wx.xml.XmlDocument¶

This class holds XML data/document as parsed by XML parser in the root node.

wx.xml.XmlDocument internally uses the expat library which comes with wxWidgets to parse the given stream.

A wx.xml.XmlDocument is in fact a list of wx.xml.XmlNode organised into a structure that reflects the XML tree being represented by the document.

A simple example of using XML classes is:

def ScanDocument():

    doc = wx.xml.XmlDocument()
    if not doc.Load("myfile.xml"):
        return False

    # start processing the XML file
    if doc.GetRoot().GetName() != "myroot-node":
        return False

    # examine prologue
    prolog = doc.GetDocumentNode().GetChildren()
    while prolog:

        if prolog.GetType() == wx.xml.XML_PI_NODE and prolog.GetName() == "target":

            # process Process Instruction contents
            pi = prolog.GetContent()

            # Other code here...

    child = doc.GetRoot().GetChildren()
    while child:

        if child.GetName() == "tag1":

            # process text enclosed by tag1/tag1
            content = child.GetNodeContent()

            # Other code here...

            # process attributes of tag1
            attrvalue1 = child.GetAttribute("attr1", "default-value")
            attrvalue2 = child.GetAttribute("attr2", "default-value")

        elif child.GetName() == "tag2":

            # process tag2 ...
            attrvalue3 = child.GetAttribute("attr3", "default-value")


        child = child.GetNext()

Note that if you want to preserve the original formatting of the loaded file including whitespaces and indentation, you need to turn off whitespace-only textnode removal and automatic indentation. For example:

doc = wx.xml.XmlDocument()
doc.Load("myfile.xml", "UTF-8", wx.xml.XMLDOC_KEEP_WHITESPACE_NODES)

# myfile2.xml will be identical to myfile.xml saving it self way:
doc.Save("myfile2.xml", wx.xml.XML_NO_INDENTATION)

Using default parameters, you will get a reformatted document which in general is different from the original loaded content:

doc = wx.xml.XmlDocument()
doc.Load("myfile.xml")
doc.Save("myfile2.xml")  # myfile2.xml != myfile.xml

wx.xml.XmlDocument can also be used to create documents. The following code gives an example of creating a simple document with two nested element nodes, the second of which has an attribute, and a text node. It also demonstrates how to write the resulting output to a String :

# Create a document and add the root node.
xmlDoc = wx.xml.XmlDocument()

root = wx.xml.XmlNode(None, wx.xml.XML_ELEMENT_NODE, "Root")
xmlDoc.SetRoot(root)

# Add some XML.
library = wx.xml.XmlNode(root, wx.xml.XML_ELEMENT_NODE, "Library")
library.AddAttribute("type", "CrossPlatformList")
name = wx.xml.XmlNode(library, wx.xml.XML_ELEMENT_NODE, "Name")
name.AddChild(wx.xml.XmlNode(wx.xml.XML_TEXT_NODE, "", "wxPython"))

# Write the output to a string.
stream = io.StringIO()
xmlDoc.Save(stream)

This will produce a document that looks something like the following:

<?xml version="1.0" encoding="UTF-8"?>
<Root>
  <Library type="CrossPlatformList">
    <Name>wxPython</Name>
  </Library>
</Root>

If the root name value of the DOCTYPE is set, either by loading a file with a DOCTYPE declaration or by setting it directly with the SetDoctype member, then a DOCTYPE declaration will be added immediately after the XML declaration.

Note

Ownership is passed to the XML tree as each wx.xml.XmlNode is added to it, and this has two implications. Firstly, the wx.xml.XmlDocument takes responsibility for deleting the node so the user should not delete it; and secondly, a wx.xml.XmlNode must always be created on the heap and never on the stack.

Class Hierarchy¶

Inheritance diagram for class XmlDocument:

Methods Summary¶

`__init__`	Default constructor.
`AppendToProlog`	Appends a Process Instruction or Comment node to the document prologue.
`DetachDocumentNode`	Detaches the document node and returns it.
`DetachRoot`	Detaches the root entity node and returns it.
`GetDoctype`	Returns the `DOCTYPE` declaration data for the document.
`GetDocumentNode`	Returns the document node of the document.
`GetEOL`	Returns the output line ending string used for documents.
`GetFileEncoding`	Returns encoding of document (may be empty).
`GetFileType`	Returns the output line ending format used for documents.
`GetLibraryVersionInfo`	Get expat library version information.
`GetRoot`	Returns the root element node of the document.
`GetVersion`	Returns the version of document.
`IsOk`	Returns `True` if the document has been loaded successfully.
`Load`	Parses filename as an xml document and loads its data.
`Save`	Saves `XML` tree creating a file named with given string.
`SetDoctype`	Sets the data which will appear in the `DOCTYPE` declaration when the document is saved.
`SetDocumentNode`	Sets the document node of this document.
`SetFileEncoding`	Sets the encoding of the file which will be used to save the document.
`SetFileType`	Sets the output line ending formats when the document is saved.
`SetRoot`	Sets the root element node of this document.
`SetVersion`	Sets the version of the `XML` file which will be used to save the document.

Properties Summary¶

`Doctype`	See `GetDoctype` and `SetDoctype`
`DocumentNode`	See `GetDocumentNode` and `SetDocumentNode`
`EOL`	See `GetEOL`
`FileEncoding`	See `GetFileEncoding` and `SetFileEncoding`
`FileType`	See `GetFileType` and `SetFileType`
`Root`	See `GetRoot` and `SetRoot`
`Version`	See `GetVersion` and `SetVersion`

Class API¶

class wx.xml.XmlDocument(Object)¶

Possible constructors:

XmlDocument()

XmlDocument(doc)

XmlDocument(filename, encoding="UTF-8")

XmlDocument(stream, encoding="UTF-8")

This class holds XML data/document as parsed by XML parser in the root node.

Methods¶

__init__(self, *args, **kw)¶

Overloaded Implementations:

__init__ (self)

Default constructor.

__init__ (self, doc)

Copy constructor.

Deep copies all the XML tree of the given document.

Parameters:: doc (wx.xml.XmlDocument) –

__init__ (self, filename, encoding=”UTF-8”)

Loads the given filename using the given encoding.

See Load .

Parameters:

filename (string) –
encoding (string) –

__init__ (self, stream, encoding=”UTF-8”)

Loads the XML document from given stream using the given encoding.

See Load .

Parameters:

stream (wx.InputStream) –
encoding (string) –

AppendToProlog(self, node)¶

Appends a Process Instruction or Comment node to the document prologue.

Calling this function will create a prologue or attach the node to the end of an existing prologue.

Parameters:: node (wx.xml.XmlNode) –

New in version 2.9.2.

DetachDocumentNode(self)¶

Detaches the document node and returns it.

The document node will be set to None and thus IsOk will return False after calling this function.

Note that the caller is responsible for deleting the returned node in order to avoid memory leaks.

Return type:: wx.xml.XmlNode

New in version 2.9.2.

DetachRoot(self)¶

Detaches the root entity node and returns it.

After calling this function, the document node will remain together with any prologue nodes, but IsOk will return False since the root entity will be missing.

Note that the caller is responsible for deleting the returned node in order to avoid memory leaks.