Skip to main content

Composition Patterns

Zymba does not have classical inheritance (extends). Instead, use composition to build complex objects from simpler ones.

Delegation​

Embed one object inside another and delegate method calls:

ZYMBA
$Logger = new object() {
    prefix;
    construct($p) { $this.prefix = $p; }

    log($msg) {
        echo "[$this.prefix] $msg\n";
    }
};

$UserService = new object() {
    logger;
    db;

    construct($db) {
        $this.logger = new $Logger("UserService");
        $this.db     = $db;
    }

    findUser($id) {
        $this.logger.log("Finding user $id");
        return $this.db.fetchOne(
            @SQL.prepare("SELECT * FROM contacts WHERE ID = ?", $id),
            true
        );
    }
};

Factory functions​

Create objects with a function instead of a class — useful when initialization requires complex logic:

ZYMBA
function $createApiClient($baseUrl, $apiKey) {
    return new object() {
        baseUrl = $baseUrl;
        apiKey  = $apiKey;

        get($path) {
            $headers  = ["Authorization": "Bearer " . $this.apiKey];
            $response = @HTTP.request($this.baseUrl . $path, "GET", null, $headers);
            return @Var.fromJSON($response);
        }

        post($path, $data) {
            $headers = [
                "Authorization": "Bearer " . $this.apiKey,
                "Content-Type":  "application/json"
            ];
            $body     = @Var.toJSON($data);
            $response = @HTTP.request($this.baseUrl . $path, "POST", $body, $headers);
            return @Var.fromJSON($response);
        }
    };
}

$client = $createApiClient("https://api.example.com", "key123");

Mixin pattern​

Attach behaviors from multiple sources by augmenting an object's properties:

ZYMBA
function $withLogging($obj, $prefix) {
    $obj.log = function($msg) use ($prefix) {
        echo "[$prefix] $msg\n";
    };
    return $obj;
}

function $withValidation($obj) {
    $obj.validateEmail = function($email) {
        return $email ~= "/^[^@]+@[^@]+\\.[^@]+$/";
    };
    return $obj;
}

$service = new object() {
    processUser($email) {
        if (!$this.validateEmail($email)) {
            $this.log("Invalid email: " . $email);
            return false;
        }
        $this.log("Processing: " . $email);
        return true;
    }
};

$service = $withLogging($service, "UserSvc");
$service = $withValidation($service);
$service.processUser("alice@example.com");

ZeyOS platform objects​

ZeyOS provides built-in object classes for entity management. These are covered in detail in Platform Integration.

@ZeyOS.Object​

Access database entities as objects:

ZYMBA
$item  = new @ZeyOS.Object("items", $itemId);
$name  = $item.getField("name");
$price = $item.getField("sellingprice");

@ZeyOS.ObjectTransaction​

Create and modify records with transactional safety:

ZYMBA
$tx = new @ZeyOS.ObjectTransaction();
$tx.setFields([
    name:         "New Product",
    sellingprice: 29.99,
    status:       1
]);
$tx.save();

@ZeyOS.TransactionContext​

Wrap multiple operations in an atomic transaction:

ZYMBA
with (new @ZeyOS.TransactionContext) {
    $order = new @ZeyOS.ObjectTransaction(@orderId);
    $order.book();

    for ($lineItems as $item) {
        $itemTx = new @ZeyOS.ObjectTransaction();
        $itemTx.setFields($item);
        $itemTx.save();
    }
}