ACEXML_NamespaceSupport provides namespace management operation for an XML parser. More...

#include <ACEXML/common/NamespaceSupport.h>

Collaboration diagram for ACEXML_NamespaceSupport:

Public Member Functions
	ACEXML_NamespaceSupport (void)
	~ACEXML_NamespaceSupport (void)
int	init (void)
int	declarePrefix (const ACEXML_Char prefix, const ACEXML_Char uri)
int	getDeclaredPrefixes (ACEXML_STR_LIST &prefixes) const
const ACEXML_Char *	getPrefix (const ACEXML_Char *uri) const
int	getPrefixes (ACEXML_STR_LIST &prefixes) const
int	getPrefixes (const ACEXML_Char *uri, ACEXML_STR_LIST &prefixes) const
const ACEXML_Char *	getURI (const ACEXML_Char *prefix) const
int	popContext (void)
int	processName (const ACEXML_Char qName, const ACEXML_Char &uri, const ACEXML_Char *&name, int is_attribute) const
int	pushContext (void)
int	reset (void)
Static Public Attributes
static const ACEXML_Char *	XMLNS_PREFIX = ACEXML_XMLNS_PREFIX_name
static const ACEXML_Char *	XMLNS = ACEXML_XMLNS_URI_name
Private Attributes
ACEXML_Namespace_Context_Stack	ns_stack_
ACEXML_NS_CONTEXT *	effective_context_

Detailed Description

ACEXML_NamespaceSupport provides namespace management operation for an XML parser.

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 (in Java :-p):

  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.

See also:: ACEXML_Exception

Definition at line 126 of file NamespaceSupport.h.

Constructor & Destructor Documentation

ACEXML_NamespaceSupport::ACEXML_NamespaceSupport ( void )

Default constructor.

Definition at line 78 of file NamespaceSupport.cpp.

  : ns_stack_ (),
    effective_context_ (0)
{}

ACEXML_NamespaceSupport::~ACEXML_NamespaceSupport ( void )

Default destructor.

Definition at line 94 of file NamespaceSupport.cpp.

{
  while (this->popContext () == 0)
    ;
}

Member Function Documentation

int ACEXML_NamespaceSupport::declarePrefix	(	const ACEXML_Char *	prefix,
		const ACEXML_Char *	uri
	)

Declare a Namespace prefix. Return -1 if the prefix was illegal or an internal error occured. Return 0 if the prefix gets declared successfully, 1 if the prefix replaces an existing prefix definition.

Definition at line 101 of file NamespaceSupport.cpp.

{
  if (!prefix || !uri)
    return -1;

  // Unless predefined by w3.org(?) NS prefix can never start with
  // "xml".
  if (ACE_OS::strcmp (ACEXML_TABOO_NS_PREFIX, prefix) == 0)
    return -1;

  ACEXML_String ns_prefix (prefix, 0, false);
  ACEXML_String ns_uri (uri, 0, false);

  return this->effective_context_->rebind (ns_prefix, ns_uri);
}

int ACEXML_NamespaceSupport::getDeclaredPrefixes ( ACEXML_STR_LIST & prefixes ) const

Return all prefixes declared in current context in the user-supplied list prefixes. It is user's reponsibility to ensure the list was empty originally.

Definition at line 119 of file NamespaceSupport.cpp.

{
  ACEXML_NS_CONTEXT_ENTRY *entry = 0;

  // The prefix for default namespace (empty string) is included in
  // the return list.
  for (ACEXML_NS_CONTEXT_ITER iter (*this->effective_context_);
       iter.next (entry) != 0;
       iter.advance ())
    prefixes.enqueue_tail (entry->ext_id_.c_str ());

  return 0;
}

const ACEXML_Char * ACEXML_NamespaceSupport::getPrefix ( const ACEXML_Char * uri ) const

Return one of the prefixes mapped to a Namespace URI.

Definition at line 134 of file NamespaceSupport.cpp.

{
  if (!uri || *uri == 0)
    return 0;

  ACEXML_NS_CONTEXT_ENTRY *entry = 0;

  for (ACEXML_NS_CONTEXT_ITER iter (*this->effective_context_);
       iter.next (entry) != 0;
       iter.advance ())
    if (entry->int_id_ == ACEXML_String (uri, 0, false))
      return entry->ext_id_.c_str ();

  return 0;                     // Nothing found.
}

int ACEXML_NamespaceSupport::getPrefixes ( ACEXML_STR_LIST & prefixes ) const

Return all prefixes currently declared in the user-supplied list. @ Known bug: This function should only return user-defined prefixes.

Definition at line 151 of file NamespaceSupport.cpp.

{
  ACEXML_NS_CONTEXT_ENTRY *entry = 0;

  // The prefix for default namespace (empty string) is not included
  // in the return list.
  for (ACEXML_NS_CONTEXT_ITER iter (*this->effective_context_);
       iter.next (entry) != 0;
       iter.advance ())
    prefixes.enqueue_tail (entry->ext_id_.c_str ());
  return 0;
}

int ACEXML_NamespaceSupport::getPrefixes	(	const ACEXML_Char *	uri,
		ACEXML_STR_LIST &	prefixes
	)			const

Return all prefixes currently declared for a URI in the user-supplied list.

Definition at line 165 of file NamespaceSupport.cpp.

