图像扩展验证不起作用

My uploaded image validation is not working..

add.ctp

<?php echo $this->Form->create('User',array('enctype'=>'multipart/form-data', 'novalidate'=>'true')); ?>
<?php echo $this->Form->file('users_image', array('type' => 'file', 'class' => 'm-wrap large','id'=>'ProfileImage')); ?>
<?php echo $this->Form->end(__('Submit')); ?>

User.php

public $validate = array(
'uesrs_image' => array(
            'rule' => array(
                'extension',
                array('jpeg', 'jpg')
            ),
         'message' => 'Please supply a valid image.'
    )
);

When i uploaded .png image, it uploaded successfully

try this

public $validate = array(
'uesrs_image' => array(
       'extension' => array(
            'rule' => array('extension', array('jpeg', 'jpg')),
            'message' => 'Only jpeg, jpg files',
        ),
        'upload-file' => array(
            'rule' => array('uploadFile'), // Is a function below
            'message' => 'Error uploading file'
        )
    )
);