Magento - getEmail（）在哪里定义？

Question

You can find out the e-mail of the logged in user by using the following code:

$customer = Mage::getSingleton('customer/session')->getCustomer();
$mail = $customer->getEmail();

How to find out where getEmail() is defined?

I searched in app\code\core\Mage\Customer\Model\Resource\Customer.php but there is no function called getEmail().

I only found this:

So I tracked it back with NetBeans, and found the definition for Varien_Object in lib\Varien\Object.php.

But in there is no function getEmail() either.

I searched the whole project for the string public function getEmail(),

This is the result:

$ grep -iR "public function getEmail()"
app/code/core/Mage/Catalog/Block/Product/Send.php:    public function getEmail()
app/code/core/Mage/Newsletter/Model/Subscriber.php:    public function getEmail()
app/code/core/Mage/Sendfriend/Block/Send.php:    public function getEmail()
app/code/core/_193_Mage/Catalog/Block/Product/Send.php:    public function getEmail()
app/code/core/_193_Mage/Newsletter/Model/Subscriber.php:    public function getEmail()
app/code/core/_193_Mage/Sendfriend/Block/Send.php:    public function getEmail()
app/code/_core/Mage/Catalog/Block/Product/Send.php:    public function getEmail()
app/code/_core/Mage/Newsletter/Model/Subscriber.php:    public function getEmail()
app/code/_core/Mage/Sendfriend/Block/Send.php:    public function getEmail()
lib/Payone/Api/Request/Parameter/Authorization/PersonalData.php:    public function getEmail()
lib/Payone/Api/Request/Parameter/CreateAccess/PersonalData.php:    public function getEmail()
lib/Payone/Api/Request/Parameter/ManageMandate/PersonalData.php:    public function getEmail()
lib/Payone/Api/Request/Parameter/Vauthorization/PersonalData.php:    public function getEmail()
lib/Zend/Gdata/App/Extension/Person.php:    public function getEmail()
lib/Zend/Gdata/Extension/Who.php:    public function getEmail()
lib/Zend/Service/ReCaptcha/MailHide.php:    public function getEmail()
lib/Zend/View/Helper/Gravatar.php:    public function getEmail()

Answer 1

You wont find getEmail() definition because it doesn't exist.

As you can see in the piece of code you are sharing, $customer is an instance of a Varien_Object. That class is defined in lib\Varien\Object.php.

If you peek there, you'll see that the method isn't defined either... but that's because for better or worse Magento takes advantage of PHP's magic methods.

When a non-existing method is called on this $customer instance, __call() is executed instead.

This is the method definition for Varien_Object::_call():

/**
 * Set/Get attribute wrapper
 *
 * @param   string $method
 * @param   array $args
 * @return  mixed
 */
public function __call($method, $args)
{
    switch (substr($method, 0, 3)) {
        case 'get' :
            $key = $this->_underscore(substr($method,3));
            $data = $this->getData($key, isset($args[0]) ? $args[0] : null);
            return $data;
        case 'set' :
            $key = $this->_underscore(substr($method,3));
            $result = $this->setData($key, isset($args[0]) ? $args[0] : null);
            return $result;
        case 'uns' :
            $key = $this->_underscore(substr($method,3));
            $result = $this->unsetData($key);
            return $result;
        case 'has' :
            $key = $this->_underscore(substr($method,3));
            return isset($this->_data[$key]);
    }
    throw new Varien_Exception("Invalid method ".get_class($this)."::".$method."(".print_r($args,1).")");
}

From here on, the logic is pretty simple. Since $method will be getEmail, the first branch of the switch will be executed, and $key will be got from the method name (skipping the first three characters, since they must necessarily be "get", "set", "uns", or "has") and in this case it'll become "email".