Multi selection lookup on Form class

 class CMCSysMultiselectionLookup extends SysLookupMultiSelectGrid

{

    #SysOperation

    private const str CollectionValueSeparator = #CollectionValueSeparator;

    public static CMCSysMultiselectionLookup lookup(Query _query, container _selectField, FormStringControl _callingCtrl, FormStringControl _recIdsControl, FormStringControl _strIdsControl, str _currentStrIds, queryRun _queryRun = null)

    {

     //   _strIdsControl.text(_currentStrIds);

     //   _recIdsControl.text('');

        var lookupMS = new CMCSysMultiselectionLookup();

        lookupMS.parmCallingControl(_callingCtrl);

        lookupMS.parmCallingControlId(_recIdsControl);

        lookupMS.parmCallingControlStr(_strIdsControl);

        lookupMS.parmQuery(_query);

        lookupMS.parmQueryRun(_queryRun);

        lookupMS.parmSelectField(_selectField);

        lookupMS.parmSelectedId(conNull());

        lookupMS.run();

        return lookupMS;

    }

    public container getSelectedStrings()

    {

        return selectedStr;

    }

    public SysLookupMultiSelectValues getSelectedStringsJoined()

    {

        return SysOperationHelper::convertMultiSelectedValueString(selectedStr);

    }

    public static boolean stringListContainsItem(str _stringList, str _possibleItem)

    {

        container items = str2con(_stringList, CollectionValueSeparator);

        for (int i = 1 ; i <= conLen(items) ; i++)

        {

            str item = conPeek(items, i);

            if (item == _possibleItem)

            {

                return true;

            }

        }

        return false;

    }

}

// calling lookup class in form control

 [Control("String")]

    class JournalName

    {

        /// <summary>

        ///

        /// </summary>

        public void lookup()

        {

            super();

            Query lookupQuery = new Query();

            var selectField = [tableNum(LedgerJournalName), fieldNum(LedgerJournalName, JournalName)];

            QueryBuildDataSource qbds = lookupQuery.addDataSource(tableNum(LedgerJournalName));

            qbds.addRange(fieldNum(LedgerJournalName,JournalType)).value(SysQuery::value(LedgerJournalType::Daily));

            

            qbds.addSelectionField(fieldNum(LedgerJournalName, JournalName));

            qbds.addSelectionField(fieldNum(LedgerJournalName, name));

        

            qbds.addSortField(fieldNum(LedgerJournalName, JournalName));

            var lookup =  CMCSysMultiselectionLookup::lookup(lookupQuery, selectField, this,this,this,this.text());

           // lookupTxt = lookup.getSelectedStringsJoined();

        }

    }