Re: JavaScript not being blocked/synched by Applet init()

From:
"Richard Maher" <maher_rj@hotspamnotmail.com>
Newsgroups:
comp.lang.java.programmer,comp.lang.javascript
Date:
Mon, 27 Apr 2009 12:23:09 +0800
Message-ID:
<gt3bti$ljr$1@news-01.bur.connect.com.au>
(Shameless bump.)

Just in case you were on school holidays and missed the opportunity to solve
this conundrum, here it is again :-)

Cheers Richard Maher

"Richard Maher" <maher_rj@hotspamnotmail.com> wrote in message
news:gsmp8k$hfo$1@news-01.bur.connect.com.au...

Hi,

I'm probably seeing-things again but here goes: -

IE6 with JRE 1.6.0_12 looks to continue the Javascript processing while my
Applet.init() has yet to return. FireFox is fine and when I went for a

small

reproducer IE also performed as expected. (Both with Applet appended in a
<div> or document.writeN() as an <object> in the body)

See below for a reasonable code snippet, but the critical bit is this: -

    var tier3Chan;
    try {
        document.body.appendChild(appletDiv);
        tier3Chan = document.getElementById(appletId);
        alert("Auth = " + tier3Chan.getThree());
        var userAuthorized = tier3Chan.isAuthorized();
    }
    catch(err) {
        alert("Err =" + err.description);
        tier3Chan = null;
    };

If I take out that 'alert("Auth =' bit then isAuthorised() gets called and
returns false even though the user hasn't had a chance to enter their
Username/Password yet. (Pop-up dialog currently sitting on the screen)

I understand when it would be valid to let the JS run past the
getElementById so I normally stick a method call (such as isAuthorized())

in

their to force the block-for-init but this time it doesn't seem to work

:-(

For a similar setup please see: -
http://manson.vistech.net/t3$examples/demo_client_flex.html
Username: TIER3_DEMO
Password: QUEUE

All (slightly dated) Java/Javascript/HTML source code is at: -
http://manson.vistech.net/t3$examples/

Unfortunately that example works but the one below doesn't :-(

Anyone know the mechanics behind what Javascript is looking for on IE to
tell it that the Applet has finished init()ing? Or how I might be stomping
on it? (Or at least failing to flag it?)

Cheers Richard Maher

/**
 * Copyright (c) Richard Maher. All rights reserved.
 */

function Tier3Client(application,
                     codeBase,
                     port,
                     maxBuf,
                     hostCharSet,
                     sslReqd)
{
    this.application = application;
    this.codeBase = codeBase;
    this.port = port;
    this.maxBuf = maxBuf;
    this.hostCharSet = hostCharSet;
    this.sslReqd = sslReqd;

    var appletId = "Tier3__" + application + "_Applet";

    try {
        var idTaken = document.getElementById(appletId);
    }
    catch (err) {};

    if (idTaken != null) {
        throw new Error("Tier3 Client already registered for " +
this.application);
        return;
    }

    var archiveName = "tier3Client.jar";
    var className = "tier3Client/Tier3Application";

    var appletParams = [{"name":"archive", "value":archiveName},
                        {"name":"codebase", "value":codeBase },
                        {"name":"code", "value":className },
                        {"name":"mayscript", "value":"true" },
                        {"name":"scriptable", "value":"true" },
                        {"name":"APPLICATION", "value":application},
                        {"name":"PORT", "value":port },
                        {"name":"MAXBUF", "value":maxBuf },
                        {"name":"HOSTCHARSET", "value":hostCharSet},
                        {"name":"SSLREQD", "value":sslReqd }];
    var startParam = 0;

    var objectTag = "<object classid=";

    if (/Internet Explorer/.test(navigator.appName)) {
        objectTag = objectTag +
            '"clsid:8AD9C840-044E-11D1-B3E9-00805F499D93" ';
    } else {
        objectTag = objectTag +
            '"java:' + className + '.class"

type="application/x-java-applet

" ' +
            'archive="' + codeBase + archiveName + '"';
        startParam = 1;
    }

    objectTag = objectTag + ' width= "0" height= "0" id="' + appletId +
'">';

    for (i=startParam; i<appletParams.length; i++){
        objectTag = objectTag + '<param name ="' + appletParams[i].name

+

'" ' +
                                       'value ="' + appletParams[i].value

+

'">';
    }

    objectTag = objectTag + "</object>";

    var appletDiv = document.createElement("div");
    appletDiv.innerHTML = objectTag;

    var tier3Chan;
    try {
        document.body.appendChild(appletDiv);
        tier3Chan = document.getElementById(appletId);
        alert("Auth = " + tier3Chan.getThree());
        var userAuthorized = tier3Chan.isAuthorized();
    }
    catch(err) {
        alert("Err =" + err.description);
        tier3Chan = null;
    };
    alert("After check");
    if (tier3Chan == null) {
        throw new Error("Tier3 was unable to initialize the applet for " +
this.application);
        return;
    } else {
        if (!userAuthorized) {
            throw new Error("Tier3 User authentication unsuccessful for "

+

this.application);
            return;
        }
    }

    this.chan = tier3Chan;

    Tier3Client.applications[this.application] = this;

    return this;
}

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