Decorate PHP

Easily create decorators and proxies with a simple (composer) command.

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Do you enjoy using decorators in PHP, but hate having to implement one with large amounts of methods? Then this is the plugin for you! You can now quickly create a (final or abstract) class from an interface with all the methods already implemented and forwarded to the next instance. This little time saver lets you get on with the things you enjoy.

Installation

composer global require doekenorg/decorate-php

Notice: This is a global plugin, so don't forget global in the command!

Usage

The plugin adds a decorate command to your composer instance. It needs a source class (the interface you want to decorate) and a target class. You can optionally provide the name of the variable it uses for the next class. Currently, the plugin only works for composer projects.

Create a new decorator

composer decorate "Package\Namespace\SomeInterface" "My\Namespace\DestinationClass"

This will create, and write, a file called DestinationClass.php in the appropriate folder mapped in your psr-4 autoloader configuration.

A file like this will be created:

<?php

namespace My\Namespace;

use Package\Namespace\SomeInterface;

class DestinationClass implements SomeInterface {
    public function __construct(private SomeInterface $next) {
    }
    
    public function any_method(string $variable, ...$variadic_variable): void {
        $this->next->any_method($variable, ...$variadic_variable);
    }
}

Create a new decorator with a specific variable name.

By default, the decorated instance is mapped to a variable called $next. You can overwrite this by providing it as the third parameter. In the next example the variable will be called $client.

composer decorate "Package\Namespace\ClientInterface" "My\Namespace\MyClient" "client"

Here the output will be something like:

<?php

namespace My\Namespace;

use Package\Namespace\ClientInterface;

class MyClient implements ClientInterface {
    public function __construct(private ClientInterface $client) {
    }

    // ...
}

Note: The command will not overwrite an existing file. Provide the --overwrite option to force write.

Options

The command comes with the following options:

• --spaces will replace the indentation from tabs to 4 spaces by default. If you want 2 spaces; use --spaces=2. You can also provide a default in the global configuration (see next section).
• --output will output the code to the console instead of writing it.
• --overwrite will force-overwrite the file if it already exists.
• --abstract will create an abstract class. The next variable will now be protected instead of private.
• --final will create a final class.

Global configuration

You can use the following configuration in the extra key of your global composer.json (usually in ~/.composer).

{
  //...
  "extra": {
    "decorate-php": {
      "spaces": 4,
      "variable": "next",
      "use-property-promotion": true,
      "use-func-get-args": false,
      "use-final-class": true
    }
  }
}

• spaces will set the indentation to this amount of spaces by default; removing the need for --spaces.
• variable will overwrite the default of next with this value.
• use-property-promotion whether to use property promotion in the constructor (true by default).
• use-func-get-args whether to replace the actual arguments on the method call with ...func_get_args().
• use-final-class whether to create a final class by default.

Other information

PSR-4 only

Writing files is only supported for PSR-4 namespaces provided in the autoload key of your project. No PSR-0 support.

No decorating final classes

Obviously, you cannot create a decorator for a final class.

Decorating abstract classes

Although not common, you can also decorate abstract classes. In this case, any final methods are ignored when creating the decorator.

(Decorating non-abstract classes isn't really useful; but I kept the possibility for the extenders among us.)

Constructors

When an abstract class or interface declares a __construct method; it will append the next instance as the first argument. In case of an abstract class, it will also call the parent::__construct() method with the appropriate arguments.

Caveats

• Because composer uses some packages under the hood; it might use those interfaces, instead of the one in your project. For example: Psr\Container and Psr\Log namespaces. There might be a version discrepancy in that case.