我正在向PHP发送带有JavaScript HTTP请求的数据，我希望PHP将其保存在内存中。因此，我正在使用$_SESSIONS。我这样做是因为我不想用JavaScript进行任何计算或HTML部署。
这是我的方法，我如何向PHP发送数据：
/**
* The PHP file which receives the data
*
* @type {string} The php filename
*/
const INSTALL_FILE = "install.php";
/**
* Passes roadTaxData to the php install file which could be getData with the $_POST operator
*/
function passToPHP (paramName, data) {
var httpc = new XMLHttpRequest(); // simplified for clarity"
httpc.open("POST", INSTALL_FILE, true); // sending as POST
httpc.setRequestHeader("Content-Type", "application/x-www-form-urlencoded");
httpc.send(paramName + "=" + data);
}
我正在使用这样的方法：
/**
* @type {string} The data which is getting send to PHP
*/
var data = "";
/**
* Parses the road tax data and stores it into the data string as JSON format
*/
function parseRoadTaxData () {
var object = {};
/*
Loop through all the road tax data
*/
for (var vehicleFormatType in roadTaxData) {
/*
Define all vehicle types which belong to that vehicle type format
*/
var vehicleTypes = roadTaxData[vehicleFormatType];
/*
Loop through all the vehicle types
*/
for (var vehicleType in vehicleTypes) {
/*
Add the vehicle data to the JSON object
*/
object[vehicleType.toLowerCase()] = vehicleTypes[vehicleType];
}
}
/*
Parse the javascript object (converted to JSON format) into the data string.
*/
data = JSON.stringify(object);
}
/**
* Gets the data which is going to be send to PHP
*
* @returns {string} The JSON data string
*/
function getData () {
return data;
}
/*
Call the function to parse all data into the HTTP query string
*/
parseRoadTaxData();
/*
Call the function to pass the whole HTTP query to PHP in seperate $_POST variables
*/
passToPHP('road-tax_data', getData());
接收数据的install.php文件如下所示：它打开一个会话并将数据存储在RoadTaxDataTemporaryRegistry类中。
require "RoadTaxDataTemporaryRegistry.php";
/*
* Start the session
*/
session_start();
RoadTaxDataTemporaryRegistry::store(json_decode($_POST['road-tax_data'], true));
我的RoadTaxDataTemporaryRegistry课程如下：
/**
* Storage for all road tax data
*/
class RoadTaxDataTemporaryRegistry
{
/**
* The character which gets and sets the specific $_SESSION
*/
const SESSION_NAME = 'rtd';
/**
* Stores all data in a session
*
* @param $data array The data which is getting stored
*/
public static function store ($data) {
$_SESSION[self::SESSION_NAME] = $data;
}
/**
* Gets the road tax data of a vehicle
*
* @param string $vehicle
*
* @return array
*/
public static function getStorageByVehicle ($vehicle) {
return $_SESSION[self::SESSION_NAME]["$vehicle"];
}
}
这个类只会将变量存储到特定的$_SESSION键中。
我的index.php看起来像这样：
<!DOCTYPE html>
<html>
<head lang="en">
<meta charset="UTF-8">
<title></title>
<script src="data/js-files/data_personen_auto.js" type="application/javascript"></script>
<script src="js/road_tax_data_mapper.js" type="application/javascript"></script>
<script src="js/utility.js" type="application/javascript"></script>
<script src="js/data_parser.js" type="application/javascript"></script>
</head>
<body>
<?php
require "RoadTaxDataTemporaryRegistry.php";
session_start();
var_dump(RoadTaxDataTemporaryRegistry::getStorageByVehicle($myCar));
?>
</body>
</html>
我首先导入所有JavaScript脚本，这些脚本将数据发送到PHP。
然后在我的html页面的正文中，我正在打开会话并调用并打印出我刚刚通过HTTP请求在该类中解析的数据。
问题
当我第一次在浏览器中打开它时（通过我的IDE PhpStorm打开），我收到此错误消息：
注意：未定义的索引：第30行的C：\ Users \ Bas。\ Cars \ RoadTaxDataTemporaryRegistry.php中的rtd NULL
当我刷新页面时，数据将被打印出来：
