fwolf / fwlib

Adding explicit visibility (private, protected, or public) is generally recommend to communicate to other developers how, and from where this method is intended to be used.

This function has been deprecated. The supplier of the file has supplied an explanatory message.

The explanatory message should give you some clue as to whether and when the function will be removed from the class and what other function to use instead.

This class, trait or interface has been deprecated. The supplier of the file has supplied an explanatory message.

The explanatory message should give you some clue as to whether and when the type will be removed from the class and what other constant to use instead.

In PHP it is possible to write to properties without declaring them. For example, the following is perfectly valid PHP code:

class MyClass { }

$x = new MyClass();
$x->foo = true;

Generally, it is a good practice to explictly declare properties to avoid accidental typos and provide IDE auto-completion:

class MyClass {
    public $foo;
}

$x = new MyClass();
$x->foo = true;

This function has been deprecated. The supplier of the file has supplied an explanatory message.

The explanatory message should give you some clue as to whether and when the function will be removed from the class and what other function to use instead.

If you return a value from a function or method, it should be a sub-type of the type that is given by the parent type f.e. an interface, or abstract method. This is more formally defined by the Lizkov substitution principle, and guarantees that classes that depend on the parent type can use any instance of a child type interchangably. This principle also belongs to the SOLID principles for object oriented design.

Let’s take a look at an example:

class Author {
    private $name;

    public function __construct($name) {
        $this->name = $name;
    }

    public function getName() {
        return $this->name;
    }
}

abstract class Post {
    public function getAuthor() {
        return 'Johannes';
    }
}

class BlogPost extends Post {
    public function getAuthor() {
        return new Author('Johannes');
    }
}

class ForumPost extends Post { /* ... */ }

function my_function(Post $post) {
    echo strtoupper($post->getAuthor());
}

Our function my_function expects a Post object, and outputs the author of the post. The base class Post returns a simple string and outputting a simple string will work just fine. However, the child class BlogPost which is a sub-type of Post instead decided to return an object, and is therefore violating the SOLID principles. If a BlogPost were passed to my_function, PHP would not complain, but ultimately fail when executing the strtoupper call in its body.

This function has been deprecated. The supplier of the file has supplied an explanatory message.

The explanatory message should give you some clue as to whether and when the function will be removed from the class and what other function to use instead.

Using a closing tag in PHP files that only contain PHP code is not recommended as you might accidentally add whitespace after the closing tag which would then be output by PHP. This can cause severe problems, for example headers cannot be sent anymore.

A simple precaution is to leave off the closing tag as it is not required, and it also has no negative effects whatsoever.