Errai: The browser as a platform

Wednesday, May 21, 2014

What's new in Errai 3? Part 3: The Smaller (But No Less Powerful) Features

This is the third post in a series describing new features in Errai 3.0. This post is a summary of some of the smaller features and enhancements coming in 3.0.0.Final.

Improved HTML Form Support

Asynchronous form submission can make it difficult to trigger useful events in the web browser (such as prompting to remember a user's password). To help you overcome this issue, Errai UI now contains a base class for @Templated Widgets that provides better HTML form support.

By extending the AbstractForm class and invoking its submit method, Errai simulates native HTML form submission. Below is an example login form that causes modern browsers to prompt the user to remember a password when the "Login" button is clicked.

Test Generation with the Errai Forge Addon

If you haven't heard, there is an Errai Addon for JBoss Forge 2. This addon can set up Errai in an existing Java project for running in Dev Mode or compiling to production mode. But in the 3.0.0.Final release, you will be able to use the addon to generate unit and integration tests.

Unit tests are generated with GWT Mockito. Mockito is a test framework that allows you to inject mocks into classes and assert conditions on how these mocks are used. GWT Mockito adds extra GWT compatibility, allowing you to test classes with GWT.create calls or JSNI methods.

Integration tests extend the AbstractErraiCDITest (which in turn extends the GWTTestCase). In addition to the normal GWTTestCase functionality, the AbstractErraiCDITest initializes the Errai framework, including the Message Bus and IoC/CDI container.

WildFly 8.0 Support for Dev Mode

Previously we announced an improved Dev Mode setup using the JBossLauncher. This setup allowed the GWT Dev Mode to control a full JBoss 7 instance, making it easier to develop a GWT app using Java EE on the server.

It is now possible to use the this launcher with WildFly 8.0. If you haven't yet, give it a try since there have been many performance improvements to WildFly 8.0 that make a noticeable difference in startup time.

Asynchronous IOC with Fragment Control

Errai's @LoadAsync annotation allows for managed beans to be loaded asynchronously. That means the code for these beans will reside in a separate JavaScript file that will be downloaded the first time it is needed. In Errai 3.0.0.Final you have more control over these split points. A code fragment name can optionally be specified using a Java class literal (i.e. @LoadAsync(Admin.class) to group all beans related to admin functionality). GWT's code splitter will then put the code of all managed bean types with the same fragment name into the same code fragment (JavaScript file).

Error Detection for Common Pitfalls in Your IDE

By adding the following dependency to your project you will get automatic error detection for common Errai pitfalls directly in your IDE. While this covers an increasing amount of pitfalls, we are happy to accept your contributions. If you can think of more checks we should include please let us know or send us a pull request! Note that in Eclipse you will have to manually enable annotation processing: Go to Eclipse Workspace Preferences->Maven->Annotation Processing and select the "Automatically Configure JDT APT" radio button. In Eclipse you will also need to install the m2e-apt plugin.


That is all for today. Happy Coding!

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