# NamedEventManager.java

    /*
    ** Module   : NamedEventManager.java
    ** Abstract : provides a publish/subscribe mechanism for interprogram linkage
    **
    ** Copyright (c) 2007-2022, Golden Code Development Corporation.
    **
    ** -#- -I- --Date-- --JPRM-- -----------------------------------Description-----------------------------------
    ** 001 GES 20070221   @32210 Created initial version which provides a publish/subscribe mechanism
    **                           for interprogram linkage.
    ** 002 CA  20130130          Added APIs to support all possible parameters for PUBLISH, SUBSCRIBE
    **                           and UNSUBSCRIBE.
    ** 003 CA  20170228          Added PUBLISH/SUBSCRIBE/UNSUBSCRIBE extensions for global support
    **                           and for external applications.
    ** 004 GES 20171206          Update javadoc to match changes to silent error mode.
    ** 005 CA  20190219          Changes from adding class event support.
    ** 006 CA  20190903          Added GLOBAL support for SUBSCRIBE/UNSUBSCRIBE (cross-session messaging).
    ** 007 CA  20220106          PUBLISH arguments must be evaluated only if the subscription is found.
    */

    /*
    ** This program is free software: you can redistribute it and/or modify
    ** it under the terms of the GNU Affero General Public License as
    ** published by the Free Software Foundation, either version 3 of the
    ** License, or (at your option) any later version.
    **
    ** This program is distributed in the hope that it will be useful,
    ** but WITHOUT ANY WARRANTY; without even the implied warranty of
    ** MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
    ** GNU Affero General Public License for more details.
    **
    ** You may find a copy of the GNU Affero GPL version 3 at the following
    ** location: https://www.gnu.org/licenses/agpl-3.0.en.html
    **
    ** Additional terms under GNU Affero GPL version 3 section 7:
    **
    **   Under Section 7 of the GNU Affero GPL version 3, the following additional
    **   terms apply to the works covered under the License.  These additional terms
    **   are non-permissive additional terms allowed under Section 7 of the GNU
    **   Affero GPL version 3 and may not be removed by you.
    **
    **   0. Attribution Requirement.
    **
    **     You must preserve all legal notices or author attributions in the covered
    **     work or Appropriate Legal Notices displayed by works containing the covered
    **     work.  You may not remove from the covered work any author or developer
    **     credit already included within the covered work.
    **
    **   1. No License To Use Trademarks.
    **
    **     This license does not grant any license or rights to use the trademarks
    **     Golden Code, FWD, any Golden Code or FWD logo, or any other trademarks
    **     of Golden Code Development Corporation. You are not authorized to use the
    **     name Golden Code, FWD, or the names of any author or contributor, for
    **     publicity purposes without written authorization.
    **
    **   2. No Misrepresentation of Affiliation.
    **
    **     You may not represent yourself as Golden Code Development Corporation or FWD.
    **
    **     You may not represent yourself for publicity purposes as associated with
    **     Golden Code Development Corporation, FWD, or any author or contributor to
    **     the covered work, without written authorization.
    **
    **   3. No Misrepresentation of Source or Origin.
    **
    **     You may not represent the covered work as solely your work.  All modified
    **     versions of the covered work must be marked in a reasonable way to make it
    **     clear that the modified work is not originating from Golden Code Development
    **     Corporation or FWD.  All modified versions must contain the notices of
    **     attribution required in this license.
    */

    package com.goldencode.p2j.util;

    import java.util.function.*;

    /**
     * Provides a publish/subscribe mechanism for interprogram linkage. This
     * corresponds to the following language statements in Progress 4GL. Actual
     * implementation of each statement resides in specific
     * {@link ProcedureManager} APIs.
     * <p>
     * <pre>
     * PUBLISH                         {@link ProcedureManager#publish}
     * SUBSCRIBE                       {@link ProcedureManager#subscribe}
     *                                 {@link ProcedureManager#subscribeAnywhere}
     * UNSUBSCRIBE                     {@link ProcedureManager#unsubscribe}
     *                                 {@link ProcedureManager#unsubscribeAll}
     * </pre>
     */
    public class NamedEventManager
    {
       /**
        * Notify all subscribers (to the given event) that the event has occurred. This method is
        * executed in a {@link ErrorManager#silent} bracket, as the <code>PUBLISH</code>
        * statement is executed with a default NO-ERROR clause.
        * <p>
        * All processing is done with silent error mode implicitly enabled.
        *
        * @param    event
        *           The name of the event which is being published.
        * @param    publisher
        *           The procedure handle representing the program that is the
        *           source of the event. Must not be <code>null</code>.
        */
       public static void publishGlobal(String event, handle publisher)
       {
          publishGlobal(new character(event), publisher, null, null);
       }

