Version: 3.1.1
wxXmlDocument Class Reference

#include <wx/xml/xml.h>

+ Inheritance diagram for wxXmlDocument:

Detailed Description

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

wxXmlDocument internally uses the expat library which comes with wxWidgets to parse the given stream.

A wxXmlDocument is in fact a list of wxXmlNode organised into a structure that reflects the XML tree being represented by the document.

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

A simple example of using XML classes is:

if (!doc.Load("myfile.xml"))
return false;
// Start processing the XML file.
if (doc.GetRoot()->GetName() != "myroot-node")
return false;
// Examine prologue.
while (prolog)
{
if (prolog->GetType() == wxXML_PI_NODE && prolog->GetName() == "target")
{
// Process Process Instruction (PI) contents.
wxString pi = prolog->GetContent();
...
}
}
wxXmlNode *child = doc.GetRoot()->GetChildren();
while (child)
{
if (child->GetName() == "tag1")
{
// Process text enclosed by tag1/tag1.
wxString content = child->GetNodeContent();
...
// Process attributes of tag1.
wxString attrvalue1 =
child->GetAttribute("attr1", "default-value");
wxString attrvalue2 =
child->GetAttribute("attr2", "default-value");
...
}
else if (child->GetName() == "tag2")
{
// Process tag2 ...
}
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.Load("myfile.xml", "UTF-8", wxXMLDOC_KEEP_WHITESPACE_NODES);
// myfile2.xml will be identical to myfile.xml saving it this way:
doc.Save("myfile2.xml", wxXML_NO_INDENTATION);

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

doc.Load("myfile.xml");
doc.Save("myfile2.xml"); // myfile2.xml != myfile.xml

wxXmlDocument 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 wxString:

// Create a document and add the root node.
wxXmlNode* root = new wxXmlNode(NULL, wxXML_ELEMENT_NODE, "Root");
xmlDoc.SetRoot(root);
// Add some XML.
wxXmlNode* library = new wxXmlNode (root, wxXML_ELEMENT_NODE, "Library");
library->AddAttribute("type", "CrossPlatformList");
wxXmlNode* name = new wxXmlNode(library, wxXML_ELEMENT_NODE, "Name");
name->AddChild(new wxXmlNode(wxXML_TEXT_NODE, "", "wxWidgets"));
// Write the output to a wxString.
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>wxWidgets</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.

Library:  wxXML
Category:  XML
See also
wxXmlNode, wxXmlAttribute, wxXmlDoctype

Public Member Functions

 wxXmlDocument ()
 Default constructor. More...
 
 wxXmlDocument (const wxXmlDocument &doc)
 Copy constructor. More...
 
 wxXmlDocument (const wxString &filename, const wxString &encoding="UTF-8"))
 Loads the given filename using the given encoding. More...
 
 wxXmlDocument (wxInputStream &stream, const wxString &encoding="UTF-8")
 Loads the XML document from given stream using the given encoding. More...
 
virtual ~wxXmlDocument ()
 Virtual destructor. More...
 
void AppendToProlog (wxXmlNode *node)
 Appends a Process Instruction or Comment node to the document prologue. More...
 
wxXmlNodeDetachDocumentNode ()
 Detaches the document node and returns it. More...
 
wxXmlNodeDetachRoot ()
 Detaches the root entity node and returns it. More...
 
wxString GetEncoding () const
 Returns encoding of in-memory representation of the document (same as passed to Load() or constructor, defaults to UTF-8). More...
 
const wxStringGetFileEncoding () const
 Returns encoding of document (may be empty). More...
 
const wxXmlDoctypeGetDoctype () const
 Returns the DOCTYPE declaration data for the document. More...
 
wxXmlNodeGetDocumentNode () const
 Returns the document node of the document. More...
 
wxXmlNodeGetRoot () const
 Returns the root element node of the document. More...
 
const wxStringGetVersion () const
 Returns the version of document. More...
 
bool IsOk () const
 Returns true if the document has been loaded successfully. More...
 
virtual bool Load (const wxString &filename, const wxString &encoding="UTF-8", int flags=wxXMLDOC_NONE)
 Parses filename as an xml document and loads its data. More...
 
