• PySide 模块
  • PySide.QtXml
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    QDomDocumentType

    QDomDocument

    概要

    函数

    详细描述

    PySide.QtXml.QDomDocument class represents an XML document.

    PySide.QtXml.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., cannot 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 PySide.QtXml.QDomNode.ownerDocument() function which associates them with the document within whose context they were created. The DOM classes that will be used most often are PySide.QtXml.QDomNode , PySide.QtXml.QDomDocument , PySide.QtXml.QDomElement and PySide.QtXml.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 PySide.QtXml.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 cannot be manipulated or inserted into the Document.

    PySide.QtXml.QDomDocument class has several functions for creating document data, for example, PySide.QtXml.QDomDocument.createElement() , PySide.QtXml.QDomDocument.createTextNode() , PySide.QtXml.QDomDocument.createComment() , PySide.QtXml.QDomDocument.createCDATASection() , PySide.QtXml.QDomDocument.createProcessingInstruction() , PySide.QtXml.QDomDocument.createAttribute() and PySide.QtXml.QDomDocument.createEntityReference() . Some of these functions have versions that support namespaces, i.e. PySide.QtXml.QDomDocument.createElementNS() and PySide.QtXml.QDomDocument.createAttributeNS() PySide.QtXml.QDomDocument.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 PySide.QtXml.QDomDocument.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 PySide.QtXml.QDomDocument.documentElement() . The textual representation of the document can be obtained using PySide.QtXml.QDomDocument.toString() .

    注意

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

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

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

    The QDom classes are typically used as follows:

    doc = QDomDocument("mydocument")
    file = QFile("mydocument.xml")
    if not file.open(QIODevice::ReadOnly):
        return
    if not doc.setContent(&file):
        file.close()
        return
    file.close()
    # print out the element names of all elements that are direct children
    # of the outermost element.
    docElem = doc.documentElement()
    n = docElem.firstChild()
    while not n.isNull():
        e = n.toElement() # try to convert the node to an element.
        if not e.isNull():
            print e.tagName() # the node really is an element.
        n = n.nextSibling()
    }
    # Here we append a new element to the end of the document
    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:

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

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

    另请参阅

    DOM 书签范例 Simple DOM Model Example

    class PySide.QtXml. QDomDocument
    class PySide.QtXml. QDomDocument ( x )
    class PySide.QtXml. QDomDocument ( doctype )
    class PySide.QtXml. QDomDocument ( name )
    参数:

    Constructs an empty document.

    构造副本为 x .

    The data of the copy is shared (shallow copy): modifying one node will also change the other. If you want to make a deep copy, use PySide.QtXml.QDomNode.cloneNode() .

    Creates a document with the document type doctype .

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

    PySide.QtXml.QDomDocument. createAttribute ( name )
    参数: name – unicode
    返回类型: PySide.QtXml.QDomAttr

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

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

    PySide.QtXml.QDomDocument. createAttributeNS ( nsURI , qName )
    参数:
    • nsURI – unicode
    • qName – unicode
    返回类型:

    PySide.QtXml.QDomAttr

    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 ).

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

    PySide.QtXml.QDomDocument. createCDATASection ( data )
    参数: data – unicode
    返回类型: PySide.QtXml.QDomCDATASection

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

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

    PySide.QtXml.QDomDocument. createComment ( data )
    参数: data – unicode
    返回类型: PySide.QtXml.QDomComment

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

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

    PySide.QtXml.QDomDocument. createDocumentFragment ( )
    返回类型: PySide.QtXml.QDomDocumentFragment

    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.

    PySide.QtXml.QDomDocument. createElement ( tagName )
    参数: tagName – unicode
    返回类型: PySide.QtXml.QDomElement

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

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

    QDomNode.insertAfter()

    PySide.QtXml.QDomDocument. createElementNS ( nsURI , qName )
    参数:
    • nsURI – unicode
    • qName – unicode
    返回类型:

    PySide.QtXml.QDomElement

    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 ).

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

    PySide.QtXml.QDomDocument. createEntityReference ( name )
    参数: name – unicode
    返回类型: PySide.QtXml.QDomEntityReference

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

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

    PySide.QtXml.QDomDocument. createProcessingInstruction ( target , data )
    参数:
    • target – unicode
    • data – unicode
    返回类型:

    PySide.QtXml.QDomProcessingInstruction

    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 .

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

    PySide.QtXml.QDomDocument. createTextNode ( data )
    参数: data – unicode
    返回类型: PySide.QtXml.QDomText

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

    value contains characters which cannot 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 .

    PySide.QtXml.QDomDocument. doctype ( )
    返回类型: PySide.QtXml.QDomDocumentType

    Returns the document type of this document.

    PySide.QtXml.QDomDocument. documentElement ( )
    返回类型: PySide.QtXml.QDomElement

    Returns the root element of the document.

    PySide.QtXml.QDomDocument. elementById ( elementId )
    参数: elementId – unicode
    返回类型: PySide.QtXml.QDomElement

    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 do not know which attributes are element IDs, this function returns always a null element . This may change in a future version.

