QDomImplementation Class Reference

The QDomImplementation class provides information about the features of the DOM implementation. More...

#include <qdom.h>

Public Types
enum	InvalidDataPolicy { AcceptInvalidChars = 0, DropInvalidChars, ReturnNullNode }
	This enum specifies what should be done when a factory function in QDomDocument is called with invalid data. More...

Public Functions
QDomDocument	createDocument (const QString &nsURI, const QString &qName, const QDomDocumentType &doctype)
	Creates a DOM document with the document type doctype. More...
QDomDocumentType	createDocumentType (const QString &qName, const QString &publicId, const QString &systemId)
	Creates a document type node for the name qName. More...
bool	hasFeature (const QString &feature, const QString &version) const
	The function returns true if QDom implements the requested version of a feature; otherwise returns false. More...
bool	isNull ()
	Returns false if the object was created by QDomDocument::implementation(); otherwise returns true. More...
bool	operator!= (const QDomImplementation &) const
	Returns true if x and this DOM implementation object were created from different QDomDocuments; otherwise returns false. More...
QDomImplementation &	operator= (const QDomImplementation &)
	Assigns x to this DOM implementation. More...
bool	operator== (const QDomImplementation &) const
	Returns true if x and this DOM implementation object were created from the same QDomDocument; otherwise returns false. More...
	QDomImplementation ()
	Constructs a QDomImplementation object. More...
	QDomImplementation (const QDomImplementation &)
	Constructs a copy of x. More...
	~QDomImplementation ()
	Destroys the object and frees its resources. More...

Static Public Functions
static InvalidDataPolicy	invalidDataPolicy ()
	Returns the invalid data policy, which specifies what should be done when a factory function in QDomDocument is passed invalid data. More...
static void	setInvalidDataPolicy (InvalidDataPolicy policy)
	Sets the invalid data policy, which specifies what should be done when a factory function in QDomDocument is passed invalid data. More...

Private Functions
	QDomImplementation (QDomImplementationPrivate *)

Properties
QDomImplementationPrivate *	impl

Friends
class	QDomDocument

Detailed Description

The QDomImplementation class provides information about the features of the DOM implementation.

Note

This class or function is reentrant.

Attention

Module: QtXml

This class describes the features that are supported by the DOM implementation. Currently the XML subset of DOM Level 1 and DOM Level 2 Core are supported.

Normally you will use the function QDomDocument::implementation() to get the implementation object.

You can create a new document type with createDocumentType() and a new document with createDocument().

For further information about the Document Object Model see Level 1 and Level 2 Core. For a more general introduction of the DOM implementation see the QDomDocument documentation.

The QDom classes have a few issues of nonconformance with the XML specifications that cannot be fixed in Qt 4 without breaking backward compatibility. The QtXmlPatterns module and the QXmlStreamReader and QXmlStreamWriter classes have a higher degree of a conformance.

See also

hasFeature()

Definition at line 99 of file qdom.h.

Enumerations

InvalidDataPolicy

enum QDomImplementation::InvalidDataPolicy

This enum specifies what should be done when a factory function in QDomDocument is called with invalid data.

• AcceptInvalidChars The data should be stored in the DOM object anyway. In this case the resulting XML document might not be well-formed. This is the default value and QDom's behavior in Qt < 4.1.
• DropInvalidChars The invalid characters should be removed from the data.
• ReturnNullNode The factory function should return a null node.

See also

setInvalidDataPolicy() invalidDataPolicy()

Enumerator
AcceptInvalidChars
DropInvalidChars
ReturnNullNode

Definition at line 114 of file qdom.h.

{ AcceptInvalidChars = 0, DropInvalidChars, ReturnNullNode };

Constructors and Destructors

QDomImplementation() [1/3]

QDomImplementation::QDomImplementation

(

)

Constructs a QDomImplementation object.

Definition at line 922 of file qdom.cpp.

{
    impl = 0;
}

QDomImplementation() [2/3]

QDomImplementation::QDomImplementation

(

const QDomImplementation &

x

)

Constructs a copy of x.

Definition at line 930 of file qdom.cpp.

{
    impl = x.impl;
    if (impl)
        impl->ref.ref();
}

~QDomImplementation()

QDomImplementation::~QDomImplementation

(

)

Destroys the object and frees its resources.

Definition at line 979 of file qdom.cpp.

{
    if (impl && !impl->ref.deref())
        delete impl;
}

QDomImplementation() [3/3]

QDomImplementation::QDomImplementation ( QDomImplementationPrivate *  p )

private

Definition at line 937 of file qdom.cpp.

{
    // We want to be co-owners, so increase the reference count
    impl = p;
    if (impl)
        impl->ref.ref();
}

Functions

createDocument()

QDomDocument QDomImplementation::createDocument	(	const QString &	nsURI,
		const QString &	qName,
		const QDomDocumentType &	doctype
	)

Creates a DOM document with the document type doctype.

This function also adds a root element node with the qualified name qName and the namespace URI nsURI.

Definition at line 1071 of file qdom.cpp.

{
    QDomDocument doc(doctype);
    QDomElement root = doc.createElementNS(nsURI, qName);
    if (root.isNull())
        return QDomDocument();
    doc.appendChild(root);
    return doc;
}

createDocumentType()

QDomDocumentType QDomImplementation::createDocumentType	(	const QString &	qName,
		const QString &	publicId,
		const QString &	systemId
	)

Creates a document type node for the name qName.

publicId specifies the public identifier of the external subset. If you specify an empty string (QString()) as the publicId, this means that the document type has no public identifier.

systemId specifies the system identifier of the external subset. If you specify an empty string as the systemId, this means that the document type has no system identifier.

Since you cannot have a public identifier without a system identifier, the public identifier is set to an empty string if there is no system identifier.

DOM level 2 does not support any other document type declaration features.

The only way you can use a document type that was created this way, is in combination with the createDocument() function to create a QDomDocument with this document type.

In the DOM specification, this is the only way to create a non-null document. For historical reasons, Qt also allows to create the document using the default empty constructor. The resulting document is null, but becomes non-null when a factory function, for example QDomDocument::createElement(), is called. The document also becomes non-null when setContent() is called.

See also

createDocument()

Definition at line 1038 of file qdom.cpp.

{
    bool ok;
    QString fixedName = fixedXmlName(qName, &ok, true);
    if (!ok)
        return QDomDocumentType();

    QString fixedPublicId = fixedPubidLiteral(publicId, &ok);
    if (!ok)
        return QDomDocumentType();

    QString fixedSystemId = fixedSystemLiteral(systemId, &ok);
    if (!ok)
        return QDomDocumentType();

    QDomDocumentTypePrivate *dt = new QDomDocumentTypePrivate(0);
    dt->name = fixedName;
    if (systemId.isNull()) {
        dt->publicId.clear();
        dt->systemId.clear();
    } else {
        dt->publicId = fixedPublicId;
        dt->systemId = fixedSystemId;
    }
    dt->ref.deref();
    return QDomDocumentType(dt);
}

hasFeature()

bool QDomImplementation::hasFeature	(	const QString &	feature,
		const QString &	version
	)		const

The function returns true if QDom implements the requested version of a feature; otherwise returns false.

The currently supported features and their versions:

Feature	Version
XML	1.0

Definition at line 995 of file qdom.cpp.

Referenced by QDomNode::isSupported().

{
    if (feature == QLatin1String("XML")) {
        if (version.isEmpty() || version == QLatin1String("1.0")) {
            return true;
        }
    }
    // ### add DOM level 2 features
    return false;
}

invalidDataPolicy()

QDomImplementation::InvalidDataPolicy QDomImplementation::invalidDataPolicy ( )

static

Returns the invalid data policy, which specifies what should be done when a factory function in QDomDocument is passed invalid data.

Since

4.1

Note

This class or function is not reentrant.

See also

setInvalidDataPolicy() InvalidDataPolicy

Definition at line 1137 of file qdom.cpp.

{
    return QDomImplementationPrivate::invalidDataPolicy;
}

isNull()

bool QDomImplementation::isNull

(

)

Returns false if the object was created by QDomDocument::implementation(); otherwise returns true.

Definition at line 1085 of file qdom.cpp.

{
    return (impl == 0);
}

operator!=()

bool QDomImplementation::operator!=

(

const QDomImplementation &

x

)

const

Returns true if x and this DOM implementation object were created from different QDomDocuments; otherwise returns false.

Definition at line 971 of file qdom.cpp.

{
    return (impl != x.impl);
}

operator=()

QDomImplementation & QDomImplementation::operator=

(

const QDomImplementation &

x

)

Assigns x to this DOM implementation.

Definition at line 948 of file qdom.cpp.

{
    if (x.impl)
        x.impl->ref.ref();
    if (impl && !impl->ref.deref())
        delete impl;
    impl = x.impl;
    return *this;
}

operator==()

bool QDomImplementation::operator==

(

const QDomImplementation &

x

)

const

Returns true if x and this DOM implementation object were created from the same QDomDocument; otherwise returns false.

Definition at line 962 of file qdom.cpp.

{
    return (impl == x.impl);
}

setInvalidDataPolicy()

void QDomImplementation::setInvalidDataPolicy ( InvalidDataPolicy  policy )

static

Sets the invalid data policy, which specifies what should be done when a factory function in QDomDocument is passed invalid data.

Since

4.1

Note

This class or function is not reentrant.

The policy is set for all instances of QDomDocument which already exist and which will be created in the future.

QDomDocument doc;
QDomImplementation impl;

// This will create the element, but the resulting XML document will
// be invalid, because '~' is not a valid character in a tag name.
impl.setInvalidDataPolicy(QDomImplementation::AcceptInvalidData);
QDomElement elt1 = doc.createElement("foo~bar");

// This will create an element with the tag name "foobar".
impl.setInvalidDataPolicy(QDomImplementation::DropInvalidData);
QDomElement elt2 = doc.createElement("foo~bar");

// This will create a null element.
impl.setInvalidDataPolicy(QDomImplementation::ReturnNullNode);
QDomElement elt3 = doc.createElement("foo~bar");

See also

invalidDataPolicy() InvalidDataPolicy

Definition at line 1160 of file qdom.cpp.

{
    QDomImplementationPrivate::invalidDataPolicy = policy;
}

Friends and Related Functions

QDomDocument

friend class QDomDocument

friend

Definition at line 125 of file qdom.h.

Properties

impl

QDomImplementationPrivate* QDomImplementation::impl

private

Definition at line 122 of file qdom.h.

Referenced by operator!=(), operator=(), operator==(), and QDomImplementation().

---

The documentation for this class was generated from the following files:

• /src/xml/dom/qdom.h
• /src/xml/dom/qdom.cpp