mrhash/taskmachine

Modular micro-service task pipelining & orchestration with validated state machine integrity.

dev-master 2019-11-17 22:27 UTC

This package is auto-updated.

Last update: 2024-07-18 09:01:56 UTC


README

Modular micro-service task pipelining & orchestration with validated state machine integrity.

Define micro-service tasks and arrange them into state machine managed flows with a simple and expressive API. You can create build tool chains, processing pipelines, utility services, or even serve web pages...

State machines for the masses!

Examples

Simple pipeline

We define two simple inline tasks which are independent. The machine executes the two tasks in order and then finishes.

$tmb = new TaskMachineBuilder;

// Define some tasks
$tmb->task('hello', function () {
  echo 'Hello World';
});

$tmb->task('goodbye', function () {
  echo 'Goodbye World';
});

// Define and build a machine
$tm = $tmb->machine('greetings')
  // specify an initial task and transition
  ->hello([
    'initial' => true,
    'transition' => 'goodbye'
  ])
   // specify a final task
  ->goodbye(['final' => true])
  ->build();

// Run the machine.
$tm->run('greetings');

Pipeline with DI

Now we introduce some more tasks with DI. Tasks are isolated by definition and optionally have expected inputs and outputs.

// Bootstrap your own Auryn injector and throw it in
$tmb = new TaskMachineBuilder(new TaskFactory($myInjector));

// Define some tasks
$tmb->task(
  'translate',
  function (InputInterface $input, MyTranslationInterface $translator) {
    // Auryn injects fully constructed dependencies. Run your things.
    $translation = $translator->translate($input->get('text'));
    return ['text' => $translation];
  }
);

// Input from previous task is injectable and immutable
$tmb->task('echo', function (InputInterface $input) {
  echo $input->get('text');
});

$tmb->task('goodbye', function () {
  return ['closing' => 'Goodbye World'];
});

 // Define and build machine
$tm = $tmb->machine('translator')
  ->translate([
    'initial' => true,
    'transition' => 'echo'
  ])
  ->echo(['transition' => 'goodbye'])
  ->goodbye(['final' => true])
  ->build();

// Run with input and then echo the output from the last task
$output = $tm->run('translator', ['text' => 'Hello World']);
echo $output->get('closing');

Any faults in the configuration of your machine will result in a build error! Tasks must be linked together correctly and have valid unambiguous transitions.

Conditional branching

Machines can branch to different tasks based on conditions written in Symfony Expression Language.

$tmb = new TaskMachineBuilder(new TaskFactory($myInjector));

// Define some tasks
$tmb->task('process', function () {
  // This outputs a random true or false result
  $result = (bool)random_int(0,1);
  return ['success' => $result];
});

// Task with your instantiated object which implements TaskHandlerInterface
$tmb->task('finish', new Finisher($myService));

// Task with your handler which implements TaskHandlerInterface
// Your dependencies are injected
$tmb->task('fail', MyCustomServiceInterface::class);

// Define and build a machine with different final outcomes
$tm = $tmb->machine('switcher')
  ->process([
    'initial' => true,
    // Specify switch conditions to subsequent tasks
    'transition' => [
      'output.success' => 'finish',
      '!output.success' => 'fail'
    ]
  ])
  ->finish(['final' => true])
  ->fail(['final' => true])
  ->build();
  
// Run it.
$tm->run('switcher');