Javascript AJAX未正确发送POST变量
我正在用AJAX编写一个基本应用程序,需要通过POST将一些数据发送到php页面 我在这里遇到的问题是php页面没有正确地接收$\u POST中的数据:如果我试图打印它的内容,我会得到一个空数组 你能帮我指出这个问题吗Javascript AJAX未正确发送POST变量,javascript,php,ajax,post,Javascript,Php,Ajax,Post,我正在用AJAX编写一个基本应用程序,需要通过POST将一些数据发送到php页面 我在这里遇到的问题是php页面没有正确地接收$\u POST中的数据:如果我试图打印它的内容,我会得到一个空数组 你能帮我指出这个问题吗 // global variables var sendReq = getXmlHttpRequestObject(); // get the browser dependent XMLHttpRequest object function getXmlHttpRequest
// global variables
var sendReq = getXmlHttpRequestObject();
// get the browser dependent XMLHttpRequest object
function getXmlHttpRequestObject() {
if (window.XMLHttpRequest) {
return new XMLHttpRequest();
}
else if(window.ActiveXObject) {
return new ActiveXObject("Microsoft.XMLHTTP");
}
else {
document.getElementById('status').innerHTML =
'Status: Error while creating XmlHttpRequest Object.';
}
}
// send a new message to the server
function sendMessage() {
if ( receiveReq.readyState == 0 || receiveReq.readyState == 4 ) {
sendReq.open("POST", 'chatServer.php', true);
sendReq.setRequestHeader('Content-Type','application/x-www-form-urlencoded');
// bind function call when state change
sendReq.onreadystatechange = messageSent;
var param = "message=ciao";
sendReq.send(param);
// reset the content of input
document.getElementById("message").value = "";
}
}
chatServer.php
<?php session_start();
// send headers to prevent caching
header("Expires: Mon, 1 Jul 2000 08:00:00 GMT" );
header("Last-Modified: " . gmdate( "D, d M Y H:i:s" ) . "GMT" );
header("Cache-Control: no-cache, must-revalidate" );
header("Pragma: no-cache" );
// open database
$file_db = new PDO('sqlite:chatdb.sqlite') or die("cannot open database");
if ($file_db) {
print_r($_POST); // this prints an empty array!!!
// check if a message was sent to the server
if (isset($_POST["message"]) && $_POST["message"] != '') {
$message = $_POST["message"];
// do stuff
}
}
?>
您的
sendMessage
功能不太正确-请查看此功能是否有帮助
在原始版本中,该函数检查了未引用实例化XMLHttpRequest对象的receiveReq
的状态,即使使用了sendReq
,请求也不会被发送,因为open
和send
调用位于检查响应的代码块内
var sendReq = getXmlHttpRequestObject();
function messageSent( response ){
console.info(response);
}
function getXmlHttpRequestObject() {
if (window.XMLHttpRequest) {
return new XMLHttpRequest();
} else if(window.ActiveXObject) {
return new ActiveXObject("Microsoft.XMLHTTP");
} else {
document.getElementById('status').innerHTML = 'Status: Error while creating XmlHttpRequest Object.';
}
}
/*
Set the `param` as a parameter to the function, can reuse it more easily.
*/
function sendMessage( param ) {
if( sendReq ){
/* set the listener now for the response */
sendReq.onreadystatechange=function(){
/* Check for the request Object's status */
if( sendReq.readyState==4 ) {
if( sendReq.status==200 ){
/* Process response here */
messageSent.call( this, sendReq.response );
} else {
/* there was an error */
}
}
};
/* Open & send request, outwith the listener */
sendReq.open( "POST", 'chatServer.php', true );
sendReq.setRequestHeader('Content-Type','application/x-www-form-urlencoded');
sendReq.send( param );
document.getElementById("message").value = "";
}
}
/* send some messages */
sendMessage('message=ciao');
sendMessage('message=ajax...sent via POST');
最初遗漏了param var声明,因此进行了更正
更新
chatserver.php (example)
------------------------
<?php
/*
demo_chatserver.php
*/
session_start();
if( $_SERVER['REQUEST_METHOD']=='POST' ){
/*
include your db connection
set your headers
*/
if( isset( $_POST['message'] ) && !empty( $_POST['message'] ) ){
@ob_clean();
/* Create the db conn && test that it is OK */
/* for the purposes of the tests only */
$_POST['date']=date( DATE_COOKIE );
echo json_encode( $_POST, JSON_FORCE_OBJECT );
exit();
}
}
?>
html / php page
---------------
<!doctype html>
<html>
<head>
<title>ajax tests</title>
<script type='text/javascript'>
var sendReq = getXmlHttpRequestObject();
function messageSent( response ){
console.info( 'This is the response from your PHP script: %s',response );
if( document.getElementById("message") ) document.getElementById("message").innerHTML=response;
}
function getXmlHttpRequestObject() {
if ( window.XMLHttpRequest ) {
return new XMLHttpRequest();
} else if( window.ActiveXObject ) {
return new ActiveXObject("Microsoft.XMLHTTP");
} else {
document.getElementById('status').innerHTML = 'Status: Error while creating XmlHttpRequest Object.';
}
}
/*
Set the `param` as a parameter to the function, can reuse it more easily.