       /**
        * Notify all subscribers (to the given event) that the event has occurred. This method is
        * executed in a {@link ErrorManager#silent} bracket, as the <code>PUBLISH</code>
        * statement is executed with a default NO-ERROR clause.
        * <p>
        * All processing is done with silent error mode implicitly enabled.
        *
        * @param    event
        *           The name of the event which is being published.
        * @param    publisher
        *           The procedure handle representing the program that is the
        *           source of the event. Must not be <code>null</code>.
        */
       public static void publishGlobal(character event, handle publisher)
       {
          publishGlobal(event, publisher, null, null);
       }

       /**
        * Notify all subscribers (to the given event) that the event has occurred. This method is
        * executed in a {@link ErrorManager#silent} bracket, as the <code>PUBLISH</code>
        * statement is executed with a default NO-ERROR clause.
        * <p>
        * All processing is done with silent error mode implicitly enabled.
        *
        * @param    event
        *           The name of the event which is being published.
        * @param    publisher
        *           The procedure handle representing the program that is the
        *           source of the event. Must not be <code>null</code>.
        * @param    modes
        *           The mode for each parameter, encoded in a string. When
        *           <code>null</code>, the parameter modes will not be checked
        *           against the procedure definition.
        * @param    param
        *           The parameters passed to the subscriber. May be
        *           <code>null</code> to represent no parameters.
        */
       public static void publishGlobal(String event, handle publisher, String modes, Supplier<Object[]> param)
       {
          publishGlobal(new character(event), publisher, modes, param);
       }

       /**
        * Notify all subscribers (to the given event) that the event has occurred. This method is
        * executed in a {@link ErrorManager#silent} bracket, as the <code>PUBLISH</code>
        * statement is executed with a default NO-ERROR clause.
        * <p>
        * All processing is done with silent error mode implicitly enabled.
        *
        * @param    event
        *           The name of the event which is being published.
        * @param    publisher
        *           The procedure handle representing the program that is the
        *           source of the event. Must not be <code>null</code>.
        * @param    modes
        *           The mode for each parameter, encoded in a string. When
        *           <code>null</code>, the parameter modes will not be checked
        *           against the procedure definition.
        * @param    param
        *           The parameters passed to the subscriber. May be
        *           <code>null</code> to represent no parameters.
        */
       public static void publishGlobal(character event, handle publisher, String modes, Supplier<Object[]> param)
       {
          ProcedureManager.publish(false, true, event, publisher, modes, param);
       }

       /**
        * Notify all subscribers (to the given event) that the event has occurred. This method is
        * executed in a {@link ErrorManager#silent} bracket, as the <code>PUBLISH</code>
        * statement is executed with a default NO-ERROR clause.
        * <p>
        * All processing is done with silent error mode implicitly enabled.
        *
        * @param    event
        *           The name of the event which is being published.
        * @param    publisher
        *           The procedure handle representing the program that is the
        *           source of the event. Must not be <code>null</code>.
        */
       public static void publish(String event, handle publisher)
       {
          publish(new character(event), publisher);
       }

       /**
        * Notify all subscribers (to the given event) that the event has occurred. This method is
        * executed in a {@link ErrorManager#silent} bracket, as the <code>PUBLISH</code>
        * statement is executed with a default NO-ERROR clause.
        * <p>
        * All processing is done with silent error mode implicitly enabled.
        *
        * @param    event
        *           The name of the event which is being published.
        * @param    publisher
        *           The procedure handle representing the program that is the
        *           source of the event. Must not be <code>null</code>.
        */
       public static void publish(character event, handle publisher)
       {
          publish(event, publisher, null);
       }

       /**
        * Notify all subscribers (to the given event) that the event has occurred. This method is
        * executed in a {@link ErrorManager#silent} bracket, as the <code>PUBLISH</code>
        * statement is executed with a default NO-ERROR clause.
        * <p>
        * All processing is done with silent error mode implicitly enabled.
        *
        * @param    event
        *           The name of the event which is being published.
        * @param    publisher
        *           The procedure handle representing the program that is the
        *           source of the event. Must not be <code>null</code>.
        * @param    param
        *           The parameters passed to the subscriber. May be
        *           <code>null</code> to represent no parameters.
        */
       public static void publish(String event, handle publisher, Supplier<Object[]> param)
       {
          publish(new character(event), publisher, param);
       }

