Dart编程入门指南：下一代Web开发语言

4星 · 超过85%的资源需积分: 10 4 浏览量更新于2024-07-24 3 收藏 3.05MB PDF 举报

《Dart语言程序设计》是一本专门针对Dart语言编写的英文指南，该语言被寄予厚望，有望挑战JavaScript在Web开发领域的地位，因其速度和高效性备受瞩目。这本书不仅适合希望理解Dart基础知识并将其应用于现代浏览器环境的读者，还深入探讨了未来Dart版本的特性，为开发者提供了前瞻性的学习资料。作者 Chris Strom 的《Dart for Hipsters》以其趣味性和易读性著称，即使是对编程不熟悉的人也能轻松上手。书中详尽地介绍了Dart语言的核心概念，包括其面向对象、函数式编程特性和异步编程中的Isolate（隔离区）机制。评论家Matt Margolis表示，起初他对Dart有所保留，但阅读本书后，他认识到Dart的潜力，并将其视为可靠的参考资源。 Juho Vepsäläinen认为这是关于这个新兴且前景广阔的编程语言的第一本书，文本清晰且易于理解，能吸引读者并推动Dart的发展。特别称赞了作者对Dart语言中函数式风格的深入剖析，以及对Isolates的讨论，这些内容对于熟练掌握Dart至关重要。此外，值得注意的是，这本书由The Pragmatic Bookshelf出版，出版社总部位于美国德克萨斯州达拉斯和北卡罗来纳州 Raleigh。书中还提到了一些制造商和销售商可能使用的商标声明，强调了市场上的产品区分策略。《Dart语言程序设计》是一本实用且富有前瞻性的好书，无论是初学者还是经验丰富的开发者，都能从中收获有价值的知识，帮助他们在快速发展的Web开发领域中保持竞争力。通过阅读这本书，读者可以掌握Dart语言的最新进展，并为未来的项目开发打下坚实基础。

CHAPTER 1

Project: Your First Dart Application

Most programming books start with a “Hello World!” sample. I say, screw that

—we’re all hipsters here. Let’s start coding!

Since Dart is written, above all else, to be familiar, we should not be too far

out of our depths diving right in. Let’s jump straight to something more fun:

an Ajax-powered website. Any true hipster has an extensive collection of

comic books (am I right? I’m not the only one, am I?), so let’s consider a

simple Dart application that manipulates the contents of that collection via

a REST-like interface.

At some point, this may prove too much of a whirlwind. Have no fear, we will

go into details in subsequent chapters.

1.1 The Back End

Sample code for this chapter can be found in the “your_first_dart_app” branch

https://github.com/eee-c/dart-comics

. As hipsters, we’re already using Node.js, so

the back end requires Node.js and npm. Instructions are contained in the

project’s README.

Being REST-like, the application should support the following:

•

GET /comics

(return a list of comic books)

•

GET /comics/42

(return a single comic book)

•

PUT /comics/42

(update a comic book entry)

•

POST /comics

(create a new comic book in the collection)

•

DELETE /comics/42

(delete a comic book)

We will not worry too much about the details of the back end beyond that.

report erratum • discuss

Download from Wow! eBook <www.wowebook.com>

As we will see in Chapter 10, Libraries, on page 83, there is a lot of power in

those

#import

statements. For now, we can simply think of them as a means

for pulling in functionality outside of the core Dart behavior.

All Dart applications use

main()

as the entry point for execution. Simply writing

code and expecting it to run, as we do in JavaScript, will not work here. It

might seem C-like at first, but does it honestly make sense that code lines

strewn across any number of source files and HTML will all start executing

immediately? The

main()

entry point is more than convention; it is a best

practice enforced by the language.

As for the

load_comics()

function, we take it piece by piece. We need to identify

the DOM element to which the list will attach (

#comics-list

). Next we need an

Ajax call to fill in that DOM element. To accomplish both of those things, our

first bit of Dart code might look like the following:

your_first_dart_app/_load_comics.dart

load_comics() {

var list_el = document.query('#comics-list');

ajax_populate_list(list_el);

}

Aside from the obvious omission of the

function

keyword, this example might

be JavaScript code! We will cover more differences in Chapter 3, Functional

Programming in Dart, on page 19. Still in Dart are the semicolons and curly

braces that we know and love—the language designers have certainly made

the language at least superficially familiar.

Note: Unlike in JavaScript, semicolons are not optional in Dart.

In addition to being familiar, this code is easy to read and understand at a

glance. There are no weird, legacy DOM methods. We use

document.query()

for

an element rather than

document.findByElementId()

. And we use the familiar CSS

selector of

#comics-list

, just as we have grown accustomed to in jQuery.

Having found the UL we want to populate, let’s see how to make an Ajax

request. As in JavaScript, we create a new XHR object, add a handler for

when the request loads, and then open and send the request.

your_first_dart_app/_ajax_populate_list.dart

ajax_populate_list(container) {

var req = new XMLHttpRequest();

req.on.load.add((event) {

var list = JSON.parse(req.responseText);

container.innerHTML = graphicNovelsTemplate(list);

});

6 • Chapter 1. Project: Your First Dart Application

report erratum • discuss

Download from Wow! eBook <www.wowebook.com>

剩余133页未读，继续阅读

心欲无痕6

粉丝: 2
资源: 14

Dart编程入门指南：下一代Web开发语言

总结了Dart语言知识及Flutter补充内容。

Dart语言开发的茶饮应用程序体验

Dart语言的TechNox框架深度剖析

Dart语言程序设计(英文版)

dart:DART 程序集样式脚本语言

基于Dart语言的Flutter项目设计源码

Dart 语言运行库

Dart-compiler:Dart语言变体的编译器

flutter开发之dart语言

用Dart语言构建的高效银行应用程序

最新资源