Browser Operation

The WWW browsers operate, in general, in the following manner.

Data flow

The data flow is demonstrated in a separate diagram . The application gives the navigation module the home page address. The anchor is generated (using the Anchor object ) and passed to the relevant protocol module for loading. In the case of HTTP or a file, a character stream of data is passed to the parser , which build a hypertext object. In the case of news, the protocol module builds the hypertext object itself.

The hypertext object is built as a stream of text interspersed with style changes and anchor start/end points. The parsers create the anchors, giving their addresses, and just pass the id of the object to the graphic object.

Events such as mouse clicks are picked up by the application, and passed to the hypertext object. This may determine that a link should be followed, in which case it invokes the navigation module again, passing the anchor object's id. The naviagation module asks the anchor object for its address, and so loads the next document.


Tim BL