Javascript-暂停执行，直到标志变为true

如何暂停javascript执行，直到标志变为真

例如，我有这样一条xml消息：

[...]
<action>
    <resource update>id</resourceupdate>
</action>
<action>
    <event>id1</event>
</action>
<action>
    <event>id2</event>
</action>
<action>
    <event>id3</event>
</action>
[...]

function browserLoaded() {
  if (!ready) {
    // note the missing "()"
    setTimeout(browserLoaded, 1000);
  }
} 

//this is a simple "semaphore" pattern:
var things_to_load_count = 1
var check_if_done(){
    things_to_load_count--;
    if(things_to_load_count <= 0){
        //code to do stuff after you finish loading
    }
};

$(_response).find('ACTION').each(function() {
    if (tagName=="RESOURCEUPDATE") {
        things_to_load_count++;
        run_code_to_load_stuff( check_if_done )
        //make sure that the run_code_to_load_stuff function
        //calls the callback you passed it once its done.
    } else if (tagName=="EVENT") {
        //process one of the normal nodes
    }
});

//this will run the remaining code if we loaded everything
//but will do nothing if we are still waiting.
check_if_done()

var resources = [];
$(_response).find('ACTION').each(function() {
  var deferred = resources.length > 0 ? resources[resources.length - 1] : null;

  switch (tagName) {
    case "RESOURCEUPDATE":
      deferred = $.Deferred();

      //load the resource with selected id in an iframe
      $(iframe).bind('load', function () {
        deferred.resolve(/*specific arg1, arg2, arg3, ...*/)
      });
      resources.push(deferred);
      break;
    case "EVENT":       
      if (deferred) {
         deferred.done(function (/*specific arg1, arg2, arg3, ...*/) {
            // process event node
         });
      }
      break;
  }
});

// clean up deferreds objects when all them will be processed
$.when.apply($, resources).then(function() {
  resources.length = 0;
})

等待功能是：

function browserLoaded() {
if (!ready) {
    setTimeout(browserLoaded(),1000);
}
} 

当加载iframe时，ready var变为true：

$(iframe).load(function() {
    ready = true;
});

但当执行时，我将捕获此错误：

 Maximum call stack size exceeded error

有什么想法吗？

---

谢谢

问题出在这个函数中，它调用自己直到堆栈满：

function browserLoaded() {
  if (!ready) {
    //here you call browserLoaded function instead of passing a reference to the function
    setTimeout(browserLoaded() ,1000);
  }
} 

您的函数应该如下所示：

[...]
<action>
    <resource update>id</resourceupdate>
</action>
<action>
    <event>id1</event>
</action>
<action>
    <event>id2</event>
</action>
<action>
    <event>id3</event>
</action>
[...]

function browserLoaded() {
  if (!ready) {
    // note the missing "()"
    setTimeout(browserLoaded, 1000);
  }
} 

//this is a simple "semaphore" pattern:
var things_to_load_count = 1
var check_if_done(){
    things_to_load_count--;
    if(things_to_load_count <= 0){
        //code to do stuff after you finish loading
    }
};

$(_response).find('ACTION').each(function() {
    if (tagName=="RESOURCEUPDATE") {
        things_to_load_count++;
        run_code_to_load_stuff( check_if_done )
        //make sure that the run_code_to_load_stuff function
        //calls the callback you passed it once its done.
    } else if (tagName=="EVENT") {
        //process one of the normal nodes
    }
});

//this will run the remaining code if we loaded everything
//but will do nothing if we are still waiting.
check_if_done()

var resources = [];
$(_response).find('ACTION').each(function() {
  var deferred = resources.length > 0 ? resources[resources.length - 1] : null;

  switch (tagName) {
    case "RESOURCEUPDATE":
      deferred = $.Deferred();

      //load the resource with selected id in an iframe
      $(iframe).bind('load', function () {
        deferred.resolve(/*specific arg1, arg2, arg3, ...*/)
      });
      resources.push(deferred);
      break;
    case "EVENT":       
      if (deferred) {
         deferred.done(function (/*specific arg1, arg2, arg3, ...*/) {
            // process event node
         });
      }
      break;
  }
});

// clean up deferreds objects when all them will be processed
$.when.apply($, resources).then(function() {
  resources.length = 0;
})

---

这是一个糟糕的设计。您不需要“等待”超时机制。如果您是通过jqueryajax请求加载页面，请使用回调函数继续执行代码（您也许可以跟踪正在处理的“当前”项并继续执行下一个）。如果您正在加载iFrame，这也是一个糟糕的设计，那么您应该转向jQuery ajax方式。

一个快速的技巧就是设置一个轮询循环：使用setInterval每隔一段时间检查一次变量是否已设置，然后使用clearInterval并在指定时间继续执行

不管怎样，做事都会很痛苦。本质上，用Javascript告诉某些东西运行后者的唯一方法是将其打包到函数中。但这样做之后，它会变得更容易，因为您可以传递该函数，并在完成后让异步代码调用它

例如，您的处理可能如下所示：

[...]
<action>
    <resource update>id</resourceupdate>
</action>
<action>
    <event>id1</event>
</action>
<action>
    <event>id2</event>
</action>
<action>
    <event>id3</event>
</action>
[...]

