2005/5/9

org::xml::sax::helpers::NamespaceSupport Class Reference

Inheritance diagram for org::xml::sax::helpers::NamespaceSupport:

Detailed Description

This module, both source code and documentation, is in the Public Domain, and comes with NO WARRANTY.

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.

Here is a simple session:

 String parts[] = new String[3];
 NamespaceSupport support = new NamespaceSupport();

 support.pushContext();
 support.declarePrefix(, http://www.w3.org/1999/xhtml);
 support.declarePrefix(dc, http://www.purl.org/dc#);

 String parts[] = support.processName(p, parts, false);
 System.out.println(Namespace URI:  + parts[0]);
 System.out.println(Local name:  + parts[1]);
 System.out.println(Raw name:  + parts[2]);

 String parts[] = support.processName(dc:title, parts, false);
 System.out.println(Namespace URI:  + parts[0]);
 System.out.println(Local name:  + parts[1]);
 System.out.println(Raw name:  + parts[2]);

 support.popContext();
 

Note that this class is optimized for the use case where most elements do not contain Namespace declarations: if the same prefix/URI mapping is repeated for each context (for example), this class will be somewhat less efficient.

Since:

SAX 2.0

Author:

Roger Rene Kommer

Java Original: David Megginson, sax@megginson.com

Version:

2.0r2pre

Public Member Functions
	NamespaceSupport ()
	Create a new Namespace support object.
void	reset ()
	Reset this Namespace support object for reuse.
void	pushContext ()
	Start a new Namespace context.
void	popContext ()
	Revert to the previous Namespace context.
bool	declarePrefix (IN(RString) prefix, IN(RString) uri)
	Declare a Namespace prefix.
RStringArray	processName (IN(RString) qName, IN(RStringArray) parts, bool isAttribute)
	Process a raw XML 1.0 name.
RString	getURI (IN(RString) prefix)
	Look up a prefix and get the currently-mapped Namespace URI.
acdk::util::RIterator	getPrefixes ()
	Return an enumeration of all prefixes currently declared.
RString	getPrefix (IN(RString) uri)
	Return one of the prefixes mapped to a Namespace URI.
acdk::util::RIterator	getPrefixes (IN(RString) uri)
	Return an enumeration of all prefixes currently declared for a URI.
acdk::util::RIterator	getDeclaredPrefixes ()
	Return an enumeration of all prefixes declared in this context.
Static Public Member Functions
RString	getAbsoluteURI (IN(RString) base, IN(RString) uri)
RString	getBaseURI (IN(RString) uri)
Private Attributes
RContextArray	contexts
RContext	currentContext
int	contextPos

Constructor & Destructor Documentation

org::xml::sax::helpers::NamespaceSupport::NamespaceSupport (   )  [inline]

Create a new Namespace support object.

Member Function Documentation

bool org::xml::sax::helpers::NamespaceSupport::declarePrefix (  IN(RString)  prefix, IN(RString)  uri )

Declare a Namespace prefix. 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 a default Namespace, use the empty string. The prefix must not be xml or xmlns. Note that you must not declare a prefix after you've pushed and popped another Namespace. Note that there is an asymmetry in this library: while getPrefix will not return the default prefix, even if you have declared one; to check for a default prefix, you have to look it up explicitly using getURI. This asymmetry exists to make it easier to look up prefixes for attribute names, where the default prefix is not allowed. Parameters: prefix  The prefix to declare, or null for the empty string. uri  The Namespace URI to associate with the prefix. Returns: true if the prefix was legal, false otherwise See also: processName getURI getPrefix

RString org::xml::sax::helpers::NamespaceSupport::getAbsoluteURI (  IN(RString)  base, IN(RString)  uri )  [static]

RString org::xml::sax::helpers::NamespaceSupport::getBaseURI (  IN(RString)  uri  )  [static]

acdk::util::RIterator org::xml::sax::helpers::NamespaceSupport::getDeclaredPrefixes (   )  [inline]

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 and getPrefixes. Returns: An enumeration of all prefixes declared in this context. See also: getPrefixes getURI

RString org::xml::sax::helpers::NamespaceSupport::getPrefix (  IN(RString)  uri  )  [inline]

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. Note: this will never return the empty (default) prefix; to check for a default prefix, use the getURI method with an argument of . Parameters: uri  The Namespace URI. isAttribute  true if this prefix is for an attribute (and the default Namespace is not allowed). Returns: One of the prefixes currently mapped to the URI supplied, or null if none is mapped or if the URI is assigned to the default Namespace. See also: getPrefixes(java.lang.String) getURI

acdk::util::RIterator org::xml::sax::helpers::NamespaceSupport::getPrefixes (  IN(RString)  uri  )

Return an enumeration of all prefixes currently declared for a URI. 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 . Parameters: uri  The Namespace URI. Returns: An enumeration of all prefixes declared in the current context. See also: getPrefix getDeclaredPrefixes getURI

acdk::util::RIterator org::xml::sax::helpers::NamespaceSupport::getPrefixes (   )  [inline]

Return an enumeration of all prefixes currently declared. 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 . Returns: An enumeration of all prefixes declared in the current context except for the empty (default) prefix. See also: getDeclaredPrefixes getURI

RString org::xml::sax::helpers::NamespaceSupport::getURI (  IN(RString)  prefix  )  [inline]

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. Parameters: prefix  The prefix to look up. Returns: The associated Namespace URI, or null if the prefix is undeclared in this context. See also: getPrefix getPrefixes

void org::xml::sax::helpers::NamespaceSupport::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. See also: pushContext

RStringArray org::xml::sax::helpers::NamespaceSupport::processName (  IN(RString)  qName, IN(RStringArray)  parts, bool  isAttribute )

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 return value will be the array supplied by the caller, filled in as follows: parts[0] The Namespace URI, or an empty string if none is in use. parts[1] The local name (without prefix). parts[2] The original raw name. All of the strings in the array will be internalized. If the raw name has a prefix that has not been declared, then the return value will be null. 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. Parameters: qName  The raw XML 1.0 name to be processed. parts  An array supplied by the caller, capable of holding at least three members. isAttribute  A flag indicating whether this is an attribute name (true) or an element name (false). Returns: The supplied array holding three internalized strings representing the Namespace URI (or empty string), the local name, and the raw XML 1.0 name; or null if there is an undeclared prefix. See also: declarePrefix java.lang.String#intern

void org::xml::sax::helpers::NamespaceSupport::pushContext (   )

Start a new Namespace context. Normally, you should push a new context at the beginning of each XML element: 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. The Namespace support object always starts with a base context already in force: in this context, only the xml prefix is declared. See also: popContext

void org::xml::sax::helpers::NamespaceSupport::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.

Member Data Documentation

int org::xml::sax::helpers::NamespaceSupport::contextPos [private]

RContextArray org::xml::sax::helpers::NamespaceSupport::contexts [private]

RContext org::xml::sax::helpers::NamespaceSupport::currentContext [private]