提交按钮上的 Javascript 函数 - 等待它完成

Question

我想在按下表单上的提交按钮时触发一个函数，并等待javascript函数完成，然后继续表单提交。我不希望在 javascript 函数完成之前提交表单。**

这就是我现在所拥有的: http://jsfiddle.net/njDvn/68/

function autosuggest() {
var input = document.getElementById('location');
    var options = {
    types: [],
    };
    var autocomplete = new google.maps.places.Autocomplete(input, options);
}

<!-- Get lat / long -->      
function getLatLng() {
    var geocoder = new google.maps.Geocoder();
    var address = document.getElementById('location').value;
    geocoder.geocode({
        'address': address
    }, function (results, status) {
        if (status == google.maps.GeocoderStatus.OK) {
            var latLng = results[0].geometry.location;
            $('#lat').val(results[0].geometry.location.lat());
            $('#lng').val(results[0].geometry.location.lng());
        } else {
            alert("Geocode was not successful for the following reason: " + status);
        }
    });
}

<!-- Load it --> 
window.onload = autosuggest;

Answer 1

您可以拦截表单提交、中止它并向 Google 发送地理编码请求。

当服务器响应时，您可以从回调中重新提交表单(或者在失败时显示错误)。

将请求的状态存储在某处(为了简单起见，我在示例中使用了全局变量)。在这种情况下，它只是一个标志，指示地理编码请求是否成功完成(这样，当提交表单并重新触发监听器时，它将知道不要重新发送地理编码请求)。

http://jsfiddle.net/njDvn/75/

随意删除控制台日志记录。

您可能还想隐藏纬度/经度字段。

var GeoCoded = {done: false}; // this holds the status of the geo-coding request

$(document).ready(function(){
    autosuggest(); // place your auto-suggest (now called autocomplete) box

    $('#myform').on('submit',function(e){

        if(GeoCoded.done)
            return true;

        e.preventDefault();
        console.log('submit stopped');
        var geocoder = new google.maps.Geocoder();
        var address = document.getElementById('location').value;

        // disable the submit button
        $('#myform input[type="submit"]').attr('disabled',true);

        // send the request
        geocoder.geocode({
            'address': address
        },
        function (results, status) {
            // update the status on success
            if (status == google.maps.GeocoderStatus.OK) {
                var latLng = results[0].geometry.location;
                $('#lat').val(results[0].geometry.location.lat());
                $('#lng').val(results[0].geometry.location.lng());
                // if you only want to submit in the event of successful 
                // geocoding, you can only trigger submission here.
                GeoCoded.done = true; // this will prevent an infinite loop
                $('#myform').submit();
            } else { // failure
                console.log("Geocode was not successful for the following reason: " + status);
                //enable the submit button
                $('#myform input[type="submit"]').attr('disabled',false);
            }


        });        

    });   

});