com.ctc.wstx.sw.OutputElementBase Maven / Gradle / Ivy
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/* Woodstox XML processor
*
* Copyright (c) 2005 Tatu Saloranta, [email protected]
*
* Licensed under the License specified in file LICENSE, included with
* the source code.
* You may not use this file except in compliance with the License.
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package com.ctc.wstx.sw;
import java.util.*;
import javax.xml.XMLConstants;
import javax.xml.namespace.NamespaceContext;
import javax.xml.stream.XMLStreamException;
import com.ctc.wstx.util.BijectiveNsMap;
import com.ctc.wstx.util.DataUtil;
/**
* Class that encapsulates information about a specific element in virtual
* output stack for namespace-aware writers.
* It provides support for URI-to-prefix mappings as well as namespace
* mapping generation.
*
* One noteworthy feature of the class is that it is designed to allow
* "short-term recycling", ie. instances can be reused within context
* of a simple document output. While reuse/recycling of such lightweight
* object is often useless or even counter productive, here it may
* be worth using, due to simplicity of the scheme (basically using
* a very simple free-elements linked list).
*/
public abstract class OutputElementBase
implements NamespaceContext
{
public final static int PREFIX_UNBOUND = 0;
public final static int PREFIX_OK = 1;
public final static int PREFIX_MISBOUND = 2;
final static String sXmlNsPrefix = XMLConstants.XML_NS_PREFIX;
final static String sXmlNsURI = XMLConstants.XML_NS_URI;
/*
////////////////////////////////////////////
// Namespace binding/mapping information
////////////////////////////////////////////
*/
/**
* Namespace context end application may have supplied, and that
* (if given) should be used to augment explicitly defined bindings.
*/
protected NamespaceContext mRootNsContext;
protected String mDefaultNsURI;
/**
* Mapping of namespace prefixes to URIs and back.
*/
protected BijectiveNsMap mNsMapping;
/**
* True, if {@link #mNsMapping} is a shared copy from the parent;
* false if a local copy was created (which happens when namespaces
* get bound etc).
*/
protected boolean mNsMapShared;
/*
////////////////////////////////////////////
// Life-cycle
////////////////////////////////////////////
*/
/**
* Constructor for the virtual root element
*/
protected OutputElementBase()
{
mNsMapping = null;
mNsMapShared = false;
mDefaultNsURI = "";
mRootNsContext = null;
}
protected OutputElementBase(OutputElementBase parent, BijectiveNsMap ns)
{
mNsMapping = ns;
mNsMapShared = (ns != null);
mDefaultNsURI = parent.mDefaultNsURI;
mRootNsContext = parent.mRootNsContext;
}
/**
* Method called to reuse a pooled instance.
*/
protected void relink(OutputElementBase parent)
{
mNsMapping = parent.mNsMapping;
mNsMapShared = (mNsMapping != null);
mDefaultNsURI = parent.mDefaultNsURI;
mRootNsContext = parent.mRootNsContext;
}
protected abstract void setRootNsContext(NamespaceContext ctxt);
/*
////////////////////////////////////////////
// Public API, accessors
////////////////////////////////////////////
*/
public abstract boolean isRoot();
/**
* @return String presentation of the fully-qualified name, in
* "prefix:localName" format (no URI). Useful for error and
* debugging messages.
*/
public abstract String getNameDesc();
public final String getDefaultNsUri() {
return mDefaultNsURI;
}
/*
////////////////////////////////////////////
// Public API, ns binding, checking
////////////////////////////////////////////
*/
/**
* Method similar to {@link #getPrefix}, but one that will not accept
* the default namespace, only an explicit one. Usually used when
* trying to find a prefix for attributes.
*/
public final String getExplicitPrefix(String uri)
{
if (mNsMapping != null) {
String prefix = mNsMapping.findPrefixByUri(uri);
if (prefix != null) {
return prefix;
}
}
if (mRootNsContext != null) {
String prefix = mRootNsContext.getPrefix(uri);
if (prefix != null) {
// Hmmh... still can't use the default NS:
if (prefix.length() > 0) {
return prefix;
}
// ... should we try to find an explicit one?
}
}
return null;
}
/**
* Method that verifies that passed-in prefix indeed maps to the specified
* namespace URI; and depending on how it goes returns a status for
* caller.
*
* @param isElement If true, rules for the default NS are those of elements
* (ie. empty prefix can map to non-default namespace); if false,
* rules are those of attributes (only non-default prefix can map to
* a non-default namespace).
*
* @return PREFIX_OK, if passed-in prefix matches matched-in namespace URI
* in current scope; PREFIX_UNBOUND if it's not bound to anything,
* and PREFIX_MISBOUND if it's bound to another URI.