function browserLoaded() {
  if (!ready) {
    // note the missing "()"
    setTimeout(browserLoaded, 1000);
  }
} 

//this is a simple "semaphore" pattern:
var things_to_load_count = 1
var check_if_done(){
    things_to_load_count--;
    if(things_to_load_count <= 0){
        //code to do stuff after you finish loading
    }
};

$(_response).find('ACTION').each(function() {
    if (tagName=="RESOURCEUPDATE") {
        things_to_load_count++;
        run_code_to_load_stuff( check_if_done )
        //make sure that the run_code_to_load_stuff function
        //calls the callback you passed it once its done.
    } else if (tagName=="EVENT") {
        //process one of the normal nodes
    }
});

//this will run the remaining code if we loaded everything
//but will do nothing if we are still waiting.
check_if_done()

var resources = [];
$(_response).find('ACTION').each(function() {
  var deferred = resources.length > 0 ? resources[resources.length - 1] : null;

  switch (tagName) {
    case "RESOURCEUPDATE":
      deferred = $.Deferred();

      //load the resource with selected id in an iframe
      $(iframe).bind('load', function () {
        deferred.resolve(/*specific arg1, arg2, arg3, ...*/)
      });
      resources.push(deferred);
      break;
    case "EVENT":       
      if (deferred) {
         deferred.done(function (/*specific arg1, arg2, arg3, ...*/) {
            // process event node
         });
      }
      break;
  }
});

// clean up deferreds objects when all them will be processed
$.when.apply($, resources).then(function() {
  resources.length = 0;
})

//这是一个简单的“信号量”模式：
var things\u to\u load\u count=1
var check_if_done（）{
东西要装多少；
如果（things\u to\u load\u count使用某种标志确实是个坏主意。您必须使用延迟模式。类似于以下内容：

[...]
<action>
    <resource update>id</resourceupdate>
</action>
<action>
    <event>id1</event>
</action>
<action>
    <event>id2</event>
</action>
<action>
    <event>id3</event>
</action>
[...]

function browserLoaded() {
  if (!ready) {
    // note the missing "()"
    setTimeout(browserLoaded, 1000);
  }
} 

//this is a simple "semaphore" pattern:
var things_to_load_count = 1
var check_if_done(){
    things_to_load_count--;
    if(things_to_load_count <= 0){
        //code to do stuff after you finish loading
    }
};

$(_response).find('ACTION').each(function() {
    if (tagName=="RESOURCEUPDATE") {
        things_to_load_count++;
        run_code_to_load_stuff( check_if_done )
        //make sure that the run_code_to_load_stuff function
        //calls the callback you passed it once its done.
    } else if (tagName=="EVENT") {
        //process one of the normal nodes
    }
});

//this will run the remaining code if we loaded everything
//but will do nothing if we are still waiting.
check_if_done()

var resources = [];
$(_response).find('ACTION').each(function() {
  var deferred = resources.length > 0 ? resources[resources.length - 1] : null;

  switch (tagName) {
    case "RESOURCEUPDATE":
      deferred = $.Deferred();

      //load the resource with selected id in an iframe
      $(iframe).bind('load', function () {
        deferred.resolve(/*specific arg1, arg2, arg3, ...*/)
      });
      resources.push(deferred);
      break;
    case "EVENT":       
      if (deferred) {
         deferred.done(function (/*specific arg1, arg2, arg3, ...*/) {
            // process event node
         });
      }
      break;
  }
});

// clean up deferreds objects when all them will be processed
$.when.apply($, resources).then(function() {
  resources.length = 0;
})

p.S.：
您确定在iframe加载函数中设置为true的ready变量与在调用另一个settimeout之前检查的变量相同。似乎iframe加载函数中的一个是局部变量，另一个是全局变量

或者两个就绪变量都是本地变量。
setTimeout（browserLoaded（），1000）；
执行您的函数。您只需引用您的函数；删除
（）
，使其成为
setTimeout（browserLoaded，1000）
感谢您的快速响应！好的，没有更多错误，但执行不会停止。我大大简化了代码，使其不包含不必要的信息。实际上，iframe的load函数包含多个处理程序，用于截获用户交互并将xml消息发送到servlet。这将存储这些消息，并或多或少地将它们发送给其他客户端用异步回调函数Get on through的语法表示（简化）我不能在iframe加载的回调中处理消息，因为这些消息是异步的，不一定到达加载iframehm，你不能至少利用iframe的onLoad事件吗？不处理消息，但最多触发一个变量（ready）：（如果你能触发一个变量（在iFrame的父级中）还应该能够调用函数。例如：[iFrame onLoad='parent.continueWithNextOne（）；']这难道不可能吗？如果iframe和父级在同一个域中，这应该是可能的？我不确定消息是否按此顺序到达，它可能会变得更公平。我认为这样的设计是不好的。同样地编写两个代码分支。上面解释的情况是一个特殊情况，我不会推翻特定情况下的代码有趣的是，我会看一看这是正确的答案；代码并不完全是我所需要的，但是关于延迟的建议让我找到了解决问题的最佳解决方案。thanksi declare var ready=true在我的core.js开头（在任何分支或函数之外）；在我只做了赋值之后，从不在其他地方声明变量。