DOM level 2 mandates that this object should really be called a CSS2Properties object and not a style object. It has become known as a style object due to the Element property name that points at it.

The style objects supported by MSIE and Netscape Navigator 4.x are quite different. For a start, the style objects are associated with each element in MSIE and are accessible quite easily via the style property. For Netscape Navigator 4, the style properties are documented under the JSSTag object. JSS style control permits the definition of element styles before an element has been instantiated into the document. You cannot use JSS to make dynamic style alterations.

With the release of Netscape 6.0, the style manipulation is virtually the same across both browsers. This works in both MSIE and Netscape 6 now:

document.getElementById("anID").style.backgroundColor="#003366";

Nearly all the attributes described in CSS level 1 and 2 are now supported by the style object. Because the codebase in Netscape 6.0 is totally new and it has only just been released, you may experience some minor instability in its support for styles.

When you look at the properties of the style object, you will observe that there are many alternative ways to define properties. This is quite commonplace where Microsoft define an interface to an object themselves or enhance one that has been defined by someone else (W3C or Netscape perhaps). For example, you can specify border attributes for all four borders but there are also separately defined attributes for each border. Although it's not that confusing, it does mean that there are a lot of additional keywords to learn and, from a parsing point of view, the more keywords there are, the slower the parser is going to be. It also means that programmers will employ a variety of different techniques which then forces the competing browser manufacturers to support the Microsoft extensions too.

Minimalist design is obviously not a priority here. Arguably there are benefits from this approach, too, and some people prefer having a variety of alternative ways to script around a problem. The style object could have been just as flexible with fewer properties at the expense of having scripts with a few more lines.

In the case of the border attributes, we might easily have coped with having a single border attribute that applied to all four sides because there are relatively few circumstances where we would want a different border on each side of a cell. On the other hand, we would then have lost some functionality so perhaps having individually addressable sides is beneficial, but then we could have omitted the collective reference leading to a need to explicitly define all four. At least this way, everyone's needs are catered for.

The properties for this object may apply styles to a variety of object types. Some are very specifically applicable to only a particular sub-set of objects. You should generally assume that the style attribute can apply to objects of any kind unless the property description topic enumerates a set of objects. In that case, the style attribute should only be applied to those object types and will likely be ignored by others. There is a possibility that applying a completely inappropriate styling to an object may cause problems or unpredictable behavior.

Warnings:

• Note that the object type for MSIE is a style object spelled without capitalization. The corresponding object type for Netscape 4 is a JSSTag object.

• MSIE also supports a STYLE object, which is instantiated by the <STYLE> tag. This is an object that represents an inline style element within the HTML of the document.

Inheritance chain:

Element object, Node object