本文提出一个事件驱动的超媒体模型,较好地解决了超媒体链、对象同步和用户交互3个关键问题.该模型在结构上分为数据层、容器层和表现层3层,采用直观的时间轴定义各种对象同步关系,通过交互对象和内置的描述语言定义复杂动作,兼顾了直观性、灵活性和交互性;采用完善高效的超媒体链定位方法,支持多人同时工作.以EDHM(event-driven hypermedia model)为基础研制的多媒体著作工具Ark已在国家大型应用系统的开发中得到很好的应用.
This paper proposes an EDHM(event-driven hypermedia model), which focuses on the task of defining and realizing hypermedia link, object synchronization and user interaction involved in a multimedia presentation. EDHM can be divided into three layers, which are data layer, container layer and presentation layer. Based on an event-driven scheme, timeline is applied to instinctively specify temporal and synchronous relationships between objects, and interactive objects together with an embedded simple script language——EasyScript handle the synchronization and action of objects. With an efficient hypermedia link solution, EDHM is able to support very large scale distributed demonstration system. Multiple authors can work simultaneously on a large project, and EDHM is suitable for inconstant authoring environment. An authoring tool called “Ark” based on EDHM has been used successfully.