       /**
        * Notify all subscribers (to the given event) that the event has occurred. This method is
        * executed in a {@link ErrorManager#silent} bracket, as the <code>PUBLISH</code>
        * statement is executed with a default NO-ERROR clause.
        * <p>
        * All processing is done with silent error mode implicitly enabled.
        *
        * @param    event
        *           The name of the event which is being published.
        * @param    publisher
        *           The procedure handle representing the program that is the
        *           source of the event. Must not be <code>null</code>.
        * @param    param
        *           The parameters passed to the subscriber. May be
        *           <code>null</code> to represent no parameters.
        */
       public static void publish(character event, handle publisher, Supplier<Object[]> param)
       {
          publish(new character(event), publisher, null, param);
       }

       /**
        * Notify all subscribers (to the given event) that the event has occurred. This method is
        * executed in a {@link ErrorManager#silent} bracket, as the <code>PUBLISH</code>
        * statement is executed with a default NO-ERROR clause.
        * <p>
        * All processing is done with silent error mode implicitly enabled.
        *
        * @param    event
        *           The name of the event which is being published.
        * @param    publisher
        *           The procedure handle representing the program that is the
        *           source of the event. Must not be <code>null</code>.
        * @param    modes
        *           The mode for each parameter, encoded in a string. When
        *           <code>null</code>, the parameter modes will not be checked
        *           against the procedure definition.
        * @param    param
        *           The parameters passed to the subscriber. May be
        *           <code>null</code> to represent no parameters.
        */
       public static void publish(String event, handle publisher, String modes, Supplier<Object[]> param)
       {
          publish(new character(event), publisher, modes, param);
       }

       /**
        * Notify all subscribers (to the given event) that the event has occurred. This method is
        * executed in a {@link ErrorManager#silent} bracket, as the <code>PUBLISH</code>
        * statement is executed with a default NO-ERROR clause.
        * <p>
        * All processing is done with silent error mode implicitly enabled.
        *
        * @param    event
        *           The name of the event which is being published.
        * @param    publisher
        *           The procedure handle representing the program that is the
        *           source of the event. Must not be <code>null</code>.
        * @param    modes
        *           The mode for each parameter, encoded in a string. When
        *           <code>null</code>, the parameter modes will not be checked
        *           against the procedure definition.
        * @param    param
        *           The parameters passed to the subscriber. May be
        *           <code>null</code> to represent no parameters.
        */
       public static void publish(character event, handle publisher, String modes, Supplier<Object[]> param)
       {
          ProcedureManager.publish(false, event, publisher, modes, param);
       }

       /**
        * Create a new subscription to the given event for a specified program.
        * This program will receive a call-back when the event is published.
        *
        * @param    subscriber
        *           The program to notify when the specified event is published.
        *           Must not be <code>null</code>.  The specified program must
        *           have a method that corresponds to a Progress 4GL internal
        *           procedure name created from the given event name.
        * @param    event
        *           The name of the event which is being published.
        */
       public static void subscribe(handle subscriber, String event)
       {
          subscribe(subscriber, new character(event));
       }

       /**
        * Create a new subscription to the given event for a specified program.
        * This program will receive a call-back when the event is published.
        *
        * @param    subscriber
        *           The program to notify when the specified event is published.
        *           Must not be <code>null</code>.  The specified program must
        *           have a method that corresponds to a Progress 4GL internal
        *           procedure name created from the given event name.
        * @param    event
        *           The name of the event which is being published.
        */
       public static void subscribe(handle subscriber, character event)
       {
          subscribe(subscriber, event, null);
       }

       /**
        * Create a new subscription to the given event for a specified program.
        * This program will receive a call-back when the event is published.
        *
        * @param    subscriber
        *           The program to notify when the specified event is published.
        *           Must not be <code>null</code>.  The specified program must
        *           have a method that corresponds to a Progress 4GL internal
        *           procedure name created from the given event name.
        * @param    event
        *           The name of the event which is being published.
        * @param    publisher
        *           The procedure handle representing the program that is the
        *           source of the event.  If specified, the named event will only
        *           cause a notification if the event source matches this handle.
        *           <code>null</code> represents the <code>ANYWHERE</code> option
        *           which means that the events will not be filtered by source.
        */
       public static void subscribe(handle subscriber,
                                    String event,
                                    handle publisher)
       {
          subscribe(subscriber, new character(event), publisher);
       }

