ComponentTreeSupplier

The primary interface for building a fully fluent page. Implement it to return a component tree for a given HTTP request. Bind it to a URL with a routes.yaml entry.

public interface ComponentTreeSupplier extends Component {

    default String id() {
        return this.getClass().getName();
    }

    Component component(HttpRequest httpRequest);

    default String style() { ... }

    default String cssClasses() { return null; }
}

Methods

Method	Description
component(HttpRequest)	Required. Returns the root component to render
id()	Optional component identifier (defaults to the fully-qualified class name)
style()	Optional inline CSS for the component wrapper
cssClasses()	Optional CSS class names for the component wrapper

Basic usage

public class DashboardPage implements ComponentTreeSupplier {

    @Override
    public Component component(HttpRequest httpRequest) {
        return Form.builder()
            .title("Dashboard")
            .contentItem(new Text("Welcome back!"))
            .build();
    }
}

src/main/resources/specs/ui/routes.yaml

type: Routes
routes:
  - route: dashboard
    viewModel: com.example.DashboardPage

Accessing request data

public class OrdersPage implements ComponentTreeSupplier {

    @Override
    public Component component(HttpRequest httpRequest) {
        var userId = httpRequest.getParameterValue("userId");
        return Form.builder()
            .title("Orders for " + userId)
            .contentItem(new Text("Loading..."))
            .build();
    }
}

src/main/resources/specs/ui/routes.yaml

type: Routes
routes:
  - route: orders
    viewModel: com.example.OrdersPage

Custom style

@Style("max-width: 800px; margin: auto;")
public class WelcomePage implements ComponentTreeSupplier {

    @Override
    public Component component(HttpRequest httpRequest) {
        return new Text("Welcome to Mateu");
    }
}

src/main/resources/specs/ui/routes.yaml

type: Routes
routes:
  - route: welcome
    viewModel: com.example.WelcomePage

Notes

• The default style() implementation returns "max-width:900px;margin: auto;" unless overridden or the class carries @Style.
• ComponentTreeSupplier itself implements Component, so it can be nested inside other fluent components.