Laravel Decorator

Decorate and extend functionalities of methods without causing any break to the existing codebase.

Installation

$ composer require mehradsadeghi/laravel-decorator

Usage

Assuming you have a class named Person with a method named getFullName which its inputs and output should get decorated:

class Person {

    public function makeFullName($firstName, $lastName)
    {
        return "$firstName $lastName";
    }
}

$person = new Person();
$person->makeFullName('mehrad', 'sadeghi'); // mehrad sadeghi

When using decorator without setting any decoration, The default behavior of makeFullName method will remain the same:

decorate([Person::class, 'makeFullName'], ['mehrad', 'sadeghi']); // mehrad sadeghi

In order to decorate makeFullName method:

$decorator = function ($callable) {
    return function (...$params) use ($callable) {
    
        // decorating the inputs
        foreach($params as $key => $param) {
            $params[$key] = trim($param);
        }

        // real call to makeFullName method
        $output = app()->call($callable, $params);

        // decorating the output
        $output = strtoupper($output);

        return $output;
    };
};

decorator([Person::class, 'makeFullName'])->set($decorator);

Note that the decorator should be a valid PHP callable. So it can be a Closure or an array callable, Which can be defined as follows:

class PersonDecorator {

    public function decorateFullName($callable)
    {
        return function (...$params) use ($callable) {
        
            // decorating the inputs
            foreach($params as $key => $param) {
                $params[$key] = trim($param);
            }

            // real call to makeFullName method
            $output = app()->call($callable, $params);

            // decorating the output
            $output = strtoupper($output);

            return $output;
        };
    }
}

decorator([Person::class, 'makeFullName'])->set([PersonDecorator::class, 'decorateFullName']);

Now we've assigned our decorator to the makeFullName method. Calling makeFullName with decorate helper function will apply its decoration:

decorate([Person::class, 'makeFullName'], ['  mehrad ', '     sadeghi ']); // MEHRAD SADEGHI

Multiple Decorators

You can easily set multiple decorators on a method:

decorator([Person::class, 'makeFullName'])
        ->set(function($callable) {
            // decoration
        })
        ->set(function($callable) {
            // decoration
        });

or

decorator([Person::class, 'makeFullName'])
    ->set([PersonDecorator::class, 'secondDecorator'])
    ->set([PersonDecorator::class, 'firstDecorator']);

Forgetting (Removing) Decorator(s)

You can easily remove one or all decorators assigned to a callable. From example above, Assume we have two decorators:

class PersonDecorator {

    public function decorateInput($callable)
    {
        return function (...$params) use ($callable) {

            // decorating the inputs
            foreach($params as $key => $param) {
                $params[$key] = trim($param);
            }

            // real call to makeFullName method
            $output = app()->call($callable, $params);

            return $output;
        };
    }

    public function decorateOutput($callable)
    {
        return function (...$params) use ($callable) {

            // real call to makeFullName method
            $output = app()->call($callable, $params);

            // decorating the output
            $output = strtoupper($output);

            return $output;
        };
    }
}

decorator([Person::class, 'makeFullName'])
    ->set([PersonDecorator::class, 'decorateInput'])
    ->set([PersonDecorator::class, 'decorateOutput']);

The output of calling decorate would be:

decorate([Person::class, 'makeFullName'], ['  mehrad ', '     sadeghi ']); // MEHRAD SADEGHI

Then for removing decorateOutput:

decorator([Person::class, 'makeFullName'])
    ->forget([PersonDecorator::class, 'decorateOutput']);

And the output of calling decorate would be:

decorate([Person::class, 'makeFullName'], ['  mehrad ', '     sadeghi ']); // mehrad sadeghi

Note that for removing all decorations of a callable, just leave the forget parameter empty:

decorator([Person::class, 'makeFullName'])->forget();