BusinessObjects Enterprise Administrator's Guide

Report viewing with the Report Application Server (RAS)

This section describes the process for viewing a Crystal report when using the Advanced DHTML viewer. This process flow uses the Report Application Server (RAS).

1. Upon receiving a report-viewing request, the RAS checks to see if it has the requested report data in cache. (The RAS has its own caching mechanism, which is separate from the Cache Server.)
2. If a cached version of the report (.epf file) is available:
1. The RAS checks with the CMS to see if the user has rights to view the report.
2. If the user is granted the right to view the report, the RAS returns cached pages (.epf files) to the application server.
3. If a cached page of the report (.epf file) is unavailable:
1. The RAS checks with the CMS to see if the user has rights to view the report.
2. If the user is granted the right to view the report, the RAS retrieves the report object from the Input File Repository Server.
3. The RAS then processes the report object, obtains the data from the database, generates the cached pages (.epf files), caches the pages and sends the pages to the application server.
4. If the user is granted View rights to the report object, then the RAS will only ever generate pages of the latest report instance. That is, the RAS will not retrieve the latest data from the database.

If the user is granted View On Demand rights to the report object, then the RAS will refresh the report against the database.

Note:    The interactive search and filter features provided by the Advanced DHTML viewer are available only if the user has View On Demand rights (or greater) to the report object.

4. When the application server receives the cached pages (.epf files) from the RAS, the viewer SDK generates HTML that represents both the Advanced DHTML viewer and the report itself.
5. The application server sends the HTML pages through the web server to the user's web browser.