php - 重复 JavaScript AJAX 请求，直到状态发生变化

Question

我使用 AJAX 从 PHP 文件发出和检索 API 调用，然后使用 jQuery IF 语句显示某些数据。

返回的数据有几种不同的状态，例如:“就绪”、“正在进行”、“DNS”和“错误”。每个状态都有一条附带的消息。

对于一种特定状态“进行中”，我想继续循环浏览 JavaScript 函数，直到状态更改为其他状态。如果状态为“进行中”，则更改可能需要长达 1 分钟的时间，因此如果可能的话，我希望以 5 秒的间隔循环执行 JavaScript 函数。

我在下面包含了我的 jQuery。

    $(document).ready(function() {

    //Stops the submit request
    $("#myAjaxRequestForm").submit(function(e){
           e.preventDefault();
    });

    //checks for the button click event
    $("#myButton").click(function(e){
           $("#ajaxResponse").empty();
            //get the form data and then serialize that
            dataString = $("#myAjaxRequestForm").serialize();

            //get the form data using another method
            var hostName = $("input#hostName").val();
            dataString = "host=" + hostName;

            //make the AJAX request, dataType is set to json
            //meaning we are expecting JSON data in response from the server
            $.ajax({
                type: "GET",
        url: "api.php",
                data: dataString,
                dataType: "json",

                //if received a response from the server
                success: function( response ){
                var data = response.status;
                    if ((data == 'READY' && response.endpoints[0].statusMessage == 'Ready' )) {
                    $("#ajaxResponse").append("<b>Status:</b> " + response.endpoints[0].statusMessage+ "<br>");
                    $("#ajaxResponse").append("<b>Host:</b> " + response.host+ "<br>");
                    $("#ajaxResponse").append("<b>Port:</b> " + response.port+ "<br>");
                    $("#ajaxResponse").append("<h3>Endpoint [0]</h3><b>Server Name:</b> " + response.endpoints[0].serverName+ "<br>");
                    $("#ajaxResponse").append("<b>IP Address:</b> " + response.endpoints[0].ipAddress+ "<br>");
                    $("#ajaxResponse").append("<b>Grade:</b> " + response.endpoints[0].grade+ "<br>");
                    $("#ajaxResponse").append("<h3>Endpoint [1]</h3><b>Server Name:</b> " + response.endpoints[1].serverName+ "<br>");
                    $("#ajaxResponse").append("<b>IP Address:</b> " + response.endpoints[1].ipAddress+ "<br>");
                    $("#ajaxResponse").append("<b>Grade:</b> " + response.endpoints[1].grade+ "<br>");
                    $("#ajaxResponse").append("<h3>Endpoint [2]</h3><b>Server Name:</b> " + response.endpoints[2].serverName+ "<br>");
                    $("#ajaxResponse").append("<b>IP Address:</b> " + response.endpoints[2].ipAddress+ "<br>");
                    $("#ajaxResponse").append("<b>Grade:</b> " + response.endpoints[2].grade+ "<br>");
                     }
                    else if ((data == 'READY' && response.endpoints[0].statusMessage != 'Ready')) {
                        $("#ajaxResponse").append("<b>Status: </b>" +response.endpoints[0].statusMessage+ "<br>");
                        $("#ajaxResponse").append("<b>Server Name: </b>" + response.endpoints[0].serverName+ "<br>");
                        $("#ajaxResponse").append("<b>IP Address: </b>" + response.endpoints[0].ipAddress+ "<br>");
                     }
                     else if (data == "DNS") {
                         $("#ajaxResponse").html("<div><b>No cached result found.<br><br>" +response.statusMessage+ "<br>..please wait a few mins and try again.</b></div>");
                     }
                     else if (data == "IN_PROGRESS") {
                         $("#ajaxResponse").html("<div><b>No cached result found.<br><br>" +response.endpoints[0].statusMessage+ "<br>..please wait a few mins and try again.</b></div>");
                     }
                     else if (data == "ERROR") {
                         $("#ajaxResponse").html("<div><b>Error.<br><br>" +response.statusMessage+ "<br></b></div>");
                     }
                     else {
                         $("#ajaxResponse").html("<div><b>error</b></div>");
                     }
                },

            });       
    });