       /**
        * Create a new subscription to the given event for a specified program.
        * This program will receive a call-back when the event is published.
        *
        * @param    subscriber
        *           The program to notify when the specified event is published.
        *           Must not be <code>null</code>.  The specified program must
        *           have a method that corresponds to a Progress 4GL internal
        *           procedure name created from the given event name.
        * @param    event
        *           The name of the event which is being published.
        * @param    publisher
        *           The procedure handle representing the program that is the
        *           source of the event.  If specified, the named event will only
        *           cause a notification if the event source matches this handle.
        *           <code>null</code> represents the <code>ANYWHERE</code> option
        *           which means that the events will not be filtered by source.
        */
       public static void subscribe(handle    subscriber,
                                    character event,
                                    handle    publisher)
       {
          subscribe(subscriber, event, publisher, (character) null);
       }

       /**
        * Create a new subscription to the given event for a specified program.
        * This program will receive a call-back when the event is published.
        *
        * @param    subscriber
        *           The program to notify when the specified event is published.
        *           Must not be <code>null</code>.  The specified program must
        *           have a method that corresponds to the given Progress 4GL
        *           internal procedure name (<code>method</code>).
        * @param    event
        *           The name of the event which is being published.
        * @param    publisher
        *           The procedure handle representing the program that is the
        *           source of the event.  If specified, the named event will only
        *           cause a notification if the event source matches this handle.
        *           <code>null</code> represents the <code>ANYWHERE</code> option
        *           which means that the events will not be filtered by source.
        * @param    method
        *           The Progress 4GL internal procedure name which will be
        *           translated into a method name and invoked on the
        *           <code>subscriber</code> instance.
        */
       public static void subscribe(handle subscriber,
                                    String event,
                                    handle publisher,
                                    String method)
       {
          subscribe(subscriber,
                    new character(event),
                    publisher,
                    new character(method));
       }

       /**
        * Create a new subscription to the given event for a specified program.
        * This program will receive a call-back when the event is published.
        *
        * @param    subscriber
        *           The program to notify when the specified event is published.
        *           Must not be <code>null</code>.  The specified program must
        *           have a method that corresponds to the given Progress 4GL
        *           internal procedure name (<code>method</code>).
        * @param    event
        *           The name of the event which is being published.
        * @param    publisher
        *           The procedure handle representing the program that is the
        *           source of the event.  If specified, the named event will only
        *           cause a notification if the event source matches this handle.
        *           <code>null</code> represents the <code>ANYWHERE</code> option
        *           which means that the events will not be filtered by source.
        * @param    method
        *           The Progress 4GL internal procedure name which will be
        *           translated into a method name and invoked on the
        *           <code>subscriber</code> instance.
        */
       public static void subscribe(handle    subscriber,
                                    String    event,
                                    handle    publisher,
                                    character method)
       {
          subscribe(subscriber, new character(event), publisher, method);
       }

       /**
        * Create a new subscription to the given event for a specified program.
        * This program will receive a call-back when the event is published.
        *
        * @param    subscriber
        *           The program to notify when the specified event is published.
        *           Must not be <code>null</code>.  The specified program must
        *           have a method that corresponds to the given Progress 4GL
        *           internal procedure name (<code>method</code>).
        * @param    event
        *           The name of the event which is being published.
        * @param    publisher
        *           The procedure handle representing the program that is the
        *           source of the event.  If specified, the named event will only
        *           cause a notification if the event source matches this handle.
        *           <code>null</code> represents the <code>ANYWHERE</code> option
        *           which means that the events will not be filtered by source.
        * @param    method
        *           The Progress 4GL internal procedure name which will be
        *           translated into a method name and invoked on the
        *           <code>subscriber</code> instance.
        */
       public static void subscribe(handle    subscriber,
                                    character event,
                                    handle    publisher,
                                    String    method)
       {
          subscribe(subscriber, event, publisher, new character(method));
       }

