About building a shared 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.
To support creating and maintaining standard formats, building reports in collaboration with other report developers, and avoiding error-prone, repetitious design tasks, BIRT uses the following file types:
*A library
The main purpose of a library is to provide developers of report designs with a shared repository of predesigned report elements and styles. The file-name extension for a library file is .rptlibrary. BIRT locates libraries in the resource folder.
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.
A library stores customized report elements, such as data sources, visual report items, styles, and master pages. Use a library in a report design to access the customized 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 template
The main purpose of a template is to provide a standard start position for a new report design. As such, the structure of a template file is identical to the structure of a report design file. The file-name extension for a template file is .rpttemplate. BIRT locates templates in the template folder.
A template is a static framework on which to build a new report design. A report design derived from a template modifies a copy of that template. For this reason, a report design can derive from only one template. Because report designs use copies of the template, when a template developer changes a template, report designs based on that template do not automatically reflect those changes.
A template provides a structure for a standard report layout. 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 uses libraries in the same way that a report design does. BIRT Report Designer provides a set of standard templates, such as Simple Listing and Grouped Listing report templates.
*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.
Developing a library or a template uses skills similar to those used to develop report designs. All these file types use the same report elements from the palette, Data Explorer, and the Outline view in BIRT Report Designer.