Hi all,

I have attempted this myself using code out there on the net and the forum and have come up with the following:

Could everyone look over my code and see if there are any flaws in it.  I'm new to Apex Coding so it has been a bit or trial and error as I don't fully understand it yet so can't tell if I made a mistake somewhere.

I have tested the code with the limited records I have in my org and the Visual Page seems to work.  Currently it is set with page size 4 for testing, but it allows you to sort by pressing a column header name and then go next or previous with the pages and seems to keep the ordering while going through the pages.

Thanks

Kev

Visual Force Page:

<apex:page controller="MyPagingController" tabStyle="Account">
        <apex:sectionHeader title="Accounts List with Paging"></apex:sectionHeader>
        <apex:form >
        <apex:pageBlock title="" id="pageBlock">
        <div align="right" style="display:{!IF(NOT(ISNULL(accounts)),'block','none')}">
        <font size="1pt">Page #:&nbsp;<apex:outputLabel value="{!PageNumber}"/>&nbsp;out of&nbsp;<apex:outputLabel value="{!totalPageNumber}"/>&nbsp;&nbsp;&nbsp;&nbsp;</font>
        <apex:commandButton value="Previous" action="{!previousBtnClick}" disabled="{!previousButtonEnabled}" reRender="pageBlock"></apex:commandButton>
        <apex:commandButton value="Next" action="{!nextBtnClick}" reRender="pageBlock" disabled="{!nextButtonDisabled}" ></apex:commandButton>
        </div>
        <br/><br/>
        <apex:pageBlockTable value="{!accounts}" var="a" rendered="{!NOT(ISNULL(accounts))}" rows="{!PageSize}">
        
       <apex:column >
         <apex:facet name="header">   
           <apex:commandLink action="{!ViewData}" value="Account Name{!IF(sortExpression=='name',IF(sortDirection='ASC','▼','▲'),'')}" id="cmdSort">
             <apex:param value="name" name="column" assignTo="{!sortExpression}" ></apex:param>
           </apex:commandLink>
         </apex:facet>
         <apex:outputLink value="/{!a.Id}" target="_blank">{!a.Name}</apex:outputLink>
       </apex:column>
       <apex:column value="{!a.Phone}">
         <apex:facet name="header">
           <apex:commandLink action="{!ViewData}" value="Phone{!IF(sortExpression=='Phone',IF(sortDirection='ASC','▼','▲'),'')}">
             <apex:param value="Phone" name="column" assignTo="{!sortExpression}" ></apex:param>
           </apex:commandLink>
         </apex:facet>
       </apex:column>
        <apex:column value="{!a.BillingCity}">
          <apex:facet name="header">
           <apex:commandLink action="{!ViewData}" value="Billing City{!IF(sortExpression=='BillingCity',IF(sortDirection='ASC','▼','▲'),'')}">
             <apex:param value="BillingCity" name="column" assignTo="{!sortExpression}" ></apex:param>
           </apex:commandLink>
         </apex:facet>
       </apex:column>
        <apex:column value="{!a.BillingCountry}">
          <apex:facet name="header">
           <apex:commandLink action="{!ViewData}" value="Billing Country{!IF(sortExpression=='BillingCountry',IF(sortDirection='ASC','▼','▲'),'')}">
             <apex:param value="BillingCountry" name="column" assignTo="{!sortExpression}" ></apex:param>
           </apex:commandLink>
         </apex:facet>
       </apex:column>
       
        </apex:pageBlockTable>
        <div align="right" style="display:{!IF(NOT(ISNULL(accounts)),'block','none')}">
        <br/>
        <font size="1pt">Page #:&nbsp;<apex:outputLabel value="{!PageNumber}"/>&nbsp;out of&nbsp;<apex:outputLabel value="{!totalPageNumber}"/>&nbsp;&nbsp;&nbsp;&nbsp;</font>
        <apex:commandButton value="Previous" action="{!previousBtnClick}" disabled="{!previousButtonEnabled}" reRender="pageBlock"></apex:commandButton>
        <apex:commandButton value="Next" action="{!nextBtnClick}" reRender="pageBlock" disabled="{!nextButtonDisabled}" ></apex:commandButton>
        </div>

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



Apex Class:

public class MyPagingController
    {
    private List<Account> accounts;
    private List<Account> pageAccounts;
    private String sortDirection = 'ASC';
    private String sortExp = 'name';
    private Integer pageNumber;
    private Integer pageSize;
    private Integer totalPageNumber;
    public Integer getPageNumber()
    {
    return pageNumber;
    }
    
    public String sortExpression
    {
        get 
        {
        return sortExp;
        } 
        set
        {
        if (value == sortExp)
        sortDirection = (sortDirection == 'ASC')? 'DESC' : 'ASC';
        else
        sortDirection = 'ASC';
        sortExp = value;
        }
    }

    public String getSortDirection()
    {
    if (sortExpression == null || sortExpression == '')
    return 'ASC';
    else
    return sortDirection;
    }
             
    public void setSortDirection(String value)
    {  
    sortDirection = value;
    }
    
    public List<Account> getAccounts()
    {
    return pageAccounts;
    }
    public Integer getPageSize()
    {
    return pageSize;
    }
    public Boolean getPreviousButtonEnabled()
    {
    return !(pageNumber > 1);
    }
    public Boolean getNextButtonDisabled()
    {
    if (accounts == null) return true;
    else
    return ((pageNumber * pageSize) >= accounts.size());
    }
    public Integer getTotalPageNumber()
    {
    if (totalPageNumber == 0 && accounts !=null)
    {
    totalPageNumber = accounts.size() / pageSize;
    Integer mod = accounts.size() - (totalPageNumber * pageSize);
    if (mod > 0)
    totalPageNumber++;
    }
    return totalPageNumber;
    }
    public MyPagingController()
    {
    pageNumber = 0;
    totalPageNumber = 0;
    pageSize = 4;
    ViewData();
    }
    public PageReference ViewData()
    {
    accounts = null;
    totalPageNumber = 0;
    BindData(1);
    return null;
    }
    private void BindData(Integer newPageIndex)
    {
    try
    {
    string sortFullExp = sortExpression  + ' ' + sortDirection;
    if (accounts == null)
    accounts = Database.query('Select id, Name, BillingCity, BillingCountry, Phone from Account order by ' + sortFullExp + ' limit 1000');
    pageAccounts = new List<Account>{};
    Transient Integer counter = 0;
    Transient Integer min = 0;
    Transient Integer max = 0;
    if (newPageIndex > pageNumber)
    {
    min = pageNumber * pageSize;
    max = newPageIndex * pageSize;
    }
    else
    {
    max = newPageIndex * pageSize;
    min = max - pageSize;

    }
    for(Account a : accounts)
    {
    counter++;
    if (counter > min && counter <= max)
    pageAccounts.add(a);
    }
    pageNumber = newPageIndex;
    if (pageAccounts == null || pageAccounts.size() <= 0)
    ApexPages.addmessage(new ApexPages.message(ApexPages.severity.INFO,'Data not available for this view.'));
    }
    catch(Exception ex)
    {
    ApexPages.addmessage(new ApexPages.message(ApexPages.severity.FATAL,ex.getMessage()));
    }
    }
    public PageReference nextBtnClick() {
    BindData(pageNumber + 1);
    return null;
    }
    public PageReference previousBtnClick() {
    BindData(pageNumber - 1);
    return null;
    }
    }