For better understanding of the SAPI technology, let’s analyze the process of document generation in a SAPI-based CMS. The input data for the process are the presentation definition documents for the given document group. Based on the functional scheme of the project requirements specification and graphical design, the presentation code is generated. The presentation code is converted to a document named “presentation template”. The presentation code corresponds to the syntax of the selected markup language (HTML, XHTML, SVG, etc.).

A SAPI document is also generated describing the maintenance interface for this site document. The presentation code contains pointers to SAPI objects, which implies substitution of code returned by these objects when generating site documents. Both documents are processed by a SAPI parser and, as a consequence, a site document is generated.

Figure 1. SAPI model of data presentation

The SAPI-parser analyzes the presentation code and, when finding the pointers to SAPI objects, refers to the corresponding SAPI document for description. Pointers to the query containers define the interface of the managed content queries in the CMS admin area. At the presentation level (see Presenational Level), a CMS pointer to a query container returns the corresponding content - the same that was provided by an operator in the CMS admin area. Data containers return the code in accordance with the functional scenario set in their definition.

3.2.1 Presentation Template

Within the concept of SAPI-based content management, for any type of document or a group of documents a template can be defined, which specifies the layout of the document displayed on the website. The presentation template contains a presentation code and pointers to SAPI document objects.

3.2.2 Presentation Code

To define the layout of the document displayed in the browser or in any other client-based user software for interaction with the site, the code of the selected markup language is used. SAPI has no limitations for the list of allowed markup languages. However, it is recommended to use XML-based languages or HTML.

3.2.3 SAPI Document

A SAPI document is a code that contains elements of the specification and a valid SAPI-DTD. A SAPI document defines the interfaces of the site documents.