{
  if (!uri)
    return -1;

  ACEXML_NS_CONTEXT_ENTRY *entry = 0;

  for (ACEXML_NS_CONTEXT_ITER iter (*this->effective_context_);
       iter.next (entry) != 0;
       iter.advance ())
    if (entry->int_id_ == ACEXML_String (uri, 0, false) &&
        entry->ext_id_ != ACEXML_String (ACEXML_DEFAULT_NS_PREFIX, 0, false))
      prefixes.enqueue_tail (entry->ext_id_.c_str ());
    else
      continue;

  return 0;                     // Nothing found.
}

const ACEXML_Char * ACEXML_NamespaceSupport::getURI ( const ACEXML_Char * prefix ) const

Look up a prefix and get the currently-mapped Namespace URI.

Definition at line 186 of file NamespaceSupport.cpp.

{
  if (!prefix)
    return 0;

  ACEXML_NS_CONTEXT_ENTRY *entry = 0;

  if (this->effective_context_->find (ACEXML_String (prefix, 0, false),
                                      entry) == 0)
    return entry->int_id_.c_str ();
  return 0;
}

int ACEXML_NamespaceSupport::init ( void )

Initialize the namespace support object

Definition at line 84 of file NamespaceSupport.cpp.

{
  // @@ No way to tell if the new fails.
  ACE_NEW_RETURN (effective_context_, ACEXML_NS_CONTEXT(), -1);

  ACEXML_String prefix (ACEXML_TABOO_NS_PREFIX, 0, false);
  ACEXML_String uri (ACEXML_XMLNS_URI_name, 0, false);
  return this->effective_context_->bind (prefix, uri);
}

int ACEXML_NamespaceSupport::popContext ( void )

Revert to the previous namespace context.

Definition at line 49 of file NamespaceSupport.cpp.

{
  delete this->effective_context_;

  if ((this->effective_context_ = this->ns_stack_.pop ()) == 0)
    return -1;
  return 0;
}

int ACEXML_NamespaceSupport::processName	(	const ACEXML_Char *	qName,
		const ACEXML_Char *&	uri,
		const ACEXML_Char *&	name,
		int	is_attribute
	)			const

Process a raw XML 1.0 name. qName is the raw XML name we want to parse, uri contains the URI string of the raw name. It points to a null string if the namespace is not valid or there's no namespace defined. name contains the original name without the prefix. is_attribute specifies whether the name is an attribute or not. Attributes have different scoping rules from elements.

Definition at line 200 of file NamespaceSupport.cpp.

{
  int qlen = static_cast<int> (ACE_OS::strlen (qName));
  int len = -1;
  for (int i = 0; i < qlen; ++i)
    if (qName [i] == ':')
      {
        len = i;
        break;
      }

  ACEXML_String prefix (ACE_TEXT (""), 0, false);
  if (len == -1)
      name = qName;
  else
    {
      prefix.set (qName, len, 1);
      name = qName + len + 1;
    }

  if (is_attribute && len == -1) {
    uri = ACEXML_DEFAULT_NS_PREFIX;
    return 0;
  }

  ACEXML_NS_CONTEXT_ENTRY *entry;

  if (this->effective_context_->find (prefix, entry) == 0)
    uri = entry->int_id_.c_str ();
  else
    {
      uri = ACEXML_DEFAULT_NS_PREFIX;
      return -1;
    }
  return 0;
}

int ACEXML_NamespaceSupport::pushContext ( void )

Start a new Namespace context. Prefixes defined in previous context are copied over to the new context.

Definition at line 59 of file NamespaceSupport.cpp.

{
  ACEXML_NS_CONTEXT *temp = this->effective_context_;
  ACE_NEW_RETURN (this->effective_context_,
                  ACEXML_NS_CONTEXT (),
                  -1);

  // @@ Copy everything from the old context to the new one.
  ACEXML_NS_CONTEXT_ENTRY *entry = 0;

  for (ACEXML_NS_CONTEXT_ITER iter (*temp);
       iter.next (entry) != 0;
       iter.advance ())
    this->effective_context_->bind (entry->ext_id_,
                                    entry->int_id_);
  this->ns_stack_.push (temp);
  return 0;
}

int ACEXML_NamespaceSupport::reset ( void )

Reset this Namespace support object for reuse.

Definition at line 241 of file NamespaceSupport.cpp.

{
  while (this->popContext() != -1)
    ;
  return 0;
}

Member Data Documentation

ACEXML_NS_CONTEXT* ACEXML_NamespaceSupport::effective_context_ [private]

The effective namespace context.

Definition at line 230 of file NamespaceSupport.h.

ACEXML_Namespace_Context_Stack ACEXML_NamespaceSupport::ns_stack_ [private]

Namespace Context stack. When we entering a new namespace context, the old context is duplicated and pushed into this stack.

Definition at line 225 of file NamespaceSupport.h.

const ACEXML_Char * ACEXML_NamespaceSupport::XMLNS = ACEXML_XMLNS_URI_name [static]

Definition at line 148 of file NamespaceSupport.h.

const ACEXML_Char * ACEXML_NamespaceSupport::XMLNS_PREFIX = ACEXML_XMLNS_PREFIX_name [static]

XMLNS default prefix and URI strings.

Definition at line 147 of file NamespaceSupport.h.

The documentation for this class was generated from the following files:

ACEXML_NamespaceSupport Class Reference

Public Member Functions

Static Public Attributes

Private Attributes

Detailed Description

Constructor & Destructor Documentation

Member Function Documentation

Member Data Documentation