virtual bool Load (wxInputStream &stream, const wxString &encoding="UTF-8", int flags=wxXMLDOC_NONE)
 Like Load(const wxString&, const wxString&, int) but takes the data from given input stream. More...
 
virtual bool Save (const wxString &filename, int indentstep=2) const
 Saves XML tree creating a file named with given string. More...
 
virtual bool Save (wxOutputStream &stream, int indentstep=2) const
 Saves XML tree in the given output stream. More...
 
void SetDocumentNode (wxXmlNode *node)
 Sets the document node of this document. More...
 
void SetEncoding (const wxString &enc)
 Sets the encoding of the document. More...
 
void SetFileEncoding (const wxString &encoding)
 Sets the enconding of the file which will be used to save the document. More...
 
void SetDoctype (const wxXmlDoctype &doctype)
 Sets the data which will appear in the DOCTYPE declaration when the document is saved. More...
 
void SetRoot (wxXmlNode *node)
 Sets the root element node of this document. More...
 
void SetVersion (const wxString &version)
 Sets the version of the XML file which will be used to save the document. More...
 
wxXmlDocumentoperator= (const wxXmlDocument &doc)
 Deep copies the given document. More...
 
- Public Member Functions inherited from wxObject
 wxObject ()
 Default ctor; initializes to NULL the internal reference data. More...
 
 wxObject (const wxObject &other)
 Copy ctor. More...
 
virtual ~wxObject ()
 Destructor. More...
 
virtual wxClassInfoGetClassInfo () const
 This virtual function is redefined for every class that requires run-time type information, when using the wxDECLARE_CLASS macro (or similar). More...
 
wxObjectRefDataGetRefData () const
 Returns the wxObject::m_refData pointer, i.e. the data referenced by this object. More...
 
bool IsKindOf (const wxClassInfo *info) const
 Determines whether this class is a subclass of (or the same class as) the given class. More...
 
bool IsSameAs (const wxObject &obj) const
 Returns true if this object has the same data pointer as obj. More...
 
void Ref (const wxObject &clone)
 Makes this object refer to the data in clone. More...
 
void SetRefData (wxObjectRefData *data)
 Sets the wxObject::m_refData pointer. More...
 
void UnRef ()
 Decrements the reference count in the associated data, and if it is zero, deletes the data. More...
 
void UnShare ()
 This is the same of AllocExclusive() but this method is public. More...
 
void operator delete (void *buf)
 The delete operator is defined for debugging versions of the library only, when the identifier WXDEBUG is defined. More...
 
void * operator new (size_t size, const wxString &filename=NULL, int lineNum=0)
 The new operator is defined for debugging versions of the library only, when the identifier WXDEBUG is defined. More...
 

Static Public Member Functions

static wxVersionInfo GetLibraryVersionInfo ()
 Get expat library version information. More...
 

Additional Inherited Members

- Protected Member Functions inherited from wxObject
void AllocExclusive ()
 Ensure that this object's data is not shared with any other object. More...
 
virtual wxObjectRefDataCreateRefData () const
 Creates a new instance of the wxObjectRefData-derived class specific to this object and returns it. More...
 
virtual wxObjectRefDataCloneRefData (const wxObjectRefData *data) const
 Creates a new instance of the wxObjectRefData-derived class specific to this object and initializes it copying data. More...
 
- Protected Attributes inherited from wxObject
wxObjectRefDatam_refData
 Pointer to an object which is the object's reference-counted data. More...
 

Constructor & Destructor Documentation

wxXmlDocument::wxXmlDocument ( )

Default constructor.

wxXmlDocument::wxXmlDocument ( const wxXmlDocument doc)

Copy constructor.

Deep copies all the XML tree of the given document.

wxXmlDocument::wxXmlDocument ( const wxString filename,
const wxString encoding = "UTF-8" 
)

Loads the given filename using the given encoding.

See Load().

wxXmlDocument::wxXmlDocument ( wxInputStream stream,
const wxString encoding = "UTF-8" 
)

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

See Load().

virtual wxXmlDocument::~wxXmlDocument ( )
virtual

Virtual destructor.

Frees the document root node.

