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document object

Although it’s not possible to see the URLs in the browser history, you can see how many pages are in it

by using the

length

property:

alert(“There are currently “ + history.length + “ pages in history.”);

This capability is helpful if you want to go back or forward by more than one page and want to know if

that is possible.

The document object

The

document

object is actually a property of the

window

object, but as you learned earlier, any property

or method of the window object may be accessed directly, so this line of code will return

“true”

alert(window.document == document);

It is also unique in that it is the only object that belongs to both the BOM and the DOM (the

document

it relates to the DOM is discussed in the next chapter). From the BOM perspective, the

document

object

is made up of a series of collections that access various parts of the document as well as give information

about the page itself. Once again, because the BOM has no standards guiding implementations, each

browser tends to have slightly different implementations for

document

; this section focuses on the most

common functionality.

The following table lists some of the common properties for the BOM

document

object:

Property

Description

alinkColor

The color for active links as defined by

bgColor

The color for the page background as defined by

<body

bgcolor=”color”>

fgColor

The color for text as defined by

lastModified

The date the page was last modified as a string

linkColor

The color for links as defined by

referrer

The URL one position back in the browser history

title

The text displayed in the

tag

URL

The URL of the currently loaded page

vlinkColor

The color for visited links as defined by

*These properties are deprecated because they refer to old HTML attributes of the

<body/>

tag. Style sheet

scripting should be used instead.

The

lastModified

property retrieves a string representing the date that the page was last modified,

which is of marginal use unless you want to display the last modified date on a home page (which can

also be done using server-side technology). Likewise, the

referrer

property isn’t very useful unless

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