Summary

This chapter gives a basic introduction to the traditional Document Object Models. The traditional Document object is structured as a containment hierarchy and accessed by “navigating” through general objects to those that are more specific. Most useful Document properties are found in associative arrays like images[], which can be indexed by an integer or name when an element is named using an HTML tag’s name or id attribute. Event handlers were introduced as a means to react to user events and may be set with JavaScript or markup. The chapter also introduced the specific Document Object Models of the major browsers. The early browsers such as Netscape 2/3 and Internet Explorer 3 implemented the object model that is the basis of the DOM Level 0. However, the following 4.x generation browsers introduced some powerful “DHTML” features that were highly incompatible and have led some Web developers to embrace proprietary features. While the chapter clearly illustrated the divergent and incompatible nature of different Browser Object Models, it should not suggest this is the way things should be. Instead, the W3C DOM should be embraced as it provides the way out of the cross-browser mess that plagues JavaScript developers. The next chapter explains the details of the W3C DOM and why it should revolutionize the way scripts manipulate documents.