ID Number: Q75003
3.10
WINDOWS
Summary:
Unlike the Dynamic Data Exchange Management Library (DDEML), the
object linking and embedding (OLE) libraries directly support the
following functions:
Extensibility to Future Enhancements
------------------------------------
The OLE libraries may be updated in future releases to support new
data formats, link tracking, in situ editing, and other enhancements
that will not be immediately available to applications that use the
DDEML.
Persistent Embedding and Linking of Objects
-------------------------------------------
The OLE libraries assume most of the burden of activating objects (by
reestablishing the conversation between a client and server) when an
embedded document is reopened. In contrast, the burden of establishing
a DDE link (DDE advise loop) falls on the user (if the link is not
persistent), or falls on the application (if the link is persistent).
Rendering Common Data Formats
-----------------------------
The OLE libraries assume the burden of rendering common data formats,
such as bitmaps, device-independent bitmaps (DIBs), and metafiles. In
contrast, DDE applications must do this work themselves.
Server Rendering of Specialized Data Formats
--------------------------------------------
The OLE libraries facilitate the rendering of specialized data formats
in the client's display context. The server application or object
handler actually performs the rendering, since only it has knowledge
of the format. The client application has to do very little work to
render the embedded or linked data in its display context. Such
rendering of embedded or linked data is beyond the scope of DDE
itself.
Activating Embedded and Linked Objects
--------------------------------------
The OLE libraries support activating a server to edit a linked or
embedded object, as well as activating the object to render data.
Activating servers for data rendering and editing is beyond the scope
of the DDEML.
Creating Objects and Links from the Clipboard
---------------------------------------------
The OLE libraries assume most of the burden for copying and pasting
links to and from the Clipboard. The OLE libraries assume most of the
burden for exchanging objects using the Clipboard. In contrast, DDE
applications must call the Windows Clipboard functions directly to
perform such operations.
Creating Objects and Links from Files
-------------------------------------
The OLE libraries provide direct support for exchanging data using
files. In contrast, no DDE protocol is defined to exchange data using
files. It is possible to pass file references through DDE, but
specific DDE clients and servers must agree upon the file format as
part of their communication protocol; this is rarely done.
Additional reference words: 3.10 3.1 OLE DDEML