       /**
        * Create a new subscription to the given event for a specified program.
        * This program will receive a call-back when the event is published.
        *
        * @param    subscriber
        *           The program to notify when the specified event is published.
        *           Must not be <code>null</code>.  The specified program must
        *           have a method that corresponds to the given Progress 4GL
        *           internal procedure name (<code>method</code>).
        * @param    event
        *           The name of the event which is being published.
        * @param    publisher
        *           The procedure handle representing the program that is the
        *           source of the event.  If specified, the named event will only
        *           cause a notification if the event source matches this handle.
        *           <code>null</code> represents the <code>ANYWHERE</code> option
        *           which means that the events will not be filtered by source.
        * @param    method
        *           The Progress 4GL internal procedure name which will be
        *           translated into a method name and invoked on the
        *           <code>subscriber</code> instance.
        */
       public static void subscribe(handle    subscriber,
                                    character event,
                                    handle    publisher,
                                    character method)
       {
          ProcedureManager.subscribe(false, subscriber, event, publisher, method, null);
       }

       /**
        * Create a new subscription to the given event for any program.
        * This program will receive a call-back when the event is published.
        *
        * @param    subscriber
        *           The program to notify when the specified event is published.
        *           Must not be <code>null</code>.  The specified program must
        *           have a method that corresponds to the given Progress 4GL
        *           internal procedure name (<code>method</code>).
        * @param    event
        *           The name of the event which is being published.
        */
       public static void subscribeAnywhere(handle subscriber, String event)
       {
          subscribeAnywhere(subscriber, new character(event));
       }

       /**
        * Create a new subscription to the given event for any program.
        * This program will receive a call-back when the event is published.
        *
        * @param    subscriber
        *           The program to notify when the specified event is published.
        *           Must not be <code>null</code>.  The specified program must
        *           have a method that corresponds to the given Progress 4GL
        *           internal procedure name (<code>method</code>).
        * @param    event
        *           The name of the event which is being published.
        */
       public static void subscribeAnywhere(handle subscriber, character event)
       {
          subscribeAnywhere(subscriber, event, (character) null);
       }

       /**
        * Create a new subscription to the given event for any program.
        * This program will receive a call-back when the event is published.
        *
        * @param    subscriber
        *           The program to notify when the specified event is published.
        *           Must not be <code>null</code>.  The specified program must
        *           have a method that corresponds to the given Progress 4GL
        *           internal procedure name (<code>method</code>).
        * @param    event
        *           The name of the event which is being published.
        * @param    method
        *           The Progress 4GL internal procedure name which will be
        *           translated into a method name and invoked on the
        *           <code>subscriber</code> instance.
        */
       public static void subscribeAnywhere(handle subscriber,
                                            String event,
                                            String method)
       {
          subscribeAnywhere(subscriber,
                            new character(event),
                            new character(method));
       }

       /**
        * Create a new subscription to the given event for any program.
        * This program will receive a call-back when the event is published.
        *
        * @param    subscriber
        *           The program to notify when the specified event is published.
        *           Must not be <code>null</code>.  The specified program must
        *           have a method that corresponds to the given Progress 4GL
        *           internal procedure name (<code>method</code>).
        * @param    event
        *           The name of the event which is being published.
        * @param    method
        *           The Progress 4GL internal procedure name which will be
        *           translated into a method name and invoked on the
        *           <code>subscriber</code> instance.
        */
       public static void subscribeAnywhere(handle    subscriber,
                                            character event,
                                            String    method)
       {
          subscribeAnywhere(subscriber, event, new character(method));
       }

       /**
        * Create a new subscription to the given event for any program.
        * This program will receive a call-back when the event is published.
        *
        * @param    subscriber
        *           The program to notify when the specified event is published.
        *           Must not be <code>null</code>.  The specified program must
        *           have a method that corresponds to the given Progress 4GL
        *           internal procedure name (<code>method</code>).
        * @param    event
        *           The name of the event which is being published.
        * @param    method
        *           The Progress 4GL internal procedure name which will be
        *           translated into a method name and invoked on the
        *           <code>subscriber</code> instance.
        */
       public static void subscribeAnywhere(handle    subscriber,
                                            String    event,
                                            character method)
       {
          subscribeAnywhere(subscriber, new character(event), method);
       }

       /**
        * Create a new subscription to the given event for any program.
        * This program will receive a call-back when the event is published.
        *
        * @param    subscriber
        *           The program to notify when the specified event is published.
        *           Must not be <code>null</code>.  The specified program must
        *           have a method that corresponds to the given Progress 4GL
        *           internal procedure name (<code>method</code>).
        * @param    event
        *           The name of the event which is being published.
        * @param    method
        *           The Progress 4GL internal procedure name which will be
        *           translated into a method name and invoked on the
        *           <code>subscriber</code> instance.
        */
       public static void subscribeAnywhere(handle    subscriber,
                                            character event,
                                            character method)
       {
          ProcedureManager.subscribeAnywhere(false, subscriber, event, method);
       }

