Tuesday, September 1, 2015

Dart adopts BoringSSL

Starting today, with the 1.13.0-dev.1.0 release of the Dart SDK, the Dart VM has upgraded its TLS/SSL implementation to BoringSSL. The BoringSSL library is a fork of OpenSSL that’s created and maintained by Google. Dart developers now have the same implementation of SSL as Chromium and Chrome.

The new implementation includes some breaking changes to the SecureSocket class and related classes. Dart programs that create secure servers will need to provide their server certificate chain and private key in a new, and easier, way.

We encourage you to try the dev channel build of Dart SDK and the new configurations for BoringSSL. You can learn more about Dart and TLS/SSL, and we look forward to your feedback.

--- Bill Hesse, feeling more secure

Monday, August 31, 2015

Dart 1.12 Released, with Null-Aware Operators and more

Dart 1.12.0 is now released! It contains the new null-aware operators language feature, and enhancements to pub, Observatory, dartdoc, and much more.

Null-aware operators

The new null-aware operators help you reduce the amount of code required to work with references that are potentially null. This feature is a collection of syntactic sugar for traversing (potentially null) object calls, conditionally setting a variable, and evaluating two (potentially null) expressions.

Click or tap the red Run button below to see them in action.


  if null operator. `expr1 ?? expr2` evaluates to `expr1` if not `null`, otherwise `expr2`.


  null-aware assignment. `v ??= expr` causes `v` to be assigned `expr` only if `v` is `null`.


  null-aware access. `x?.p` evaluates to `x.p` if `x` is not `null`, otherwise evaluates to `null`.

  null-aware method invocation. `x?.m()` invokes `m` only if `x` is not `null`.

Learn more about Dart's null-aware operators in our Language Tour.

.packages file

We continue in our efforts to eliminate symlinks by introducing the .packages file, which is a new way to specify where to find package dependencies. The pub package manager now writes a .packages file when getting or upgrading dependencies, and the VM and dartanalyzer use the .packages file for package resolution.

The Dart SDK still generates symlinks in 1.12, but the .packages file gets us closer to eliminating them. If you have tools that introspect packages, now is a good time to investigate the .packages file.


The dartdoc tool is a new way to generate beautiful, fast-loading API docs. It replaces dartdocgen, which we plan to remove from the SDK as soon as 1.13. dartdoc generates static docs, helps you search with find-as-you-type, and looks great on a mobile device.


Speed up your code reviews by automatically formatting your code. The dartfmt tool has been largely rewritten to support better handling for long argument lists, smarter indentation for cascades, nested functions, and collections, and fixes over 50 issues.


Help identify memory leaks with Observatory's updated allocation profiler. Turn it on for a class, and track where instances of that class are created. Also new in 1.12 is support for dart:developer's log() function, which your app can use to stream log calls into Observatory's (or any connected debugger) console.

Stepping through async/await code has been significantly improved with Observatory's new anext command. You can now step over an await call, onto the next line of your code.


The pub run commands can now toggle checked mode, with --checked. Pub now writes a .packages file when getting, upgrading, and globally activating your packages.

Lots more

The Dart SDK 1.12 CHANGELOG has lots more details about various API tweaks. We look forward to your feedback

Thursday, August 20, 2015

A New Way to Share with DartPad

Back in May, we announced the release of DartPad 1.0, a clean and zero-install tool that helps you explore Dart. To create a seamless learning experience for both experienced and new developers, today we released embeddable pads! You can now add live Dart code to web pages.

Embeddable pads have the full power of the standalone DartPad:

Tutorials and guides can use embeddings to quickly demonstrate concepts on the fly:

You can also open embedded pads in DartPad to further edit and share code. For more information, view the embedding guide.

Head over to dartpad.dartlang.org and share your first pad! We hope you enjoy this new addition and provide us with feedback—remember, sharing is caring!

Posted by George He, Chief Sharing Operator

Tuesday, August 11, 2015

5% smaller output from dart2js

dart2js now produces up to 5% smaller output in the latest dev channel release of the Dart SDK.
We measured a 5% reduction on the minified and zipped dart2js output for one of the larger Dart-based apps in Google with source code size around 17MB. While we’ve seen a 5% reduction on a large app, your milage may vary and improvements are expected to increase with the size of your app. This improvement comes on top of a previous 3% reduction since the beginning of this year.
The idea behind the latest improvement is quite simple: The symbols that will occur most often in the generated output should be assigned the shortest minified names. So when minifying the code, we rename according to the frequency of each symbol in such a way that a high frequency results in a short name in the output.

This new frequency-based namer generally produces smaller output, which is great for deployment. It does however also result in different name allocations and thus “diffing” before/after the change will not produce useful outcomes. Furthermore, with the new scheme a small change in the Dart program might lead to major changes in the naming in the output. If output stability is more important than output size, you can still use the old namer. Simply use the option --no-frequency-based-minification when invoking dart2js.

We are making the new improved namer available on dev channel to get early feedback from you in time before the first release of 1.12 on the stable channel expected later this summer. Please give it a try and report any bugs you might find.

Posted by Stephan Herhut, Frequency-Based Minifier

Thursday, June 18, 2015

Null-aware operators and generalized tear-offs in Dart

Yesterday, on June 17, 2015, the 109th Ecma General Assembly approved the ECMA-408 3rd edition - Dart Programming Language Specification.

Main additions to the 3rd edition of the spec are

  1. null-aware operators and 
  2. generalized tear-offs

Null-aware operators are currently being implemented and tear-offs will follow.

The standard has been published on the Ecma Website.

Wednesday, June 3, 2015

Dart is now on GitHub

Dart is an open-source programming language, with contributors working on the language, libraries, tools, and packages. To make working with our community even easier, today we are announcing that we've fully settled into our new home on GitHub. We invite you to follow along and contribute at https://github.com/dart-lang.

The Dart SDK now has its own repository, joining the numerous Dart tools and packages already in our GitHub org. We’ve moved all the SDK issues over (keeping the original issue numbers!), and dartbug.com now points to GitHub's issue tracker for the Dart SDK.

Getting the SDK source is easy, and we've documented the contribution workflow. Our development tools are optimized for code reviews on Rietveld, Chromium's code review system, and they make it easy to start a review and cleanly land a patch. For very small patches, contributors can use a standard GitHub pull request.

One of the easiest ways to start contributing to Dart is to work on one of our packages. Individual packages (for example, args, http, and test) now have their own repos, complete with their own issue trackers and buildbots. To get started, check them out and find issues marked "help wanted". And of course, we encourage everyone to continue filing issues with dartbug.com.

We hope our move to GitHub helps more Dartisans become active participants in the future of Dart.

Monday, May 11, 2015

Dart Developer Summit videos now available

Dart developers met in San Francisco for two days in April 2015 to share stories, meet engineers, and learn about how to deploy Dart for the web, server, and mobile. If you missed the event, don't worry. You can now watch all the Dart Developer Summit presentations on YouTube.

Check out the playlist to see a wide range of content: case studies, insight into new features and libraries (such as async/await), a game engine built with Dart, deploying Dart to Internet of Things, deploying Dart on the server, using Dart in Google, and much more.

We also saw two new interesting experiments to bring Dart to mobile: the Dart for Mobile Services project and the Sky project.

A big thank you to everyone that joined us in person and on the live stream. We hope you enjoy the videos, and we'll see you in the Dartiverse!