Legacy Document

Inside Macintosh: Macintosh Toolbox Essentials /

Chapter 1 - Introduction to the Macintosh Toolbox / Related System Software Features

Communicating With Other Applications

System software provides various means of communication between applications. You can use Event Manager routines to communicate, in the form of high-level events, with other applications. High-level events are not required to adhere to any specific protocol, so their interpretation is defined by each application that sends or receives them. Apple events are high-level events that follow a standard defined protocol (the Apple Event Interprocess Messaging Protocol). In most cases, you should use Apple events for communication between applications. Because Apple has defined a standard set of Apple events, all applications can interpret specific Apple events in the same way and respond in an expected manner.

Both the Event Manager and Apple Event Manager rely on the services of the Program-to-Program Communications (PPC) Toolbox to actually send and receive events between applications. Your application can also directly access the PPC Toolbox if you need to get additional control or services not provided by the Event Manager or Apple Event Manager.

If your application supports publish and subscribe features, the Edition Manager sends your application Apple events to notify it when new data is available for a subscriber or to request that it create a new publisher.

For information on Apple events, publish and subscribe features, or direct access to the PPC Toolbox, see Inside Macintosh: Interapplication Communication.