Connections

Named Connections

Define connections in config/packages/php_opcua_symfony_opcua.yaml:

php_opcua_symfony_opcua:
    connections:
        default:
            endpoint: '%env(OPCUA_ENDPOINT)%'
        plc-line-1:
            endpoint: 'opc.tcp://10.0.0.10:4840'
            username: operator
            password: pass123

Connecting

use PhpOpcua\SymfonyOpcua\OpcuaManager;

class PlcController
{
    public function __construct(private readonly OpcuaManager $opcua) {}

    public function index(): Response
    {
        // Default connection
        $client = $this->opcua->connect();

        // Named connection
        $client = $this->opcua->connect('plc-line-1');
    }
}

Getting a Connection Without Connecting (Managed Mode Only)

In direct mode, connection() returns an already-connected Client. The OpcUaClientInterface does not expose setter methods (setTimeout(), etc.), so there is no pre-connect configuration step. If you need to customise timeout or other settings, set them in YAML config or pass inline config to connectTo().

In managed mode (session manager running), connection() returns a ManagedClient that still supports setter methods before the first operation.

// Direct mode -- returns a connected Client (same as connect())
$client = $this->opcua->connection('plc-line-1');

// Managed mode -- setter methods are still available
// $client = $this->opcua->connection('plc-line-1');
// $client->setTimeout(15.0);

Switching the Default

Set the default key in YAML config:

php_opcua_symfony_opcua:
    default: plc-line-1
    connections:
        default:
            endpoint: '%env(OPCUA_ENDPOINT)%'
        plc-line-1:
            endpoint: 'opc.tcp://10.0.0.10:4840'

Ad-hoc Connections

Connect to endpoints not defined in config:

// Minimal
$client = $this->opcua->connectTo('opc.tcp://10.0.0.50:4840');

// With inline config
$client = $this->opcua->connectTo('opc.tcp://10.0.0.99:4840', [
    'username'        => 'operator',
    'password'        => 'secret',
    'security_policy' => 'Basic256Sha256',
    'security_mode'   => 'SignAndEncrypt',
]);

// With a name for later retrieval
$client = $this->opcua->connectTo('opc.tcp://10.0.0.99:4840', as: 'temp-plc');
$same = $this->opcua->connection('temp-plc');

Disconnecting

// Single connection
$this->opcua->disconnect('plc-line-1');

// Default connection
$this->opcua->disconnect();

// All connections (including ad-hoc)
$this->opcua->disconnectAll();

After disconnecting, the next call to connection() or connect() creates a fresh client.

Connection Caching

OpcuaManager caches client instances by name. Repeated calls to connection('plc-1') return the same instance:

$a = $this->opcua->connection('plc-1');
$b = $this->opcua->connection('plc-1');
assert($a === $b); // true

Calling disconnect() removes the cached instance.

Dependency Injection

The OpcuaManager is registered as a public service and can be injected anywhere via autowiring.

OpcuaManager for Full Control

Use OpcuaManager when you need to manage multiple connections, use ad-hoc connections, or switch between named connections:

use PhpOpcua\SymfonyOpcua\OpcuaManager;

class PlcService
{
    public function __construct(private readonly OpcuaManager $opcua) {}

    public function readFromBothLines(): array
    {
        $line1 = $this->opcua->connect('plc-line-1');
        $line2 = $this->opcua->connect('plc-line-2');

        $temp1 = $line1->read('ns=2;s=Temperature')->getValue();
        $temp2 = $line2->read('ns=2;s=Temperature')->getValue();

        $this->opcua->disconnectAll();

        return [$temp1, $temp2];
    }
}

OpcUaClientInterface for Default Connection

When you only need the default connection, inject OpcUaClientInterface directly. The bundle registers a factory that calls OpcuaManager::connection(null):

use PhpOpcua\Client\OpcUaClientInterface;

class PlcController
{
    public function __construct(private readonly OpcUaClientInterface $client) {}

    public function index(): Response
    {
        $value = $this->client->read('ns=2;i=1001');

        return new JsonResponse(['value' => $value->getValue()]);
    }
}

In direct mode, injecting OpcUaClientInterface returns an already-connected client. In managed mode, it returns a configured ManagedClient that connects on first operation.

Controller Action Injection

Symfony also supports injection via controller action parameters:

use PhpOpcua\SymfonyOpcua\OpcuaManager;
use PhpOpcua\Client\OpcUaClientInterface;

class PlcController
{
    public function readStatus(OpcuaManager $opcua): Response
    {
        $client = $opcua->connect();
        $value = $client->read('i=2259');
        $client->disconnect();

        return new JsonResponse(['status' => $value->getValue()]);
    }

    public function readDefault(OpcUaClientInterface $client): Response
    {
        $value = $client->read('i=2259');

        return new JsonResponse(['status' => $value->getValue()]);
    }
}

Session Manager Auto-Detection

When creating a client, OpcuaManager checks for the daemon's Unix socket:

session_manager.enabled is true (default)
session_manager.socket_path file exists

If both conditions are met, a ManagedClient (daemon-proxied) is created. Otherwise, a direct Client is created via ClientBuilder. This is transparent -- your application code does not change.

if ($this->opcua->isSessionManagerRunning()) {
    // ManagedClient -- session persists across requests
} else {
    // Direct Client -- new TCP connection per request
}

How Connection Configuration Works

When a connection is created, OpcuaManager applies configuration differently depending on the mode.

Direct Mode (configureBuilder)

A ClientBuilder is configured and then connect() is called, returning a fully connected Client. All settings are immutable after connection.

Security policy and mode
User credentials (username/password)
Client certificate and CA
User certificate
Timeout
Auto-retry
Batch size
Browse max depth
Trust store path and trust policy
Auto-accept and auto-accept-force
Auto-detect write type
Read metadata cache
Logger (explicit config or Symfony default via Monolog)
Cache (explicit config or Symfony default via Psr16Cache wrapping a PSR-6 pool)
Event dispatcher (Symfony EventDispatcher if available)

Managed Mode (configureManagedClient)

A ManagedClient is created and setter methods are called. Settings can be adjusted after creation.

Security policy and mode
User credentials (username/password)
Client certificate and CA
User certificate
Timeout
Auto-retry
Batch size
Browse max depth
Trust store path and trust policy
Auto-accept and auto-accept-force
Auto-detect write type
Read metadata cache
Logger (explicit config or Symfony default via Monolog)
Cache (explicit config or Symfony default via Psr16Cache wrapping a PSR-6 pool)
Event dispatcher (Symfony EventDispatcher if available)