/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
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 * The Original Code is mozilla.org code.
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 * The Initial Developer of the Original Code is 
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/*

  Interfaces for the RDF/XML sink, which parses RDF/XML into
  a graph representation.

*/

#include "nsISupports.idl"

// XXX Until these get scriptable. See nsIRDFXMLSink::AddNameSpace()
[ptr] native nsIAtomPtr(nsIAtom);
[ref] native nsStringRef(nsString);
%{C++
class nsIAtom;
class nsString;
%}

interface nsIRDFXMLSink;

/**
 * An observer that is notified as progress is made on the load
 * of an RDF/XML document in an <code>nsIRDFXMLSink</code>.
 */
[scriptable, uuid(EB1A5D30-AB33-11D2-8EC6-00805F29F370)]
interface nsIRDFXMLSinkObserver : nsISupports
{
    /**
     * Called when the load begins.
     * @param aSink the RDF/XML sink on which the load is beginning.
     */
    void onBeginLoad(in nsIRDFXMLSink aSink);

    /**
     * Called when the load is suspended (e.g., for network quantization).
     * @param aSink the RDF/XML sink that is being interrupted.
     */
    void onInterrupt(in nsIRDFXMLSink aSink);

    /**
     * Called when a suspended load is resuming.
     * @param aSink the RDF/XML sink that is resuming.
     */
    void onResume(in nsIRDFXMLSink aSink);

    /**
     * Called when an RDF/XML load completes successfully.
     * @param aSink the RDF/XML sink that has finished loading.
     */
    void onEndLoad(in nsIRDFXMLSink aSink);

    /**
     * Called when an error occurs during the load
     * @param aSink the RDF/XML sink in which the error occurred
     * @param aStatus the networking result code
     * @param aErrorMsg an error message, if applicable
     */
    void onError(in nsIRDFXMLSink aSink, in nsresult aStatus, in wstring aErrorMsg);
};



/**
 * A "sink" that receives and processes RDF/XML. This interface is used
 * by the RDF/XML parser.
 */
[scriptable, uuid(EB1A5D31-AB33-11D2-8EC6-00805F29F370)]
interface nsIRDFXMLSink : nsISupports
{
    /**
     * Set to <code>true</code> if the sink is read-only and cannot
     * be modified
     */
    attribute boolean readOnly;

    /**
     * Initiate the RDF/XML load.
     */
    void beginLoad();

    /**
     * Suspend the RDF/XML load.
     */
    void interrupt();

    /**
     * Resume the RDF/XML load.
     */
    void resume();

    /**
     * Complete the RDF/XML load.
     */
    void endLoad();

    /**
     * Add namespace information to the RDF/XML sink.
     * @param aPrefix the namespace prefix
     * @param aURI the namespace URI
     */
    [noscript] void addNameSpace(in nsIAtomPtr aPrefix,
                                 [const] in nsStringRef aURI);

    /**
     * Add an observer that will be notified as the RDF/XML load
     * progresses.
     * <p>
     *
     * Note that the sink will acquire a strong reference to the
     * observer, so care should be taken to avoid cyclical references
     * that cannot be released (i.e., if the observer holds a
     * reference to the sink, it should be sure that it eventually
     * clears the reference).
     *
     * @param aObserver the observer to add to the sink's set of
     * load observers.
     */
    void addXMLSinkObserver(in nsIRDFXMLSinkObserver aObserver);

    /**
     * Remove an observer from the sink's set of observers.
     * @param aObserver the observer to remove.
     */
    void removeXMLSinkObserver(in nsIRDFXMLSinkObserver aObserver);
};