});

Answer 1

将 AJAX 请求移至函数(例如 doAjax())，以便您可以根据需要调用它。单击按钮时调用 doAjax()。当返回的状态为“In Progress”时，使用setTimeout()在5秒后递归调用相同的函数。

AJAX 请求大约每 5 秒发出一次，直到状态变为“进行中”以外的状态。 (我说“大致”是因为 AJAX 请求本身需要时间，并且请求完成后会开始 5 秒的延迟。)

更新了 JavaScript:

$(document).ready(function () {

    //Stops the submit request
    $("#myAjaxRequestForm").submit(function (e) {
        e.preventDefault();
    });

    //checks for the button click event
    $("#myButton").click(function (e) {
        e.preventDefault(); // Prevent default button click action
        doAjax();
    });

});

function doAjax() {
    //$("#ajaxResponse").empty(); Move this to reduce appearance of refreshing
    //get the form data and then serialize that
    dataString = $("#myAjaxRequestForm").serialize();

    //get the form data using another method
    var hostName = $("input#hostName").val();
    dataString = "host=" + hostName;

    //make the AJAX request, dataType is set to json
    //meaning we are expecting JSON data in response from the server
    $.ajax({
        type: "GET",
        url: "api.php",
        data: dataString,
        dataType: "json",

        //if received a response from the server
        success: function (response) {
            var data = response.status;
            if ((data == 'READY' && response.endpoints[0].statusMessage == 'Ready')) {
                $("#ajaxResponse").empty();
                $("#ajaxResponse").append("<b>Status:</b> " + response.endpoints[0].statusMessage + "<br>");
                $("#ajaxResponse").append("<b>Host:</b> " + response.host + "<br>");
                $("#ajaxResponse").append("<b>Port:</b> " + response.port + "<br>");
                $("#ajaxResponse").append("<h3>Endpoint [0]</h3><b>Server Name:</b> " + response.endpoints[0].serverName + "<br>");
                $("#ajaxResponse").append("<b>IP Address:</b> " + response.endpoints[0].ipAddress + "<br>");
                $("#ajaxResponse").append("<b>Grade:</b> " + response.endpoints[0].grade + "<br>");
                $("#ajaxResponse").append("<h3>Endpoint [1]</h3><b>Server Name:</b> " + response.endpoints[1].serverName + "<br>");
                $("#ajaxResponse").append("<b>IP Address:</b> " + response.endpoints[1].ipAddress + "<br>");
                $("#ajaxResponse").append("<b>Grade:</b> " + response.endpoints[1].grade + "<br>");
                $("#ajaxResponse").append("<h3>Endpoint [2]</h3><b>Server Name:</b> " + response.endpoints[2].serverName + "<br>");
                $("#ajaxResponse").append("<b>IP Address:</b> " + response.endpoints[2].ipAddress + "<br>");
                $("#ajaxResponse").append("<b>Grade:</b> " + response.endpoints[2].grade + "<br>");
            } else if ((data == 'READY' && response.endpoints[0].statusMessage != 'Ready')) {
                $("#ajaxResponse").empty();
                $("#ajaxResponse").append("<b>Status: </b>" + response.endpoints[0].statusMessage + "<br>");
                $("#ajaxResponse").append("<b>Server Name: </b>" + response.endpoints[0].serverName + "<br>");
                $("#ajaxResponse").append("<b>IP Address: </b>" + response.endpoints[0].ipAddress + "<br>");
            } else if (data == "DNS") {
                $("#ajaxResponse").html("<div><b>No cached result found.<br><br>" + response.statusMessage + "<br>..please wait a few mins and try again.</b></div>");
            } else if (data == "IN_PROGRESS") {
                $("#ajaxResponse").html("<div><b>No cached result found.<br><br>" + response.endpoints[0].statusMessage + "<br>..please wait a few mins and try again.</b></div>");
                // Call this function again after 5 seconds
                setTimeout(function () {
                    doAjax();
                }, 5000);
            } else if (data == "ERROR") {
                $("#ajaxResponse").html("<div><b>Error.<br><br>" + response.statusMessage + "<br></b></div>");
            } else {
                $("#ajaxResponse").html("<div><b>error</b></div>");
            }
        },

    });
}