1. Introducing the ToolTalk Service
Using the ToolTalk Desktop Services Message Set
Using the ToolTalk Document and Media Exchange Message Set
Integrating Multimedia Functionality
Adding Multimedia Extensions to Existing Applications
Extending the X Cut and Paste Facility
Using the CASE Interoperability Message Sets
Using the ToolTalk Filename Mapping Functions
Using ToolTalk in a Multi-Threaded Environment
How Applications Use ToolTalk Messages
Modifying Applications to Use the ToolTalk Service
2. An Overview of the ToolTalk Service
4. Setting Up and Maintaining the ToolTalk Processes
5. Maintaining Application Information
6. Maintaining Files and Objects Referenced in ToolTalk Messages
7. Participating in ToolTalk Sessions
13. Managing Information Storage
A. Migrating from the Classing Engine to the ToolTalk Types Database
B. A Simple Demonstration of How the ToolTalk Service Works
The ToolTalk service provides two methods of addressing messages: process-oriented messages and object-oriented messages.
Process-oriented messages are addressed to processes. Applications that create a process-oriented message address the message to either a specific process or to a particular type of process. Process-oriented messages are a good way for existing applications to begin communication with other applications. Modifications to support process-oriented messages are straightforward and usually take a short time to implement.
Object-oriented messages are addressed to objects managed by applications. Applications that create an object-oriented message address the message to either a specific object or to a particular type of object. Object-oriented messages are particularly useful for applications that currently use objects or that are to be designed around objects. If an existing application is not object-oriented, the ToolTalk service allows applications to identify portions of application data as objects so that applications can begin to communicate about these objects.
Note - Programs coded to the ToolTalk object-oriented messaging interface are not portable to CORBA-compliant systems without source changes.
To determine which groups receive messages, you scope your messages. Scoping limits the delivery of messages to a particular session or file.
A session is a group of processes that have an instance of the ToolTalk message server in common. When a process opens communication with the ToolTalk service, a default session is located (or created if a session does not already exist) and a process identifier (procid) is assigned to the process. Default sessions are located either through an environment variable (called process tree sessions) or through the X display (called X sessions).
The concept of a session is important in the delivery of messages. Senders can scope a message to a session and the ToolTalk service will deliver it to all processes that have message patterns that reference the current session. To update message patterns with the current session identifier (sessid), applications join the session.
A container for data that is of interest to applications is called a file in this book.
The concept of a file is important in the delivery of messages. Senders can scope a message to a file and the ToolTalk service will deliver it to all processes that have message patterns that reference the file without regard to the process's default session. To update message patterns with the current file path name, applications join the file.
You can also scope a message to a file within a session. The ToolTalk service will deliver the message to all processes that reference both the file and session in their message patterns.