CopperSpice API  1.7.2
QDomDocument Class Reference

The QDomDocument class represents an XML document. More...

Inheritance diagram for QDomDocument:
QDomNode

Public Methods

 QDomDocument ()
 
 QDomDocument (const QDomDocument &other)
 
 QDomDocument (const QDomDocumentType &doctype)
 
 QDomDocument (const QString &name)
 
 ~QDomDocument ()
 
QDomAttr createAttribute (const QString &name)
 
QDomAttr createAttributeNS (const QString &nsURI, const QString &qName)
 
QDomCDATASection createCDATASection (const QString &text)
 
QDomComment createComment (const QString &text)
 
QDomDocumentFragment createDocumentFragment ()
 
QDomElement createElement (const QString &tagName)
 
QDomElement createElementNS (const QString &nsURI, const QString &qName)
 
QDomEntityReference createEntityReference (const QString &name)
 
QDomProcessingInstruction createProcessingInstruction (const QString &target, const QString &data)
 
QDomText createTextNode (const QString &text)
 
QDomDocumentType doctype () const
 
QDomElement documentElement () const
 
QDomElement elementById (const QString &elementId)
 
QDomNodeList elementsByTagName (const QString &tagname) const
 
QDomNodeList elementsByTagNameNS (const QString &nsURI, const QString &localName)
 
QDomImplementation implementation () const
 
QDomNode importNode (const QDomNode &importedNode, bool deep)
 
QDomNode::NodeType nodeType () const
 
QDomDocument & operator= (const QDomDocument &other)
 
bool setContent (const QByteArray &buffer, QString *errorMsg=nullptr, int *errorLine=nullptr, int *errorColumn=nullptr)
 
bool setContent (const QByteArray &text, bool namespaceProcessing, QString *errorMsg=nullptr, int *errorLine=nullptr, int *errorColumn=nullptr)
 
bool setContent (const QString &text, bool namespaceProcessing, QString *errorMsg=nullptr, int *errorLine=nullptr, int *errorColumn=nullptr)
 
bool setContent (const QString &text, QString *errorMsg=nullptr, int *errorLine=nullptr, int *errorColumn=nullptr)
 
bool setContent (QIODevice *device, bool namespaceProcessing, QString *errorMsg=nullptr, int *errorLine=nullptr, int *errorColumn=nullptr)
 
bool setContent (QIODevice *device, QString *errorMsg=nullptr, int *errorLine=nullptr, int *errorColumn=nullptr)
 
bool setContent (QXmlInputSource *source, bool namespaceProcessing, QString *errorMsg=nullptr, int *errorLine=nullptr, int *errorColumn=nullptr)
 
bool setContent (QXmlInputSource *source, QXmlReader *reader, QString *errorMsg=nullptr, int *errorLine=nullptr, int *errorColumn=nullptr)
 
QByteArray toByteArray (int indent=1) const
 
QString toString (int indent=1) const
 
- Public Methods inherited from QDomNode
 QDomNode ()
 
 QDomNode (const QDomNode &other)
 
 ~QDomNode ()
 
QDomNode appendChild (const QDomNode &newChild)
 
QDomNamedNodeMap attributes () const
 
QDomNodeList childNodes () const
 
void clear ()
 
QDomNode cloneNode (bool deep=true) const
 
int columnNumber () const
 
QDomNode firstChild () const
 
QDomElement firstChildElement (const QString &tagName=QString ()) const
 
bool hasAttributes () const
 
bool hasChildNodes () const
 
QDomNode insertAfter (const QDomNode &newChild, const QDomNode &refChild)
 
QDomNode insertBefore (const QDomNode &newChild, const QDomNode &refChild)
 
bool isAttr () const
 
bool isCDATASection () const
 
bool isCharacterData () const
 
bool isComment () const
 
bool isDocument () const
 
bool isDocumentFragment () const
 
bool isDocumentType () const
 
bool isElement () const
 
bool isEntity () const
 
bool isEntityReference () const
 
bool isNotation () const
 
bool isNull () const
 
bool isProcessingInstruction () const
 
bool isSupported (const QString &feature, const QString &version) const
 
bool isText () const
 
QDomNode lastChild () const
 
QDomElement lastChildElement (const QString &tagName=QString ()) const
 
int lineNumber () const
 
QString localName () const
 
QDomNode namedItem (const QString &name) const
 
QString namespaceURI () const
 
QDomNode nextSibling () const
 
QDomElement nextSiblingElement (const QString &tagName=QString ()) const
 
QString nodeName () const
 
NodeType nodeType () const
 
QString nodeValue () const
 
void normalize ()
 
bool operator!= (const QDomNode &n) const
 
QDomNode & operator= (const QDomNode &other)
 
bool operator== (const QDomNode &n) const
 
QDomDocument ownerDocument () const
 
QDomNode parentNode () const
 
QString prefix () const
 
QDomNode previousSibling () const
 
QDomElement previousSiblingElement (const QString &tagName=QString ()) const
 
QDomNode removeChild (const QDomNode &oldChild)
 
