May 11, 2021 PHP
When using PHP, AJAX provides users with a more user-friendly and interactive search experience. This section gives a specific introduction!
In the following example, we'll demonstrate a real-time search that will get search results as you type your data.
Real-time search has many advantages over traditional search:
Search the W3CSchool page in the text box below
The results in the above example are found in an XML .xml file (links). To make this example small and simple, we only provide 6 results.
When the user types characters in the input box above, the "showResult()" function is executed. The function is triggered by the "onkeyup" event:
<html>
<head>
<script>
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 interpretation:
If the input box is empty (str.length,0), the function emptys the contents of the livesearch placeholder and exits the function.
If the input box is not empty, showResult() follows these steps:
The server page called by JavaScript above is a PHP file .php "Livesearch".
The source code .php "Livesearch" searches the XML file for the title that matches 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 $response;
?> If JavaScript sends any text (i.e. strlen($q) and 0), it will occur: