php ajax php

AJAX is used to create more interactive applications.

AJAX PHP Example

The following example will demonstrate how a web page can communicate with a

web server while a user type characters in an input field:

Example

Start typing a name in the input field below:

Suggestions:

Example Explained

In the example above, when a user types a character in the input field, a function

called "showHint()" is executed.

The function is triggered by the onkeyup event.

Here is the HTML code:

Example

Code explanation:

First, check if the input field is empty (str.length == 0). If it is, clear the

content of the txtHint 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 (gethint.php) on the server

Notice that q parameter is added to the url (gethint.php?q="+str)

And the str variable holds the content of the input field

The PHP File - "gethint.php"

The PHP file checks an array of names, and returns the corresponding name(s) to the

browser:

<?php

// Array with names

$a[] = "Anna";

$a[] = "Brittany";

$a[] = "Cinderella";

$a[] = "Diana";

$a[] = "Eva";

$a[] = "Fiona";

$a[] = "Gunda";

$a[] = "Hege";

$a[] = "Inga";

$a[] = "Johanna";

$a[] = "Kitty";

$a[] = "Linda";

$a[] = "Nina";

$a[] = "Ophelia";

$a[] = "Petunia";

$a[] = "Amanda";

$a[] = "Raquel";

$a[] = "Cindy";

$a[] = "Doris";

$a[] = "Eve";

$a[] = "Evita";

$a[] = "Sunniva";

$a[] = "Tove";

$a[] = "Unni";

$a[] = "Violet";

$a[] = "Liza";

$a[] = "Elizabeth";

$a[] = "Ellen";

$a[] = "Wenche";

$a[] = "Vicky";

// 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 "no suggestion" if no hint was found or output correct values

echo $hint === "" ? "no suggestion" : $hint;?>