Dynamic Data Exchange: Macintosh Implementation

What is available to Macintosh developers to match the Dynamic Data Exchange (DDE) capability in Microsoft Windows 3.1?

We use an internally developed application which uses MS Word, FoxBase Pro, Oracle, Windows 3.1, DDE and TMS image viewer/driver technology. This application archives and indexes collected data and scanned forms, and allows users to view the image of the form whose data is selected. If a 'query' returns a list of forms, as the user steps down the list, the displayed image keeps pace, always displaying the image associated with the chosen record. This interaction is accomplished using DDE.

Now that Microsoft Word, FoxBase Pro, and TMS viewing technology are all available on Macintosh, how can we make this application available to Mac users?

What's involved both in terms of software, and in terms of effort and expertise?

Dynamic Data Exchange (DDE) enables you to transfer data or instructions between Windows applications. The capability you described is usually called Macro DDE. They are conversations between two applications and are managed by the macro language of the DDE client (or possibly by the server). This is different than what people normally think of DDE, which is solely in terms of the Clipboard metaphor.

In a DDE script, a DDE conversation is created by writing code that initiates a conversation with a server, pokes data to or receives data from the server application, and terminates the DDE conversation. You can view DDE as a cross between Apple's Publish and Subscribe and Apple Events.

Another Windows component called Object Linking and Embedding (OLE) allows objects to be embedded in documents and objects can contain data from other applications.

On the Macintosh, we implement this capability in InterApplication Communication (IAC).

IAC includes these elements:

Cut and Paste
Apple Events (which allows an application to request services or information from other applications)
Edition Manager (which enables an application to share dynamic data)
PPC Toolbox (which provides a mechanism for application to exchange blocks of data)
AppleScript (which provides the ability to write scripts, supports recording user actions, and translate scripts into more complex Apple Events)
OpenDoc

You can view OpenDoc as Apple's response to OLE. However, OLE can't have overlapping parts or irregular shapes - they must be rectangles.

To make this application available to Macintosh users, the software involved has to support more than the Required and Core Suites of Apple Events required for the business application. Many applications only support the Required Suite, and many receive but not send Apple Events. You should check with the software vendors to verify that your applications can use AppleScript and to what degree.