Sharing Information Using OLE in Windows Vista

Object Linking and Embedding is far more flexible and can be far more complicated than cut-and-paste or drag-and-drop. OLE enables you to use all your software applications to create an integrated document. (Find special prices for all components online.) For instance, you might want to create an annual report that includes these components:

• Text you create and format by using a word processor, such as Microsoft Word or Corel WordPerfect

• A company logo stored in a graphics file created by Adobe Photoshop, Paint, or some other graphics application

• Data and calculations on operating costs stored in a Microsoft Excel spreadsheet

• Graphs and charts, which may come from your spreadsheet package or another graphics package

These components may not reflect exactly what you want to do, but the point is the same-if you want to combine the output of different applications, OLE offers many advantages over the Clipboard. Why? Because, when you use OLE, the original program retains ownership of the object, and you can use the program to edit the object. For instance, if you use OLE to embed a portion of a spreadsheet in a word processing document, you can always use the spreadsheet application to edit the object and the spreadsheet in the word processing document will reflect those changes. If, instead, you use the Clipboard to copy the numbers from the spreadsheet and then you paste the numbers to the word processor, they would just sit in the word processor, oblivious to their origins-you could use only the tools available in the word processor to edit the numbers. This means that if you later change the original spreadsheet, the numbers pasted in the word processing document won't change.

In OLE, an object refers to a piece of information from one application that is placed in a container file created by another application. For example, a spreadsheet or graphic is an object when it is included in a word processing document. OLE actually is two similar methods of sharing information between applications-embedding and linking. Sticking with the previous example, embedding means putting the spreadsheet object in the word processing document (container file) and asking the word processor to take care of storing the object. So, although the word processor enables you to edit the spreadsheet object by using the spreadsheet application, the spreadsheet object is stored with the word processing document. Linking, on the other hand, allows the object to retain a close relationship with its origins-so close, in fact, if the numbers in the original spreadsheet file change, the linked spreadsheet object in the word processing document changes to match. This occurs because the word processing document doesn't really contain the object it displays-it only contains a reference to the file where the information is stored.

You may also choose to insert a package into another file. A package is a small file that uses OLE, but instead of displaying content owned by another application, it displays an icon, which, when clicked, opens the owner application and displays the object. Packages can be either linked or embedded. Whether you choose to embed or link objects, the process is similar: you create an object in one application, and then link or embed the object into another application.

Although using OLE to link files can be wonderfully convenient and can save you hours of revisions, it should be used judiciously. If you plan ever to move the file containing linked objects or to send it to someone, you must make sure one of the following occurs:

• The linked files also get moved or sent.

• The linked objects don't get updated. This means the host application won't go looking for the information in the linked file. To break the link, delete the object and paste in a nonlinked version instead.

• You edit the links so the host file knows where to find the source files for the linked objects.

Otherwise, your beautifully organized and time-saving document can become a complete mess. If you are going to move a document with linked objects in it, you need to know how to maintain links.

If you don't need the automatic updating you get with linked objects (for instance, if the source file isn't going to change, or if you don't want the object to reflect changes) or if you know you are going to move or send files, then stick with embedded objects-they're easier to maintain. However, embedding a large object may take more disk space than linking.

Some applications enable you to link one file to another in a different way-by using a hyperlink. A hyperlink actually takes you from one file to another, opening the application for the second file, if necessary.

Source of Information : Windows Vista The Complete Reference