3.7 Link Command Buttons

At the bottom of the Links dialog box, three push buttons allow the user to update, cancel, and change the selected links.

Update Now updates all links selected in the Links list. In other words, the presentations of the linked objects in the client application are updated to reflect the current data in the linked files. Suppose that the selected links are all associated with a file called SOURCE.DOC. It is possible that the client contains other, currently unselected links associated with the same file. In this case, after the selected links are updated, the client application displays the message dialog shown in Figure 23. If the links selected originally are associated with several files and if the document contains other unselected links to those files, the message dialog is displayed once for each file.

Figure 23. Message for updating additional links to the same file

Cancel Link permanently breaks the link between the client and the server. The linked object in the container document is changed to a picture that can no longer be updated or edited with the standard OLE techniques. The picture can still be edited with the older Cut, Copy, and Paste techniques, but it is unlikely that the picture will retain all the data present in the original linked object. When the user presses the Cancel Link button, the entry for the link disappears from the Links list in the Links dialog. Offering the option of changing an embedded object into a picture should be part of an application's controls (for example, using a menu or a button).

The Change Link button is dimmed if the selection in the Links list includes multiple links that are not all linked to the same file. Otherwise, the button is active and leads to a dialog exactly like the File Open dialog, except that the title is Change Link (see Figure 24). The standard File Open dialog is described in The Windows Interface: An Application Design Guide which is part of the Microsoft Windows Software Development Kit for Microsoft Windows Version 3.1.

The Change Link dialog box allows the user to change the file to which a link refers. For example, if a linked file is renamed or moved to a new location, this dialog lets the user reconnect the link in the container document, using the new name or the new location of the linked file.

Figure 24. Change Link dialog box

When the user chooses a file and presses OK in the Change Link dialog, the client application disconnects the links that were selected in the Links list from their previous file and connected to the newly chosen file. It is possible that the previous file was also associated with other, currently unselected links in the container document. In this case, after the client application changes the selected links, the client application displays the message dialog shown in Figure 25 (this message is analogous to the one shown in Figure 23).

Figure 25. Message for changing additional links to the same file