haXe 2 Beginner's Guide

By Benjamin Dasnois

This book is part of the Packt Beginner's Guide series. Written in an engaging style, it offers step-by-step examples with screenshots at key steps and clear explanation of what is happening in each task. This book is written for both Beginners and Developers who want to learn this multi-platform programming language to build web applications from scratch.

• Language: English
• Publisher: Packt Publishing
• Release date: Jul 26, 2011
• ISBN: 9781849512572

Book preview

Table of Contents

haxe 2

Credits

Foreword

About the Author

About the Reviewers

www.PacktPub.com

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Why subscribe?

Free access for Packt account holders

Preface

Here is haXe

Where and for what is haXe used?

Where is haXe used?

What is haXe used for?

One language to rule them all

Object-oriented programming

haXe versions

haXe and the new models of web applications

haXe as an universal language

Getting help

Reading some documentation

Asking questions

The haXe forum

The haXe mailing list

Some advice

Reading some blogs

Nicolas Cannasse

Weblob

GameHaXe

A Bug's Life

Blog.haxe.org

Helping the community

The mailing list and the forum

The wiki

Write on your blog or website

Writing libraries or tools

Talking about haXe

What this book covers

What you need for this book

Who this book is for

Conventions

Time for action – heading

What just happened?

Pop quiz – heading

Have a go hero – heading

Reader feedback

Customer support

Downloading the example code for this book

Errata

Piracy

Questions

1. Getting to know haXe

Installing haXe

Two ways to install: The installer and sources compilation

Installing on Windows

Installing on MacOSX

Installing on Linux

Installing nightly builds

Verifying your installation

Choosing an editor

FlashDevelop 3

The TextMate bundle

VIM

Writing your first program

Time for action – Writing a Hello World

What just happened?

A program with some interaction

Time for action – Interacting with the user

What just happened?

Pop quiz – basic knowledge

Summary

2. Basic Syntax and Branching

Modules, packages, and classes

Packages

Modules

Classes

Accessing a class

Constants and its types

Booleans

Integers

Floats

Base 10

Scientific notation

Strings

Regular expressions

The null value

Flash9 and above

Binary and unary operators

Binary operators

Assigning values

Comparison operators

Arithmetic operators

Boolean operators

Bitwise operators

Unary operators

Blocks

Variable declaration and scope

Declaring a variable

At class level

Time for action – Declaring some fields

What just happened?

In a block of instructions

Field access and function calls

Constructing class instance

Conditional branching

If

Switch

Loops

While

For

Break and continue

Time for action – Using the break keyword

What just happened?

Time for action – Using the continue keyword

What just happened?

Return

Exception handling

Anonymous objects

Local functions

Managing a fridge

Time for action – Managing a fridge

What just happened?

Have a go hero – Throw Exceptions to prevent crashes

Summary

3. Being Cross-platform with haXe

What is cross-platform in the library

Object storage

The Std class

The haxe package

The haxe.remoting package

The haxe.rtti package

The haxe.Http class

Regular expressions and XML handling

Regular expressions

XML handling

Input and output

The DOM interface

The Flash interface

The standard input/output interface

Platform-specific packages

JavaScript

Flash

Neko

PHP

C++

Conditional compilation

Conditional compilation depending on flags

Conditional compilation depending on the target

The remap switch

Coding cross-platform using imports

Time for action – Welcoming the user on Neko & PHP

What just happened?

Pop quiz – Writing cross-platform code

Have a go hero – Handle XML

Time for action – Reading from the XML file

What just happened?

Time for action – Writing to an XML file

What just happened?

Testing our sample

Making it cross-platform

Summary

4. Understanding Types

Explicitly typed variables

Static typing

Values with several types

Defining a type

Inheritance

Multi-inheritance

Implementing an interface

Representing a blog article

Time for action – Representing different types of articles

Function's type

Expressing a function's type

Functions using functions

Dynamic functions

Anonymous objects

Duck typing

Creating a function to apply another one

Time for action – Applying a function on every item

What just happened?

