Here are the first 8 paragraphs of Chapter 19 of Essential ActionScript 3.0. 19. Flash Player Security Restrictions To protect data from being transferred to unauthorized destinations without appropriate permission, Flash Player scrutinizes all requests to load or access external resources, or interact with other .swf files or HTML files. Each request a .swf file makes for an external resource (a resource not compiled into the .swf file making the...

Here are the first 5 paragraphs of Chapter 18 of Essential ActionScript 3.0 18. XML and E4X Since Flash Player 5, ActionScript has included tools for working with XML-structured data. In ActionScript 1.0 and ActionScript 2.0, XML data was created and manipulated with the variables and methods of the built-in XML class (e.g., firstChild, nextSibling, appendChild(), etc.). The XML class was based on the W3C Document Object Model, or DOM,...

Here are the first 5 paragraphs of Chapter 17 of Essential ActionScript 3.0 17. Namespaces In very general terms, a namespace is a set of names that contains no duplicates. That is, within the set, each name is unique. For example, in English, the names of fruits could be considered a namespace because each fruit has its own unique name—apple, pear, orange, and so on. Likewise, the names of colors...

Here are the first 7 paragraphs of Chapter 16 of Essential ActionScript 3.0 16. Scope A scope is a physical region of a program in which code executes. In ActionScript there are five possible scopes: * A function body * An instance method body * A static method body * A class body * Everywhere else (i.e., global scope) At any specific point in the execution of a program, the...

Here are the first 6 paragraphs of Chapter 15 of Essential ActionScript 3.0 15. Dynamic ActionScript ActionScript was originally conceived of as a language for adding basic programmatic behavior to content created manually in the Flash authoring tool. In early versions of ActionScript, most code was intended to be written in short scripts that implemented limited functionality compared with the code required to create a complex desktop application. As such,...

Here are the first 3 paragraphs of Chapter 14 of Essential ActionScript 3.0 14. Garbage Collection Every time a program creates an object, ActionScript stores it in system memory (for example, in RAM). As a program creates hundreds, thousands, or even millions of objects, it slowly occupies more and more memory. To prevent system memory from being fully depleted, ActionScript automatically removes objects from memory when they are no longer...

Here are the first two paragraphs of Chapter 13 of Essential ActionScript 3.0 13. Exceptions and Error Handling In this chapter, weýll explore ActionScriptýs system for generating and responding to runtime errorsýor exceptions. In ActionScript, errors can be generated both by the Flash runtime and by the program that is executing. Errors generated by the Flash runtime are known as built-in errors; errors generated by a program are known as...

Here are the first 10 paragraphs of Chapter 12 of Essential ActionScript 3.0 12. Events and Event Handling In general terms, an event is a noteworthy runtime occurrence that has the potential to trigger a response in a program. In ActionScript, events can be broken into two categories: built-in events, which describe changes to the state of the runtime environment; and custom events, which describe changes to the state of...

Here are the first 5 paragraphs of Chapter 11 of Essential ActionScript 3.0 11. Arrays Arrays are used to store and manipulate ordered lists of information and are, therefore, a fundamental tool in sequential, repetitive programming. We use arrays to do everything from storing user input, to generating pull-down menus, to keeping track of enemy spacecraft in a game. Practically speaking, an array is just a list of items, like...

Here are the first 3 paragraphs of Chapter 10 of Essential ActionScript 3.0 10. Statements and Operators This chapter provides a reference-style overview of ActionScriptýs statements and operatorsýmany of which weýve already seen in this book. Rather than discussing each statement and operator in isolation, this book teaches the use of statements and operators in the context of other programming topics. Accordingly, this chapter lists many cross-references to discussion and...