QDomNode replaceChild (const QDomNode &newChild, const QDomNode &oldChild)
 
void save (QTextStream &stream, int indent, QDomNode::EncodingPolicy policy=QDomNode::EncodingFromDocument) const
 
void setNodeValue (const QString &value)
 
void setPrefix (const QString &prefix)
 
QDomAttr toAttr () const
 
QDomCDATASection toCDATASection () const
 
QDomCharacterData toCharacterData () const
 
QDomComment toComment () const
 
QDomDocument toDocument () const
 
QDomDocumentFragment toDocumentFragment () const
 
QDomDocumentType toDocumentType () const
 
QDomElement toElement () const
 
QDomEntity toEntity () const
 
QDomEntityReference toEntityReference () const
 
QDomNotation toNotation () const
 
QDomProcessingInstruction toProcessingInstruction () const
 
QDomText toText () const
 

Friends

class QDomNode
 

Additional Inherited Members

- Public Types inherited from QDomNode
enum  EncodingPolicy
 
enum  NodeType
 

Detailed Description

The QDomDocument class represents an XML document.

The QDomDocument class represents the entire XML document. Conceptually, it is the root of the document tree, and provides the primary access to the document's data.

Since elements, text nodes, comments, processing instructions, etc., can not exist outside the context of a document, the document class also contains the factory functions needed to create these objects. The node objects created have an ownerDocument() function which associates them with the document within whose context they were created. The DOM classes that will be used most often are QDomNode, QDomDocument, QDomElement and QDomText.

The parsed XML is represented internally by a tree of objects that can be accessed using the various QDom classes. All QDom classes only reference objects in the internal tree. The internal objects in the DOM tree will get deleted once the last QDom object referencing them and the QDomDocument itself are deleted.

Creation of elements, text nodes, etc. is done using the various factory functions provided in this class. Using the default constructors of the QDom classes will only result in empty objects that can not be manipulated or inserted into the Document.

The QDomDocument class has several functions for creating document data, for example, createElement(), createTextNode(), createComment(), createCDATASection(), createProcessingInstruction(), createAttribute() and createEntityReference(). Some of these functions have versions that support namespaces, i.e. createElementNS() and createAttributeNS(). The createDocumentFragment() function is used to hold parts of the document; this is useful for manipulating for complex documents.

The entire content of the document is set with setContent(). This function parses the string it is passed as an XML document and creates the DOM tree that represents the document. The root element is available using documentElement(). The textual representation of the document can be obtained using toString().

Note
The DOM tree might end up reserving a lot of memory if the XML document is big. For big XML documents, the QXmlStreamReader or the QXmlQuery classes might be better solutions.

It is possible to insert a node from another document into the document using importNode().

You can obtain a list of all the elements that have a particular tag with elementsByTagName() or with elementsByTagNameNS().

The QDom classes are typically used as follows:

QDomDocument doc("mydocument");
QFile file("mydocument.xml");
if (! file.open(QIODevice::ReadOnly))
return;
if (! doc.setContent(&file)) {
file.close();
return;
}
file.close();
// print the names of all elements that are direct children of the outermost element
QDomElement docElem = doc.documentElement();
QDomNode n = docElem.firstChild();
while(! n.isNull()) {
QDomElement e = n.toElement(); // try to convert the node to an element.
if(! e.isNull()) {
cout << csPrintable(e.tagName()) << endl; // the node really is an element.
}
n = n.nextSibling();
}
// append a new element to the end of the document
QDomElement elem = doc.createElement("img");
elem.setAttribute("src", "myimage.png");
docElem.appendChild(elem);

Once doc and elem go out of scope, the whole internal tree representing the XML document is deleted.