Type inference

Assigning a value

Assigning the value of the variable to another one

Passing the variable as a parameter

Casting

Safe casting

Unsafe casting

Untyped

Type parameters

Usage of Type parameters

Creating a parameterized class

Constraint parameters

Extending the fridge

Time for action – A fridge with constraints

What just happened?

Have a go hero – Creating a typed container

Pop quiz – Verify your knowledge

Summary

5. The Dynamic Type and Properties

Freeing yourself from the typing system

Time for action – Assigning to Dynamic variables

Time for action – Assigning from Dynamic variables

Field access

Functions in Dynamic variables

Parameterized Dynamic class

Classes implementing Dynamic

Time for action – Implementing a non-parameterized Dynamic

What just happened?

Time for action – Implementing a parameterized Dynamic

What just happened?

Using a resolve function when implementing Dynamic

Time for action – Writing our Component class

Time for action – Parsing the configuration file

Time for action – Testing our parser

Time for action – Writing the configuration file

Time for action – Testing the writer

The dot-notation

Thoughts on writing our parser

The dynamic keyword

Warning

Properties in classes

Use

Implementation

Writing the getter

Writing the setter

Defining the property

Accessibility

The default getter

The default setter

The dynamic getter and setter

The never getter and setter

A compile-time feature

Have a go hero – Writing a person class

Pop Quiz – Doing the things

Summary

6. Using and Writing Interfaces, Typedefs, and Enums

Interfaces

Purpose

Default visibility

Type inference

Implementing an interface

Implementation and type inference

Implementation and visibility

Making use of interfaces

Typedefs

Time for action – Naming Anonymous Types

What just happened?

Aliases

Visibility

Private typedefs

Duck typing

Typedefs to access private members

Creating iterable objects

Enums

Basic enums

Enums' constructors

Switching on basic enums

Enums with parameters

Time for action – Switching over enums with parameters

What just happened?

Have a go hero – Write a fridge with an iterator

Time for action – Writing our Fridge class

What just happened?

Time for action – Making it possible to iterate over a fridge

What just happened?

Time for action – Creating the iterator

What just happened?

Our main function

Pop quiz – Typedef, interfaces, and Enums

Summary

7. Communication Between haXe Programs

The haXe serializer

Usefulness

Possibilities

Class instances

Custom serialization

Enum instances

Unserializing exceptions

Reducing size and preventing infinite loops

haXe remoting

Supported protocols and layers

Over HTTP

Implementation

Using the ExternalInterface

The JavaScript side

The Flash side

Using AMF

Time for action – Writing a zoo management tool

The Animal class

Representing the zoo

Time for action – Saving the list

Time for action – Loading the list

The remoting service

The getList function

The createAnimal function

Tying it together

The client

Time for action – Initializing the client connection

What just happened?

The createAnimal function

The listAnimals function

The main menu

Compiling the client

Have a go hero – Represent data from JS in Flash

Pop quiz – Doing the things

Summary

8. Accessing Databases

Connecting to databases

php.db.Connection and neko.db.Connection

SQL usage

The interface

The close function

The commit function

The rollback function

The escape function

The quote function

The request function

The addValue function

The dbName function

The lastInsertId function

Connecting to the database

MySQL

SQLite

Dealing with results

Typing

The SPOD

Setting a SPOD object

The table name

Non-mapped fields

The cache

A concrete example of SPOD use

Setting the object

Setting the connection

The Manager

The all function

The count function

The delete function

The get function

The getWithKeys function

The object function

The objects function

The search function

Handling relations

Creating a blogging system

Time for action – Creating the Users table

What just happened?

Time for action – Creating the User class

What just happened?

Time for action – Creating the Posts table

Time for action – Creating the Post class

What just happened?

Time for action – Creating the connection to the database

What just happened?

Time for action – Listing posts

Time for action – Listing users

Time for action – Adding a user

Time for action – Adding a post

Time for action – Branching it with the main function

Have a go hero – Listing posts from a specific user

Pop quiz – Doing the things

Summary

9. Templating

Introduction to the haxe.Template class

Printing a value

Branching

Using lists, arrays, and other iterables

Time for action – Executing code from a template

What just happened?

