PHP Basic

<html>
<head>
<script type="text/javascript">
function showResult(str)
{
if (str.length==0)
{
   document.getElementById("livesearch").innerHTML="";
   document.getElementById("livesearch").style.border="0px";
return;
}
if (window.XMLHttpRequest)
{// code for IE7+, Firefox, Chrome, Opera, Safari
xmlhttp=new XMLHttpRequest();
}
else
{// code for IE6, IE5
xmlhttp=new ActiveXObject("Microsoft.XMLHTTP");
}
xmlhttp.onreadystatechange=function()
{
if (xmlhttp.readyState==4 && xmlhttp.status==200)
    {
   document.getElementById("livesearch").innerHTML=xmlhttp.responseText;
    document.getElementById("livesearch").style.border="1px solid #A5ACB2";
    }
}
xmlhttp.open("GET","livesearch.php?q="+str,true);
xmlhttp.send();
}
</script>
</head>
<body>

<form>
<input type="text" size="30" onkeyup="showResult(this.value)" />
<div id="livesearch"></div>
</form>

</body>
</html>

Source code explanation:

If the input field is empty (str.length==0), the function clears the content of the livesearch placeholder and exits the function.

If the input field is not empty, the showResult() function executes the following:

Create an XMLHttpRequest object
Create the function to be executed when the server response is ready
Send the request off to a file on the server
Notice that a parameter (q) is added to the URL (with the content of the input field)

The PHP File

The page on the server called by the JavaScript above is a PHP file called "livesearch.php".

The source code in "livesearch.php" searches an XML file for titles matching the search string and returns the result:

<?php
$xmlDoc=new DOMDocument();
$xmlDoc->load("links.xml");

$x=$xmlDoc->getElementsByTagName('link');

//get the q parameter from URL
$q=$_GET["q"];

//lookup all links from the xml file if length of q>0
if (strlen($q)>0)
{
$hint="";
for($i=0; $i<($x->length); $i++)
   {
   $y=$x->item($i)->getElementsByTagName('title');
   $z=$x->item($i)->getElementsByTagName('url');
   if ($y->item(0)->nodeType==1)
     {
     //find a link matching the search text
     if (stristr($y->item(0)->childNodes->item(0)->nodeValue,$q))
       {
       if ($hint=="")
         {
         $hint="<a href='" .
         $z->item(0)->childNodes->item(0)->nodeValue .
         "' target='_blank'>" .
         $y->item(0)->childNodes->item(0)->nodeValue . "</a>";
         }
       else
         {
         $hint=$hint . "<br /><a href='" .
         $z->item(0)->childNodes->item(0)->nodeValue .
         "' target='_blank'>" .
         $y->item(0)->childNodes->item(0)->nodeValue . "</a>";
         }
       }
     }
   }
}

// Set output to "no suggestion" if no hint were found
// or to the correct values
if ($hint=="")
   {
   $response="no suggestion";
   }
else
   {
   $response=$hint;
   }

//output the response
echo $response;
?>

If there is any text sent from the JavaScript (strlen($q) > 0), the following happens:

Load an XML file into a new XML DOM object
Loop through all <title> elements to find matches from the text sent from the JavaScript
Sets the correct url and title in the "$response" variable. If more than one match is found, all matches are added to the variable
If no matches are found, the $response variable is set to "no suggestion"

« Previous

Next Chapter »

PHP Basic

PHP Advanced

PHP Database

PHP XML

PHP and AJAX

PHP Reference

PHP Quiz

PHP Example - AJAX Live Search

AJAX Live Search

Example Explained - The HTML Page

The PHP File

抱歉！大部分内容只有英文