: KNullDesC8

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• One of the system-wide error codes

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 <element ...> tag.

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 also: TXmlEngAttr TXmlEngNamespace Please read the documentation for this class: TXmlEngElement

Copies are taken of descripters passed in.

See also: LookupNamespacebyUriL

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 also: AddNamespaceDeclarationL

Copies are taken of descripters passed in.

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:

          ...
          TXmlEngElement root = doc.DocumentElement();
          RXmlEngNodeList<TXmlEngAttr>    attlist;
          root.GetAttributes(attlist);
          while (attlist.HasNext())
              processAttribute(attlist.Next());
          ...
	      attlist.Close();

If there are no attributes the list will be empty.

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.

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 also: KNullDesC8

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• One of the system-wide error codes

Check if the element has an attribute with given parameters.

This function is the same as AttributeNodeL(uri,name).NotNull().

See also: KNullDesC8

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• One of the system-wide error codes

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.

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 also: KNullDesC8

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• One of the system-wide error codes

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.

Removes the attribute with the given name and namespace URI (if it exists). Memory allocated for the attribute is freed.

See also: KNullDesC8

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• One of the system-wide error codes

Resets element's attributes

Removes the child element with the given name and namespace URI (if it exists). Memory allocated for the element is freed.

Resets element's content: all child nodes are removed

Resets all namespace declarations made in the element

Note: There can be references to these namespace declarations elsewhere! Use ReconcileNamespacesL() to fix that.

Renames the element with the given name, namespace URI, and namespace prefix.

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 also: KNullDesC8

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KXmlEngErrNullNode The element is NULL

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KXmlEngErrWrongUseOfAPI Attribute name not specified

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• One of the system-wide error codes

Adds an attribute to this element. If an attribute of the same name exists, it will be destroyed.

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 also: KNullDesC8

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KXmlEngErrNullNode Element is NULL

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KXmlEngErrWrongUseOfAPI URI is not specified

leave

• One of the system-wide error codes

Sets the text content of the element from an escaped string.

See also: TXmlEngAttr::SetEscapedValueL(TDesC8&)

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KXmlEngErrNullNode Element is NULL

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• One of the system-wide error codes

Undeclares any default namespace for this element and its descendants.

If there is already a default namespace, a 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 xmlns="" undeclaration, no action is taken.

Note: Use AddNamespaceDeclarationL(KNullDesC8,KNullDesC8) to force the creation of a 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 also: KNullDesC8

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KXmlEngErrNullNode Element is NULL

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• One of the system-wide error codes

Sets text contents for the element. Any child nodes are removed. This function is the same as TXmlEngNode::SetValueL(TDesC8&)

See also: TXmlEngNode::SetValueL(TDesC8&)

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KXmlEngErrNullNode Element is NULL

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• One of the system-wide error codes

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 also: TXmlEngAttr::SetValueNoEncL(const TDesC8& aNewValue);

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KXmlEngErrNullNode Element is NULL

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• One of the system-wide error codes

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 also: TXmlEngNode::WholeTextContentsCopyL()

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.