Integrating subtemplates

Creating a blog's front page

Time for action – Creating our SPOD class

Time for action – Connecting to the database

Time for action – Creating our template

Time for action – Reading the template from resources

Time for action – Executing the template

Time for action – Testing the result

Pop quiz – Doing the thing

Have a go hero – Doing more with the thing

Summary

10. Interfacing with the Target Platform

Extern classes

Time for action – Writing an extern

What just happened?

Using an extern

Class path

Limitations

The __init__ magic

Native types and haXe types

The Neko and PHP cases

PHP functions

Neko functions

Magic functions

The Flash magic

__new__

__arguments__

__typeof__

__delete__

__eval__

__gettimer__

__geturl__

__instanceof__

__random__

__trace__

__keys__

__global__

__as__

__is__

__in__

The Neko magic

Arrays and strings

The PHP magic

__php__

__call__

__var__

__physeq__

Have a go hero – Wrapping parameters in an array

Pop quiz – Doing the things

Summary

11. A Dynamic Website Using JavaScript

Manipulating the DOM

The browser's DOM

Nodes

Events

Level 1

Level 2

Time for action – Using events from the DOM level 0

What just happened?

Time for action – Using DOM level 2 events

What just happened?

Time for action – Working around by storing reference to functions

What just happened?

Have a go hero – A dynamic website with JavaScript

Time for action – Setting up the model

Time for action – Setting up our view

What just happened?

Time for action – Setting up the controller

Time for action – Creating a computer view

What just happened?

The main class

Summary

12. Creating a Game with haXe and Flash

Embedding assets

Time for action – Installing SWFMILL

Time for action – Creating a library

Time for action – Using assets

Event handling

Have a go hero – A game with Flash

The game design

The assets

The player's character

Time for action – Drawing the character

Time for action – Handling moves

What just happened?

Time for action – Moving the character

What just happened?

Time for action – Adding balls

What just happened?

Time for action – Updating the position

What just happened?

Time for action – Detecting collisions

What just happened?

Have a go hero – Adding a proper score display

Have a go hero – Adding an online score table

Pop quiz – Software used

Summary

A. Pop Quiz Answers

Chapter 1: Getting to know haXe

Chapter 3: Being Cross-platform with haXe

Chapter 4: Understanding Types

Chapter 5: The Dynamic Type and Properties

Chapter 6: Using and Writing Interfaces, Typedefs, and Enums

Chapter 7: Communication Between haXe Programs

Chapter 8: Accessing Databases

Chapter 9: Templating

Chapter 10: Interfacing with the Target Platform

Chapter 12: Creating a Game with haXe and Flash

Index

haXe 2

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haxe 2

Copyright © 2011 Packt Publishing

All rights reserved. No part of this book may be reproduced, stored in a retrieval system, or transmitted in any form or by any means, without the prior written permission of the publisher, except in the case of brief quotations embedded in critical articles or reviews.

Every effort has been made in the preparation of this book to ensure the accuracy of the information presented. However, the information contained in this book is sold without warranty, either express or implied. Neither the author, nor Packt Publishing, and its dealers and distributors will be held liable for any damages caused or alleged to be caused directly or indirectly by this book.

Packt Publishing has endeavored to provide trademark information about all of the companies and products mentioned in this book by the appropriate use of capitals. However, Packt Publishing cannot guarantee the accuracy of this information.

First published: July 2011

Production Reference: 1180711

Published by Packt Publishing Ltd.

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Birmingham, B27 6PA, UK.

ISBN 978-1-849512-56-5

www.packtpub.com

Cover Image by Asher Wishkerman ( <[e-mail] >)

Credits

Author

Benjamin Dasnois

Reviewers

Marcus Bergström

Andy Li

Franco Ponticelli

Acquisition Editor

Dilip Venkatesh

Development Editor

Maitreya Bhakal

Technical Editors

Kavita Iyer

Azharuddin Sheikh

Copy Editor

Neha Shetty

Project Coordinator

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Proofreader

Lisa Brady

Indexer

Tejal Daruwale

Production Coordinator

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Cover Work

ArvindKumar Gupta

Foreword

Remember the olden days?

