dynamic content, navigation:
automatically loading a new document

How can JavaScript automatically load a new document?

The window object has a property called "location" which can be used to obtain the current document's URL or to specify the URL of a new document to be loaded.

window.location can be read from or assigned to. When window.location is read, the result is a string containing the full URL of the current document. For example, the statement

loc = window . location;

when executed within this document, sets the variable loc equal to

On the other hand, when window.location is set by assignment, the document whose URL matches the new value is automatically loaded. For example, the statement

window . location = "http://sharkysoft.com/"; ,

if executed, would cause the browser window to be updated with Sharkysoft's home page.

The example just shown demonstrates how full, absolute URLs can be assigned to the window.location object. It is also acceptable to assign partial URL strings to window.location, in which case the new string is treated as a relative URL.

For example, if the current document's URL is

http://www.mysite.com/funstuff/index.html ,

then the abbreviated assignment statement

window . location = "intro.html";

is equivalent to full assignment statement

window . location = "http://www.mysite.com/funstuff/intro.html";

because the JavaScript interpreter automatically inserts the missing portion of the URL into the new string.

To help you become more acquainted with the window.location object, here is a "laboratory form" which you can use to experiment with the effects of reading and writing its value:

display window.location's current value in the text window
set window.location to the value shown in the text window
text window:
clear the text window

Before you head off and start using window.location in your code, please consider some final notes on the subject:

window.location is really a special object with many properties. When no property of window.location is specified, the interpreter automatically assumes that you mean "window.location.href." Thus, in our discussion of window.location above, all references to window.location can be replaced with window.location.href, since the former is just a synonym for the latter. (For simplicity I have chosen the shorter form.)
Previous versions of JavaScript have encouraged programmers to use document.location and document.location.href to achieve the same effects described in this article. However, this practice should be avoided because Netscape Communications recently announced that in future versions of JavaScript, location will no longer exist as a property of the document object. In its place, document.URL will continue to be available, but only as a read-only string.
Because JavaScript interprets most statements within the scope of the window object, the terse expression location is usually equivalent to window . location. Statements executed within event handlers, however, do not necessarily operate within this same scope. Because of this, it is a good idea to to preface the property "location" with its parent object "window" when it is used within event handlers. Failure to do so causes the interpreter to inadvertently treat location as a property of document. Detailed information on the window.location object can be found in Netscape's JavaScript Guide.
Charlton Rose
30 Jan. 1997

dynamic content, navigation: automatically loading a new document

dynamic content, navigation:
automatically loading a new document