Electronic document delivery system employing distributed document object model (dom) based transcoding and providing assistive technology support

Abstract

Several embodiments of an electronic document delivery system are described including a client machine (e.g., a palmtop/handheld computer or wireless communication device) coupled to a transcoder proxy. The system allows a client machine with limited resources to provide an assistive technology solution for a physically challenged user. In one embodiment, the client machine includes an assistive technology which functions as an interface for a device (e.g., a Braille display or a speech engine). The transcoder proxy receives an electronic document expressed in a first digital format (e.g., HTML or XML). The transcoder proxy assigns a unique identifier to the element, and forms a model of a logical structure of the document (e.g., a document object model or DOM). The transcoder proxy uses the model to produce an “original” script including a portion of the document expressed in a second digital format (e.g., a scripting language). The client machine uses the original script to present the document portion. The client machine generates an assistive technology event in response to user input via the assistive technology device, associates the assistive technology event with the element, and provides assistive technology event information and the element identifier to the transcoder proxy. The transcoder proxy accesses the element within the model using the identifier, uses the model to produce a “modification” script, and provides the modification script to the client machine. The client machine uses the modification script to modify the presented portion of the document.