Review: the xdebug_call_function() method - PHP

Before I start teaching you how to use the "var_dump()" function included with the X-debug extension, I will reintroduce the hands-on example created in the preceding article of this series. It demonstrated how to track function calls via the "xdebug_call_function()" method.

Put in a simple way, the example in question made use of a sample "User" class, whose signature looked like this:

(example on using the 'xdebug_call_function()' function)

class User{

private $firstName;

private $lastName;

private $email;

public function __construct($firstName,$lastName,$email){

if(!$firstName){

throw new Exception('Invalid parameter First Name.');

}

if(!$lastName){

throw new Exception('Invalid parameter Last Name.');

}

if(!$email){

throw new Exception('Invalid parameter Email.');

}

$this->firstName=$firstName;

$this->lastName=$lastName;

$this->email=$email;

}

// get first name

public function getFirstName(){

return $this->firstName;

}

// get last name

public function getLastName(){

return $this->lastName;

}

// get email

public function getEmail(){

return $this->email;

}

// get the function that was called

public function getFunction(){

return 'Called from function '.xdebug_call_function();

}

}

As you'll probably recall, the above "User" class implemented a basic method called "getFunction()," which utilized the "xdebug_call_function()" function to return to client code the name of the function that originally called the method in question.

To help you understand this concept more clearly, below there's a short code sample that demonstrates the functionality of the "xdebug_call_function()" function. Here it is:

try{

$user=new User('Alejandro','Gervasio','alejandro@domain.com');

echo $user->getFunction();

/* displays the following

Called from function {main}

*/

}

catch(Exception $e){

echo $e->getMessage();

exit();

}

Definitely, the previous script is very easy to follow. It shows that the pertinent "getFunction()" method that belongs to the "User" class was called originally from the "main" function in C (remember that PHP was built with this medium-level programming language). Simple and pretty illustrative, right?

Now that you've recalled how to use the "xdebug_call_function()" function of the X-debug library to keep track of the different function calls performed during the execution of a PHP script, it's time to explore a few other features provided by this debugging library.

In the following section I'll be explaining how to use the enhanced version of the native "var_dump()" PHP function for retrieving useful and abundant information on a specified variable.

To see how this function works you'll have to click on the link that appears below and keep reading.