zicht/service-wrapper

Service Wrapper classes

5.0.0 2022-08-11 08:45 UTC

Requires

• php: ^7.4 || ^8.0

Requires (Dev)

• friendsofphp/php-cs-fixer: ^3
• phpunit/phpunit: ^9

MIT

• Zicht online

README

Provides a wrapper to easily allow for an aspect-oriented approach of influencing response and requests to the service.

Scripts

• unit test: composer test
• lint test: composer lint

General approach

All calls to the service are wrapped in a call that notifies all observers of the call. The observers get a change to do their own housekeeping, or even alter the request or the response.

Any observer must implement the notifyBefore, alterRequest, alterResponse and notifyAfter methods. Each observer will get an instance of a ServiceCall object, which contains the request and the response objects. This more or less works the same as an event loop, but is intentionally not implemented as such to avoid the overhead of having a dispatcher and listener structure in place.

Common observers

For two very common practices, a logger and a cache observer are available.

Example

class MyService
{
    public function doIt($name)
    {
        return sprintf("Hi, %s, you have %d marbles in your pocket!", $name, rand());
    }
}

class MyObserver implements ServiceObserverInterface
{
    public function notifyBefore(ServiceCallInterface $call) {}
    public function notifyAfter(ServiceCallInterface $call) {}
    public function alterRequest(ServiceCallInterface $call) {}
    public function alterResponse(ServiceCallInterface $call)
    {
        $call->setResponse(strrev($call->getResponse()->getResponse()));
    }
}

$wrapper = new ServiceWrapper(new MyService());
$wrapper->registerObserver(new MyObserver());

echo $wrapper->doIt("Bart");
echo $wrapper->doIt("Lisa");

See doc/example.php for a more thorough example.

Applications

You can implement observer that:

• Add more data to responses, i.e. to enrich data
• Add basic logging
• Extensively monitor requests and responses with your own observers
• Add sanity checks and such that are costly in development, but can now easily be isolated in one object.
• Add caching

Maintainer

• Boudewijn Schoon [e-mail]
• Erik Trapman [e-mail]