Nalu

Nalu is a tiny framework that helps you to create GWT based applications quite easily. Using the HTML 5 history for routing and navigation, Nalu supports the browser's back-, forward-, and reload-button by default and without any need to implement anything.

Nalu supports:

• Route based navigation

• HTML links and programmatically routing thanks to a router

• Browser's back-, forward- and reload-button (In case the hasHistory-attribute of the Application-annotation is set to true)

• An optional loader that will be executed at application start to load data from the server

• Client side context, router and event bus which will be automatically injected in every controller, filter, loader and handler (Handlers have only access to the context and the event bus)

• Filters to intercept routing.

• Separation of views into controllers and components with framework sided injection - similar to GWT Activities.

• A controller life-cycle using start-, mayStop- and stop- similar to GWT Activities.

• Popups

• Controller based handler manager, that will remove all handlers from the event bus in case the controller is stopped to prevent memory leaks (handler registrations must be added to the manager).

• UiBinder (nalu-plugin-gwt)

• Composites to support smaller units of work

• Controller & composite caching

• Component creation inside a controller to support GWT replacement rules and static factory methods

• Multi Shell Support

• (nearly) Every widget lib (tested with: GWT, GXT, Domino-UI v1 & v2, Elemento, Elemental2, GWT-Material)

• Maven multi module projects to separate an application in smaller parts (module feature)

• Tracking user routing (in case a tracker is added)

Basic Concept

Nalu uses a hash to navigate. Starting with version 1.1.0 Nalu supports the use of hash less URLs. Everything explained here will also work without hash. In case of working with a hash less URL, you need to implement something on the server to handle a reload.

Example hash:

#[shell]/[route]/:[parameter_1]/:[parameter_2]

where

• shell: the shell to be used to display the route
• route: navigation end point (a controller)
• parameter_x: parameters of the route

The following flow shows the steps, once a routing is initiated. The flow will end with appending the new component to the DOM.

To connect a component to a route, just create a controller class which extend AbstractComponentController and add the controller annotation @Controller.

@Controller(route = "/shell/route/{parameter_01}/{parameter_02}",
            selector = "content",
            component = MyComponent.class,
            componentInterface = IMyComponent.class)
public class MyController
    extends AbstractComponentController<MyApplicationContext, IMyComponent, HTMLElement>
    implements ISearchComponent.Controller {
    
  @AcceptParameter("parameter_01")
  public void setParaemter01(String p01)
      throws RoutingInterceptionException {
      ...
  }
    
  @AcceptParameter("parameter_02")
  public void setParaemter02(String p02)
      throws RoutingInterceptionException {
      ...
  }


}

To navigate to a new route use inside a controller:

    this.router.route("/shell/route/{parameter_01}/{parameter_02}",
                      parameter_1,
                      parameter_2);

The router is injected in the controller. To route to a new component call the route method and add at least the new route. In case the route has parameters, just add them as additional parameters. (Important note: parameters are always Strings!)

Using

Dependencies

To use Nalu add the following dependencies to your pom:

• GWT 2.8.2

<dependency>
    <groupId>com.github.nalukit</groupId>
    <artifactId>nalu</artifactId>
    <version>2.10.1-gwt-2.8.2</version>
</dependency>
<dependency>
    <groupId>com.github.nalukit</groupId>
    <artifactId>nalu-processor</artifactId>
    <version>2.10.1-gwt-2.8.2</version>
    <scope>provided</scope>
</dependency>

• GWT 2.9.0 (and newer) - SNAPSHOT

<dependency>
    <groupId>com.github.nalukit</groupId>
    <artifactId>nalu</artifactId>
    <version>HEAD-SNAPSHOT</version>
</dependency>
<dependency>
    <groupId>com.github.nalukit</groupId>
    <artifactId>nalu-processor</artifactId>
    <version>HEAD-SNAPSHOT</version>
    <scope>provided</scope>
</dependency>

• GWT 2.9.0 (and newer) - Release

<dependency>
    <groupId>com.github.nalukit</groupId>
    <artifactId>nalu</artifactId>
    <version>2.20.3</version>
</dependency>
<dependency>
    <groupId>com.github.nalukit</groupId>
    <artifactId>nalu-processor</artifactId>
    <version>2.20.3</version>
    <scope>provided</scope>
</dependency>

Depending on the widget set your project is using, add one of the following plugins:

If the project uses a widget set based on Elemental2, Elemento or Domino-UI, use the Nalu-Plugin-Elemental2 by adding the following lines to your pom:

• GWT 2.8.2

<dependency>
    <groupId>com.github.nalukit</groupId>
    <artifactId>nalu-plugin-elemental2</artifactId>
    <version>2.10.1-gwt-2.8.2</version>
</dependency>

• GWT 2.9.0 (and newer) - SNAPSHOT

<dependency>
    <groupId>com.github.nalukit</groupId>
    <artifactId>nalu-plugin-elemental2</artifactId>
    <version>HEAD-SNAPSHOT</version>
</dependency>

