# Building a Custom List Controller

A custom list controller is similar to a standard list controller. Custom list controllers can implement Apex logic that you define to show or act on a set of records.

For example you can create the following custom list controller based on a SOQL query:

```controller
public class opportunityList2Con {
    // ApexPages.StandardSetController must be instantiated
    // for standard list controllers
    public ApexPages.StandardSetController setCon {
        get {
            if(setCon == null) {
                setCon = new ApexPages.StandardSetController(Database.getQueryLocator(
                    [SELECT Name, CloseDate FROM Opportunity]));
            }
            return setCon;
        }
        set;
    }

    // Initialize setCon and return a list of records
    public List<Opportunity> getOpportunities() {
        return (List<Opportunity>) setCon.getRecords();
    }
}
```

:::note
The list of sObjects returned by `getRecords()` is immutable. For example, you can’t call `clear()` on it. You can make changes to the sObjects contained in the list, but you can’t add items to or remove items from the list itself.
:::

The following Visualforce markup shows how the custom controller above can be used in a page:

```markup
<apex:page controller="opportunityList2Con">
    <apex:pageBlock>
        <apex:pageBlockTable value="{!opportunities}" var="o">
            <apex:column value="{!o.Name}"/>
            <apex:column value="{!o.CloseDate}"/>
        </apex:pageBlockTable>
    </apex:pageBlock>
</apex:page>
```

You can also create a custom list controller that uses anti- and semi-joins as part of the SOQL query. The following code is implemented as an extension to the account standard controller:

```controller
public with sharing class AccountPagination {
    private final Account acct;  

    // The constructor passes in the standard controller defined
    // in the markup below
    public AccountPagination(ApexPages.StandardSetController controller) {
        this.acct = (Account)controller.getRecord(); 
    }    
    
    public ApexPages.StandardSetController accountRecords {
        get {
            if(accountRecords == null) {
                accountRecords = new ApexPages.StandardSetController(
                    Database.getQueryLocator([SELECT Name FROM Account WHERE Id NOT IN 
                        (SELECT AccountId FROM Opportunity WHERE IsClosed = true)]));
            }
            return accountRecords;
        }
        private set;
    }
    public List<Account> getAccountPagination() {
         return (List<Account>) accountRecords.getRecords();
    }  
}

```

The page that displays these records uses a mix of standard list controller actions, but depends on iterating over the records returned from the custom list controller:

```markup
<apex:page standardController="Account" recordSetVar="accounts" extensions="AccountPagination">
    <apex:pageBlock title="Viewing Accounts">
        <apex:form id="theForm">
            <apex:pageBlockSection >
                <apex:dataList value="{!accountPagination}" var="acct" type="1">
                    {!acct.name}
                </apex:dataList>
            </apex:pageBlockSection>
            <apex:panelGrid columns="2">
                <apex:commandLink action="{!previous}">Previous</apex:commandlink>
                <apex:commandLink action="{!next}">Next</apex:commandlink>
            </apex:panelGrid>
        </apex:form> 
    </apex:pageBlock>
</apex:page>
```