Inside Macintosh: Interapplication Communication /

Chapter 3 - Introduction to Apple Events

This chapter introduces Apple events and the Apple Event Manager. Later chapters describe how your application can use the Apple Event Manager to respond to and send Apple events, locate Apple event objects, and record Apple events.

The interapplication communication (IAC) architecture for Macintosh computers consists of five parts: the Edition Manager, the Open Scripting Architecture (OSA), the Apple Event Manager, the Event Manager, and the Program-to-Program Communications (PPC) Toolbox. The chapter "Introduction to Interapplication Communication" in this book provides an overview of the relationships among these parts.

The Apple Event Registry: Standard Suites defines both the actions performed by the standard Apple events, or "verbs," and the standard Apple event object classes, which can be used to create "noun phrases" describing objects on which Apple events act. If your application uses the Apple Event Manager to respond to some of these standard Apple events, you can make it scriptable--that is, capable of responding to scripts written in a scripting language such as AppleScript. In addition, your application can use the Apple Event Manager to create and send Apple events and to allow user actions in your application to be recorded as Apple events.

Before you use this chapter or any of the other chapters about the Apple Event Manager, you should be familiar with the chapters "Event Manager" in Inside Macintosh: Macintosh Toolbox Essentials and "Process Manager" in Inside Macintosh: Processes.

This chapter begins by describing Apple events and some of the data structures they contain. The rest of the chapter introduces the use of the Apple Event Manager to

• respond to Apple events
• send Apple events to request services or information
• work with object specifier records
• classify Apple event objects
• locate Apple event objects

Finally, this chapter summarizes the tasks you can perform with the Apple Event Manager and explains where to locate information you need to perform those tasks.

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Chapter Contents

About Apple Events

Apple Events and Apple Event Objects

Apple Event Attributes and Parameters

Apple Event Attributes

Apple Event Parameters

Interpreting Apple Event Attributes and Parameters

Data Structures Within Apple Events

Descriptor Records

Keyword-Specified Descriptor Records

Descriptor Lists

Responding to Apple Events

Accepting and Processing Apple Events

About Apple Event Handlers

Extracting and Checking Data

Interacting With the User

Performing the Requested Action and Returning a Result

Creating and Sending Apple Events

Creating an Apple Event Record

Adding Apple Event Attributes and Parameters

Sending an Apple Event and Handling the Reply

Working With Object Specifier Records

Data Structures Within an Object Specifier Record

The Classification of Apple Event Objects

Object Classes

Properties and Elements

Finding Apple Event Objects

About the Apple Event Manager

Supporting Apple Events as a Server Application

Supporting Apple Events as a Client Application

Supporting Apple Event Objects

Supporting Apple Event Recording