Multiple Inheritance in PHP

by

Alex, most of the times you need multiple inheritance is a signal your object structure is somewhat incorrect. In situation you outlined I see you have class responsibility simply too broad. If Message is part of application business model, it should not take care about rendering output. Instead, you could split responsibility and use MessageDispatcher that sends the Message passed using text or html backend. I don’t know your code, but let me simulate it this way:

$m = new Message();
$m->type="text/html";
$m->from = 'John Doe <[email protected]>';
$m->to = 'Random Hacker <[email protected]>';
$m->subject="Invitation email";
$m->importBody('invitation.html');

$d = new MessageDispatcher();
$d->dispatch($m);

This way you can add some specialisation to Message class:

$htmlIM = new InvitationHTMLMessage(); // html type, subject and body configuration in constructor
$textIM = new InvitationTextMessage(); // text type, subject and body configuration in constructor

$d = new MessageDispatcher();
$d->dispatch($htmlIM);
$d->dispatch($textIM);

Note that MessageDispatcher would make a decision whether to send as HTML or plain text depending on type property in Message object passed.

// in MessageDispatcher class
public function dispatch(Message $m) {
    if ($m->type == 'text/plain') {
        $this->sendAsText($m);
    } elseif ($m->type == 'text/html') {
        $this->sendAsHTML($m);
    } else {
        throw new Exception("MIME type {$m->type} not supported");
    }
}

To sum it up, responsibility is split between two classes. Message configuration is done in InvitationHTMLMessage/InvitationTextMessage class, and sending algorithm is delegated to dispatcher. This is called Strategy Pattern, you can read more on it here.

More Related Contents:

  1. How can I get the classname from a static call in an extended PHP class?
  2. Understanding IoC Containers and Dependency Injection
  3. How do I get a PHP class constructor to call its parent’s parent’s constructor?
  4. Call parent constructor before child constructor in PHP
  5. Interface implementation: declaration must be compatible
  6. remove duplicate key array from php [duplicate]
  7. When should I use ‘self’ over ‘$this’?
  8. Is there a use-case for singletons with database access in PHP?
  9. PHP method chaining or fluent interface?
  10. What does the variable $this mean in PHP?
  11. What is the best method to merge two PHP objects?
  12. Best practice on PHP singleton classes [duplicate]
  13. Why does PHP 5.2+ disallow abstract static class methods?
  14. PHP OOP core framework
  15. What is the syntax for accessing PHP object properties? [closed]
  16. PHP: How to call function of a child class from parent class
  17. Is it possible to create static classes in PHP (like in C#)?
  18. When should I declare variables in a PHP class?
  19. Autoload classes from different folders
  20. If Singletons are bad then why is a Service Container good?
  21. When should I use stdClass and when should I use an array in php oo code?
  22. How to use class methods as callbacks
  23. Getting the name of a child class in the parent class (static context)
  24. Chaining Static Methods in PHP?
  25. Dynamically create PHP object based on string
  26. Nested or Inner Class in PHP
  27. Performance of static methods vs. functions
  28. How do I access static member of a class?
  29. dynamic class names in php
  30. Best way to handle dirty state in an ORM model

Leave a Comment