Member Function Documentation

void wxXmlDocument::AppendToProlog ( wxXmlNode 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.

Since
2.9.2
wxXmlNode* wxXmlDocument::DetachDocumentNode ( )

Detaches the document node and returns it.

The document node will be set to NULL 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.

Since
2.9.2
wxXmlNode* wxXmlDocument::DetachRoot ( )

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.

const wxXmlDoctype& wxXmlDocument::GetDoctype ( ) const

Returns the DOCTYPE declaration data for the document.

Since
3.1.0
wxXmlNode* wxXmlDocument::GetDocumentNode ( ) const

Returns the document node of the document.

Since
2.9.2
wxString wxXmlDocument::GetEncoding ( ) const

Returns encoding of in-memory representation of the document (same as passed to Load() or constructor, defaults to UTF-8).

Note
this is meaningless in Unicode build where data are stored as wchar_t*.
const wxString& wxXmlDocument::GetFileEncoding ( ) const

Returns encoding of document (may be empty).

Note
This is the encoding original file was saved in, not the encoding of in-memory representation!
static wxVersionInfo wxXmlDocument::GetLibraryVersionInfo ( )
static

Get expat library version information.

Since
2.9.2
See also
wxVersionInfo
wxXmlNode* wxXmlDocument::GetRoot ( ) const

Returns the root element node of the document.

const wxString& wxXmlDocument::GetVersion ( ) const

Returns the version of document.

This is the value in the <?xml version="1.0"?> header of the XML document. If the version attribute was not explicitly given in the header, this function returns an empty string.

bool wxXmlDocument::IsOk ( ) const

Returns true if the document has been loaded successfully.

virtual bool wxXmlDocument::Load ( const wxString filename,
const wxString encoding = "UTF-8",
int  flags = wxXMLDOC_NONE 
)
virtual

Parses filename as an xml document and loads its data.

If flags does not contain wxXMLDOC_KEEP_WHITESPACE_NODES, then, while loading, all nodes of type wxXML_TEXT_NODE (see wxXmlNode) are automatically skipped if they contain whitespaces only.

The removal of these nodes makes the load process slightly faster and requires less memory however makes impossible to recreate exactly the loaded text with a Save() call later. Read the initial description of this class for more info.

Returns true on success, false otherwise.

virtual bool wxXmlDocument::Load ( wxInputStream stream,
const wxString encoding = "UTF-8",
int  flags = wxXMLDOC_NONE 
)
virtual

Like Load(const wxString&, const wxString&, int) but takes the data from given input stream.

wxXmlDocument& wxXmlDocument::operator= ( const wxXmlDocument doc)

Deep copies the given document.

virtual bool wxXmlDocument::Save ( const wxString filename,
int  indentstep = 2 
) const
virtual

Saves XML tree creating a file named with given string.

If indentstep is greater than or equal to zero, then, while saving, an automatic indentation is added with steps composed by indentstep spaces.

If indentstep is wxXML_NO_INDENTATION, then, automatic indentation is turned off.

virtual bool wxXmlDocument::Save ( wxOutputStream stream,
int  indentstep = 2 
) const
virtual

Saves XML tree in the given output stream.

See Save(const wxString&, int) for a description of indentstep.

void wxXmlDocument::SetDoctype ( const wxXmlDoctype doctype)

Sets the data which will appear in the DOCTYPE declaration when the document is saved.

Since
3.1.0
void wxXmlDocument::SetDocumentNode ( wxXmlNode node)

Sets the document node of this document.

Deletes any previous document node. Use DetachDocumentNode() and then SetDocumentNode() if you want to replace the document node without deleting the old document tree.

Since
2.9.2
void wxXmlDocument::SetEncoding ( const wxString enc)

Sets the encoding of the document.

void wxXmlDocument::SetFileEncoding ( const wxString encoding)

Sets the enconding of the file which will be used to save the document.

void wxXmlDocument::SetRoot ( wxXmlNode node)

Sets the root element node of this document.

Will create the document node if necessary. Any previous root element node is deleted.

void wxXmlDocument::SetVersion ( const wxString version)

Sets the version of the XML file which will be used to save the document.