       /**
        * Create a new subscription to the given event for any program.
        * This program will receive a call-back when the event is published.
        *
        * @param    subscriber
        *           The program to notify when the specified event is published.
        *           Must not be <code>null</code>.  The specified program must
        *           have a method that corresponds to the given Progress 4GL
        *           internal procedure name (<code>method</code>).
        * @param    event
        *           The name of the event which is being published.
        */
       public static void subscribeGlobal(handle subscriber, String event)
       {
          subscribeGlobal(subscriber, new character(event));
       }

       /**
        * Create a new subscription to the given event for any program.
        * This program will receive a call-back when the event is published.
        *
        * @param    subscriber
        *           The program to notify when the specified event is published.
        *           Must not be <code>null</code>.  The specified program must
        *           have a method that corresponds to the given Progress 4GL
        *           internal procedure name (<code>method</code>).
        * @param    event
        *           The name of the event which is being published.
        */
       public static void subscribeGlobal(handle subscriber, character event)
       {
          subscribeGlobal(subscriber, event, (character) null);
       }

       /**
        * Create a new subscription to the given event for any program.
        * This program will receive a call-back when the event is published.
        *
        * @param    subscriber
        *           The program to notify when the specified event is published.
        *           Must not be <code>null</code>.  The specified program must
        *           have a method that corresponds to the given Progress 4GL
        *           internal procedure name (<code>method</code>).
        * @param    event
        *           The name of the event which is being published.
        * @param    method
        *           The Progress 4GL internal procedure name which will be
        *           translated into a method name and invoked on the
        *           <code>subscriber</code> instance.
        */
       public static void subscribeGlobal(handle subscriber, String event, String method)
       {
          subscribeGlobal(subscriber, new character(event), new character(method));
       }

       /**
        * Create a new subscription to the given event for any program.
        * This program will receive a call-back when the event is published.
        *
        * @param    subscriber
        *           The program to notify when the specified event is published.
        *           Must not be <code>null</code>.  The specified program must
        *           have a method that corresponds to the given Progress 4GL
        *           internal procedure name (<code>method</code>).
        * @param    event
        *           The name of the event which is being published.
        * @param    method
        *           The Progress 4GL internal procedure name which will be
        *           translated into a method name and invoked on the
        *           <code>subscriber</code> instance.
        */
       public static void subscribeGlobal(handle subscriber, character event, String method)
       {
          subscribeGlobal(subscriber, event, new character(method));
       }

       /**
        * Create a new subscription to the given event for any program.
        * This program will receive a call-back when the event is published.
        *
        * @param    subscriber
        *           The program to notify when the specified event is published.
        *           Must not be <code>null</code>.  The specified program must
        *           have a method that corresponds to the given Progress 4GL
        *           internal procedure name (<code>method</code>).
        * @param    event
        *           The name of the event which is being published.
        * @param    method
        *           The Progress 4GL internal procedure name which will be
        *           translated into a method name and invoked on the
        *           <code>subscriber</code> instance.
        */
       public static void subscribeGlobal(handle subscriber, String event, character method)
       {
          subscribeGlobal(subscriber, new character(event), method);
       }

       /**
        * Create a new subscription to the given event for any program.
        * This program will receive a call-back when the event is published.
        *
        * @param    subscriber
        *           The program to notify when the specified event is published.
        *           Must not be <code>null</code>.  The specified program must
        *           have a method that corresponds to the given Progress 4GL
        *           internal procedure name (<code>method</code>).
        * @param    event
        *           The name of the event which is being published.
        * @param    method
        *           The Progress 4GL internal procedure name which will be
        *           translated into a method name and invoked on the
        *           <code>subscriber</code> instance.
        */
       public static void subscribeGlobal(handle subscriber, character event, character method)
       {
          ProcedureManager.subscribeAnywhere(true, subscriber, event, method);
       }

