Flourish PHP Unframework

Flourish Callback Syntax

In most programming languages where functions are first-class members, the syntax for a function or method callback is simply the function/method name without the parenthesis. The below snippet of javascript defines a function and then uses a callback for setTimeout to cause the function to be executed at a later time.

function foo() {
    // Do stuff
setTimeout(foo, 100);

Unfortunately PHP does not treat function at first-class members of the language. It uses strings and arrays for function and method callbacks respectively. In an attempt to make the callback syntax a little more intuitive, Flourish uses class constants and the __get() magic method to make javascript-style callbacks.

Flourish defines class constants with the same name as all static methods:

// Uppercase a UTF-8 string
$string = fUTF8::upper($string);

// Uppercase an array of UTF-8 strings (PHP 5.2 only)
$strings = array_map(fUTF8::upper, $strings);

The only caveat with these class constants is that in PHP 5.1 they need to be passed to fCore::callback() if they are going to be used with built-in PHP functions. This is because the constants are the string-style static method callbacks, which were added in PHP 5.2. The method fCore::callback() translates them into the array-style syntax that works in 5.1.

// PHP 5.1 compatible callbacks for PHP functions
$string = array_map(fCore::callback(fUTF8::upper), $strings);

For instance method callbacks, Flourish uses the __get() magic method to create the appropriate array-syntax callback for the object being called.

$ten_dollars = new fMoney(10);
echo $ten_dollars->format();

// Callback syntax for format

Both the instance and static method callback syntaxes work on every method of every Flourish class.