File Watcher Essentials

File Watcher is the Broadcast Agent feature that permits the processing of tasks when and only when a specified file is present in its specified location.

A typical use of this feature is the database administrator who posts a text file to signal the successful reload of a data warehouse; when the text file is present in the specified location, Broadcast Agent refreshes and distributes the document(s).

The File Watcher feature means that Broadcast Agent can interoperate with all existing systems, even legacy systems anywhere on the network. For example, a legacy system could create a file that Broadcast Agent is watching for. Broadcast Agent would then execute the scheduled task. This would create a new document that in turn would trigger the creation of another document. This cascading chain of reactions and documents depending on specific conditions is called "report chaining."

What kind of file can you use?

You can use any kind of file.

Where can the file be located?

The file can be located wherever you want--on a server, on the client or on a file system--as long as the Broadcast Agent machine can access the file where it has been defined.

What kind of access rights are required?

Each Broadcast Agent has a component called BusinessObjects Manager. The Manager is a server-based version of BusinessObjects that allows Broadcast Agent to display and refresh BusinessObjects documents.

When Broadcast Agent detects a document in the repository that is due to be processed, its BusinessObjects Manager launches a BusinessObjects session, which extracts the document from the repository and processes it.

Each BusinessObjects Manager is configured with the user name and password of an NT user, and therefore has defined access rights to machines, disks and directories.

In order to use the File Watcher, the BusinessObjects Manager used for a particular task must have access rights to the specified file and location.

For example, if you enter x:\Temp\Business Objects\file.txt in the File Watcher box in the Scheduling Options page, the BusinessObjects Manager associated with the Broadcast Agent you've chosen must have read rights for the server x and the directory Temp\Business Objects on that machine.

How do you indicate where to find the file in the Scheduling Options dialog box?

You can use either of two name and path conventions:

• A standard local or remote pathname, such as
  c:\Program Files\Business Objects\Demo\file.txt, or
  x:\Temp\Business Objects\file.txt
• A valid UNC

UNC stands for Universal Naming Convention, PC format for specifying the location of resources on a local-area network (LAN). UNC uses the following format:

\\server-name\shared-resource-pathname

So, for example, to access the file.txt file in the directory examples on the shared server silo, enter:

\\silo\examples\file.txt

Note: We highly recommend that you use a UNC. Why? Because Broadcast Agent is distributed, and therefore a scheduled job may run on one of any number of servers.
If you use a remote path name, the drive used must be properly configured on the BOManager server if it is to find the file. When you use a UNC, however, the name of the server or PC on which the file is located is included, thereby ensuring that the Broadcast Agent server can find it.

What happens if Broadcast Agent can't find the file?

If the Broadcast Agent can't locate the file at task execution time, it simply doesn't run the task.

What rights are required to delete the file after task execution?

The Scheduling Options page contains the option Delete the file each time a refresh starts. If you check it, the BusinessObjects Manager used for the task must have read and write rights to the specified file and location.

Return to topic: Scheduling Documents with Broadcast Agent