title: Members
# Member
## Introduction
The `[api:Member]` class is used to represent user accounts on a SilverStripe site (including newsletter recipients).
## Testing For Logged In Users
The `[api:Member]` class comes with 2 static methods for getting information about the current logged in user.
**Member::currentUserID()**
Retrieves the ID (int) of the current logged in member. Returns *0* if user is not logged in. Much lighter than the
next method for testing if you just need to test.
:::php
// Is a member logged in?
if( Member::currentUserID() ) {
// Yes!
} else {
// No!
}
**Member::currentUser()**
Returns the full *Member* Object for the current user, returns *null* if user is not logged in.
:::php
if( $member = Member::currentUser() ) {
// Work with $member
} else {
// Do non-member stuff
}
## Subclassing
This is the least desirable way of extending the `[api:Member]` class. It's better to use `[api:DataExtension]`
(see below).
You can define subclasses of `[api:Member]` to add extra fields or functionality to the built-in membership system.
:::php
class MyMember extends Member {
private static $db = array(
"Age" => "Int",
"Address" => "Text",
);
}
To ensure that all new members are created using this class, put a call to `[api:Object::useCustomClass()]` in
(project)/_config.php:
:::php
Object::useCustomClass("Member", "MyMember");
Note that if you want to look this class-name up, you can call Object::getCustomClass("Member")
## Overloading getCMSFields()
If you overload the built-in public function getCMSFields(), then you can change the form that is used to view & edit member
details in the newsletter system. This function returns a `[api:FieldList]` object. You should generally start by calling
parent::getCMSFields() and manipulate the `[api:FieldList]` from there.
:::php
public function getCMSFields() {
$fields = parent::getCMSFields();
$fields->insertBefore("HTMLEmail", new TextField("Age"));
$fields->removeByName("JobTitle");
$fields->removeByName("Organisation");
return $fields;
}
## Extending Member or DataObject?
Basic rule: Class `[api:Member]` should just be extended for entities who have some kind of login.
If you have different types of `[api:Member]`s in the system, you have to make sure that those with login-capabilities have
unique email-addresses (as this is used for login-credentials).
For persons without login-capabilities (e.g. for an address-database), you shouldn't extend `[api:Member]` to avoid conflicts
with the Member-database. This enables us to have a different subclass of `[api:Member]` for an email-address with login-data,
and another subclass for the same email-address in the address-database.
## Member Role Extension
Using inheritance to add extra behaviour or data fields to a member is limiting, because you can only inherit from 1
class. A better way is to use role extensions to add this behaviour. Add the following to your
`[config.yml](/topics/configuration)`.
:::yml
Member:
extensions:
- MyMemberExtension
A role extension is simply a subclass of `[api:DataExtension]` that is designed to be used to add behaviour to `[api:Member]`.
The roles affect the entire class - all members will get the additional behaviour. However, if you want to restrict
things, you should add appropriate `[api:Permission::checkMember()]` calls to the role's methods.
:::php
class MyMemberExtension extends DataExtension {
/**
* Modify the field set to be displayed in the CMS detail pop-up
*/
public function updateCMSFields(FieldList $currentFields) {
// Only show the additional fields on an appropriate kind of use
if(Permission::checkMember($this->owner->ID, "VIEW_FORUM")) {
// Edit the FieldList passed, adding or removing fields as necessary
}
}
// define additional properties
private static $db = array();
private static $has_one = array();
private static $has_many = array();
private static $many_many = array();
private static $belongs_many_many = array();
public function somethingElse() {
// You can add any other methods you like, which you can call directly on the member object.
}
}
## API Documentation
`[api:Member]`