PHP code example of milpa / orchestrator

    
        
<?php
require_once('vendor/autoload.php');

/* Start to develop here. Best regards https://php-download.com/ */

    

milpa / orchestrator example snippets

use Milpa\Orchestrator\ProcessDefinition;
use Milpa\Workflow\Entities\GateDefinition;
use Milpa\Workflow\Entities\StateDefinition;
use Milpa\Workflow\Entities\TransitionDefinition;
use Milpa\Workflow\Enums\ApprovalPolicy;

$draft     = (new StateDefinition())->setDomain('publish_post')->setCode('draft')->setLabel('Draft')->setIsInitial(true);
$review    = (new StateDefinition())->setDomain('publish_post')->setCode('review')->setLabel('In review');
$published = (new StateDefinition())->setDomain('publish_post')->setCode('published')->setLabel('Published')->setIsTerminal(true);

$gate = (new GateDefinition())
    ->setDomain('publish_post')->setCode('review_gate')->setName('Editorial review')
    ->setRequesterRole('author')->setApproverRole('editor')
    ->setApprovalPolicy(ApprovalPolicy::SINGLE);

$submit  = (new TransitionDefinition())->setDomain('publish_post')->setCode('submit')->setFromState($draft)->setToState($review);
$approve = (new TransitionDefinition())->setDomain('publish_post')->setCode('approve')->setFromState($review)->setToState($published);
$reject  = (new TransitionDefinition())->setDomain('publish_post')->setCode('reject')->setFromState($review)->setToState($draft);
$approve->addGateDefinition($gate);   // both outcomes share the SAME gate: one checkpoint,
$reject->addGateDefinition($gate);    // two options (approve | reject)

$definition = new ProcessDefinition([$draft, $review, $published], [$submit, $approve, $reject]);

use Milpa\EventStore\FileEventStore;
use Milpa\Eventing\EventDispatcher;
use Milpa\Orchestrator\HumanGate;
use Milpa\Orchestrator\ProcessDefinitionRegistry;
use Milpa\Orchestrator\ProcessRunner;
use Milpa\Orchestrator\Tools\ProcessInstantiateTool;
use Milpa\Orchestrator\Tools\ProcessListPendingApprovalsTool;
use Milpa\Orchestrator\Tools\ProcessSubmitDecisionTool;
use Milpa\ToolRuntime\Contracts\ToolContext;
use Psr\Log\NullLogger;

$store      = new FileEventStore('/tmp/posts.jsonl');   // the append-only log
$dispatcher = new EventDispatcher(new NullLogger());    // milpa/events
$dispatcher->subscribe('process.terminal', function (string $name, array $payload): void {
    // Reaching `published` runs the real domain effect HERE — the engine itself touches no
    // domain entity. $payload = {instance_id, final_state, context}.
});

$registry = new ProcessDefinitionRegistry();
$registry->register('publish_post', $definition);

$gate   = new HumanGate(new YourDecisionSurfaceFactory());   // a milpa/live surface, consumer-supplied
$runner = new ProcessRunner($dispatcher);

$instantiate = new ProcessInstantiateTool($store, $gate, $runner, $registry);
$instantiate->setCurrentContext(ToolContext::mcp('req-1', 'agent:author', ['*']));
$list   = new ProcessListPendingApprovalsTool($store, $gate, $registry);
$submit = new ProcessSubmitDecisionTool($store, $gate, $runner, $registry);

use Milpa\Orchestrator\ProcessInstance;

// 1. Instantiate — auto-advances draft --submit--> review and PARKS at the human gate.
$started    = $instantiate->instantiate('publish_post', ['post_id' => 42]);
$instanceId = $started->data['instance_id'];
$started->data['current_state'];   // 'review' — the runner stopped at the gate, not past it

// 2. The gate is pending; its options are projected 1:1 from the process's OWN transitions.
$pending = $list->list()->data['pending'][0];
$pending['assignee'];   // 'editor'
$pending['options'];    // ['approve', 'reject']
$gateId  = $pending['gate_id'];

// 3. An editor — NOT the author — resolves it. Self-approval is refused by construction:
//    submitting as 'agent:author' here returns error SELF_APPROVAL_FORBIDDEN instead.
$done = $submit->submit($instanceId, $gateId, 'approve', 'human:editor');
$done->data['current_state'];   // 'published' — auto-advanced past the gate to terminal;
                                //  `process.terminal` fired exactly once.

// 4. State is a projection: a FRESH store + handle over the SAME log reconstructs it, no cache.
$replayed = new ProcessInstance($instanceId, $definition);
$replayed->currentState(new FileEventStore('/tmp/posts.jsonl'));   // 'published'