Introduction¶

Several useful services are now offered through the technologies that make up the Worldwide Web (WWW). The great majority of these Web sites provide access to said services exclusively through HTML interfaces designed to be used by humans through an Internet browser.

At times, it is desirable to be able to automate some sequences of operations in Web sites, making them executable by a program instead of a human user. For example, this can be useful in speeding up queries to multiple data sources or for automating transaction processes that involve completing various HTML forms. Although the http protocol offers some basic support for these operations, it is insufficient in many sources due to problems such as scripting languages executed in the Internet browser (JavaScript, JScript, etc.), session tracking in the server side, certain types of redirections, etc.

NSEQL (Navigation SEQuence Language) is a language designed for programming action sequences on the Internet browser interface: the current version supports Microsoft Internet Explorer (MSIE), and Denodo Browser. NSEQL can be used in a computer program to reproduce any operation sequence a human user may have conducted through the browser.

It is important to highlight that it is not normally necessary to create NSEQL programs manually. The ITPilot graphical generation environment (ITPilot Generation Environment Guide) allows NSEQL programs to be created graphically by simply providing an example of the required sequence through an Internet browser. This manual provides an exhaustive description of the language for advanced users that want to manually create or edit NSEQL programs.