Helper Class for copyOppLineItems Trigger

copyOppItemHelper.apxc

public class copyOppItemHelper {
    
    public static List<Id> getOppIds(List<Order> orderList) {
        List<Id> oppIds = new List<Id>();
        for(Order newOrder: orderList) {
            oppIds.add(newOrder.OpportunityId);
        }
        return oppIds;
    }
    
    public static List<OpportunityLineItem> getOppItemList(List<Id> oppIds) {
        List<OpportunityLineItem> oppItemList = [SELECT  Id, Description,  
                                                 IsDeleted, ListPrice, Name, OpportunityId, Product2Id, PricebookEntryId, 
                                                 ProductCode, Quantity, ServiceDate, TotalPrice, UnitPrice 
                                                 FROM OpportunityLineItem WHERE IsDeleted = false AND OpportunityId IN :oppIds];
        return oppItemList;
    }
    
    public static List<OrderItem> getOrderItemList(List<Order> orderList, List<OpportunityLineItem> oppItemList) {
        List<OrderItem> orderItemList = new List<OrderItem>();
        
        for(Order nOrder: OrderList)
        {
            for(OpportunityLineItem item: oppItemList){
                
                if(nOrder.OpportunityId == item.OpportunityId) {                
                    OrderItem newItem = new OrderItem();
                    newItem.EndDate = nOrder.EndDate;
                    newItem.OrderId = nOrder.Id;
                    newItem.Description = item.Description;
                    newItem.Quantity = item.Quantity;              
                    newItem.UnitPrice = item.UnitPrice;
                    newItem.PricebookEntryId = item.PricebookEntryId;
                    //newItem.ListPrice = item.ListPrice; //not writable                
                    //newItem.Product2Id = item.Product2Id; //not writable
                    //newItem.ServiceDate = ?? // Which Date to give?                    
                    orderItemList.add(newItem);                     
                }
            }
        }
        
        return orderItemList;
    }
}