如何等待Java applet在Safari上完成加载？ [英] How to wait for a Java applet to finish loading on Safari?
问题描述
这在Safari中不起作用：
This doesn't work in Safari:
<html>
<body>
<applet id="MyApplet" code="MyAppletClass" archive="MyApplet.jar">
<script type="text/javascript">
alert(document.getElementById('MyApplet').myMethod);
</script>
</body>
</html>
myMethod 是在<...中声明的公共方法code> MyAppletClass 。
当我第一次在Safari中加载页面时，它会在applet加载完成之前显示警告（所以消息框显示 undefined ）。如果我刷新页面，applet已经加载，警报会显示 function myMethod（）{[native code]} ，正如您所期望的那样。
When I first load the page in Safari, it shows the alert before the applet has finished loading (so the message box displays undefined) . If I refresh the page, the applet has already been loaded and the alert displays function myMethod() { [native code] }, as you'd expect.
当然，这意味着applet方法在加载之前不可用，但Safari并没有阻止JavaScript运行。 < body onLoad> 也会出现同样的问题。
Of course, this means that the applet methods are not available until it has loaded, but Safari isn't blocking the JavaScript from running. The same problem happens with <body onLoad>.
我需要的是像< body onAppletLoad =doSomething（）> 。我如何解决这个问题？
What I need is something like <body onAppletLoad="doSomething()">. How do I work around this issue?
谢谢
PS：我不确定它是否相关，但JAR已签名。
PS: I'm not sure if it's relevant, but the JAR is signed.
推荐答案
我使用的计时器会在放弃之前重置并保持多次检查。
I use a timer that resets and keeps checking a number of times before it gives up.
<script language="text/javascript" defer>
function performAppletCode(count) {
var applet = document.getElementById('MyApplet');
if (!applet.myMethod && count > 0) {
setTimeout( function() { performAppletCode( --count ); }, 2000 );
}
else if (applet.myMethod) {
// use the applet for something
}
else {
alert( 'applet failed to load' );
}
}
performAppletCode( 10 );
</script>
请注意，这假定applet将在Safari中运行。我有一些实例，其中一个applet需要Java 6，即使使用类似于上面的代码，它也只是挂起Safari。我选择在服务器上进行浏览器检测，并在浏览器不支持applet时将用户重定向到错误页面。
Note that this assumes that the applet will run in Safari. I've had some instances where an applet required Java 6 that simply hangs Safari even with code similar to the above. I chose to do browser detection on the server and redirect the user to an error page when the browser doesn't support the applet.
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