AJAX是用來創造更多的交互式應用程序。
AJAX PHP實例
下面的例子將演示如何網頁可以同時輸入字段的用戶類型字符的Web服務器通信：
例
Start typing a name in the input field below:
First name:Suggestions:
例子解釋：
在上面的例子中，當用戶在輸入字段的字符，調用函數"showHint()"被執行。
該功能是由觸發onkeyup事件。
下面是HTML代碼：
例
<html>
<head>
<script>
function showHint(str) {
if (str.length == 0) {
document.getElementById("txtHint").innerHTML = "";
return;
} else {
var xmlhttp = new
XMLHttpRequest();
xmlhttp.onreadystatechange = function()
{
if (xmlhttp.readyState == 4 && xmlhttp.status == 200) {
document.getElementById("txtHint").innerHTML = xmlhttp.responseText;
}
};
xmlhttp.open("GET", "gethint.php?q=" + str, true);
xmlhttp.send();
}
}
</script>
</head>
<body>
<p><b>Start typing a name in the
input field below:</b></p>
<form>
First name: <input type="text"
onkeyup="showHint(this.value)">
</form>
<p>Suggestions: <span id="txtHint"></span></p>
</body>
</html> 試一試» 代碼解釋：
首先，檢查輸入字段為空(str.length == 0) 如果是，清除的內容txtHint佔位符和退出的功能。
然而，如果輸入字段不為空，執行以下步驟：
- 創建XMLHttpRequest對象
- 創建功能被執行時，服務器響應就緒
- 發送請求開了一個PHP文件(gethint.php)在服務器上
- 注意， q參數被添加gethint.php?q="+str
- 該str變量保存輸入字段的內容
PHP文件- "gethint.php"
PHP文件檢查名稱的數組，並返回相應的name(s)到瀏覽器：
<?php
// Array with names
$a[] = "Anna";
$a[] = "Brittany";
$a[] = "Cinderella";
$a[] = "Diana";
$a[] = "Eva";
$a[] = "Fiona";
$a[] = "Gunda";
$a[] = "Hege";
$a[] = "Inga";
$a[] = "Johanna";
$a[] = "Kitty";
$a[] = "Linda";
$a[] = "Nina";
$a[] = "Ophelia";
$a[] = "Petunia";
$a[] = "Amanda";
$a[] = "Raquel";
$a[] = "Cindy";
$a[] = "Doris";
$a[] = "Eve";
$a[] = "Evita";
$a[] = "Sunniva";
$a[] = "Tove";
$a[] = "Unni";
$a[] = "Violet";
$a[] = "Liza";
$a[] = "Elizabeth";
$a[] = "Ellen";
$a[] = "Wenche";
$a[] = "Vicky";
// get the q parameter from URL
$q = $_REQUEST["q"];
$hint = "";
//
lookup all hints from array if $q is different from ""
if ($q !== "")
{
$q = strtolower($q);
$len=strlen($q);
foreach($a as
$name) {
if (stristr($q, substr($name, 0, $len)))
{
if ($hint === "") {
$hint = $name;
} else
{
$hint .= ", $name";
}
}
}
}
// Output "no suggestion" if no hint was found
or output correct values
echo $hint === "" ? "no suggestion" : $hint;
?>