Skip to main content

Dart 1.23: Better strong mode support

Dart 1.23 is now available. It introduces support for overriding fields in strong mode and a lot of other improvements. Get it now!

Screen Shot 2017-04-21 at 16.15.20.png
Figure 1: Overriding fields in strong mode

We have been spending a lot of our time on our unified front-end (explained by Vyacheslav Egorov in this short talk from the Dart Developer Summit). We're also doing a lot of work to support our critical customers (for example, Flutter gets better Windows support with this release) and solidifying strong mode.

Some notable changes in this release:
  • Overriding fields is now supported in strong mode. You don’t need to tag them with @virtual anymore.
  • Strong mode inference error messages are more helpful.
  • Strong mode now prefers the expected type to infer generic types, functions, and methods.
  • The UriData.parse method now normalizes and validates its input better.
  • Importing dart:io is now allowed in the browser, as a stopgap measure to make it easier to write libraries that share code between platforms (like package http that needs to run in the browser, on mobile, and on the command line).
  • pub publish now warns you when you’re importing a package that is not a direct dependency in pubspec.yaml.
  • pub get/upgrade now produces a more informative error message for Flutter.
  • dartfmt now makes precedence of cascades more visible, and adds other small formatting tweaks.
  • Fixes for Unicode character printing in the Windows console, inconsistencies between dartanalyzer and the analysis server in finding the options file, pub “UID too large” errors on OS X, and more.
For more information, see the changelog.

Please download the latest release and let us know what you think!

Popular posts from this blog

Dart in 2016: The fastest growing programming language at Google, 2nd fastest growing in TIOBE Index

Dart was the fastest growing programming language at Google in 2016 with millions of lines of code written. It also made it to TIOBE Index Top 20 this month (see TIOBE's methodology).

It takes time to build something as ambitious as Dart and, in some ways, Dart is still in its infancy. But we're glad the hard work is starting to pay off.

Many thanks to our amazing community!

We're going to celebrate by ... releasing 1.22 next week (as per our usual 6 week release schedule).

AngularDart is going all Dart

Until now, the multiple language flavors of Angular 2 were written as TypeScript source, and then automatically compiled to both JavaScript and Dart. We're happy to announce that we’re splitting the Angular 2 codebase into two flavors – a Dart version and a TypeScript/JavaScript version – and creating a dedicated AngularDart team.

This is amazing news for Dart developers because:

The framework will feel more like idiomatic Dart.It will make use of Dart features that couldn't work with the TypeScript flavor. It will be faster.
This is equally great news for our TypeScript and JavaScript developers, by the way. Cleaner API, performance gains, easier contributions. Read more on the Angular blog.

Angular 2 for Dart is used by many teams at Google. Most famously by the AdWords team, but many other Google teams build large, mobile-friendly web apps. Some of the top requests from these teams were: make the API feel like Dart, provide a faster edit-refresh cycle, and improve applicat…

The new Google AdSense user interface: built with AngularDart

AdSense is a free, simple way to earn money by placing ads on your website. The team just launched a completely new version of their app for publishers. Read all about it here. We asked Daniel White, the tech lead for the project, some questions because the new UI happens to be built with Dart and Angular2.


AdSense launched way back in 2003. How long is it since the last big redesign?
Last big redesign was called ‘AdSense 3’ and launched about 6 years ago. It was written in Google Web Toolkit (GWT) and the UI has evolved through several iterations - but this is the first ground-up redesign in 6 years. There are a number of long-standing UX issues that we’ve taken the opportunity to solve. A big shout-out to our UX team who’ve been 100% behind this project. We couldn’t have done it without them!

How many software engineers worked on the project?
Purely on the AdSense applications, we have a team of close to 100. Around 25% of them write Dart.

How many lines of code?
We have around 160K LO…