if (aListeners[oEvent.data.id]) { aListeners[oEvent.data.id](oEvent.data.evaluated); }
delete aListeners[oEvent.data.id];
};
return function (sCode, fListener) {
aListeners.push(fListener || null);
oParser.postMessage({
"id": aListeners.length - 1,
"code": sCode
});
};
})();
示例使用：
// asynchronous alert message...
asyncEval("3 + 2", function (sMessage) {
alert("3 + 2 = " + sMessage);
});
// asynchronous print message...
asyncEval(""Hello World!!!"", function (sHTML) {
document.body.appendChild(document.createTextNode(sHTML));
});
// asynchronous void...
asyncEval("(function () {ntvar oReq = new XMLHttpRequest();ntoReq.open("get", "http://www.mozilla.org/", false);ntoReq.send(null);ntreturn oReq.responseText;n})()");例子 #2：传输 JSON 的高级方式和创建一个交换系统
如果你需要传输非常复杂的数据，还要同时在主页与 Worker 内调用多个方法，那么可以考虑创建一个类似下面的系统。
example.html(the main page):
<!doctype html>
<html>
<head>
<meta charset="UTF-8" />
<title>MDN Example - Queryable worker</title>
<script type="text/javascript">
/*
QueryableWorker instances methods:
* sendQuery(queryable function name, argument to pass 1, argument to pass 2, etc. etc): calls a Worker's queryable function
* postMessage(string or JSON Data): see Worker.prototype.postMessage()
* terminate(): terminates the Worker
* addListener(name, function): adds a listener
* removeListener(name): removes a listener
QueryableWorker instances properties:
* defaultListener: the default listener executed only when the Worker calls the postMessage() function directly
*/
function QueryableWorker (sURL, fDefListener, fOnError) {
var oInstance = this, oWorker = new Worker(sURL), oListeners = {};
this.defaultListener = fDefListener || function () {};
oWorker.onmessage = function (oEvent) {
if (oEvent.data instanceof Object && oEvent.data.hasOwnProperty("vo42t30") && oEvent.data.hasOwnProperty("rnb93qh")) {
oListeners[oEvent.data.vo42t30].apply(oInstance, oEvent.data.rnb93qh);
} else {
this.defaultListener.call(oInstance, oEvent.data);
}
};
if (fOnError) { oWorker.onerror = fOnError; }
this.sendQuery = function (/* queryable function name, argument to pass 1, argument to pass 2, etc. etc */) {
if (arguments.length < 1) { throw new TypeError("QueryableWorker.sendQuery - not enough arguments"); return; }
oWorker.postMessage({ "bk4e1h0": arguments[0], "ktp3fm1": Array.prototype.slice.call(arguments, 1) });
