Question

单击按钮，我正在运行ajax请求。我也在更改body类来执行css动画（为ajax数据腾出空间）并且需要大约1.5秒。我不希望ajax在此之前返回数据。

我的ajax请求如下所示：

function ajax(url) {
    $.ajax({
        url: API.hostname + url,
        dataType: "json",
        complete: function() {
            $html.css("cursor", "default");
        },
        success: function (response) {
            callback(response);
        }
    });
}

理想情况下，我运行一个计时器，并检查它是否已经完整的1.5秒，如果是，则运行回调。关于在这里做什么的任何想法？我基本上想避免在动画完成之前加载数据的情况。

Answer 1

所以这是交易。您将在启动ajax的同时启动动画，并且在动画完成之前不会触发回调。所以......

|--------------------------------|
animation starts                 animation completes
|---------------|----------------|
ajax starts     ajax completes   callback fires

或

|--------------------------------|
animation starts                 animation completes
|------------------------------------------|
ajax starts                                ajax completes / callback fires

所以如果ajax在动画完成之前回来，它会等待动画，如果ajax在动画之后出现，它会立即开始。这是两个世界中最好的，因为动画总是受到尊重，用户不必等待懒惰的ajax请求（一个在动画之后发生）。

function ajax(url) {
    // init cb to null
    var cb = null;
    // start the 1.5 second long animation
    animationStart();
    // set timeout for 1.5 seconds
    setTimeout(function(){
        // cb will be set to a function if the ajax has completed already
        if(cb){
            // ajax has already completed
            cb(); // run the function set by ajax success
        }else{
            // ajax has not yet completed
            cb = true; // set value to true
        }        
    }, 1500);
    // start the ajax request
    $.ajax({
        url: API.hostname + url,
        dataType: "json",
        complete: function() {
            $html.css("cursor", "default");
        },
        success: function (response) {
            // the cb will be set by the timeout if the animation is complete already
            if(cb){
                // animation was already complete, fire the callback right away
                callback(response);    
            }else{
                // animation is not yet complete, set cb to a function, so the callback can
                // run it when the animation is complete
                cb = function(){ callback(response);   };
            }

        }
    });
}

Answer 2

这是我的解决方案：

function startanim(){
    //here is the script for starting the animation
}
function stopanim(){
    //here is the script for stopping the animation
}
function ajax(url) {

    startanim();//start your animation before the ajax call
    //set a timeout if you want to set the minimum time for animation
    setTimeout(function (){
        $.ajax({
            url: API.hostname + url,
            dataType: "json",
            complete: function() {
                $html.css("cursor", "default");
            },
            success: function (response) {

                callback(response);
            },
            error   : function (a){
                alert(a.responseText); //trap the cause of error
            }
        }).done(function (){
            stopanim();//stop your animation after the ajax done 
        });

    },"1400",url);
    //timeout is 1400ms. Let's say that the ajax needs 100ms to complete, so it will be 1500ms.
}

Answer 3

您可以简单地编写一个ajax done方法，只有在请求完成后才会触发。

jQuery网站上的官方文档：http://api.jquery.com/ajaxcomplete/

function ajax(url) {
    $.ajax({
        url: API.hostname + url,
        dataType: "json",
        complete: function() {
            $html.css("cursor", "default");
        }.done(function(event){
        do something cool
        }),
        success: function (response) {
            callback(response);
        }
    });
}

设置ajax调用返回数据的最短时间

3 个答案: