PHP Ajax搜索

Ajax被用于与网页和Web服务器进行通信。下面的示例演示了使用Ajax的搜索字段。

<html>
   <head>

      <style>
         span {
            color: green;
         }
      </style>

      <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", "php_ajax.php?q=" + str, true);
               xmlhttp.send();
            }
         }
      </script>

   </head>
   <body>

      <p><b>Search your favourite tutorials:</b></p>

      <form>
         <input type = "text" onkeyup = "showHint(this.value)">
      </form>

      <p>Entered Course name: <span id="txtHint"></span></p>

   </body>
</html>

以上代码打开一个名为php_ajax.php的文件，并使用GET方法。所以我们需要在同一目录下创建一个名为php_ajax.php的文件，输出将附加到txtHint上。

php_ajax.php

它包含了课程名称的数组，并将值返回给网页浏览器。

<?php
   // Array with names
    $a[] = "Android";$ a[] = "B programming language";
    $a[] = "C programming language";$ a[] = "D programming language";
    $a[] = "euphoria";$ a[] = "F#";
    $a[] = "GWT";$ a[] = "HTML5";
    $a[] = "ibatis";$ a[] = "Java";
    $a[] = "K programming language";$ a[] = "Lisp";
    $a[] = "Microsoft technologies";$ a[] = "Networking";
    $a[] = "Open Source";$ a[] = "Prototype";
    $a[] = "QC";$ a[] = "Restful web services";
    $a[] = "Scrum";$ a[] = "Testing";
    $a[] = " UML ";$ a[] = "VB Script";
    $a[] = "Web Technologies";$ a[] = "Xerox Technology";
    $a[] = "YQL";$ a[] = "ZOPL";

    $q =$ _REQUEST["q"];
    $hint = ""; if ($ 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";
            }
         }
      }
   }
   echo  $hint === "" ? "Please enter a valid course name" :$ hint;
?>