# AbstractSimpleParameter.java

    /*
    ** Module   : AbstractSimpleParameter.java
    ** Abstract : Common logic for assigns [input-]output parameter values (database fields and normal
    **            variables) upon exit from procedure/function
    **
    ** Copyright (c) 2015-2022, Golden Code Development Corporation.
    **
    ** -#- -I- --Date-- ----------------------------------------Description---------------------------------------
    ** 001 OM  20150626 First version based on the old FieldAssigner code.
    ** 002 CA  20220609 Release all the callee's resources for this parameter, after assignment has taken place.
    **     CA  20220613 Do not release memptr variables, as these are passed 'by pointer'.
    */
    /*
    ** 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.lang.reflect.*;

    /**
     * Delegate worker for the variables or data-type wrapper implementations, which assigns an OUTPUT
     * or INPUT-OUTPUT parameter's value back to the variable / database field with which it is
     * associated, upon exit from a procedure or function.
     * <p>
     * Upon exit from the procedure or function with which it is associated, it attempts to assign the
     * current value of its contained variable back into the associated item (variable / DMO)
     * optionally using the conversion constructor provided. This may trigger normal validation
     * processing, which may produce error conditions.
     */
    public abstract class AbstractSimpleParameter
    extends AbstractParameter
    {
       /**
        * Data wrapper which is used as a procedure or function parameter.
        * <p>
        * The variable is used as a key for fast-finding the original item that needs to be updated
        * at the return form the called procedure. In this regard it must be unique in the scope!
        * Indeed, it's at least a strange construct to have the same variable declared twice in
        * OUTPUT mode when calling a procedure.
        */
       protected BaseDataType outputValue;

       /**
        * The optional conversion constructor that will cast the new variable to old variable type in
        * order to be assigned to field.
        */
       protected Constructor<?> convCtor = null;

       /**
        * Constructor. Register this as output parameter.
        *
        * @param   outputValue
        *          Parameter value to and from which we will assign.
        */
       protected AbstractSimpleParameter(BaseDataType outputValue)
       {
          this.outputValue = outputValue;
          getCurrentScope().addSimpleParameter(this);
       }

       /**
        * Release all the callee's resources for this parameter, after assignment has taken place.
        */
       @Override
       protected void release()
       {
          if (canRelease(outputValue))
          {
             outputValue.setUnknown();
          }
       }

       /**
        * Get the variable container used as parameter inside the procedure body.
        *
        * @return  The data wrapper which is used as a procedure or function parameter.
        */
       protected BaseDataType getLocalParam()
       {
          return this.outputValue;
       }

       /**
        * Assign the current value of the parameter variable back to the associated item (variable or
        * DMO property. This is expected to occur upon exit from the function or procedure with which
        * this object is associated. Must be implemented in subclasses.
        */
       abstract protected void assign();

       /**
        * Update the wrapper variable for a {@code OutputParameterAssigner}. Sometimes is required to
        * change the wrapper variable for an item (Eg. when the {@link ControlFlowOps} detects a
        * conversion type is necessary).
        *
        * @param   key
        *          The old key variable. May be the intermediary wrapper for a field or the real
        *          variable passed as *OUTPUT parameter.
        * @param   newVar
        *          The new wrapper variable that will be used inside the calling procedure. At the end
        *          of the call its value will be converted using {@code convCtor} and assigned to
        *          wrapped field or original variable.
        * @param   convCtor
        *          The conversion constructor that will cast the new variable to old variable type in
        *          order to be assigned to field.
        */
       public static void update(BaseDataType key, BaseDataType newVar, Constructor<?> convCtor)
       {
          if (key == newVar) // comparing 'pointers', not their value
          {
             return; // same var, NO-OP
          }

          WorkArea local = context.get();
          Scope scope = local.getCurrentScope();
          scope.updateSimpleParameter(key, newVar, convCtor);
       }
    }