Re: [basex-talk] Problem with DOM LS serialization

Dear Christian,

thank you for quickly attacking the problem! But sorry, but the problem is not fixed.I get the same error.

I have a general note.

I have implemented a special serializer which implements org.xml.sax .XMLReader. This is used to directly dispatch the query result to JAXB and to created objects. I can now extend this technique to generate a new DOM by implementing a SAX ContentHandler which generates a DOM.

Unfortunately the serializer API is not documented nor stable (it changed from 7.3 to 7.5). I propose to add a standard SAX serializer to BaseX. This would be a very useful extension.

Here is my implementation:

import static org.basex.util.Token.XMLNS; import static org.basex.util.Token.startsWith; import static org.basex.util.Token.string; import static org.basex.util.Token.substring;

import java.io.IOException; import java.util.HashMap; import java.util.Map;

import org.basex.io.serial.Serializer; import org.basex.query.value.item.Item; import org.xml.sax.ContentHandler; import org.xml.sax.DTDHandler; import org.xml.sax.EntityResolver; import org.xml.sax.ErrorHandler; import org.xml.sax.InputSource; import org.xml.sax.SAXException; import org.xml.sax.SAXNotRecognizedException; import org.xml.sax.SAXNotSupportedException; import org.xml.sax.XMLReader; import org.xml.sax.ext.LexicalHandler; import org.xml.sax.helpers.AttributesImpl;

/** * Bridge to translate BaseX items to SAX events. * The parse() methods does the following: * <ol> * <li>notify startDocument()</li> * <li>serialize the item</li> * <li>notify endDocument()</li> */ public class FragmentSerializer extends Serializer implements XMLReader { /** * The item to be serialized */ private Item item;

private ContentHandler contentHandler; private EntityResolver entityResolver; private DTDHandler dtdHandler; private ErrorHandler errorHandler; private LexicalHandler lexicalHandler;

public FragmentSerializer() { }

public Item getItem() { return item; }

/** * Sets the item to be serialized. */ public void setItem(Item item) { this.item = item; }

////////////////////////////////////////////////// // XMLReader //////////////////////////////////////////////////

@Override public ContentHandler getContentHandler() { return contentHandler; }

@Override public boolean getFeature(final String name) { return false; }

@Override public Object getProperty(final String name) { return null; }

public void parse() throws SAXException { parse(""); }

@Override public void parse(final InputSource input) throws SAXException { parse(""); }

@Override public void parse(final String id) throws SAXException { try { contentHandler.startDocument(); item.serialize(this); contentHandler.endDocument(); } catch (final Exception ex) { throw new SAXException(ex); } }

@Override public void setContentHandler(final ContentHandler c) { contentHandler = c; }

public void setLexicalHandler(final LexicalHandler l) { lexicalHandler = l; }

@Override public void setEntityResolver(EntityResolver entityResolver) { this.entityResolver = entityResolver; }

@Override public EntityResolver getEntityResolver() { return entityResolver; }

@Override public void setDTDHandler(DTDHandler dtdHandler) { this.dtdHandler = dtdHandler; }

@Override public DTDHandler getDTDHandler() { return dtdHandler; }

@Override public void setErrorHandler(ErrorHandler errorHandler) { this.errorHandler = errorHandler; }

@Override public ErrorHandler getErrorHandler() { return errorHandler; }

@Override public void setFeature(final String name, final boolean value) throws SAXNotRecognizedException, SAXNotSupportedException { throw new SAXNotRecognizedException(); }

@Override public void setProperty(final String name, final Object value) throws SAXNotRecognizedException, SAXNotSupportedException { throw new SAXNotRecognizedException(); }

////////////////////////////////////////////////// // Serializer //////////////////////////////////////////////////

private final HashMap<String, String> attributes = new HashMap<String, String>(); private NSDecl namespaces;

@Override protected void startOpen(byte[] n) throws IOException { attributes.clear(); this.namespaces = new NSDecl(this.namespaces); }

@Override protected void attribute(byte[] n, byte[] v) throws IOException { String value = string(v);

String prefix = null; if (startsWith(n, XMLNS)) { if (n.length == 5) { prefix = ""; } else if (n[5] == ':') { prefix = string(substring(n, 6)); } }

if (prefix != null) { namespaces.put(prefix, value); } else { String name = string(n); attributes.put(name, value); } }

@Override protected void finishOpen() throws IOException { try { AttributesImpl attrs = new AttributesImpl(); for (Map.Entry<String, String> e : attributes.entrySet()) { String rname = e.getKey(); String[] qname = qname(rname); String ns = namespaces.get(qname[0]); String lname = qname[1]; attrs.addAttribute(ns, lname, rname, null, e.getValue()); }

String rname = string(elem); String[] qname = qname(rname); String ns = namespaces.get(qname[0]); String lname = qname[1]; contentHandler.startElement(ns, lname, rname, attrs);

// System.out.println("{" + ns + "}" + lname); // for (int i = 0; i < attrs.getLength(); i++) // { // System.out.println(" {" + attrs.getURI(i) + "}" + attrs.getLocalName(i) + "=" + attrs.getValue(i)); // } } catch (final SAXException e) { throw new IOException(e.getMessage()); } }

public String[] qname(String rname) { String prefix = ""; String lname = rname;

int i = rname.indexOf(':'); if (i > 0) { prefix = rname.substring(0, i); lname = rname.substring(i + 1); } return new String[] { prefix, lname }; }

@Override protected void finishEmpty() throws IOException { finishOpen(); finishClose(); }

@Override protected void finishClose() throws IOException { try { String name = string(elem); contentHandler.endElement("", name, name); this.namespaces = namespaces.getParent(); } catch (final SAXException e) { throw new IOException(e.getMessage()); } }

@Override protected void finishText(byte[] text) throws IOException { try { String s = string(text); final char[] c = s.toCharArray(); contentHandler.characters(c, 0, c.length); } catch (final SAXException e) { throw new IOException(e.getMessage()); } }

@Override protected void finishComment(byte[] comment) throws IOException { if (lexicalHandler != null) { try { String s = string(comment); final char[] c = s.toCharArray(); lexicalHandler.comment(c, 0, c.length); } catch (final SAXException e) { throw new IOException(e.getMessage()); } } }

@Override protected void finishPi(byte[] n, byte[] v) throws IOException { //ignored }

@Override protected void atomic(Item i) throws IOException { //ignored } }

class NSDecl { private final NSDecl parent; private Map<String, String> decls;

public NSDecl(NSDecl parent) { this.parent = parent; }

public NSDecl getParent() { return parent; }

public void put(String prefix, String uri) { if (decls == null) { decls = new HashMap<String, String>(); } decls.put(prefix, uri); }

public String get(String prefix) { String ns = null; for (NSDecl c = this; c != null; c = c.parent) { if (c.decls != null) { ns = c.decls.get(prefix); if (ns != null) { break; } } } return ns != null ? ns : ""; } }