[SalesForce] Object clone does not work as expected

I have an object (not SObject!) with a member of type List, when I clone the object and add something to the list, the original record will also be modified:

public class ThingToClone {
    public List<Integer> values = new List<Integer>();    
}

ThingToClone original = new ThingToClone();
ThingToClone clone = original.clone();
clone.values.add(1);

System.debug(LoggingLevel.ERROR, original);

results in

12:04:15:022 USER_DEBUG [5]|ERROR|ThingToClone:[values=(1)]

This is not what I expected, and I was not able to find any "Apex Object" documentation. Is there something like that? All I found was SObject related.

Edit:

To see if it creates a shadow object, I also tried to modify a class member, that was not part of the list. called it Integer anyNumber

ThingToClone original = new ThingToClone();
ThingToClone clone = original.clone();
clone.values.add(1);
clone.anyNumber = 2;
original.anyNumber = 3;

The new debug result is something really strange:

System.debug(LoggingLevel.ERROR, clone);
System.debug(LoggingLevel.ERROR, original);

USER_DEBUG [6]|ERROR|ThingToClone:[anyNumber=2, values=(1)]
USER_DEBUG [7]|ERROR|ThingToClone:[anyNumber=3, values=(1)]

So it's clearly not the same(shadow) object

Best Answer

I disagree and say it works as expected. My assumption is that Apex clone() uses Java's clone() internally. Java's clone() is a shallow clone, meaning the list in ThingToClone will just point to the original objects list.

As described here (http://howtodoinjava.com/core-java/cloning/a-guide-to-object-cloning-in-java/#deep_cloning):

By default, java cloning is ‘field by field copy’ i.e. as the Object class does not have idea about the structure of class on which clone() method will be invoked. So, JVM when called for cloning, do following things:

1) If the class has only primitive data type members then a completely new copy of the object will be created and the reference to the new object copy will be returned.

2) If the class contains members of any class type then only the object references to those members are copied and hence the member references in both the original object as well as the cloned object refer to the same object.

So I guess @IllusiveBrain is right in his comment, where he states that clone() copies primitive variables by value and non-primitive variables by reference. I'd expect this to be NO platform bug but intended behavior.

Related Solutions

[SalesForce] Clone sObject field values from Wrapper class

I think you need to clone an sObject first, and then add it to a new instane of the wrapper. I've created a simple example page and controlle where the wrapper records could be cloned:

Page:

<apex:page controller="test1">
<apex:form>
<apex:pageBlock>

    List 1
    <apex:pageBlockTable value="{!wrapperList}" var="w">
        <apex:column>
            <apex:commandButton action="{!cloneWrappeer}" reRender="clones" value="clone"/>
        </apex:column>
        <apex:column value="{!w.index}"/>
        <apex:column value="{!w.acc.Street__c}"/>
    </apex:pageBlockTable>

    <br/>

    Clones
    <apex:pageBlockTable value="{!wrapperClonedList}" var="w" id="clones">
        <apex:column value="{!w.index}"/>
        <apex:column value="{!w.acc.Street__c}"/>
    </apex:pageBlockTable>

</apex:pageBlock>
</apex:form>
</apex:page>

Controller:

public with sharing class test1 {
    public List<MyWrapper> wrapperList { get; set; }
    public List<MyWrapper> wrapperClonedList { get; set; }

    public class MyWrapper{
        public String index { get; set; }
        public Account acc { get; set; }

        public MyWrapper(Account a){
            this.acc = a;
            this.index = a.name;
        }
    }

    public void cloneWrappeer(){
        Account a = wrapperList[0].acc.clone(false, true, false, false);
        wrapperClonedList.add(new MyWrapper(a));
    }

    public test1() {
        wrapperList = new List<MyWrapper>();
        wrapperClonedList = new List<MyWrapper>();
        testacc = [select id, name, Street__c from account limit 1];
        wrapperList.add(new MyWrapper(testacc));
    }
}

The result page:

enter image description here

[SalesForce] Nested Tables – How to Add A Child Row Dynamically

If you can post your code it would be helpful.

Here are my assumptions and solution

Lets consider you are using List<record> lstrec and iterating this list to create a row in your Visualforce page.
On click of button "Add Schedule" call method addrow() in controller.
In this method create new instance of record/object, Visualforce will automatically add row.

As per your code, you need to have addRow() method something like this -

public void addRow(){ 
    thisOppProductId = ApexPages.currentPage().getParameters().get('rIndex');
    Opportunity_Product__c oppc= [Select Id,
                                  Name,
                                  Product__c,
                                  Sales_Price__c,
                                  ServiceDate__c,
                                  Start_Period__c,
                                  Number_of_Installments__c 
                                  from Opportunity_Product__c where id =: thisOppProductId];
    if(oliSchEdit != null)
    {
        oliSchEdit.add(new Opportunity_Product_Schedule__c (Opportunity_Product__c= oppc.Id,Amount__c=0.0,Product__c = oppc.Product__c,Start_Period__c =oppc.Start_Period__c));
    } 
}

I am not sure what is meaning of parameter rIndex , just copied it from your code.

Edit:

Best Answer

Related Solutions

[SalesForce] Clone sObject field values from Wrapper class

[SalesForce] Nested Tables – How to Add A Child Row Dynamically

Related Topic