Loading an extension

The Crystal Management Console (CMC) and Crystal Enterprise SDK provide methods for enabling your processing extensions and for specifying which objects each extension should be applied to. By enabling processing extensions, you configure the appropriate Crystal Enterprise server components to dynamically load your processing extensions at runtime.

Note:    

• In the current release, processing extensions can be applied to Crystal report objects only. Use either the CMC or the Report object's ProcessingExtensions Property to apply an extension to a specific report.
• If a report that you schedule uses a processing extension, then the instance that is created will need to use the same processing extension.

All Page Server and Job Servers have a list of the processing extensions that are installed on them. As well, each report has a list of processing extensions that apply to it. When either a view or schedule report request is issued, Crystal Enterprise will try to load the extension for that particular report. If the extension cannot be loaded—for example, if the needed extension is not installed on that particular Job or Page Server—then an error will be sent, and the operation will be aborted for security reasons.

If the extension is successfully loaded, then it can be used to do the following:

• Request that the server retrieve information such as the user ID and report title.
• Create a new selection formula that will be appended to a selection formula that already exists in the report. The resulting selection formula is a combination (using the logical operator "AND") of the original selection formula and the new selection formula created by the processing extension.
• Change the prompt values for the report and its subreport.

Once the processing extension is used, then the data and threading will change from being shared to unshared.

Before processing extensions can be loaded, you must make them available to each machine that will process the relevant schedule or view requests. You can register them on a machine by doing one of the following:

• Copying processing extensions onto each server
• Sharing processing extensions between multiple servers