作为 PHP 和 ajax XmlHttpRequest 调用的新手，我正在努力找出我的代码出了什么问题。浏览了文档，但我似乎正在努力将数据库行名称放入数组中。理想情况下，我希望在输入下方异步显示一个 innerHTML 来指示该项目是否在数据库中。现在它显示“未定义”，如下所示，直到我在数据库中输入最后一项。它仅响应数据库中的最后一项，这意味着我的循环可能存在问题。欢迎任何帮助。
index.php
<?php
include 'db.php';
?>
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<meta name="viewport" content="width=device-width, initial-scale=1.0">
<link href="http://fonts.googleapis.com/css?family=Open+Sans" rel="stylesheet">
<link href="css/main.css" rel="stylesheet">
<script
src="https://code.jquery.com/jquery-3.2.1.min.js"
integrity="sha256-hwg4gsxgFZhOsEEamdOYGBf13FyQuiTwlAQgxVSNgt4="
crossorigin="anonymous">
</script>
<script src="js/todo.js" type="text/javascript"></script>
<script>
</script>
</head>
<body onload="process()">
<div class="list">
<h1 class="header">My To Do</h1>
<form>
<ul class="items">
<?php
$sql = "SELECT * FROM items ORDER BY items.id ASC";
$result = mysqli_query($conn, $sql);
if(mysqli_num_rows($result) > 0){
while ($row = mysqli_fetch_assoc($result)){
echo "<li><input type='checkbox' /><label>";
echo $row['name'];
echo "</label></li><br>";
}
} else {
echo "There are no to-dos!";
}
echo "<br/><br/>";
echo "<li><input type='checkbox' /><label>Mark all as completed</label></li>";
?>
</ul><br />
</form>
</div>
<div class="list">
<form class="item-add" method="post">
<input type="text" id="name" name="name" placeholder="Enter new item" class="input" autocomplete="off" required>
<input name="myBtn" type="submit" value="Add Item">
<div id="status"></div>
</form>
</div>
</body>
item.php
<?php
include 'db.php';
header('Content-Type: text/xml');
echo '<?xml version="1.0" encoding="UTF-8" standalone="yes" ?>';
echo '<response>';
if (mysqli_connect_errno()) {
printf("Connect failed: %s\n", mysqli_connect_error());
exit();
}
$sql = "SELECT * FROM items ORDER BY items.id ASC";
$result = mysqli_query($conn, $sql);
$itemArray = array();
$rowNum = mysqli_num_rows($result);
//is this the correct way to add db items to an array?
if($rowNum > 0){
while ($row = mysqli_fetch_assoc($result)){
for ($x = 0; $x <= $rowNum; $x++) {
$itemArray[$x] = $row['name'];
}
}
} else {
echo "There are no to-dos!";
}
$entry = $_GET['name'];
if(in_array($entry, $itemArray))
echo 'Item ' .$entry. ' already exists! Please enter a new item...';
elseif ($name == '')
echo "Please enter an item...";
else {
//code for insertion
echo "Successfully Inserted";
}
echo '</response>';
?>
item.js
var xmlHttp = createXmlHttpRequestObject();
function createXmlHttpRequestObject() {
var xmlHttp;
if(window.ActiveXObject) {
try {
xmlHttp = new ActiveXObject("Microsoft.XMLHTTP");
} catch(e) {
xmlHttp = false;
}
} else {
try {
xmlHttp = new XMLHttpRequest();
} catch(e) {
xmlHttp = false;
}
}
if(!xmlHttp) {
alert("cant create that object hoss");
} else {
return xmlHttp;
}
}
function process() {
if (xmlHttp.readyState==0 || xmlHttp.readyState==4) {
name = encodeURIComponent(document.getElementById('name').value);
xmlHttp.open("GET", "item.php?name="+name, true);
xmlHttp.onreadystatechange = handleServerResponse;
xmlHttp.send(null);
} else {
setTimeout('process()', 1000);
}
}
function handleServerResponse(){
if(xmlHttp.readyState==4) {
if(xmlHttp.status==200){
xmlResponse = xmlHttp.responseXML;
xmlDocumentElement = xmlResponse.documentElement;
console.log(xmlResponse.documentElement);
message = xmlDocumentElement.firstChild.data;
document.getElementById('status').innerHTML =
'<span style="color:blue">' + message + '</span>';
setTimeout('process()', 1000);
} else {
alert('Something went wrong!');
}
}
}
最佳答案
$name 未在您的 PHP 文件中定义，您检查下面的 elseif 条件是否应该是 $entry
$entry = $_GET['name'];
if(in_array($entry, $itemArray))
echo 'Item ' .$entry. ' already exists! Please enter a new item...';
elseif ($entry == '')
echo "Please enter an item...";
else {
//code for insertion
echo "Successfully Inserted";
}
将数据库列分配给数组的正确方法应该如下所示。
if($rowNum > 0){
while ($row = mysqli_fetch_assoc($result)){
$itemArray[] = $row['name'];
}
} else {
echo "There are no to-dos!";
}
关于javascript - PHP XmlHttpRequest 错误与简单的待办事项列表，我们在Stack Overflow上找到一个类似的问题： https://stackoverflow.com/questions/46240056/