php
AJAX and PHP

Create an PHP Ajax application

We will create a simple example that allows users to search for popular PHP frameworks.
Our application will have a text box that users will type in the names of the frameworks.
Will use AJAX to search for a match then display the frameworks's complete name just below the search form.

The following example will demonstrate how a web page can communicate with a web server while a user type characters in an input field :
Sample Application
simple-ajax.php
<!DOCTYPE html>
<html>
<head>
	<title>PHP - AJAX and PHP</title>
</head>
<body>
<style type="text/css">
	.ajax_php_font{ 
		color:#F60; 
		font-weight:bold; 
		font-style:italic; 
		font-size:16px;
		}
</style>
<script type="text/javascript">
function showHint(str) {
    if (str.length == 0) { 
        document.getElementById("tut_name").innerHTML = "";
        return;
    } else {
        var xmlhttp = new XMLHttpRequest();
        xmlhttp.onreadystatechange = function() {
            if (this.readyState == 4 && this.status == 200) {
                document.getElementById("tut_name").innerHTML = this.responseText;
            }
        };
        xmlhttp.open("GET", "get_data.php?q=" + str, true);
        xmlhttp.send();
    }
}
</script>
</head>
<body>

<h4>Search  your tutorial in the input field below :</h4>
<form> 
Tutorial Name: <input type="text" onkeyup="showHint(this.value)">
</form>

<p>Your tutorial name is : <span id="tut_name" class="ajax_php_font"></span></p>

</body>
</html>

First, check if the input field is empty (str.length == 0). If it is, clear the content of the tut_name placeholder and exit the function.

However, if the input field is not empty, do the following :

  • Create an XMLHttpRequest object
  • Create the function to be executed when the server response is ready
  • Send the request off to a PHP file (get_datat.php) on the server
  • Notice that q parameter is added to the url (get_datat.php?q="+str)
  • And the str variable holds the content of the input field
get_data.php
<?php
// Array with tutorials
$a[] = "C Language";
$a[] = "C++";
$a[] = "Bootstrap";
$a[] = "HTML5";
$a[] = "HTML";
$a[] = "CSS";
$a[] = "CSS3";
$a[] = "JAVA";
$a[] = "JavaScript";
$a[] = "jQuery";
$a[] = "PHP";
$a[] = "MySQL";
$a[] = "SQL";
$a[] = "Adv Java";
$a[] = "Python";
$a[] = "AngularJS";
$a[] = "Photoshop";
$a[] = "C#";
$a[] = "ASP.NET";
$a[] = "SAP";
$a[] = "ORACLE";
$a[] = "Wordpress";
$a[] = "Android";
$a[] = "iOS";
$a[] = "SEO";
$a[] = "Illustrator";
$a[] = "Flash";
$a[] = "Action Script";

// 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 correct values 
echo $hint === "" ? "no suggestion" : $hint;
?>