Guice Vaadin is the official [Guice](https://github.com/google/guice) integration for [Vaadin Framework](https://github.com/vaadin/framework). ## Usage ### setting up the servlet first step is to set up the GuiceVaadinServlet, which needs a packagesToScan parameter holding the names of all packages that should be scanned for UIs, Views, ViewChangeListeners and VaadinServiceInitListeners. Sub-packages of these packages are scanned as well. This can be done either by subclassing GuiceVaadinServlet and annotating it with @PackagesToScan, or by configuring a GuiceVaadinServlet in the deployment-descriptor. ### configuration in java ```java package org.mypackage; @javax.servlet.annotation.WebServlet(name = "Guice-Vaadin-Servlet", urlPatterns = "/*") @com.vaadin.guice.annotation.PackagesToScan({"org.mycompany.ui", "org.mycompany.moreui"}) public class MyServlet extends com.vaadin.guice.server.GuiceVaadinServlet{ } ``` ### configuration in xml ```xml packagesToScan org.mycompany.ui, org.mycompany.moreui Guice-Vaadin-Servlet com.vaadin.guice.server.GuiceVaadinServlet Guice-Vaadin-Servlet /* ``` ## Scopes Available scopes are UIScope and VaadinSessionScope, similar to what the Spring addon offers. UIScope is what MUST be the scope for all Vaadin-components, since they must belong to exactly one UI. VaadinSessionScope may be used to sync data between multiple tabs in the same browser. ```java import com.vaadin.guice.annotation.UIScope; @UIScope public class MyButton extends Button { } ``` ## Guice-Module loading Since Guice is configured via so called Modules, we need a way to load these modules. All Modules in the packages contained by 'packagesToScan' will be instantiated and loaded by default. ```java package org.mycompany.ui; import com.google.inject.AbstractModule; //will be loaded, since the 'org.mycompany.ui'-package is included in //the packagesToScan public class MyModule extends AbstractModule{ protected void configure(){ //... } } ``` The alternative way to load modules is via the @Import-Annotation. This was introduced to make sort of an addon-development for guice-vaadin possible, similar to what Spring offers with it's own @Import-annotation. First, a new Annotation is needed that points to the module to be loaded via @Import: ```java package org.mycompany.ui; import java.lang.annotation.ElementType; import java.lang.annotation.Retention; import java.lang.annotation.Target; @Target(ElementType.Type) @Retention(RUNTIME) @Import(SomeModule.class) public @interface UseSomeModule { } ``` Second, the annotation is pinned on the servlet and that's it. ```java package org.mypackage; @UseSomeModule @javax.servlet.annotation.WebServlet(name = "Guice-Vaadin-Servlet", urlPatterns = "/*") @com.vaadin.guice.annotation.PackagesToScan({"org.mycompany.ui", "org.mycompany.moreui"}) public class MyServlet extends com.vaadin.guice.server.GuiceVaadinServlet{ } ``` Copyright 2015-2017 Vaadin Ltd. Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except in compliance with the License. You may obtain a copy of the License at http://www.apache.org/licenses/LICENSE-2.0 Unless required by applicable law or agreed to in writing, software distributed under the License is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the License for the specific language governing permissions and limitations under the License.