/**
 * An apex class that creates a portal user
 */
public with sharing class SiteRegisterController {
    // PORTAL_ACCOUNT_ID is the account on which the contact will be created on and then enabled as a portal user.
    // you need to add the account owner into the role hierarchy before this will work - please see Customer Portal Setup help for more information.
    private static Id PORTAL_ACCOUNT_ID = '001x000xxx35tPN';

    public SiteRegisterController() {
    }

    public String username { get; set; }
    public String email { get; set; }
    public String password {
        get;
        set {
            password = value == null ? value : value.trim();
        }
    }
    public String confirmPassword {
        get;
        set {
            confirmPassword = value == null ? value : value.trim();
        }
    }
    public String communityNickname {
        get;
        set {
            communityNickname = value == null ? value : value.trim();
        }
    }

    private boolean isValidPassword() {
        return password == confirmPassword;
    }

    public PageReference registerUser() {
        // it's okay if password is null - we'll send the user a random password in that case
        if (!isValidPassword()) {
            ApexPages.Message msg = new ApexPages.Message(ApexPages.Severity.ERROR, Label.site.passwords_dont_match);
            ApexPages.addMessage(msg);
            return null;
        }
        User u = new User();
        u.Username = username;
        u.Email = email;
        u.CommunityNickname = communityNickname;

        String accountId = PORTAL_ACCOUNT_ID;

        // lastName is a required field on user, but if it isn't specified, we'll default it to the username
        String userId = Site.createPortalUser(u, accountId, password);
        if (userId != null) {
            if (password != null && password.length() > 1) {
                return Site.login(username, password, null);
            } else {
                PageReference page = System.Page.SiteRegisterConfirm;
                page.setRedirect(true);
                return page;
            }
        }
        return null;
    }
}