> ## Building a Shared Report Development Framework

> Previous sections describe how to create and use data sources and data sets and lay out and format report items. A single report developer with a requirement for only a few reports can use these approaches effectively. For a larger project, either one with more developers or one that requires more reports, many designs need to use the same elements or layouts. In these cases, manual techniques are cumbersome. Developing the same components repeatedly wastes time and is prone to errors. Even if you use the copy-and-paste features of BIRT Report Designer, a report design does not provide convenient access to standard elements and layouts.

> BIRT provides the following solutions for designing reports that must conform to standards, including using common design elements and data sources:

> n | A library

> This type of file stores customized report features, such as data sources, data sets, visual report items, styles, and master pages. Use a library in a report design to access the customized report elements. You can use multiple libraries in a single report design. By using multiple libraries, you can separate the styles and functionality that different projects or processes need.
> A library is a dynamic component of a report design. When a library developer makes changes to a library, the report design synchronizes itself with the changed library. In this way, changes propagate easily within a suite of report designs.

> n | A template

> This type of file provides a structure for a standard report layout. BIRT Report Designer provides a set of standard templates, such as Simple Listing and Grouped Listing report templates. A template can contain visual report items that appear in the report’s layout, data sources and data sets, and master page layouts. A template can also use one or more libraries in the same way that a report design does.
> A template is a static framework on which to build a new report design. For this reason, a report design can derive from only one template. Additionally, when a template developer changes a template, report designs that are based on that template do not automatically reflect the changes to the template.

> n | A CSS file

> This type of file provides styles for formatting items in a report, similar to the formatting of items on a web page. Formatting Report Content provides detailed information about using CSS files in BIRT.

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