To create a document using DOM use code like this:

QDomDocument doc("MyML");
QDomElement root = doc.createElement("MyML");
doc.appendChild(root);
QDomElement tag = doc.createElement("Greeting");
root.appendChild(tag);
QDomText t = doc.createTextNode("Hello World");
tag.appendChild(t);
QString xml = doc.toString();

For further information about the Document Object Model see the Document Object Model (DOM) Level 1 and Level 2 Core Specifications.

See also
QDomImplementation::createDocumentType()

Constructor & Destructor Documentation

QDomDocument::QDomDocument ( )

Constructs an empty document.

QDomDocument::QDomDocument ( const QString name)
explicit

Creates a document and sets the name of the document type to name.

QDomDocument::QDomDocument ( const QDomDocumentType doctype)
explicit

Creates a document with the document type doctype.

See also
QDomImplementation::createDocumentType()
QDomDocument::QDomDocument ( const QDomDocument &  other)

Copy constructs a new QDomDocument from other.

QDomDocument::~QDomDocument ( )

Destroys the object and frees its resources.

Method Documentation

QDomAttr QDomDocument::createAttribute ( const QString name)

Creates a new attribute called name that can be inserted into an element, e.g. using QDomElement::setAttributeNode().

If name is not a valid XML name, the behavior of this function is governed by QDomImplementation::InvalidDataPolicy.

See also
createAttributeNS()
QDomAttr QDomDocument::createAttributeNS ( const QString nsURI,
const QString qName 
)

Creates a new attribute with namespace support that can be inserted into an element. The name of the attribute is qName and the namespace URI is nsURI. This function also sets QDomNode::prefix() and QDomNode::localName() to appropriate values (depending on qName).

If qName is not a valid XML name, the behavior of this function is governed by QDomImplementation::InvalidDataPolicy.

See also
createAttribute()
QDomCDATASection QDomDocument::createCDATASection ( const QString text)

Creates a new CDATA section for the string text that can be inserted into the document, e.g. using QDomNode::appendChild().

If value contains characters which can not be stored in a CDATA section, the behavior of this function is governed by QDomImplementation::InvalidDataPolicy.

See also
QDomNode::appendChild(), QDomNode::insertBefore(), QDomNode::insertAfter()
QDomComment QDomDocument::createComment ( const QString text)

Creates a new comment for the string text that can be inserted into the document, e.g. using QDomNode::appendChild().

If value contains characters which can not be stored in an XML comment, the behavior of this function is governed by QDomImplementation::InvalidDataPolicy.

See also
QDomNode::appendChild(), QDomNode::insertBefore(), QDomNode::insertAfter()
QDomDocumentFragment QDomDocument::createDocumentFragment ( )

Creates a new document fragment, that can be used to hold parts of the document, e.g. when doing complex manipulations of the document tree.

QDomElement QDomDocument::createElement ( const QString tagName)

Creates a new element called tagName that can be inserted into the DOM tree, e.g. using QDomNode::appendChild().

If tagName is not a valid XML name, the behavior of this function is governed by QDomImplementation::InvalidDataPolicy.

QDomNode::insertAfter()

See also
createElementNS(), QDomNode::appendChild(), QDomNode::insertBefore()
QDomElement QDomDocument::createElementNS ( const QString nsURI,
const QString qName 
)

Creates a new element with namespace support that can be inserted into the DOM tree. The name of the element is qName and the namespace URI is nsURI. This function also sets QDomNode::prefix() and QDomNode::localName() to appropriate values (depending on qName).

If qName is an empty string, returns a null element regardless of whether the invalid data policy is set.

See also
createElement()
QDomEntityReference QDomDocument::createEntityReference ( const QString name)

Creates a new entity reference called name that can be inserted into the document, e.g. using QDomNode::appendChild().

If name is not a valid XML name, the behavior of this function is governed by QDomImplementation::InvalidDataPolicy.

See also
QDomNode::appendChild(), QDomNode::insertBefore(), QDomNode::insertAfter()
QDomProcessingInstruction QDomDocument::createProcessingInstruction ( const QString target,
const QString data 
)

Creates a new processing instruction that can be inserted into the document, e.g. using QDomNode::appendChild(). This function sets the target for the processing instruction to target and the data to data.

If target is not a valid XML name, or data if contains characters which can not appear in a processing instruction, the behavior of this function is governed by QDomImplementation::InvalidDataPolicy.

