IBM Cognos Report Design Best Practices – Item Positioning and Sizing

Item Positioning and Sizing

A report consists of three main areas: the page header, page footer, and the body. Reporting Services supports the freeform placement of report items in a report. Data regions can be side-by-side with other regions, or nested within groups.

When designing reports, it is important to understand how items will behave if they grow. The items in a report may grow either horizontally or vertically, depending on section repeats, content size, and on such rendering-specific reasons as font substitutions.

When an item grows, such as a table, it pushes peer items out of the way. Specifically, peer items are those items within the same parent container. Following are the two ways in which peer items are shifted:

• Each item moves down to maintain minimum spacing between itself and all the items ending above it.
• Each item moves to the right to maintain minimum spacing between itself and the items ending to the left of it.

If an item grows so that it would extend beyond the bounds of the containing item, the container grows to accommodate the contained item.

If an item overlaps another item, the Index element in the report definition determines which element overlaps the other. The item with the higher Index value is rendered on top of the item with the lower value.

There also are techniques you can use to control the way items grow and move other report items. For information about using rectangles to group items, see the section “Useful Tips for Report Design” later in this paper.

Pagination

One key design issue for long reports is controlling where the page breaks occur. Page breaks are controlled by two factors:

• Page size
• Page breaks that you specifically include before or after objects

Page Size

To control page size, set the page height and width properties for the report by using the following guidelines:

• For rendering formats that render physical pages, use the Page Height and Page Width properties for the report.
• Interactive rendering formats, such as HTML, do not render physical page breaks. Instead, use the Interactive Height and Interactive Width properties to create a soft page break.
• Some rendering formats, such as Excel, do not support page size. For these reports, you will have to specifically include page breaks to break the report into multiple pages.

Note that if the report itself is wider than the defined page width, the report will break across multiple pages horizontally.