       /**
        * Create a new subscription to the given event for a specified external resource.
        * This resource will receive a notification when the event is published.
        *
        * @param    global
        *           Flag indicating if the subscription is for global (cross-session) events.
        * @param    subscriber
        *           The resource to notify when the specified event is published. If <code>null</code>,
        *           a {@link ExternalResource} will be built and its ID return.
        * @param    event
        *           The name of the event which is being published.
        * @param    publisher
        *           The handle representing the program or resource that is the source of the event.
        *           If specified, the named event will only cause a notification if the event source
        *           matches this handle. <code>null</code> represents the <code>ANYWHERE</code> option
        *           which means that the events will not be filtered by source.
        *
        * @return   The subscriber's ID.
        */
       public static handle subscribeExternal(boolean global,
                                              handle  subscriber,
                                              String  event,
                                              handle  publisher)
       {
          return ProcedureManager.subscribeExternal(global, subscriber, event, publisher);
       }

       /**
        * Delete a subscription to the given event for the specified external resource.  This method is
        * executed in a {@link ErrorManager#silent} bracket, as the <code>UNSUBSCRIBE</code>
        * statement is executed with a default NO-ERROR clause.
        *
        * @param    global
        *           Flag indicating if the search is done in the global (cross-session) event register.
        * @param    subscriber
        *           The resource whose subscription is to be deleted.  Must not be <code>null</code>.
        * @param    event
        *           The name of the event which is being published. If this is <code>null</code>, then
        *           subscriptions to all events will be deleted.
        * @param    publisher
        *           The procedure or resource handle representing the source of the event.
        *           If specified, the subscription will only be deleted if the event source matches
        *           this handle.  <code>null</code> represents the <code>ALL</code> option which means
        *           that the events will not be filtered by source. When <code>null</code>, it means
        *           that the publisher was not set.
        */
       public static void unsubscribeExternal(boolean global,
                                              handle  subscriber,
                                              String  event,
                                              handle  publisher)
       {
          ProcedureManager.unsubscribeExternal(global, subscriber, event, publisher);
       }

       /**
        * Notify all subscribers (to the given event) that the event has occurred. This method is
        * executed in a {@link ErrorManager#silent} bracket, as the <code>PUBLISH</code>
        * statement is executed with a default NO-ERROR clause.
        * <p>
        * All processing is done with silent error mode implicitly enabled.
        * <p>
        * The subscriptions are fired in the order they were subscribed. Although 4GL
        * documentation specifically states, that "If a named event has multiple subscribers,
        * the order in which the AVM notifies subscribers is undefined.", the actual
        * 4GL implementation (OpenEdge 10.2B) does fire the events in the order the subscriptions
        * get subscribed.
        *
        * @param    event
        *           The name of the event which is being published.
        * @param    publisher
        *           The procedure or resource handle representing the program that is the source of
        *           the event. Must not be <code>null</code>.
        * @param    args
        *           The parameters passed to the subscriber. May be <code>null</code> to represent no
        *           parameters. When <code>null</code>, it means that no parameters were specified for
        *           this call.
        */
       public static void publishExternal(String event, handle publisher, String[] args)
       {
          ProcedureManager.publishExternal(event, publisher, args);
       }

       /**
        * Delete a subscription to the given event for the specified program. This method is
        * executed in a {@link ErrorManager#silent} bracket, as the <code>UNSUBSCRIBE</code>
        * statement is executed with a default NO-ERROR clause.
        *
        * @param    subscriber
        *           The program whose subscription is to be deleted.  Must not
        *           be <code>null</code>.
        * @param    event
        *           The name of the event which is being published. If this is
        *           <code>null</code>, then subscriptions to all events will be
        *           deleted.
        */
       public static void unsubscribe(handle subscriber, String event)
       {
          unsubscribe(subscriber, new character(event));
       }

       /**
        * Delete a subscription to the given event for the specified program. This method is
        * executed in a {@link ErrorManager#silent} bracket, as the <code>UNSUBSCRIBE</code>
        * statement is executed with a default NO-ERROR clause.
        *
        * @param    subscriber
        *           The program whose subscription is to be deleted.  Must not
        *           be <code>null</code>.
        * @param    event
        *           The name of the event which is being published. If this is
        *           <code>null</code>, then subscriptions to all events will be
        *           deleted.
        */
       public static void unsubscribe(handle subscriber, character event)
       {
          unsubscribe(subscriber, event, null);
       }

