Learning Dart – A solid guide to basic development using Google’s Dart #programming language – #bookreview

Learning Dart

Learn how to program applications with Dart 1.0, a language specifically designed to produce better-structured, high performance applications 

Ivo Balbaert and Dzenan Ridjanovic

(Packt – Kindle, paperback)

 

The programming language Dart was introduced in late 2011 by Google as a potential replacement for aging JavaScript. But JavaScript, of course, has continued to spread all over the Internet and planet since it first appeared in 1995.

Not surprisingly, Google found itself getting some pushback from software developers and others who have a lot of time, education, sweat and money invested into creating, supporting and modernizing files that have .js extensions.

Dart today is billed as “a new platform for scalable web app engineering.” It is a long way from replacing JavaScript. Indeed, it compiles to JavaScript.

At the same time,  Dart is a good and powerful Open Source language. And, while it is not yet seen on most lists of top languages to know, it is gaining momentum and followers in the software world.

“Dart looks instantly familiar to the majority of today’s programmers coming from a Java, C#, or JavaScript/ActionScript background; you will feel at ease with Dart,” write the authors of Learning Dart.

“However, this does not mean it [Dart] is only a copy of what already exists; it takes the best features of the statically typed ‘Java-C#’ world and combines these with features more commonly found in dynamic languages such as JavaScript, Python, and Ruby. On the nimble, dynamic side[,] Dart allows rapid prototyping, evolving into a more structured development familiar to business app developers when application requirements become more complex.”

In their recent book,  Balbaert and Ridjanovic note this about Dart: “Its main emphasis lies on building complex (if necessary), high-performance, and scalable-rich client apps for the modern web.”

Likewise, they point out that  “Dart can also run independently on servers. Because Dart clients and servers can communicate through web sockets (a persistent connection that allows both parties to start sending data at any time), it is in fact an end-to-end solution. It is perfect on the frontend for developing web components with all the necessary application logic, nicely integrated with HTML5 and the browser document model (DOM).

“On the backend server side, it can be used to develop web services, for example, to access databases, or cloud solutions in Google App Engine or other cloud infrastructures. Moreover, it is ready to be used in the multicore world (remember, even your cell phone is multicore nowadays) because a Dart program can divide its work amongst any number of separate processes, called isolates, an actor-based concurrency model as in Erlang.”

Their well-written book, from Packt Publishing, delivers a structured and nicely paced overview of how to use the Dart programming language. The book is suited for inexperienced developers and experienced developers alike who are curious about, or ready to dig into, Dart .

The intended audience, the authors state, includes “…web application programmers, game developers, and other software engineers. Because of its dual focus (Dart and HTML5), the book can appeal to both web developers who want to learn a modern way of developing web applications, and to developers who seek guidance on how to use HTML5.”

Indeed, in the first chapter, you get more than the obligatory “Hello, World!” program. You also learn how to use the Eclipse-based Dart Editor to create some simple command-line and web applications.

From there, the 12-chapter work focuses on topics and software examples that range from variables, classes and libraries, to combining HTML forms with Dart, building games with HTML5 and Dart, developing business apps with Polymer web components, using Dart with MVC web and UI frameworks, working with local data and client-server communications, and creating data-driven web applications using Dart and MySQL or MongoDB.

I have tested some of the book’s code examples both on Linux and Windows machines and have enjoyed working with the Dart Editor. However, I did find a couple of code typos in the print version while hand-typing some of the shorter examples. The better choice is to download and use the book’s code examples found on the Packt website.

One other matter that some new Dartisans may encounter: Norton 360 antivirus software currently tends to throw dart.exe into quarantine on Windows machines–and that stops Dart cold. There is a fairly simple way to retrieve the file from quarantine and tell Norton 360 to let it run. However, check the Dart community page on Google+ for info on that and some other approaches to avoiding the problem.

Learning Dart was published soon after Dart 1.0 was released, and Dart has continued to evolve fairly quickly. (Its stable version was 1.4.3 at the time this was written.) So there will be some small differences in screen displays and other matters.

