2012年4月3日 星期二

Ajax Login 登入範例

這是一個 AJAX Login 登入的範例

1. HTML Code(user_login.htm):

<html>
  <head>
    <meta charset="utf-8"/>
    <title>AJAX Login</title>
    <script src="user_login.js"></script>
  </head>
  <body>
    <h3><a href="http://www.aleixcortadellas.com/main/2009/03/01/ajax-post/">AJAX Login</a></h3>
    <form name="myform" id="myform">
      <div id="msg" style="color:red;display:none;"></div>
      Account: <input type="text" name="account"><br/>
      Password: <input type="password" name="pwd"><br/>
      <span id="btn"><input type="button" name="sb" id="sb" value="Login"></span><br/>
      <span style="color:blue;">(tip: guest / guest)</span><br/>
      <a href="index.htm">Home</a>
    </form>
  </body>
</html>



2. Javascript Code(user_login.js):

window.onload = initPage;
function initPage() {
  // 取得「送出」按鈕的參考
  var subBtn = document.getElementById("sb");
  // 為按鈕加入事件處理器
  subBtn.onclick = function () {
    MakeRequest(); // 建立請求的函式
  }
}

function createRequest() {
  if (window.XMLHttpRequest) {
    return new XMLHttpRequest();
  } else if(window.ActiveXObject) {
    return new ActiveXObject("Microsoft.XMLHTTP");
  } else {
    alert("Your Browser Sucks!\nIt's about time to upgrade don't you think?");
  }
}

var request = createRequest(); // 建立請求物件

function MakeRequest() {
  form = document.getElementById("myform");
  if (request != null) {
    // 取得輸入的文字
    var sPost = "";
    for(i=0;i<form.elements.length;i++) {
      inp = form.elements[i];
      switch(inp.type) {
        case "text":
        case "textarea":
        case "select-one":
        case "radio":
        case "password":
          if (inp.name && inp.value) {
            sPost+="&"+escape(inp.name)+"="+escape(inp.value);
          }
          break;
        default:
          break;
      }
    }

    var url = "user_login.php?1=1";

    // 利用 POST 方法、請求目的地 url、true 為非同步
    request.open("POST", url, true);

    // 回應處理函式 displayResult
    request.onreadystatechange = displayResult;
    request.setRequestHeader("Content-Type","application/x-www-form-urlencoded");
    request.send(sPost); // 送出請求
  }
}

function displayResult() {
  if (request.readyState == 4) { // 確認 readState
    if (request.status == 200) { // 確認 status
      var disp = document.getElementById("msg"); // 取得顯示位置
      disp.innerHTML = request.responseText;
      if (request.responseText=="Succcess") {
        var btnInput = document.getElementById("btn"); // 取得按鈕位置
        btnInput.style.display="none";
      }
      disp.style.display="block";
    }
  }
}



3. PHP Code(user_login.php):

<?php

$aRow =&$_POST;
$aStr = array();

if (!isset($aRow['account'])) $aRow['account']="";
if (!isset($aRow['pwd'])) $aRow['pwd']="";

if (!$aRow['account']) $aStr[] = "Enter account";
if (!$aRow['pwd']) $aStr[] = "Enter password";

if (!count($aStr)) {
  if ($aRow['account']=="guest" and $aRow['pwd']=="guest") {
    $aStr[] = "Succcess";
  } else {
    $aStr[] = "Account and password is not correct";
  }
}
echo implode("<br>",$aStr);

?>



4. 寫好後, 執行 user_login.htm , 完成!

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