JavaScript Examples Bible - UserWorks Technologies

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JavaScript Examples Bible: The Essential Companion to JavaScript Bible
Caution
One warning about setTimeout() functions that dive into themselves as frequently
as this one does: Each call eats up a bit more memory for the browser
application in Navigator 2. If you let this clock run for a while, some browsers may
encounter memory difficulties, depending on which operating system they’re
using. But considering the amount of time the typical user spends on Web pages
(even if only 10 or 15 minutes), the function shouldn’t present a problem. And any
reloading invoked by the user (such as by resizing the window in Navigator 2)
frees up memory once again.
showModalDialog(“URL”[, arguments]
[, features])
showModelessDialog(“URL”[, arguments]
[, features])
NN2 NN3 NN4 NN6 IE3/J1 IE3/J2 IE4 IE5 IE5.5
Compatibility (✓) ✓ ✓
Example
To demonstrate the two styles of dialog boxes, I have implemented the same
functionality (setting some session visual preferences) for both modal and modeless
dialog boxes. This tactic shows you how to pass data back and forth between
the main page and both styles of dialog box windows.
The first example demonstrates how to use a modal dialog box. In the process,
data is passed into the dialog box window and values are returned. Listing 16-39 is
the HTML and scripting for the main page. A button’s onClick event handler invokes
a function that opens the modal dialog box. The dialog box’s document (Listing
16-40) contains several form elements for entering a user name and selecting a few
color styles for the main page. Data from the dialog is fashioned into an array to be
sent back to the main window. That array is initially assigned to a local variable,
prefs, as the dialog box closes. If the user cancels the dialog box, the returned value
is an empty string, so nothing more in getPrefsData() executes. But when the user
clicks OK, the array comes back. Each of the array items is read and assigned to its
respective form value or style property. These values are also preserved in the global
currPrefs array. This allows the settings to be sent to the modal dialog box (as the
second parameter to showModalDialog()) the next time the dialog box is opened.
Listing 16-39: Main Page for showModalDialog()
window.setModalDialog() Method
var currPrefs = new Array()
windowObject.showModalDialog()