javascript 简单的 ajax 调用似乎被阻塞
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Simple ajax call seems to be blocking
提问by meta.matt
Really simple question. I trying to test a Restful webservice that I am developing, and have this simple ajax call (using jquery):
真的很简单的问题。我试图测试我正在开发的 Restful webservice，并进行这个简单的 ajax 调用（使用 jquery）：
<script type="text/javascript">
$(document).ready(function() {
var url = '/index.php/gettest/reallyLongRequest';
$.ajax({
url: url,
dataType:'text',
success:function(data) { $('#result').html(data);},
error:function(xhr,err,e) { alert ("Error: " + err);}
});
});
</script>
This runs when the page loads. As it's running, the page is blocking; i.e., (I can see the hourglass next to the mouse pointer) no other user actions can be handled. (Btw, this particular get request--intentionally--takes a very long time to return).
这会在页面加载时运行。当它运行时，页面被阻塞；即，（我可以看到鼠标指针旁边的沙漏）无法处理其他用户操作。（顺便说一句，这个特殊的获取请求——有意——需要很长时间才能返回）。
Why is this? A(asynchronous)JAX right? Obviously I am making a beginners mistake. Any ideas, please?
为什么是这样？A（异步）JAX 对吗？显然我犯了一个初学者的错误。有什么想法吗？
When I attempt this using plain javascript (no library) it works as expected. Does this have something to do with Jquery's handling of the xhr onreadystatechange?
当我尝试使用普通的 javascript（没有库）时，它按预期工作。这与 Jquery 对 xhr onreadystatechange 的处理有关吗？
Thank you for looking.
感谢您的关注。
EDIT: multiple people have suggested setting async: true, which as it happens, is the default in jquery, and as such has no effect.
编辑：很多人建议设置 async: true，它恰好是 jquery 中的默认值，因此没有任何效果。
EDIT: As previously mentioned, if I use plain javascript and start this with a timer, e.g., window.setInterval(function() { startLongPoll(); }, 5000)It updates as expected, without appearing to block. Ideas, anyone?
编辑：如前所述，如果我使用普通的 javascript 并使用计时器启动window.setInterval(function() { startLongPoll(); }, 5000)它，例如，它会按预期更新，而不会出现阻塞。想法，有人吗？
采纳答案by meta.matt
Here is an example of what I did to solve the problem:
这是我为解决问题所做的一个示例：
jQuery(document).ready(function() {
setTimeout(function () {
$.getJSON("veryLongRequest", function(json) {
alert("JSON Result: " + json[0].id);});
}, 500); // You may need to adjust this to a longer delay.
});
Note: I am using the short-hand jquery method, "getJSON" which is a wrapper for the ajax call with datatype set to "json". However, this solution will work for all ajax requests.
注意：我使用的是简写 jquery 方法“getJSON”，它是数据类型设置为“json”的 ajax 调用的包装器。但是，此解决方案适用于所有 ajax 请求。
Referenced:
参考：
Stop the browser "throbber of doom" while loading comet/server push iframe
回答by RSG
I think that this should default to true, but try adding async: trueto your ajax json parameter.
我认为这应该默认为 true，但尝试添加async: true到您的 ajax json 参数中。
回答by Francesco Terenzani
Does the code below work as expected?
下面的代码是否按预期工作？
<script type="text/javascript">
//$(document).ready(function() {
var url = '/index.php/gettest/reallyLongRequest';
$.ajax({
url: url,
dataType:'text',
success:function(data) { $('#result').html(data);},
error:function(xhr,err,e) { alert ("Error: " + err);}
});
//});
</script>
回答by Chris Kooken
May want to try and Add async:true
可能想尝试并添加 async:true
<script type="text/javascript">
$(document).ready(function() {
var url = '/index.php/gettest/reallyLongRequest';
$.ajax({
url: url,
async:true,
dataType:'text',
success:function(data) { $('#result').html(data);},
error:function(xhr,err,e) { alert ("Error: " + err);}
});
});
</script>
