内容

公共类型
公共函数
静态公共成员
详细描述

QDomImplementation 类

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

头：	#include <QDomImplementation>
qmake:	QT += xml

所有成员列表，包括继承成员

注意： 此类的所有函数可重入除以下外：

invalidDataPolicy ()
setInvalidDataPolicy (InvalidDataPolicy policy)

公共类型

enum	InvalidDataPolicy { AcceptInvalidChars, DropInvalidChars, ReturnNullNode }

公共函数

	QDomImplementation ()
	QDomImplementation (const QDomImplementation & x )
	~QDomImplementation ()
QDomDocument	createDocument (const QString & nsURI , const QString & qName , const QDomDocumentType & doctype )
QDomDocumentType	createDocumentType (const QString & qName , const QString & publicId , const QString & systemId )
bool	hasFeature (const QString & feature , const QString & version ) const
bool	isNull ()
bool	operator!= (const QDomImplementation & x ) const
QDomImplementation &	operator= (const QDomImplementation & x )
bool	operator== (const QDomImplementation & x ) const

静态公共成员

InvalidDataPolicy	invalidDataPolicy ()
void	setInvalidDataPolicy (InvalidDataPolicy policy )

详细描述

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

此类描述由 DOM 实现所支持的特征。目前支持 DOM 级别 1 和 DOM 级别 2 核心 XML 子集。

通常，使用函数 QDomDocument::implementation () 能获取实现对象。

可以创建新的文档类型采用 createDocumentType () 和新的文档采用 createDocument ().

有关文档对象模型的进一步信息，见级别 1 and 级别 2 核心。有关 DOM 实现的更一般介绍，见 QDomDocument 文档编制。

QDom 类有一些不符合 XML 规范的问题，Qt 4 无法在不破坏向后兼容性的情况下修复这些问题。Qt XML 模式模块和 QXmlStreamReader and QXmlStreamWriter 类拥有更高一致性。

另请参阅 hasFeature ().

成员类型文档编制

enum QDomImplementation:: InvalidDataPolicy

此枚举指定应做什么，当工厂函数在 QDomDocument 被调用采用无效数据。

常量	值	描述
`QDomImplementation::AcceptInvalidChars`	`0`	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.
`QDomImplementation::DropInvalidChars`	`1`	应从数据中移除无效字符。
`QDomImplementation::ReturnNullNode`	`2`	工厂函数应返回 null 节点。

另请参阅 setInvalidDataPolicy () 和 invalidDataPolicy ().

成员函数文档编制

QDomImplementation:: QDomImplementation ()

构造 QDomImplementation 对象。

QDomImplementation:: QDomImplementation (const QDomImplementation & x )

构造副本为 x .

QDomImplementation:: ~QDomImplementation ()

销毁对象并释放其资源。

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

创建的 DOM (文档对象模型) 文档具有文档类型 doctype . This function also adds a root element node with the qualified name qName 和名称空间 URI nsURI .

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

创建文档类型节点为名称 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.

另请参阅 createDocument ().

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

函数返回 true if QDom implements the requested version of a feature ；否则返回 false .

目前支持的特征及其版本：

特征	版本
XML	1.0

`[static]` InvalidDataPolicy QDomImplementation:: invalidDataPolicy ()

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

警告： 此函数不可重入 .

该函数在 Qt 4.1 引入。

另请参阅 setInvalidDataPolicy () 和 InvalidDataPolicy .

bool QDomImplementation:: isNull ()

返回 false 如果对象被创建由 QDomDocument::implementation ()；否则返回 true .

`[static]` void QDomImplementation:: setInvalidDataPolicy ( InvalidDataPolicy policy )

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

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");