Convert null date from outer join on view to maxDate with SysComputedColumn

Example Code :

public static server str ReleasePostingDate()
{

    return SysComputedColumn::if(
            SysComputedColumn::isNullExpression(SysComputedColumn::returnField(
            tableStr(TIDAPUninvoiceConsignmentItem) ,
            identifierStr(LedgerJournalTableRealease),
            fieldStr(LedgerJournalTable, PostedDateTime))),
            SysComputedColumn::cast(strFmt("'%1'",DateTimeUtil::date(DateTimeUtil::maxValue())),'NVARCHAR'),
            SysComputedColumn::cast(SysComputedColumn::returnField(
            tableStr(TIDAPUninvoiceConsignmentItem) ,
            identifierStr(LedgerJournalTableRealease),
            fieldStr(LedgerJournalTable, PostedDateTime)),'NVARCHAR')
            );
}