If you want to learn Dart and get up to speed for using it in application development, Learning Dart can be your handy and solid how-to guide.

Si Dunn

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Ready to get Learning Dart? Click here: Kindlepaperback

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JavaScript as Compilation Target: ClojureScript and Dart – #programming #bookreview

Despite its widespread success, JavaScript has a reputation for being a computer language with many flaws. Still, it is now everywhere on the planet, so it is here to stay, very likely for a long, long time.

Not surprisingly, several new languages have emerged that jump over some of JavaScript’s hurdles, offer improved capabilities, and also compile to optimized JavaScript code.

Two of these languages are the focus of noteworthy new “Up and Running” books from O’Reilly: ClojureScript: Up and Running and Dart: Up and Running.

Here are short reviews of each book:

ClojureScript: Up and Running
Stuart Sierra and Luke VanderHart
(O’Reilly, paperback, Kindle)

ClojureScript, the authors contend, “provides developers with a language that is more powerful than JavaScript, which can reach all the same places JavaScript can, with fewer of JavaScript’s shortcomings.”

The primary targets of ClojureScript are “web browser applications, but it is also applicable to any environment where JavaScript is the only programmable technology available,” they add.

“ClojureScript is more than Clojure syntax layered on top of JavaScript: it supports the full semantics of the Clojure language, including immutable data structures, lazy sequences, first-class functions, and macros,” they emphasize.

Their 100-page book focuses on how to use ClojureScript’s features, starting at the “Hello world” level and gradually advancing to “Development Process and Workflow” and “Integrating with Clojure.” (ClojureScript is designed for building client-side applications, but it can be merged with Clojure on the JVM to create client-server applications.)

Early in the book, they also describe how to compile a ClojureScript file to JavaScript and emit code “that is fully compatible with the Advanced Optimizations mode of the Google Closure Compiler.”

The two writers are Clojure/ClojureScript developers with a previous book to their credit.

ClojureScript: Up and Running is written well and appropriately illustrated with code samples, flow charts, and other diagrams. The authors recommend using the Leiningen build system for Clojure, plus the lein-cljsbuild plug-in for ClojureScript.

Their book is a smooth introduction to ClojureScript that requires no prior knowledge of Clojure. But you do need a basic working knowledge of JavaScript, HTML, CSS, and the Document Object Model (DOM).

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Dart: Up and Running
Kathy Walrath and Seth Ladd
(O’Reilly, paperback, Kindle)

Google created Dart to be “an open-source, batteries-included developer platform for building structured HTML5 web apps,” the two authors note.

Dart provides not only a new language, but libraries, an editor, a virtual machine (VM), a browser that can run Dart apps natively, and a compiler to JavaScript.”

Indeed, Dart looks very similar to JavaScript and is “easy to learn,” the two writers state. “A wide range of developers can learn Dart quickly. It’s an object-oriented language with classes, single inheritance, lexical scope, top-level functions, and a familiar syntax. Most developers are up and running with Dart in just a few hours.”

The authors work at Google and note that some of the software engineers who helped develop the V8 JavaScript engine that is “responsible for much of Chrome’s speed” are now “working on the Dart project.”

Dart has been designed to scale from simple scripts all the way up to complex apps, and it can run on both the client and the server.

Those who choose to code with Dart are urged to download the open-source Dart Editor tool, because it also comes with a “Dart-to-JavaScript compiler and a version of Chromium (nicknamed Dartium) that includes the Dart VM.”

Since Dart is new, the writers also urge readers to keep an eye periodically on the Dart website and on their book’s GitHub site, where code can be downloaded and errors and corrections noted.

Dart: Up and Running is a well-structured, well-written how-to book, nicely fortified with short code examples and other illustrations. While the book appears very approachable and simple, it is not for complete beginners. You should have a basic working knowledge of JavaScript, HTML, CSS, and the Document Object Model (DOM).

If you are looking for a web development language that matches JavaScript’s dynamic nature but also addresses JavaScript’s sometimes-aggravating shortcomings, consider trying Dart—with this book in hand.

Si Dunn