topical media & game development
lib-of-vs-libs-Poco-include-Poco-SAX-NamespaceSupport.h / h
//
// NamespaceSupport.h
//
//
//
// Library: XML
// Package: SAX
// Module: SAX
//
// Namespace support for SAX2.
//
// Copyright (c) 2004-2006, Applied Informatics Software Engineering GmbH.
// and Contributors.
//
// Permission is hereby granted, free of charge, to any person or organization
// obtaining a copy of the software and accompanying documentation covered by
// this license (the "Software") to use, reproduce, display, distribute,
// execute, and transmit the Software, and to prepare derivative works of the
// Software, and to permit third-parties to whom the Software is furnished to
// do so, all subject to the following:
//
// The copyright notices in the Software and this entire statement, including
// the above license grant, this restriction and the following disclaimer,
// must be included in all copies of the Software, in whole or in part, and
// all derivative works of the Software, unless such copies or derivative
// works are solely in the form of machine-executable object code generated by
// a source language processor.
//
// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
// FITNESS FOR A PARTICULAR PURPOSE, TITLE AND NON-INFRINGEMENT. IN NO EVENT
// SHALL THE COPYRIGHT HOLDERS OR ANYONE DISTRIBUTING THE SOFTWARE BE LIABLE
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// ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
// DEALINGS IN THE SOFTWARE.
//
ifndef SAX_NamespaceSupport_INCLUDED
define SAX_NamespaceSupport_INCLUDED
include "Poco/XML/XML.h"
include "Poco/XML/XMLString.h"
include <set>
include <map>
include <vector>
namespace Poco {
namespace XML {
class XML_API NamespaceSupport
Encapsulate Namespace logic for use by SAX drivers.
This class encapsulates the logic of Namespace processing:
it tracks the declarations currently in force for each context and
automatically processes qualified XML 1.0 names into their Namespace
parts; it can also be used in reverse for generating
XML 1.0 from Namespaces.
Namespace support objects are reusable, but the reset method
must be invoked between each session.
{
public:
typedef std::set<XMLString> PrefixSet;
NamespaceSupport();
Creates a NamespaceSupport object.
~NamespaceSupport();
Destroys a NamespaceSupport object.
bool declarePrefix(const XMLString& prefix, const XMLString& namespaceURI);
Declare a Namespace prefix. All prefixes must be declared before they are
referenced. For example, a SAX driver (parser) would scan an element's attributes
in two passes: first for namespace declarations, then a second pass using
processName() to interpret prefixes against (potentially redefined) prefixes.
This method declares a prefix in the current Namespace context; the prefix
will remain in force until this context is popped, unless it is shadowed
in a descendant context.
To declare the default element Namespace, use the empty string as the prefix.
Note that you must not declare a prefix after you've pushed and popped another
Namespace context, or treated the declarations phase as complete by processing
a prefixed name.
Returns true if the prefix was legal, false otherwise.
bool undeclarePrefix(const XMLString& prefix);
Remove the given namespace prefix.
void getDeclaredPrefixes(PrefixSet& prefixes) const;
Return an enumeration of all prefixes declared in this context.
The empty (default) prefix will be included in this enumeration; note that
this behaviour differs from that of getPrefix(java.lang.String) and getPrefixes().
const XMLString& getPrefix(const XMLString& namespaceURI) const;
Return one of the prefixes mapped to a Namespace URI.
If more than one prefix is currently mapped to the same URI, this method
will make an arbitrary selection; if you want all of the prefixes, use the
getPrefixes() method instead.
bool isMapped(const XMLString& namespaceURI) const;
Returns true if the given namespaceURI has been mapped to a prefix,
false otherwise.
void getPrefixes(PrefixSet& prefixes) const;
Return an enumeration of all prefixes whose declarations are active in the
current context. This includes declarations from parent contexts that have
not been overridden.
Note: if there is a default prefix, it will not be returned in this enumeration;
check for the default prefix using the getURI with an argument of "".
void getPrefixes(const XMLString& namespaceURI, PrefixSet& prefixes) const;
Return an enumeration of all prefixes for a given URI whose declarations
are active in the current context. This includes declarations from parent
contexts that have not been overridden.
This method returns prefixes mapped to a specific Namespace URI. The xml:
prefix will be included. If you want only one prefix that's mapped to the
Namespace URI, and you don't care which one you get, use the getPrefix() method
instead.
Note: the empty (default) prefix is never included in this enumeration;
to check for the presence of a default Namespace, use the getURI() method
with an argument of "".
const XMLString& getURI(const XMLString& prefix) const;
Look up a prefix and get the currently-mapped Namespace URI.
This method looks up the prefix in the current context. Use the empty string
("") for the default Namespace.
void pushContext();
Start a new Namespace context. The new context will automatically inherit
the declarations of its parent context, but it will also keep track of which
declarations were made within this context.
Event callback code should start a new context once per element. This means
being ready to call this in either of two places. For elements that don't
include namespace declarations, the ContentHandler::startElement() callback
is the right place. For elements with such a declaration, it'd done in the
first ContentHandler::startPrefixMapping() callback. A boolean flag can be
used to track whether a context has been started yet. When either of those
methods is called, it checks the flag to see if a new context needs to be
started. If so, it starts the context and sets the flag. After
ContentHandler::startElement() does that, it always clears the flag.
Normally, SAX drivers would push a new context at the beginning of each
XML element. Then they perform a first pass over the attributes to process
all namespace declarations, making ContentHandler::startPrefixMapping() callbacks.
Then a second pass is made, to determine the namespace-qualified names for
all attributes and for the element name. Finally all the information for
the ContentHandler::startElement() callback is available, so it can then
be made.
The Namespace support object always starts with a base context already in
force: in this context, only the "xml" prefix is declared.
void popContext();
Revert to the previous Namespace context.
Normally, you should pop the context at the end of each XML element. After
popping the context, all Namespace prefix mappings that were previously
in force are restored.
You must not attempt to declare additional Namespace prefixes after popping
a context, unless you push another context first.
bool processName(const XMLString& qname, XMLString& namespaceURI, XMLString& localName, bool isAttribute) const;
Process a raw XML 1.0 name.
This method processes a raw XML 1.0 name in the current context
by removing the prefix and looking it up among the
prefixes currently declared. The result will be returned in
namespaceURI and localName.
If the raw name has a prefix that has not been declared, then the return
value will be false, otherwise true.
Note that attribute names are processed differently than element names:
an unprefixed element name will received the
default Namespace (if any), while an unprefixed element name will not.
void reset();
Reset this Namespace support object for reuse.
It is necessary to invoke this method before reusing the Namespace support
object for a new session. If namespace declaration URIs are to be supported,
that flag must also be set to a non-default value.
Reset this Namespace support object for reuse.
static const XMLString XML_NAMESPACE;
static const XMLString XML_NAMESPACE_PREFIX;
static const XMLString XMLNS_NAMESPACE;
static const XMLString XMLNS_NAMESPACE_PREFIX;
private:
NamespaceSupport(const NamespaceSupport&);
NamespaceSupport& operator = (const NamespaceSupport&);
typedef std::map<XMLString, XMLString> Context;
typedef std::vector<Context> ContextVec;
ContextVec _contexts;
static const XMLString EMPTY_STRING;
};
} } // namespace Poco::XML
endif // SAX_NamespaceSupport_INCLUDED
(C) Æliens
04/09/2009
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