Next: , Previous: , Up: Class Module Design   [Contents]


B.1.3 Constructor Implementation

ease.js uses a PHP-style constructor. Rather than using the class name as the constructor, a __construct() method is used. This was chosen primarily because ease.js does not always know the name of the class. In fact, in the early stages of development, named classes were unsupported. With the PHP-style constructor, the class name does not need to be known, allowing constructors to be written for anonymous and named classes alike.

In addition, the PHP-style constructor is consistent between class definitions. To look up a constructor, one need only search for “__construct”, rather than the class name. This makes certain operations, such as global searching (using grep or any other utility), much simpler.

One difference from PHP is the means of preventing instantiation. In PHP, if the constructor is declared as non-public, then an error will be raised when the developer attempts to instantiate the class. ease.js did not go this route, as the method seems cryptic. Instead, an exception should be thrown in the constructor if the developer doesn’t wish the class to be instantiated. In the future, a common method may be added for consistency/convenience.

The constructor is optional. If one is not provided, nothing is done after the class is instantiated (aside from the internal ease.js initialization tasks).

The constructor is called after all initialization tasks have been completed.