*
* @throws XMLStreamException True if default (no) prefix is allowed to
* match a non-default URI (elements); false if not (attributes)
*/
public final int isPrefixValid(String prefix, String nsURI,
boolean isElement)
throws XMLStreamException
{
// Hmmm.... caller shouldn't really pass null.
if (nsURI == null) {
nsURI = "";
}
/* First thing is to see if specified prefix is bound to a namespace;
* and if so, verify it matches with data passed in:
*/
// Checking default namespace?
if (prefix == null || prefix.length() == 0) {
if (isElement) {
// It's fine for elements only if the URI actually matches:
if (nsURI == mDefaultNsURI || nsURI.equals(mDefaultNsURI)) {
return PREFIX_OK;
}
} else {
/* Attributes never use the default namespace: "no prefix"
* can only mean "no namespace"
*/
if (nsURI.length() == 0) {
return PREFIX_OK;
}
}
return PREFIX_MISBOUND;
}
/* Need to handle 'xml' prefix and its associated
* URI; they are always declared by default
*/
if (prefix.equals(sXmlNsPrefix)) {
// Should we thoroughly verify its namespace matches...?
// 01-Apr-2005, TSa: Yes, let's always check this
if (!nsURI.equals(sXmlNsURI)) {
throwOutputError("Namespace prefix '"+sXmlNsPrefix
+"' can not be bound to non-default namespace ('"+nsURI+"'); has to be the default '"
+sXmlNsURI+"'");
}
return PREFIX_OK;
}
// Nope checking some other namespace
String act;
if (mNsMapping != null) {
act = mNsMapping.findUriByPrefix(prefix);
} else {
act = null;
}
if (act == null && mRootNsContext != null) {
act = mRootNsContext.getNamespaceURI(prefix);
}
// Not (yet) bound...
if (act == null) {
return PREFIX_UNBOUND;
}
return (act == nsURI || act.equals(nsURI)) ?
PREFIX_OK : PREFIX_MISBOUND;
}
/*
////////////////////////////////////////////
// Public API, mutators
////////////////////////////////////////////
*/
public abstract void setDefaultNsUri(String uri);
public final String generateMapping(String prefixBase, String uri, int[] seqArr)
{
// This is mostly cut'n pasted from addPrefix()...
if (mNsMapping == null) {
// Didn't have a mapping yet? Need to create one...
mNsMapping = BijectiveNsMap.createEmpty();
} else if (mNsMapShared) {
/* Was shared with parent(s)? Need to create a derivative, to
* allow for nesting/scoping of new prefix
*/
mNsMapping = mNsMapping.createChild();
mNsMapShared = false;
}
return mNsMapping.addGeneratedMapping(prefixBase, mRootNsContext,
uri, seqArr);
}
public final void addPrefix(String prefix, String uri)
{
if (mNsMapping == null) {
// Didn't have a mapping yet? Need to create one...
mNsMapping = BijectiveNsMap.createEmpty();
} else if (mNsMapShared) {
/* Was shared with parent(s)? Need to create a derivative, to
* allow for nesting/scoping of new prefix
*/
mNsMapping = mNsMapping.createChild();
mNsMapShared = false;
}
mNsMapping.addMapping(prefix, uri);
}
/*
//////////////////////////////////////////////////
// NamespaceContext implementation
//////////////////////////////////////////////////
*/
@Override
public final String getNamespaceURI(String prefix)
{
if (prefix.length() == 0) { //default NS
return mDefaultNsURI;
}
if (mNsMapping != null) {
String uri = mNsMapping.findUriByPrefix(prefix);
if (uri != null) {
return uri;
}
}
return (mRootNsContext != null) ?
mRootNsContext.getNamespaceURI(prefix) : null;
}
@Override
public final String getPrefix(String uri)
{
if (mDefaultNsURI.equals(uri)) {
return "";
}
if (mNsMapping != null) {
String prefix = mNsMapping.findPrefixByUri(uri);
if (prefix != null) {
return prefix;
}
}
return (mRootNsContext != null) ?
mRootNsContext.getPrefix(uri) : null;
}
@Override
public final Iterator getPrefixes(String uri)
{
List l = null;
if (mDefaultNsURI.equals(uri)) {
l = new ArrayList();
l.add("");
}
if (mNsMapping != null) {
l = mNsMapping.getPrefixesBoundToUri(uri, l);
}
// How about the root namespace context? (if any)
/* Note: it's quite difficult to properly resolve masking, when
* combining these things (not impossible, just tricky); for now
* let's do best effort without worrying about masking:
*/
if (mRootNsContext != null) {
Iterator it = mRootNsContext.getPrefixes(uri);
while (it.hasNext()) {
String prefix = (String) it.next();
if (prefix.length() == 0) { // default NS already checked
continue;
}
// slow check... but what the heck
if (l == null) {
l = new ArrayList();
} else if (l.contains(prefix)) { // double-defined...
continue;
}
l.add(prefix);
}
}
if (l == null) {
return DataUtil.emptyIterator();
}
return l.iterator();
}
/*
////////////////////////////////////////////
// Internal methods
////////////////////////////////////////////
*/
protected final void throwOutputError(String msg)
throws XMLStreamException
{
throw new XMLStreamException(msg);
}
}