*/
function sendMessage( param ) {
if( sendReq ){
/* set the listener now for the response */
sendReq.onreadystatechange=function(){
/* Check for the request Object's status */
if( sendReq.readyState==4 ) {
if( sendReq.status==200 ){
/* Process response here */
messageSent.call( this, sendReq.response );
} else {
/* there was an error */
}
}
};
/* Open & send request, outwith the listener */
/*NOTE: I have this in a folder called `test`, hence the path below!! */
sendReq.open( "POST", '/test/demo_chatserver.php', true );
sendReq.setRequestHeader('Content-Type','application/x-www-form-urlencoded');
sendReq.send( param );
if( document.getElementById("message") ) document.getElementById("message").innerHTML = "";
}
}
/* send some data - including original 'message=ciao' but other junk too */
window.onload=function(event){
sendMessage('message=ciao&id=23&banana=yellow&php=fun&method=post&evt='+event);
}
</script>
</head>
<body>
<output id='message' style='display:block;width:80%;float:none;margin:5rem auto;padding:1rem;box-sizing:content-box;border:1px solid black;'>
<!--
Expect to see content appear here....
-->
</output>
</body>
</html>
Should output something like:-
------------------------------
{"message":"ciao","id":"23","banana":"yellow","php":"fun","method":"post","evt":"[object Event]","time":1446730182,"date":"Thursday, 05-Nov-15 13:29:42 GMT"}
chatserver.php(示例)
------------------------
html/php页面
---------------
ajax测试
var sendReq=getXmlHttpRequestObject();
函数messageSent(响应){
info('这是来自PHP脚本的响应:%s',response);
if(document.getElementById(“message”))document.getElementById(“message”).innerHTML=响应;
}
函数getXmlHttpRequestObject(){
if(window.XMLHttpRequest){
返回新的XMLHttpRequest();
}else if(window.ActiveXObject){
返回新的ActiveXObject(“Microsoft.XMLHTTP”);
}否则{
document.getElementById('status')。innerHTML='status:创建XmlHttpRequest对象时出错';
}
}
/*
将'param'设置为函数的参数,可以更容易地重用它。
*/
函数sendMessage(参数){
如果(发送请求){
/*现在为响应设置侦听器*/
sendReq.onreadystatechange=函数(){
/*检查请求对象的状态*/
if(sendReq.readyState==4){
如果(发送请求状态==200){
/*在此处理响应*/
messageSent.call(这是sendReq.response);
}否则{
/*有一个错误*/
}
}
};
/*打开并发送请求,超出侦听器*/
/*注意:我把它放在一个名为“test”的文件夹中,因此路径如下*/
open(“POST”,'/test/demo_chatserver.php',true);
setRequestHeader('Content-Type','application/x-www-form-urlencoded');
sendReq.send(参数);
if(document.getElementById(“message”))document.getElementById(“message”).innerHTML=“”;
}
}
/*发送一些数据-包括原始的“message=ciao”,但也发送其他垃圾数据*/
window.onload=函数(事件){
sendMessage('message=ciao&id=23&banana=yellow&php=fun&method=post&evt='+事件);
}
应该输出如下内容:-
------------------------------
{“message”:“ciao”,“id”:“23”,“banana”:“yellow”,“php”:“fun”,“method”:“post”,“evt”:“object Event]”,“time”:1446730182,“date”:“周四,05-11-15 13:29:42 GMT”}
这里我将展示如何发送/接收基本CRUD(创建、读取、删除、更新)应用程序的Ajax请求,您可以在代码中实现它
首先是HTML中带有输入元素的简单表单
<form action="controller.php" method="POST">
<input type="text" class="form-control" name="userName"/>
<input type="text" class="form-control" name="password"/>
<input type="Submit" value="Log In" onclick="logIn(); return false;"/>
</form>
之后,我们编写了JavaScript函数,该函数使用formData对象并使用AJax技术发送请求:
function logIn()
{
//Creating formData object
var formData = new FormData();
//Getting input elements by their classNames
var formElements = document.getElementsByClassName("form-control");
//Append form elements to formData object
for(var i = 0; i < formElements.length; i++)
formData.append(formElements[i].name, formElements[i].value)
//Creating XMLHttpRequest Object
var xmlHttp = new XMLHttpRequest();
xmlHttp.onreadystatechange = function()
{
if(xmlHttp.readyState == 4 && xmlHttp.status == 200)
{
alert(xmlHttp.responseText);
}
}
xmlHttp.open("POST", "controller.php");
xmlHttp.send(formData);
}
函数登录()
{
//创建formData对象
var formData=new formData();
//通过类名获取输入元素
var formElements=document.getElementsByClassName(“表单控件”);
//将表单元素附加到formData对象
对于(var i=0;i
出于对否决票的好奇,请求被发送,从而纠正了OP的问题。。。你可能被否决了,因为你应该解释你的解决方案为什么有效以及你做了什么。谢谢你的回答。除了打字错误,我还修改了我函数的结构以匹配你的结构,谢谢你的解释。问题是它仍然无法工作,并且我的php页面无法正确接收$\u POST变量。我正在更新op,让您可以使用window.location.replace查看我更新的代码。如果您发送请求,但不等待答复,而是加载php脚本,那么将无法工作。使用控制台查看ajax请求中发生的情况。谢谢,这正是发生的情况。这篇文章很有效,但我用错误的方式测试了它。
function logIn()
{
//Creating formData object
var formData = new FormData();
//Getting input elements by their classNames
var formElements = document.getElementsByClassName("form-control");
//Append form elements to formData object
for(var i = 0; i < formElements.length; i++)
formData.append(formElements[i].name, formElements[i].value)
//Creating XMLHttpRequest Object
var xmlHttp = new XMLHttpRequest();
xmlHttp.onreadystatechange = function()
{
if(xmlHttp.readyState == 4 && xmlHttp.status == 200)
{
alert(xmlHttp.responseText);
}
}
xmlHttp.open("POST", "controller.php");
xmlHttp.send(formData);
}