Magic Methods

The “magic” methods are ones with special names, starting with two underscores, which denote methods which will be triggered in response to particular PHP events. That might sound slightly automagical but actually it’s pretty straightforward, we already saw an example of this in the last post, where we used a constructor – so we’ll use this as our first example.

PHP functions that start with a double underscore – a “__” – are called magic functions (and/or methods) in PHP. They are functions that are always defined inside classes, and are not stand-alone (outside of classes) functions. The magic functions available in PHP are: __construct(), __destruct(), __call(), __callStatic(), __get(), __set(), __isset(), __unset(), __sleep(), __wakeup(), __toString(), __invoke(), __set_state(), __clone(), and __autoload().

KeepAlive

HTTP is a session less protocol. A connection is made to transfer a single file and closed once the transfer is complete. This keeps things simple but it’s not very efficient.

To improve efficiency something called KeepAlive was introduced. With KeepAlive the web browser and the web server agree to reuse the same connection to transfer multiple files.

JavaScript innerHTML Disadvantages

  • Content is replaced everywhere
  • We cannot use like “appending to innerHTML”
  • Even if you use +=like “innerHTML = innerHTML + ‘html’” still the old content is replaced by html
  • The entire innerHTML content is re-parsed and build into elements, therefore its much slower
  • The innerHTML does not provide validation and therefore we can potentially insert valid and broken HTML in the document and break it

Beginners' Guide