synchronous

JavaScript: Global variables after Ajax requests [duplicate]

由 安稳与你 提交于 2019-11-27 10:06:30
问题 This question already has an answer here: How do I return the response from an asynchronous call? 36 answers the question is fairly simple and technical: var it_works = false; $.post("some_file.php", '', function(data) { it_works = true; }); alert(it_works); # false (yes, that 'alert' has to be here and not inside $.post itself) What I want to achieve is: alert(it_works); # true Is there a way to do that? If not can $.post() return a value to be applied to it_works ? 回答1: What you expect is

How to force Sequential Javascript Execution?

由 我的梦境 提交于 2019-11-27 09:12:29
问题 I've only found rather complicated answers involving classes, event handlers and callbacks (which seem to me to be a somewhat sledgehammer approach). I think callbacks may be useful but I cant seem to apply these in the simplest context. See this example: <html> <head> <script type="text/javascript"> function myfunction() { longfunctionfirst(); shortfunctionsecond(); } function longfunctionfirst() { setTimeout('alert("first function finished");',3000); } function shortfunctionsecond() {

How I can implement sync calls to WCF services in SIlverlight?

由 我的未来我决定 提交于 2019-11-27 07:17:27
问题 Sometimes I need to call WCF service in Silverlight and block UI until it returns. Sure I can do it in three steps: Setup handlers and block UI Call service Unblock UI when everything is done. However, I'd like to add DoSomethingSync method to service client class and just call it whenever I need. Is it possible? Has anyone really implemented such a method? UPDATE: Looks like the answer is not to use sync calls at all. Will look for some easy to use pattern for async calls. Take a look at

Ajax jquery synchronous callback success

由 橙三吉。 提交于 2019-11-27 07:11:14
问题 I have this function that makes an ajax call. I'm describing the problem in the last chunk of code comments. function doop(){ var that = this; var theold = "theold"; var thenew = "thenew"; $.ajax({ url: 'doop.php', type: 'POST', data: 'before=' + theold + '&after=' + thenew, success: function(resp) { if(resp == 1) { $(that).siblings('.theold').html(thenew); } } }); // I have some code here (out of the ajax) that **further** changes // the .theold's html beyond what it was changed inside ajax

Promise is synchronous or asynchronous in node js

由 帅比萌擦擦* 提交于 2019-11-27 06:46:56
问题 I have lot of confusion in promise. It's a synchronous or asynchronous ? return new Promise (function(resolved,reject){ //sync or async? }); 回答1: The function you pass into the Promise constructor runs synchronously, but anything that depends on its resolution will be called asynchronously. Even if the promise resolves immediately, any handlers will execute asynchronously (similar to when you setTimeout(fn, 0) ) - the main thread runs to the end first. This is true no matter your Javascript

Is map() in javascript synchronous?

由 泄露秘密 提交于 2019-11-27 06:39:57
问题 Function is : [1,2,3].map( function (item) { console.log(item); //return 'something'; }); My expected behaviour is getting only 1 as output, unless i uncomment the //return 'something' But i really get 1 2 3 What am i doing wrong ? UPDATE: i am testing that with nodejs. i really dont understand. var async = require("async"); [1,2,3].map( function (item) { console.log(item); //return 'something'; }); async.map([1,2,3], function (item,callback) { console.log(item); //callback(null,true) },

How are the O_SYNC and O_DIRECT flags in open(2) different/alike?

由 雨燕双飞 提交于 2019-11-27 06:12:37
The use and effects of the O_SYNC and O_DIRECT flags is very confusing and appears to vary somewhat among platforms. From the Linux man page (see an example here ), O_DIRECT provides synchronous I/O, minimizes cache effects and requires you to handle block size alignment yourself. O_SYNC just guarantees synchronous I/O. Although both guarantee that data is written into the hard disk's cache, I believe that direct I/O operations are supposed to be faster than plain synchronous I/O since they bypass the page cache (Though FreeBSD's man page for open(2) states that the cache is bypassed when O

Javascript Promises with FileReader()

由 泪湿孤枕 提交于 2019-11-27 05:43:24
问题 I have the following HTML Code: <input type='file' multiple> And Here's my JS Code: var inputFiles = document.getElementsByTagName("input")[0]; inputFiles.onchange = function(){ var fr = new FileReader(); for(var i = 0; i < inputFiles.files.length; i++){ fr.onload = function(){ console.log(i) // Prints "0, 3, 2, 1" in case of 4 chosen files } } fr.readAsDataURL(inputFiles.files[i]); } So my question is, how can I make this loop synchronous ? That is first wait for the file to finish loading

Synchronous calls with jquery

由 巧了我就是萌 提交于 2019-11-27 05:07:05
Can I make use of jQuery AJAX API and make a synchronous calls? Like Obama would say: YES YOU CAN ! jQuery .ajax() Setting async = false within the .ajax() handler will do the trick. While jQuery can make sync AJAX calls by setting the synch:false property, this causes the browser to hang until the AJAX completes. Using a flow control library like Frame.js enables you to make synchronous calls without tying up the browser: $.each(ajaxObjects, function(i, ajaxCall){ Frame(function(next)){ // declare the callback next here ajaxCall.complete = function(data){ // do something with the data next();

How to make JQuery-AJAX request synchronous

由 对着背影说爱祢 提交于 2019-11-27 04:48:42
How do i make an ajax request synchronous? I have a form which needs to be submitted. But it needs to be submitted only when the user enters the correct password. Here is the form code: <form name="form" action="insert.php" method="post" onSubmit="return ajaxSubmit(this);" > And the jquery code for sending and checking password is this: var ajaxSubmit = function(formE1) { var password = $.trim($('#employee_password').val()); $.ajax({ type: "POST", async: "false", url: "checkpass.php", data: "password="+password, success: function(html) { var arr=$.parseJSON(html); if(arr == "Successful") {
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