See also
QDomNode::appendChild(), QDomNode::insertBefore(), QDomNode::insertAfter()
QDomText QDomDocument::createTextNode ( const QString text)

Creates a text node for the string text that can be inserted into the document tree, e.g. using QDomNode::appendChild().

If value contains characters which can not be stored as character data of an XML document (even in the form of character references), the behavior of this function is governed by QDomImplementation::InvalidDataPolicy.

See also
QDomNode::appendChild(), QDomNode::insertBefore(), QDomNode::insertAfter()
QDomDocumentType QDomDocument::doctype ( ) const

Returns the document type of this document.

QDomElement QDomDocument::documentElement ( ) const

Returns the root element of the document.

QDomElement QDomDocument::elementById ( const QString elementId)

Returns the element whose ID is equal to elementId. If no element with the ID was found, this function returns a null element.

Since the QDomClasses does not know which attributes are element IDs, this function returns always a null element.

QDomNodeList QDomDocument::elementsByTagName ( const QString tagname) const

Returns a QDomNodeList, that contains all the elements in the document with the name tagname. The order of the node list is the order they are encountered in a preorder traversal of the element tree.

See also
elementsByTagNameNS(), QDomElement::elementsByTagName()
QDomNodeList QDomDocument::elementsByTagNameNS ( const QString nsURI,
const QString localName 
)

Returns a QDomNodeList that contains all the elements in the document with the local name localName and a namespace URI of nsURI. The order of the node list is the order they are encountered in a preorder traversal of the element tree.

See also
elementsByTagName(), QDomElement::elementsByTagNameNS()
QDomImplementation QDomDocument::implementation ( ) const

Returns a QDomImplementation object.

QDomNode QDomDocument::importNode ( const QDomNode importedNode,
bool  deep 
)

Imports the node importedNode from another document to this document. importedNode remains in the original document; this function creates a copy that can be used within this document.

This function returns the imported node that belongs to this document. The returned node has no parent. It is not possible to import QDomDocument and QDomDocumentType nodes. In those cases this function returns a null node.

If deep is true, this function imports not only the node importedNode but its whole subtree; if it is false, only the importedNode is imported. The argument deep has no effect on QDomAttr and QDomEntityReference nodes, since the descendants of QDomAttr nodes are always imported and those of QDomEntityReference nodes are never imported.

The behavior of this function is slightly different depending on the node types:

Node TypeBehavior
QDomAttrThe owner element is set to 0 and the specified flag is set to true in the generated attribute. The whole subtree of importedNode is always imported for attribute nodes: deep has no effect.
QDomDocumentDocument nodes can not be imported.
QDomDocumentFragmentIf deep is true, this function imports the whole document fragment, otherwise it only generates an empty document fragment.
QDomDocumentTypeDocument type nodes can not be imported.
QDomElementAttributes for which QDomAttr::specified() is true are also imported, other attributes are not imported. If deep is true, this function also imports the subtree of importedNode, otherwise it imports only the element node (and some attributes, see above).
QDomEntityEntity nodes can be imported, but at the moment there is no way to use them since the document type is read-only in DOM level 2.
QDomEntityReferenceDescendants of entity reference nodes are never imported: deep has no effect.
QDomNotationNotation nodes can be imported, but at the moment there is no way to use them since the document type is read-only in DOM level 2.
QDomProcessingInstructionThe target and value of the processing instruction is copied to the new node.
QDomTextThe text is copied to the new node.
QDomCDATASectionThe text is copied to the new node.
QDomCommentThe text is copied to the new node.

QDomNode::insertAfter() QDomNode::replaceChild() QDomNode::removeChild() QDomNode::appendChild()

See also
QDomElement::setAttribute(), QDomNode::insertBefore()
QDomNode::NodeType QDomDocument::nodeType ( ) const
inline

Returns DocumentNode.

QDomDocument & QDomDocument::operator= ( const QDomDocument &  other)

Copy assigns from other and returns a reference to this object.

bool QDomDocument::setContent ( const QByteArray buffer,
QString errorMsg = nullptr,
int *  errorLine = nullptr,
int *  errorColumn = nullptr 
)

This method reads the XML document from the buffer, returning true if the content was successfully parsed, otherwise returns false. No namespace processing is performed.

bool QDomDocument::setContent ( const QByteArray text,
bool  namespaceProcessing,
QString errorMsg = nullptr,
int *  errorLine = nullptr,
int *  errorColumn = nullptr 
)

This function parses the XML document from the byte array text and sets it as the content of the document. It tries to detect the encoding of the document as required by the XML specification.