    PySide.QtXml.QDomDocument. elementsByTagName ( tagname )
    参数: tagname – unicode
    返回类型: PySide.QtXml.QDomNodeList

    返回 PySide.QtXml.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.

    PySide.QtXml.QDomDocument. elementsByTagNameNS ( nsURI , localName )
    参数:
    • nsURI – unicode
    • localName – unicode
    返回类型:

    PySide.QtXml.QDomNodeList

    返回 PySide.QtXml.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.

    PySide.QtXml.QDomDocument. 实现 ( )
    返回类型: PySide.QtXml.QDomImplementation

    返回 PySide.QtXml.QDomImplementation 对象。

    PySide.QtXml.QDomDocument. importNode ( importedNode , deep )
    参数:
    返回类型:

    PySide.QtXml.QDomNode

    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 PySide.QtXml.QDomDocument and PySide.QtXml.QDomDocumentType nodes. In those cases this function returns a null node .

    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 PySide.QtXml.QDomAttr and PySide.QtXml.QDomEntityReference nodes, since the descendants of PySide.QtXml.QDomAttr nodes are always imported and those of PySide.QtXml.QDomEntityReference nodes are never imported.

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

    Node Type Behavior
    PySide.QtXml.QDomAttr The 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.
    PySide.QtXml.QDomDocument Document nodes cannot be imported.
    PySide.QtXml.QDomDocumentFragment deep is true, this function imports the whole document fragment; otherwise it only generates an empty document fragment.
    PySide.QtXml.QDomDocumentType Document type nodes cannot be imported.
    PySide.QtXml.QDomElement Attributes 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).
    PySide.QtXml.QDomEntity Entity 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.
    PySide.QtXml.QDomEntityReference Descendants of entity reference nodes are never imported: deep has no effect.
    PySide.QtXml.QDomNotation Notation 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.
    PySide.QtXml.QDomProcessingInstruction The target and value of the processing instruction is copied to the new node.
    PySide.QtXml.QDomText The text is copied to the new node.
    PySide.QtXml.QDomCDATASection The text is copied to the new node.
    PySide.QtXml.QDomComment The text is copied to the new node.

    QDomNode.insertAfter() QDomNode.replaceChild() QDomNode.removeChild() QDomNode.appendChild()

    PySide.QtXml.QDomDocument. setContent ( text , namespaceProcessing )
    参数:
    返回类型:

    (retval, errorMsg, errorLine, errorColumn)

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

    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 PySide.QtXml.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.

    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 won't appear in the PySide.QtXml.QDomDocument . If this behavior is not desired, one can use the PySide.QtXml.QDomDocument.setContent() overload that allows a PySide.QtXml.QXmlReader to be supplied.

    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 PySide.QtXml.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 PySide.QtXml.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 PySide.QtXml.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()

    PySide.QtXml.QDomDocument. setContent ( text )
    参数: text – unicode
    返回类型: (retval, errorMsg, errorLine, errorColumn)

    这是重载函数。

    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 performed.

    No namespace processing is performed either.

    PySide.QtXml.QDomDocument. setContent ( text , namespaceProcessing )
    参数:
    • text – unicode
    • namespaceProcessing PySide.QtCore.bool
    返回类型:

    (retval, errorMsg, errorLine, errorColumn)

    这是重载函数。

    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.

    PySide.QtXml.QDomDocument. setContent ( text )
    参数: text PySide.QtCore.QByteArray
    返回类型: (retval, errorMsg, errorLine, errorColumn)

    这是重载函数。

    This function reads the XML document from the byte array buffer , returning true if the content was successfully parsed; otherwise returns false.

    No namespace processing is performed.

    PySide.QtXml.QDomDocument. setContent ( dev , namespaceProcessing )
    参数:
    返回类型:

    (retval, errorMsg, errorLine, errorColumn)

    这是重载函数。

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

    PySide.QtXml.QDomDocument. setContent ( dev )
    参数: dev PySide.QtCore.QIODevice
    返回类型: (retval, errorMsg, errorLine, errorColumn)

    这是重载函数。

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

    No namespace processing is performed.

    PySide.QtXml.QDomDocument. setContent ( source , namespaceProcessing )
    参数:
    返回类型:

    (retval, errorMsg, errorLine, errorColumn)

    这是重载函数。

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

    PySide.QtXml.QDomDocument. setContent ( source , reader )
    参数:
    返回类型:

    (retval, errorMsg, errorLine, errorColumn)

    这是重载函数。

    This function reads the XML document from the PySide.QtXml.QXmlInputSource source and parses it with the PySide.QtXml.QXmlReader reader , returning true if the content was successfully parsed; otherwise returns false.

    This function doesn't 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.

    PySide.QtXml.QDomDocument. toByteArray ( [ arg__1=1 ] )
    参数: arg__1 PySide.QtCore.int
    返回类型: PySide.QtCore.QByteArray

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

    此函数使用 indent as the amount of space to indent subelements.

    PySide.QtXml.QDomDocument. toString ( [ arg__1=1 ] )
    参数: arg__1 PySide.QtCore.int
    返回类型: unicode

    Converts the parsed document back to its textual representation.

    此函数使用 indent as the amount of space to indent subelements.

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