Understanding Yii Basic User Authentication

Basicly, Yii basic skeleton already come with aunthentication system which is very simple by checking username and password both admin or demo.

The default authentication files is

1. UserIdentity.php
2. LoginForm.php
3. SiteController.php
4. Login.php

1. root/webapps/protected/components/UserIdentity.php

[php]

class UserIdentity extends CUserIdentity
{
/**
* Authenticates a user.
* The example implementation makes sure if the username and password
* are both ‘demo’.
* In practical applications, this should be changed to authenticate
* against some persistent user identity storage (e.g. database).
* @return boolean whether authentication succeeds.
*/
public function authenticate()
{
$users=array(
// username => password
‘demo’=>’demo’,
‘admin’=>’admin’,
);
if(!isset($users[$this->username]))
$this->errorCode=self::ERROR_USERNAME_INVALID;
else if($users[$this->username]!==$this->password)
$this->errorCode=self::ERROR_PASSWORD_INVALID;
else
$this->errorCode=self::ERROR_NONE;
return !$this->errorCode;
}
}

[/php]

2. root/webapps/protected/model/LoginForm.php

[php]

<?php

/**
* LoginForm class.
* LoginForm is the data structure for keeping
* user login form data. It is used by the ‘login’ action of ‘SiteController’.
*/
class LoginForm extends CFormModel
{
public $username;
public $password;
public $rememberMe;

private $_identity;

/**
* Declares the validation rules.
* The rules state that username and password are required,
* and password needs to be authenticated.
*/
public function rules()
{
return array(
// username and password are required
array(‘username, password’, ‘required’),
// rememberMe needs to be a boolean
array(‘rememberMe’, ‘boolean’),
// password needs to be authenticated
array(‘password’, ‘authenticate’),
);
}

/**
* Declares attribute labels.
*/
public function attributeLabels()
{
return array(
‘rememberMe’=>’Remember me next time’,
);
}

/**
* Authenticates the password.
* This is the ‘authenticate’ validator as declared in rules().
*/
public function authenticate($attribute,$params)
{
if(!$this->hasErrors())
{
$this->_identity=new UserIdentity($this->username,$this->password);
if(!$this->_identity->authenticate())
$this->addError(‘password’,’Incorrect username or password.’);
}
}

/**
* Logs in the user using the given username and password in the model.
* @return boolean whether login is successful
*/
public function login()
{
if($this->_identity===null)
{
$this->_identity=new UserIdentity($this->username,$this->password);
$this->_identity->authenticate();
}
if($this->_identity->errorCode===UserIdentity::ERROR_NONE)
{
$duration=$this->rememberMe ? 3600*24*30 : 0; // 30 days
Yii::app()->user->login($this->_identity,$duration);
return true;
}
else
return false;
}
}

[/php]

3. root/webapps/protected/controllers/SiteController.php

[php]

…

/**
* Displays the login page
*/
public function actionLogin()
{
$model=new LoginForm;

// if it is ajax validation request
if(isset($_POST[‘ajax’]) && $_POST[‘ajax’]===’login-form’)
{
echo CActiveForm::validate($model);
Yii::app()->end();
}

// collect user input data
if(isset($_POST[‘LoginForm’]))
{
$model->attributes=$_POST[‘LoginForm’];
// validate user input and redirect to the previous page if valid
if($model->validate() && $model->login())
$this->redirect(Yii::app()->user->returnUrl);
}
// display the login form
$this->render(‘login’,array(‘model’=>$model));
}

…

[/php]

4. root/webapps/protected/views/site/login.php

[php]

<?php
$this->pageTitle=Yii::app()->name . ‘ – Login’;
$this->breadcrumbs=array(
‘Login’,
);
?>

<h1>Login</h1>

<p>Please fill out the following form with your login credentials:</p>

<div class="form">
<?php $form=$this->beginWidget(‘CActiveForm’, array(
‘id’=>’login-form’,
‘enableClientValidation’=>true,
‘clientOptions’=>array(
‘validateOnSubmit’=>true,
),
)); ?>

<p class="note">Fields with <span class="required">*</span> are required.</p>

<div class="row">
<?php echo $form->labelEx($model,’username’); ?>
<?php echo $form->textField($model,’username’); ?>
<?php echo $form->error($model,’username’); ?>
</div>

<div class="row">
<?php echo $form->labelEx($model,’password’); ?>
<?php echo $form->passwordField($model,’password’); ?>
<?php echo $form->error($model,’password’); ?>
<p class="hint">
Hint: You may login with <tt>demo/demo</tt> or <tt>admin/admin</tt>.
</p>
</div>

<div class="row rememberMe">
<?php echo $form->checkBox($model,’rememberMe’); ?>
<?php echo $form->label($model,’rememberMe’); ?>
<?php echo $form->error($model,’rememberMe’); ?>
</div>

<div class="row buttons">
<?php echo CHtml::submitButton(‘Login’); ?>
</div>

<?php $this->endWidget(); ?>
</div><!– form –>

[/php]