How the viewers work with your reporting application

Before looking at any particular SAP Crystal Reports product or architecture, it is useful to view an abstract reporting model to identify several logical components of a reporting application.
Abstract reporting model
The report viewer renders a report source into DHTML and provides interaction controls, such as Search, Zoom, Drill Down, Export, and Print.
Report sources
A report source is an object used by the viewer to access the properties of a report. It provides the viewer with the means to query for report data, page information, and other internal report information. Report sources are obtained from report servers such as the Crystal Reports 2011 Processing Server and the Crystal Reports 2011 Report Application Server.
Choosing a report server
Although some applications that you develop may work equally well using the Crystal Reports 2011 Processing Server or the Crystal Reports 2011 Report Application Server, there are likely to be situations when the requirements of a particular application mean that you must use one type of report server instead of the other.
In general, the Crystal Reports 2011 Report Application Server provides greater functionality over the Crystal Reports 2011 Processing Server, including such features as the ability to schedule reports, receive alerts, and make runtime changes to reports. However, running reports through the Crystal Reports 2011 Processing Server provides greater scalability because once a report on the Crystal Reports 2011 Processing Server has been viewed by one user, a copy of it is kept on the Crystal Reports Cache Server, providing quick access to the same report by hundreds of other users.
When to use a Crystal Reports 2011 Processing Server as your report server
You should choose to access your Crystal reports through a Crystal Reports 2011 Processing Server when any of these conditions are true:
  • You are using the viewers within an SAP BusinessObjects Business Intelligence platform environment and do not have the Crystal Reports 2011 Report Application Server running.
  • You wish to take advantage of the Crystal Reports 2011 Processing Server's interaction with the Crystal Reports Cache Server, so that individual report pages are not generated every time they are requested.
  • Your application delivers reports that do not need to be changed at run-time.
When to use a Crystal Reports 2011 Report Application Server as your report server
You should choose to access your Crystal reports through a Crystal Reports 2011 Report Application Server when any of these conditions are true:
  • Your application needs to display reports that it has opened for modification on the Crystal Reports 2011 Report Application Server.
  • Your application accesses Crystal report files (.rpt files) directly from a file system. This functionality is only provided by an unmanaged Crystal Reports 2011 Report Application Server.
A report source served by a Crystal Reports 2011 Report Application Server can be used to modify report elements programatically, using the Report Application Server SDK. For example, depending on a user’s preferences, your application can apply a template to an existing report.