If namespaceProcessing is true, the parser recognizes namespaces in the XML file and sets the prefix name, local name and namespace URI to appropriate values. If namespaceProcessing is false, the parser does no namespace processing when it reads the XML file.

If a parse error occurs, this function returns false and the error message is placed in *errorMsg, the line number in *errorLine and the column number in *errorColumn (unless the associated pointer is set to 0), otherwise this function returns true. The various error messages are described in the QXmlParseException class documentation. Note that, if you want to display these error messages to your application's users, they will be displayed in English unless they are explicitly translated.

If namespaceProcessing is true, the function QDomNode::prefix() returns a string for all elements and attributes. It returns an empty string if the element or attribute has no prefix.

Text nodes consisting only of whitespace are stripped and will not appear in the QDomDocument. If this behavior is not desired, one can use the setContent() overload that allows a QXmlReader to be supplied.

If namespaceProcessing is false, the functions QDomNode::prefix(), QDomNode::localName() and QDomNode::namespaceURI() return an empty string.

Entity references are handled as follows:

  • References to internal general entities and character entities occurring in the content are included. The result is a QDomText node with the references replaced by their corresponding entity values.
  • References to parameter entities occurring in the internal subset are included. The result is a QDomDocumentType node which contains entity and notation declarations with the references replaced by their corresponding entity values.
  • Any general parsed entity reference which is not defined in the internal subset and which occurs in the content is represented as a QDomEntityReference node.
  • Any parsed entity reference which is not defined in the internal subset and which occurs outside of the content is replaced with an empty string.
  • Any unparsed entity reference is replaced with an empty string.

QDomNode::prefix() QString::isNull() QString::isEmpty()

Warning
This method is not conditionally thread safe.
See also
QDomNode::namespaceURI(), QDomNode::localName()
bool QDomDocument::setContent ( const QString text,
bool  namespaceProcessing,
QString errorMsg = nullptr,
int *  errorLine = nullptr,
int *  errorColumn = nullptr 
)

This function reads the XML document from the string text, returning true if the content was successfully parsed, otherwise returns false. Since text is already a Unicode string, no encoding detection is done.

bool QDomDocument::setContent ( const QString text,
QString errorMsg = nullptr,
int *  errorLine = nullptr,
int *  errorColumn = nullptr 
)

This method reads the XML document from the string text, returning true if the content was successfully parsed, otherwise returns false. Since text is already a Unicode string, no encoding detection is performed.

No namespace processing is performed either.

bool QDomDocument::setContent ( QIODevice device,
bool  namespaceProcessing,
QString errorMsg = nullptr,
int *  errorLine = nullptr,
int *  errorColumn = nullptr 
)

This method reads the XML document from the IO device device, returning true if the content was successfully parsed, otherwise returns false.

bool QDomDocument::setContent ( QIODevice device,
QString errorMsg = nullptr,
int *  errorLine = nullptr,
int *  errorColumn = nullptr 
)

This method reads the XML document from the IO device device, returning true if the content was successfully parsed, otherwise returns false.

No namespace processing is performed.

bool QDomDocument::setContent ( QXmlInputSource source,
bool  namespaceProcessing,
QString errorMsg = nullptr,
int *  errorLine = nullptr,
int *  errorColumn = nullptr 
)

This method reads the XML document from the QXmlInputSource source, returning true if the content was successfully parsed, otherwise returns false.

bool QDomDocument::setContent ( QXmlInputSource source,
QXmlReader reader,
QString errorMsg = nullptr,
int *  errorLine = nullptr,
int *  errorColumn = nullptr 
)

This method reads the XML document from the QXmlInputSource source and parses it with the QXmlReader reader, returning true if the content was successfully parsed, otherwise returns false. This method does not change the features of the reader. If you want to use certain features for parsing you can use this function to set up the reader appropriately.

See also
QXmlSimpleReader
QByteArray QDomDocument::toByteArray ( int  indent = 1) const

Converts the parsed document back to its textual representation and returns a QByteArray containing the data encoded as UTF-8.

This function uses indent as the amount of space to indent subelements.

See also
toString()
QString QDomDocument::toString ( int  indent = 1) const

Converts the parsed document back to its textual representation. This function uses indent as the amount of space to indent subelements.

If indent is -1, no whitespace at all is added.