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location object

var oNewWin = window.open(“about:blank”, “newwindow”,

“height=150,width=300,top=10,left=10,resizable=yes”);

oNewWin.document.open();

oNewWin.document.write(“<html><head><title>New Window</title></head>”);

oNewWin.document.write(“<body>This is a new window!</body></html>”);

oNewWin.document.close();

This example opens a blank page (using the native

“about:blank”

URL) and then writes a new page to

it. To do this appropriately, the

open()

method is called before the using

write()

. After the writing is

complete,

close()

is called to complete the rendering. This technique is useful when you want to dis-

play a page without going back to the server.

The location object

One of the most useful objects in the BOM is

location

, which is a property of both

window

and

docu-

ment

(this is where a lack of standards leads to some real confusion). The

location

object represents

the URL loaded in a window and, as an added bonus, it also parses the URL into various segments:

hash

— If the URL contains a pound sign (

), this returns the content after it (for example,

http://www.somewhere.com/index#section1

has a hash equal to

“#section1”

host

— The name of the server (for example, www.wrox.com)

hostname

— Most often equal to

host

, this sometimes eliminates the

www.

from the front.

href

— The full URL of the currently loaded page

pathname

— Everything after the host in the URL. For example, the

pathname

for

http://www.somewhere.com/pictures/index.htm

“/pictures/index.htm”

port

— The port of the request if specified in the URL. By default, most URLs don’t include

the port as part of the URL so this property is typically blank. If a URL is used such as

http://www.somewhere.com:8080/index.htm

, the

port

is equal to 8080.

protocol

— The protocol used in the URL. This is everything before the two forward slashes

(

) in the URL. For example, the

protocol

for

http://www.wrox.com

http:

and the

protocol

for

ftp://www.wrox.com

ftp:

— Otherwise known as the query string, this is everything after a question mark (

)

in a URL performing a GET request. For example, the

for

http://www.somewhere

.com/search.htm?term=javascript

?term=javascript

The

location.href

property is used most often to either get or set the URL of the window (in this

regard, it is similar to

document.URL

). You can navigate to a new page just by changing its value:

location.href = “http://www.wrox.com/”;

When navigating this way, the new location is added to the history stack after the previous page, mean-

ing that the Back button goes to the page that made this call.

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JavaScript in the Browser

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