Opening External Links in new window from AS3

You most probably know that there are issues opening links using the navigateToURL() method in Flex. The three most common problems / issues are:

• allowScriptAccess not set to all in the HTML Wrapper
• Window Mode set to transparent in IE
• Popup blockers blocking the new window – specially when target is _blank

Many people have tried solving this issue. My approach is simply a hack over FlexMerge’s code. Which in turn is a hack on “Jason the SAJ”‘s approach. Another approach I liked in detecting if popup blockers blocked your window is Andrew Trice’s solution on InsideRIA.

Essentially, use JavaScript window.open method for Firefox, a little tweak on that for IE and use navigateToURL() for other browsers.

Continue reading for the code…

What I wanted to achieve was show help for a Flex application. Help is contextual, and we are using a separate knowledge base system to store help articles. Flex has to open a link and pass a keyword to look up for that help.

I created a class PopupWin that handles everything about opening a new window, ensuring it’s not blocked. (methods are called statically, you can change them if you wish).

[AS]
package
{
import flash.external.ExternalInterface;
import flash.net.URLRequest;
import flash.net.navigateToURL;

public class PopupWin
{
public static var baseURL:String = ”;
private static var browserName:String = ”;

public static function openWindow(url:String, target:String = ‘_blank’, features:String=””):void
{
//Sets function name into a variable to be executed by ExternalInterface.
//Otherwise Flex will try to find a local function or value by that name.
var WINDOW_OPEN_FUNCTION:String = “window.open”;

// Prefix baseURL if specified
if (PopupWin.baseURL != ”)
{
url = PopupWin.baseURL + url;
}
var myURL:URLRequest = new URLRequest(url);

if (PopupWin.browserName == ”)
{
PopupWin.browserName = PopupWin.getBrowserName();
}

switch (PopupWin.browserName)
{
//If browser is Firefox, use ExternalInterface to call out to browser
//and launch window via browser’s window.open method.
case “Firefox”:
ExternalInterface.call(WINDOW_OPEN_FUNCTION, url, target, features);
break;
//If IE,
case “IE”:
ExternalInterface.call(“function setWMWindow() {window.open(‘” + url + “‘, ‘”+target+”‘, ‘”+features+”‘);}”);
break;
// If Safari or Opera or any other
case “Safari”:
case “Opera”:
default:
navigateToURL(myURL, target);
break;
}

/*Alternate methodology…
var popSuccess:Boolean = ExternalInterface.call(WINDOW_OPEN_FUNCTION, url, target, features);
if(popSuccess == false){
navigateToURL(myURL, target);
}*/
}

private static function getBrowserName():String
{
var browser:String;

//Uses external interface to reach out to browser and grab browser useragent info.
var browserAgent:String = ExternalInterface.call(“function getBrowser(){return navigator.userAgent;}”);

//Determines brand of browser using a find index. If not found indexOf returns (-1).
if(browserAgent != null && browserAgent.indexOf(“Firefox”) >= 0) {
browser = “Firefox”;
}
else if(browserAgent != null && browserAgent.indexOf(“Safari”) >= 0){
browser = “Safari”;
}
else if(browserAgent != null && browserAgent.indexOf(“MSIE”) >= 0){
browser = “IE”;
}
else if(browserAgent != null && browserAgent.indexOf(“Opera”) >= 0){
browser = “Opera”;
}
else {
browser = “Undefined”;
}
return (browser);
}

public static function showHelp(screen:String = ‘home’) :void
{
//var features:String = “menubar=yes,status=no,toolbar=yes,location=1,scrollbars=yes,resizable=1”;
PopupWin.openWindow(screen, ‘_help’);
}
}
}
[/AS]

Here’s how I used it in my MXML Application:
[AS]

[/AS]

Note that the KMS URLs are specific to my implementation. You can use PopupWin.openWindow() directly.

Hope this helps! And thanks to FlexMerge and SAJ for their excellent work.