• GWT 2.9.0 (and newer) - Release

<dependency>
    <groupId>com.github.nalukit</groupId>
    <artifactId>nalu-plugin-elemental2</artifactId>
    <version>2.20.3</version>
</dependency>

For Elemento there's a dedicated plugin which supports org.jboss.gwt.elemento.core.IsElement<E> as widget type:

• GWT 2.8.2

<dependency>
    <groupId>com.github.nalukit</groupId>
    <artifactId>nalu-plugin-elemento</artifactId>
    <version>2.10.1-gwt-2.8.2</version>
</dependency>

• GWT 2.9.0 (and newer) - SNAPSHOT

<dependency>
    <groupId>com.github.nalukit</groupId>
    <artifactId>nalu-plugin-elemento</artifactId>
    <version>HEAD-SNAPSHOT</version>
</dependency>

• GWT 2.9.0 (and newer) - Release

<dependency>
    <groupId>com.github.nalukit</groupId>
    <artifactId>nalu-plugin-elemento</artifactId>
    <version>2.20.3</version>
</dependency>

For Domino-UI Version 2 there's also a dedicated plugin which supports org.dominokit.domino.ui.IsElement as widget type:

• GWT 2.9.0 (and newer) - SNAPSHOT

<dependency>
    <groupId>com.github.nalukit</groupId>
    <artifactId>nalu-plugin-domino-v2</artifactId>
    <version>HEAD-SNAPSHOT</version>
</dependency>

• GWT 2.9.0 (and newer) - Release

<dependency>
    <groupId>com.github.nalukit</groupId>
    <artifactId>nalu-plugin-domino-v2</artifactId>
    <version>2.20.3</version>
</dependency>

(These plugins are ready to use with J2CL / GWT 3)

If your project uses a widget set based on GWT 2.8.2 or newer, use the Nalu-Plugin-GWT by adding the following lines to your pom:

• GWT 2.8.2

   <dependency>
     <groupId>com.github.nalukit</groupId>
     <artifactId>nalu-plugin-gwt</artifactId>
     <version>2.10.1-gwt-2.8.2</version>
   </dependency>
   <dependency>
      <groupId>com.github.nalukit</groupId>
      <artifactId>nalu-plugin-gwt-processor</artifactId>
      <version>2.10.1-gwt-2.8.2</version>
      <scope>provided</scope>
   </dependency>

• GWT 2.9.0 (and newer) - SNAPSHOT

   <dependency>
      <groupId>com.github.nalukit</groupId>
      <artifactId>nalu-plugin-gwt</artifactId>
      <version>HEAD-SNAPSHOT</version>
   </dependency>
   <dependency>
      <groupId>com.github.nalukit</groupId>
      <artifactId>nalu-plugin-gwt-processor</artifactId>
      <version>HEAD-SNAPSHOT</version>
      <scope>provided</scope>
   </dependency>

• GWT 2.9.0 (and newer) - Release

   <dependency>
      <groupId>com.github.nalukit</groupId>
      <artifactId>nalu-plugin-gwt</artifactId>
      <version>2.20.3</version>
   </dependency>
   <dependency>
      <groupId>com.github.nalukit</groupId>
      <artifactId>nalu-plugin-gwt-processor</artifactId>
      <version>2.20.3</version>
      <scope>provided</scope>
   </dependency>

(This plugin will not work with J2CL / GWT 3)

See the wiki for more information about Nalu and how to use it.

Configuration

Due to a bug in older version of the maven-compiler-plugin, the output of a annotation processor - during a Maven build - will not be logged. To ensure, that the processor output is logged, use the latest maven-compiler-plugin.

Wiki

More useful information about Nalu and how to use it, can be found inside the Wiki.

J2CL / GWT3

With the next version of GWT (GWT 3) and the new J2CL transpiler, there will be major changes in the GWT development. For example: JSNI and generators, besides other things, will be gone. To be prepared for the future things like JSNI, generators or any other dependency to GWT has to be removed and must be avoided.

Nalu uses only the already migrated gwt-events from org.gwtproject.

Nalu has no dependency to gwt-user nor Nalu's dependencies! Nalu does not use JSNI, generators or anything else from GWT (except the nalu-plugin-gwt) which will block moving to J2CL.

Nalu is ready to use with J2CL / GWT 3 as long as you do not use the nalu-plugin-gwt!

To get in touch with the developer

Please visit use us at Nalu Gitter room.

Examples

Here you will find many examples that show Nalu in action: https://github.com/nalukit/nalu-examples.

YouTube

You will find a session about Nalu at the GWT Community Channel here.

Notes

In case you find a bug, please open an issue or post it inside the Nalu Gitter room.

Comparsion between GWT Activities & Places versus Nalu

Anyone, who is familiar with GWT Activities & Places, will find here a comparison between GWT Activities & Places and Nalu.