[英]Making javascript synchronous code from nested asychronous calls with a modal library?
因此,这可能有点令人困惑。 早在Chromium决定取消其模式支持时,我们所在的地方发现了一个似乎运行良好的库(是的,他们希望在webkit / non-webkit之间进行解析[基本上,在这两个Firefox中都可以运行此东西的两个版本或Chrome])
function AddToConfig(){
....
....
....
if(/ipad|android|webkit/i.test(navigator.userAgent)){
$.showModalDialog({
url: "get_required.php?maxSelect="+max+"&forceReload="+Math.random(),
dialogArguments: window,
height: 270,
width: 510,
position: 'top',
onClose: function(){ numReq = this.returnValue; return retAction(numReq); }
});
}else{
numReq = window.showModalDialog ("get_required.php?maxSelect="+max+"&forceReload="+Math.random(), window, "dialogHeight:250px; dialogWidth:500px; center:yes; help:no; resizable:no; scroll:no; status:no; edge:raised");
return numReq;
}
(此处提供了举升/更多信息) http://extremedev.blogspot.com/2011/03/windowshowmodaldialog-cross-browser-new.html
有一阵子,它工作正常。 到目前为止,所有代码替换都是在用户单击按钮,弹出窗口(现在是模式窗口)的情况下发生的,它会执行其操作并返回一个值,该值表示99%的时间需要iFrame或刷新某些内容,因此计时不是问题。 太好了
我现在所处的情况是,此模态调用处于其他一系列计算的中间。 如果它到达ifthens链,它将触发。 但是,上面的代码似乎使它成为问题。 我已经尝试过像下面这样的回调(也许我只是在写错它们)而没有用。 地狱,上面URL中的注释说这样做有点棘手。 这有点(我希望)就足够了。 因此,我想点击AddToConfig(),ClearSelections(),printText()本身似乎很简单,但是GetRequired的yy-y调用使所有操作都无法进行。
有问题的主要代码(原始):
//What kicks it off
<input type=button class="button3" id=btnAdd onClick='AddToConfig()' value='Add' onMouseDown="this.className='button3down'" onMouseUp="this.className='button3over'" onMouseOver="this.className='button3over'" onMouseOut="this.className='button3'">
function AddToConfig(){
....
...
if (meowmeowmeowmeow)
{
....
}
else
{
//Modal - NEEDS TO PAUSE
var requiredCount = GetRequired(arrConfigSet[--lenS][2]);
//Modal - NEEDS TO PAUSE
arrConfigSet[lenS][1] = requiredCount;
arrConfigSet[lenS][2]++;
}
arrConfigItem[lenI] = new Array ();
...
...
ClearSelections();
}
function GetRequired(max)
{
//This is modal and dumb and makes me cry
var numReq = '';
if(/ipad|android|webkit/i.test(navigator.userAgent)){
$.showModalDialog({
url: "get_required.php?maxSelect="+max+"&forceReload="+Math.random(),
dialogArguments: window,
height: 270,
width: 510,
position: 'top',
onClose: function(){ numReq = this.returnValue; return numReq; }
});
}else{
//This is fine, because it pops up a new window.
numReq = window.showModalDialog ("get_required.php?maxSelect="+max+"&forceReload="+Math.random(), window, "dialogHeight:250px; dialogWidth:500px; center:yes; help:no; resizable:no; scroll:no; status:no; edge:raised");
return numReq;
}
}
function ClearSelections(){
//various UI resetting of values
printText();
}
有问题的主要代码(我的回调版本):
<input type=button class="button3" id=btnAdd onClick='AddToConfig(function(){ClearSelections();})' value='Add' onMouseDown="this.className='button3down'" onMouseUp="this.className='button3over'" onMouseOver="this.className='button3over'" onMouseOut="this.className='button3'">
if (meowmeowmeowmeow)
{
....
}
else
{
var requiredCount = GetRequired(arrConfigSet[--lenS][2]);
//So, here's my problem, that line above works fine with Firefox/non webkit because
//Popup windows make things work fine and great. With this modal thing we found
//on the internet (in getRequired()) this line of code keeps going and runs stuff below
// the line and keeps going. I need this to
//stop here. I've tried to do something like put that requiredCount in a while loop, but
//then it says Uncaught TypeError: Cannot read property '2' of undefined on that var requiredCount.
//For the record, this is all done from a onClick event on a button if it makes a difference.
//
//
//alert('test:' + arrConfigSet[--lenS][2]); //Returns a value!
// var requiredCount;
// while(typeof variable_here === 'undefined'){
// requiredCount = GetRequired(arrConfigSet[--lenS][2]);
// }
//This keeps running when in Webkit, I need that requiredCount to be set and finalized with
//the modal window gone before this continues.
arrConfigSet[lenS][1] = requiredCount;
arrConfigSet[lenS][2]++;
}
arrConfigItem[lenI] = new Array ();
...
...
callback();
}
function GetRequired(max)
{
//This is modal and dumb and makes me cry
var numReq = '';
if(/ipad|android|webkit/i.test(navigator.userAgent)){
$.showModalDialog({
url: "get_required.php?maxSelect="+max+"&forceReload="+Math.random(),
dialogArguments: window,
height: 270,
width: 510,
position: 'top',
onClose: function(){ numReq = this.returnValue; return numReq; }
});
}else{
//This is fine, because it pops up a new window.
numReq = window.showModalDialog ("get_required.php?maxSelect="+max+"&forceReload="+Math.random(), window, "dialogHeight:250px; dialogWidth:500px; center:yes; help:no; resizable:no; scroll:no; status:no; edge:raised");
return numReq;
}
}
function ClearSelections(){
//various UI resetting of values
printText();
}
有人对我如何使JS停止运行直到脚本获得该返回值有任何想法吗? 它可以正常运行,但是到了它运行时,它运行之后的其余代码就可以了。
请注意,我们正在运行jQuery 1.4,所以promise()不可能了,我也无力推动任何更新。 该代码有点像老鼠的窝。
您可以实现自己的简单延迟库,也可以简单地传入一个在完成所有操作后就会调用的函数。 简单的例子:
var whenDone = function(res) { alert('I\'m Done: ' + res); };
doComplexTask(whenDone);
和doComplexTask:
function doComplexTask(completeFn) {
//Do some crazy work here that takes a long time (Or is asynchronous)
var res = crazyWork();
completeFn(res);
}
在这里可以找到一个简单的jfiddle。
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