       /**
        * Delete a subscription to the given event for the specified program. This method is
        * executed in a {@link ErrorManager#silent} bracket, as the <code>UNSUBSCRIBE</code>
        * statement is executed with a default NO-ERROR clause.
        *
        * @param    subscriber
        *           The program whose subscription is to be deleted.  Must not
        *           be <code>null</code>.
        * @param    event
        *           The name of the event which is being published. If this is
        *           <code>null</code>, then subscriptions to all events will be
        *           deleted.
        * @param    publisher
        *           The procedure handle representing the program that is the
        *           source of the event.  If specified, the subscription will only
        *           be deleted if the event source matches this handle.
        *           <code>null</code> represents the <code>ALL</code> option
        *           which means that the events will not be filtered by source.
        */
       public static void unsubscribe(handle subscriber, String event, handle publisher)
       {
          unsubscribe(subscriber, new character(event), publisher);
       }

       /**
        * Delete a subscription to the given event for the specified program. This method is
        * executed in a {@link ErrorManager#silent} bracket, as the <code>UNSUBSCRIBE</code>
        * statement is executed with a default NO-ERROR clause.
        *
        * @param    subscriber
        *           The program whose subscription is to be deleted.  Must not
        *           be <code>null</code>.
        * @param    event
        *           The name of the event which is being published. If this is
        *           <code>null</code>, then subscriptions to all events will be
        *           deleted.
        * @param    publisher
        *           The procedure handle representing the program that is the
        *           source of the event.  If specified, the subscription will only
        *           be deleted if the event source matches this handle.
        *           <code>null</code> represents the <code>ALL</code> option
        *           which means that the events will not be filtered by source.
        */
       public static void unsubscribe(handle subscriber, character event, handle publisher)
       {
          ProcedureManager.unsubscribe(false, subscriber, event, publisher, null);
       }

       /**
        * Delete a subscription to ALL events for the specified program. This method is
        * executed in a {@link ErrorManager#silent} bracket, as the <code>UNSUBSCRIBE</code>
        * statement is executed with a default NO-ERROR clause.
        *
        * @param    subscriber
        *           The program whose subscription is to be deleted.  Must not
        *           be <code>null</code>.
        */
       public static void unsubscribeAll(handle subscriber)
       {
          unsubscribeAll(subscriber, null);
       }

       /**
        * Delete a subscription to ALL events for the specified program. This method is
        * executed in a {@link ErrorManager#silent} bracket, as the <code>UNSUBSCRIBE</code>
        * statement is executed with a default NO-ERROR clause.
        *
        * @param    subscriber
        *           The program whose subscription is to be deleted.  Must not
        *           be <code>null</code>.
        * @param    publisher
        *           The procedure handle representing the program that is the
        *           source of the event.  If specified, the subscription will only
        *           be deleted if the event source matches this handle.
        *           <code>null</code> represents the <code>ALL</code> option
        *           which means that the events will not be filtered by source.
        */
       public static void unsubscribeAll(handle subscriber, handle publisher)
       {
          ProcedureManager.unsubscribeAll(false, subscriber, publisher);
       }

       /**
        * Delete a subscription to the given event for the specified program. This method is
        * executed in a {@link ErrorManager#silent} bracket, as the <code>UNSUBSCRIBE</code>
        * statement is executed with a default NO-ERROR clause.
        *
        * @param    subscriber
        *           The program whose subscription is to be deleted.  Must not
        *           be <code>null</code>.
        * @param    event
        *           The name of the event which is being published. If this is
        *           <code>null</code>, then subscriptions to all events will be
        *           deleted.
        */
       public static void unsubscribeGlobal(handle subscriber, String event)
       {
          unsubscribeGlobal(subscriber, new character(event));
       }

       /**
        * Delete a subscription to the given event for the specified program. This method is
        * executed in a {@link ErrorManager#silent} bracket, as the <code>UNSUBSCRIBE</code>
        * statement is executed with a default NO-ERROR clause.
        *
        * @param    subscriber
        *           The program whose subscription is to be deleted.  Must not
        *           be <code>null</code>.
        * @param    event
        *           The name of the event which is being published. If this is
        *           <code>null</code>, then subscriptions to all events will be
        *           deleted.
        */
       public static void unsubscribeGlobal(handle subscriber, character event)
       {
          ProcedureManager.unsubscribe(true, subscriber, event, null, null);
       }

       /**
        * Delete a subscription to ALL events for the specified program. This method is
        * executed in a {@link ErrorManager#silent} bracket, as the <code>UNSUBSCRIBE</code>
        * statement is executed with a default NO-ERROR clause.
        *
        * @param    subscriber
        *           The program whose subscription is to be deleted.  Must not
        *           be <code>null</code>.
        */
       public static void unsubscribeAllGlobal(handle subscriber)
       {
          ProcedureManager.unsubscribeAll(true, subscriber, null);
       }
    }