I vaguely remember this odd box called a computer gradually conquering corners of my living room and bedroom. Can you recall those times? We would use a computer for some specific tasks, such as writing a letter.

The term computer was quite popular back then. Now, the word is no longer part of our active vocabulary, let alone use a computer, who says that anymore? Nobody does. That is because computers are no longer odd boxes in corners. They are the notebooks and mobile phones that we use every day. They are also the hybrids between the two, such as tablets and netbooks. They are the servers that run websites we constantly use as well. Even today's TVs are full-blown computers.

I find this change fascinating. I think we live in a very exciting time to be participating in the business. All these new devices bring us opportunities enabling us to express our creativity, while their differences challenge us and keep us inventive.

Unlike PHP or ActionScript, haXe is not designed for one specific purpose. It is just a programming language. That is why it is so versatile. Whether it is the hip new phone in the hands of a Japanese ad girl or a big bulky machine in a server room; whether it has a mouse, a multi-touch screen, a bendable/deformable interface; or even a mind reading sensor, haXe can be remixed and used for the device.

This means that you can use the same language and even the same codebase across the browser and the server part of your project, for example. To me, that is why haXe is so relevant.

Benjamin Dasnois is one of the people that has been around since haXe-day one. He remixes haXe to make it fit new needs. Benjamin is best known within the community for working on the Java target. (I would also say, that he is second to none for his funny French accent.)

In this book, Benjamin will introduce you to the world of haXe. Once you get to the last page, you will have the skill set to start developing for a browser and a big bulky server using the same language.

However, remember: a programming language is never your goal; it is a tool that assists you in achieving your goal, be it creating awesome software that enriches all of our lives or helping us achieve world domination.

Pimm Hogeling

haXe Developer and Interface Designer

About the Author

Benjamin Dasnois has always been fascinated by open source software and as such, has been giving courses about Linux in an IT school in France. In the meantime, Benjamin has been following and working with haXe since its beginning and uses it in his professional life. He now works on an open source project, started the integration of haXe into it, and made it work with the technologies that were already in use.

I would like to thank the entire haXe community, my schoolmates, and former students who really made me discover the contribution I could make by imparting my knowledge or communicating my skills.

About the Reviewers

Marcus Bergström is the Technical Director and a co-owner of the digital creative studio Quickform. Working on a day-to-day basis with projects, spanning everything from websites to business applications, he knows the importance of choosing the right tool for the job. With a portfolio packed with world known brands, quality assurance is paramount, as well as production speed.

As one of the early adopters of the language, Marcus has been using haXe as his secret weapon while spearheading all the developments of haXe within the company for years. His favorite features include the strict typing and the ability to write both client and server-side applications in one language.

His business is located in the sunny south of Spain where he lives with his wife and two children. He believes that Sundays are best enjoyed with a cold beer after a good round of golf with friends.

Andy Li is a haXe developer in Hong Kong, with a Bachelor's Degree (first class honors) in Creative Media from City University of Hong Kong. He is now a PhD student in the School of Creative Media, City University of Hong Kong, researching in the fields of computer vision, computer graphics, and installation art.

He has been actively involved in the haXe community, producing several open source haXe libraries, including CasaHx (haXe port of CasaLib for AS3), hxColorToolkit (toolkit for managing colors), hxOpenFrameworks (haXe binding to openFrameworks), and jQueryExtern (haXe extern file for jQuery).

His personal blog, http://blog.onthewings.net/, contains many open source experiments and programming tips.

Franco Ponticelli is an experienced software developer and a problem solver. An Architecture graduate with specialization in Industrial Design, he performs many different activities in the Information Technology area from 3D computer graphics to hard-core software development. In his constant research for the perfect development environment, he found haXe and fell in love with it.

He is the author of the book Professional haXe and Neko published by Wrox.

I would like to thank my wife and kids for their support.

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Preface

haXe is the universal programming language which is completely cross-platform and provides a standard library that remains the same—regardless of platform.

haXe 2 Beginner's Guide will get you up and running with this exciting language and will guide you through its features in the easiest way possible.

haXe has filled the gap in creating multi-platform applications, and this book will fill the gap in learning all you need to know about haXe—even if it is the first time you have heard of it.

This