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Chapter 14: The Report Engine Processing Model
Overview
Despite the multitasking cloak that surrounds the world of computers, the typical personal computer is inherently a sequential processing device. In computer time, each task is carried out incredibly fast, which gives you the feeling that things are all happening at the same time; but way down deep in the internals, the processor ultimately executes one task after another to fulfill your requests. This is true of your Crystal report as well. At the point that a page of a report displays on a computer screen, it has gone through a processing cycle that involves several sequential steps. Crystal combines its report engine processing with a page-on-demand approach to displaying information.The order in which the processing steps take place affects the outcome of the report. As a good report designer, you must understand the processing cycle so that you know which report elements are available to you and when and where to place your elements to maximize their effectiveness. The placement of report elements and in which sections they are placed matters a great deal. The focus of this chapter is on helping you understand the evaluation process of the report as a whole and the individual report elements it contains so that you can use the elements correctly.Featured in this chapter:
Multi-pass report processing
The three evaluation passes defined
Order of report element evaluation
Subreport evaluation
Page on demand architecture
Evaluation time formulas