array(1) { ["noord_holland"]=> array(46) { [0]=> string(14) "1#26#90#26#101" [1]=> string(17) "551#34#109#34#124" [2]=> string(17) "651#42#129#42#147" [3]=> string(17) "751#55#154#55#175" [4]=> string(17) "851#73#189#87#203" [5]=> string(18) "951#94#223#123#238" [6]=> string(20) "1051#115#257#159#273" [7]=> string(20) "1151#137#290#195#309" [8]=> string(20) "1251#158#324#230#344" [9]=> string(20) "1351#180#358#266#379" [10]=> string(20) "1451#201#392#302#414" [11]=> string(20) "1551#222#426#338#449" [12]=> string(20) "1651#244#460#374#485" [13]=> string(20) "1751#265#494#409#520" [14]=> string(20) "1851#286#528#445#555" [15]=> string(20) "1951#308#562#481#590" [16]=> string(20) "2051#329#596#517#625" [17]=> string(20) "2151#351#630#553#661" [18]=> string(20) "2251#372#664#588#696" [19]=> string(20) "2351#393#698#624#731" [20]=> string(20) "2451#415#732#660#766" [21]=> string(20) "2551#436#766#696#801" [22]=> string(20) "2651#458#800#732#837" [23]=> string(20) "2751#479#834#768#872" [24]=> string(20) "2851#500#868#803#907" [25]=> string(20) "2951#522#902#839#942" [26]=> string(20) "3051#543#936#875#977" [27]=> string(21) "3151#564#969#911#1013" [28]=> string(22) "3251#582#1000#943#1044" [29]=> string(22) "3351#600#1030#975#1075" [30]=> string(23) "3451#617#1060#1006#1106" [31]=> string(23) "3551#634#1089#1038#1138" [32]=> string(23) "3651#651#1119#1070#1169" [33]=> string(23) "3751#669#1149#1102#1200" [34]=> string(23) "3851#686#1179#1133#1231" [35]=> string(23) "3951#703#1209#1165#1262" [36]=> string(23) "4051#720#1239#1197#1293" [37]=> string(23) "4151#738#1269#1228#1324" [38]=> string(23) "4251#755#1298#1260#1355" [39]=> string(23) "4351#772#1328#1292#1386" [40]=> string(23) "4451#790#1358#1324#1418" [41]=> string(23) "4551#807#1388#1355#1449" [42]=> string(23) "4651#824#1418#1387#1480" [43]=> string(23) "4751#841#1448#1419#1511" [44]=> string(23) "4851#859#1477#1450#1542" [45]=> string(23) "4951#876#1507#1482#1573" } }
问题
如何在不刷新页面的情况下自动加载页面？
我自己尝试
我已将此JavaScript代码放入passPHP()函数：
httpc.onreadystatechange = function () { //Call a function when the state changes.
if (httpc.readyState == 4 && httpc.status == 200) { // complete and no errors
window.location.href = "index.php";
}
};
这会自动刷新页面，但这很慢，你实际上看到的页面表明数组索引没有被定义。
答案 0 :(得分：0)
一旦前一个请求返回，我应该再次使用AJAX加载值。
流程：
parseRoadTaxData onreadystatechange readystate 4并进行新的AJAX调用，现在通过运行RoadTaxDataTemporaryRegistry::getStorageByVehicle($myCar) 使用onreadystate扩展您的AJAX调用
function setAndLoadData(INSTALL_FILE, paramName , data)
{
var httpc = new XMLHttpRequest(); // simplified for clarity"
httpc.open("POST", INSTALL_FILE, true); // sending as POST
httpc.setRequestHeader("Content-Type", "application/x-www-form-urlencoded");
httpc.onreadystatechange = retrieveVarsFromPHP //<-- call this on readystatechange.
httpc.send(paramName + "=" + data);
}
function retrieveVarsFromPHP()
{
if (this.readyState == 4)
{
//AJAX call to retrieve data.
var httpc = new XMLHttpRequest(); // simplified for clarity"
httpc.open("get", retrieveSessionData.php, true);
httpc.onreadystatechange = function()
{
if (this.readyState == 4)
{
sessionData = JSON.parse(this.responseText); //Store the data in a global, which can be accessed in the index.html
callBack() //this can be a function in your page called upon to handle displaying the retrieved data.
}
}
httpc.send();
}
}
PHP文件retrieveSessionData.php
<?php
require "RoadTaxDataTemporaryRegistry.php";
session_start();
echo (RoadTaxDataTemporaryRegistry::getStorageByVehicle($myCar));
?>
在index.php上执行
<script>
setAndLoadData();
</script>
您检索数据的问题在asynchronous的{{1}}部分。在AJAX开始解析数据时，数据尚未真正设置。你需要等待这个完成。页面的刷新是这个方向的暗示，但你仍然不能依赖它。因为页面完成加载的事实没有说明除了页面加载之外你的异步AJAX调用已经完成的事实。
我希望我有道理。