1 2 3 4 5 6 7 8 9 10 11 12 13 14 15
Line 1 opens the script element, and line 2 opens a comment (as you should always do in scripts).
Line 3 begins the
popup() function, taking two arguments. The first argument,
mylink, is the object (the link or image map) calling the function, or it can be a string representing the URL for the popup.
The second argument,
is a unique name for the popup window. Every popup window must have a unique name. More than one link can target the same popup by using the same unique popup name.
4 has the opening bracket for the function.
5 tests for the existence of the
window.focus is how we bring the popup to the front every time, even though it was already open. Some older browsers do not have
window.focus -- those browsers degrade gracefully by failing out of the function and going to the popup's URL in the current window. Note that there are no parentheses after
window.focus because we are testing for the existence of the function, not running it.
Line 6 declares the
href variable, which holds the URL to which the popup should navigate. Lines 7 to
10 figure out what that URL is. In 7 we test if
mylink is a string. If it is a string, in line 8 we assign to
href the value of the string. If
is not a string then we assume it is an
href the value of the objects
href property (which was set in the
11 is the real kernel of the whole function -- this is where the popup is actually opened.
window.open() takes three arguments. The first is the URL to open in the popup. In our script we use the
mylink variable. The second is a unique name of the popup -- we use the
windowname variable. The third argument is a string containing a comma separated list of properties of the window. These properties are explained in more detail starting at
Popup Windows: open() Parameters.
In line 12 we return false to cancel the click on the link. If we don't return false the link will navigate the current window to the URL of the popup.
Finally, line 13 closes the
14 closes the comment, and
15 closes the script.
<A HREF="popupbasic.html" onClick="return popup(this, 'notes')">my popup</A>
Like regular link, the
The code begins with
return. One of the properties of
return, the code calls the
popup() function with two arguments. The first argument,
this, indicates the link object itself. The script uses this object reference to get a URL for the popup. By passing an object reference instead of typing the URL twice we avoid the problems inherent with redundant information. If you change the URL or copy and paste the code for a different link, you only need to change the URL in one place. Note that
this should not be in quotes.
The second argument is a unique name for the popup. Every popup window must have its own unique name. Different links can target the same popup by all using the same name. Note that the name should be in single quotes
return, the browser watches to see if a true or false value is returned. The command after
popup()function, passing a reference to the link object and a string containing the unique name of the popup.
The script first checks if the browser understands the
If the browser doesn't have
window.focus (which will happen in some older browsers)
then the script returns true, which is in turn returned from the
Most browsers will have
window.focus, so the script continues. Starting in line 7 the script checks if the first argument
mylink) is a string or an object reference. This test gives the function flexibility by allowing us to call it from a link object or from the
Next, the script actually opens the popup using the URL and the unique name. Finally, the script returns false. Back in the link, the false value cancels the click event -- which is no longer needed because the popup has been opened.Copyright 1997-2002 Idocs Inc. Content in this guide is offered freely to the public under the terms of the Open Content License and the Open Publication License. Contents may be redistributed or republished freely under these terms so long as credit to the original creator and contributors is maintained.