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AngularDart 4

AngularDart v4 is now available. We've been busy since the release angular2 v3.1.0 in May. Not only did we "drop the 2", but we also improved the compiler and tightened up the framework to give you smaller code, we updated the package structure to improve usability, and we added several new features. Check out the updated documentation to get started.

Just angular

Upgrading to v4 will require more than updating your version constraint. The package has changed names (back) to angular – dropping the 2. You'll need to update your pubspec.yaml and the corresponding imports in your code. In most instances, find-and-replace should do the trick. Going forward, the package will be called package:angular. We'll just update the version number.

Smaller code

The updated compiler in 4.0 allows type-based optimizations that not only improve runtime performance but generate better code because we are able to strongly type templates. A big result of the update is that many applications will see compiled JavaScript sizes drop. In one case, we saw a 40KB (~10%) size drop in minified JavaScript by simply upgrading to v4. Every application is different, but we expect most applications will experience some code size reduction.

Separation of concerns

Until now, AngularDart was a single package that contained not only core functionality, but also routing, forms, and testing. We've separated these libraries into separate packages:
The code is managed under one repository, but each package can be used, versioned, and released separately. A breaking change in package:angular_forms won't require a breaking release of package:angular, for example. Having clear boundaries between packages also simplifies interdependencies between libraries, allowing dart2js to generate more efficient JavaScript.

New features

Besides being renamed and refactored, AngularDart v4 includes a number of new features. A couple of examples:
Functional directives. A lightweight and stateless way to apply one-time transformations.
@Directive(selector: '[autoId]')
void autoIdDirective(Element element,
IdGenerator generator) { =;
Metadata inheritance. Inheritance for both component and directive metadata is now complete! Any field- or method-level annotations are now inherited through supertypes. Check out Leon's write-up of this feature and how it can help you.

Updated components

The angular_components package has also been updated to use AngularDart v4. The update contains new components and updates for existing components. Go to the component gallery to see examples of many of the components in action.

Jump in

To get started with AngularDart, check out the documentation. Post questions to StackOverflow and Gitter. Check out the code and file issues on our GitHub repository.

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