webaware/gist:3110728

## gistfile1.phtml
<?php

/*
-- the SQL database table
create table form_ajax (
    ID varchar(5) not null,
    Name varchar(100),
    Address varchar(100),
    Phone varchar(20),
    Email varchar(255),
    constraint form_ajax_pk primary key (ID)
);

-- the data
insert into form_ajax(ID, Name, Address, Phone, Email)
values('123', 'Test Only', '123 Smith Street Jonestown 2000 NSW', '0123456789', 'test@example.com');
*/

// simplified to provide an example; deal with non-standards browsers yourself
// please use some common sense and add more structure, error handling, etc.

// NB: the PHP stuff is all server side, and is the AJAX service

// check for AJAX request
if (isset($_GET['action'])) {
    if ($_GET['action'] == 'fetch') {
        // tell the browser what's coming
        header('Content-type: application/json');

        // open database connection
        $db = new PDO('mysql:dbname=test;host:localhost;', 'website', 'website');

        // use prepared statements!
        $query = $db->prepare('select * from form_ajax where ID = ?');
        $query->execute(array($_GET['ID']));
        $row = $query->fetch(PDO::FETCH_OBJ);

        // send the data encoded as JSON
        echo json_encode($row);
        exit;
    }
}

?>
<!DOCTYPE html>
<html lang="en-au">
<head>
<meta charset="utf-8" />
<title>Form from AJAX</title>

<script>

// NB: the JavaScript stuff here is all client side and is the AJAX client

// encapsulate the lot within a function scope called on document ready
window.addEventListener("DOMContentLoaded", function() {

    // hook the submit action on the form
    var frm = document.getElementById("form-ajax");
    frm.addEventListener("submit", frm_submit, false);

    /**
    * function to handle form submit, and request data from server
    * @param {Event} event
    */
    function frm_submit(event) {
        // stop the form submitting
        event.preventDefault();

        // grab the ID and send AJAX request if not (empty / only whitespace)
        var ID = this.elements.ID.value;
        if (/\S/.test(ID)) {
            ajax_request(this.action, {"action" : "fetch", "ID" : ID}, process_response);
        }
        else {
            alert("No ID supplied");
        }
    }

    /**
    * send an ajax request, with successful response handled by callback
    * @param {String} url the url to send the request to
    * @param {Object} data map of the data that we'll send
    * @param {Function} callback the function that will process the AJAX response
    */
    function ajax_request(url, data, callback) {
        var i, parts, xhr;

        // if data is an object, unroll as HTTP post data (a=1&b=2&c=3 etc.)
        if (typeof data == "object") {
            parts = [];
            for (i in data) {
                parts.push(encodeURIComponent(i) + '=' + encodeURIComponent(data[i]));
            }
            data = parts.join("&");
        }

        // create an XML HTTP Request object
        xhr = new XMLHttpRequest();
        if (xhr) {
            // set a handler for changes in ready state
            xhr.onreadystatechange = function() {
                if (xhr.readyState == 4) {
                    // check for HTTP status of OK
                    if (xhr.status == 200) {
                        try {
                            callback(JSON.parse(xhr.responseText));
                        }
                        catch(e) {
                            console.log(xhr.responseText);      // for debug
                            alert("AJAX request incomplete:\n" + e.toString());
                        }
                    }
                    else {
                        alert("AJAX request failed: " + xhr.status);
                    }
                }
            };
            // open connection and send payload
            xhr.open("GET", url + "?" + data, true);
            xhr.send(null);
        }
    }

    /**
    * process the response, populating the form fields from the JSON data
    * @param {Object} response the JSON data parsed into an object
    */
    function process_response(response) {
        var frm = document.getElementById("form-ajax");
        var i;

        console.dir(response);      // for debug

        for (i in response) {
            if (i in frm.elements) {
                frm.elements[i].value = response[i];
            }
        }
    }

}, false);

</script>

</head>

<body>

    <form id="form-ajax" action="form-ajax.php">
        <label>ID:</label><input type="text" name="ID" /><br />
        <label>Name:</label><input type="text" name="Name" /><br />
        <label>Address:</label><input type="text" name="Address" /><br />
        <label>Phone:</label><input type="text" name="Phone" /><br />
        <label>Email:</label><input type="email" name="Email" /><br />
        <input type="submit" value="fill from db" />
    </form>

</body>

</html>
	<?php

	/*
	-- the SQL database table
	create table form_ajax (
	ID varchar(5) not null,
	Name varchar(100),
	Address varchar(100),
	Phone varchar(20),
	Email varchar(255),
	constraint form_ajax_pk primary key (ID)
	);

	-- the data
	insert into form_ajax(ID, Name, Address, Phone, Email)
	values('123', 'Test Only', '123 Smith Street Jonestown 2000 NSW', '0123456789', 'test@example.com');
	*/

	// simplified to provide an example; deal with non-standards browsers yourself
	// please use some common sense and add more structure, error handling, etc.

	// NB: the PHP stuff is all server side, and is the AJAX service

	// check for AJAX request
	if (isset($_GET['action'])) {
	if ($_GET['action'] == 'fetch') {
	// tell the browser what's coming
	header('Content-type: application/json');

	// open database connection
	$db = new PDO('mysql:dbname=test;host:localhost;', 'website', 'website');

	// use prepared statements!
	$query = $db->prepare('select * from form_ajax where ID = ?');
	$query->execute(array($_GET['ID']));
	$row = $query->fetch(PDO::FETCH_OBJ);

	// send the data encoded as JSON
	echo json_encode($row);
	exit;
	}
	}

	?>
	<!DOCTYPE html>
	<html lang="en-au">
	<head>
	<meta charset="utf-8" />
	<title>Form from AJAX</title>

	<script>

	// NB: the JavaScript stuff here is all client side and is the AJAX client

	// encapsulate the lot within a function scope called on document ready
	window.addEventListener("DOMContentLoaded", function() {

	// hook the submit action on the form
	var frm = document.getElementById("form-ajax");
	frm.addEventListener("submit", frm_submit, false);

	/**
	* function to handle form submit, and request data from server
	* @param {Event} event
	*/
	function frm_submit(event) {
	// stop the form submitting
	event.preventDefault();

	// grab the ID and send AJAX request if not (empty / only whitespace)
	var ID = this.elements.ID.value;
	if (/\S/.test(ID)) {
	ajax_request(this.action, {"action" : "fetch", "ID" : ID}, process_response);
	}
	else {
	alert("No ID supplied");
	}
	}

	/**
	* send an ajax request, with successful response handled by callback
	* @param {String} url the url to send the request to
	* @param {Object} data map of the data that we'll send
	* @param {Function} callback the function that will process the AJAX response
	*/
	function ajax_request(url, data, callback) {
	var i, parts, xhr;

	// if data is an object, unroll as HTTP post data (a=1&b=2&c=3 etc.)
	if (typeof data == "object") {
	parts = [];
	for (i in data) {
	parts.push(encodeURIComponent(i) + '=' + encodeURIComponent(data[i]));
	}
	data = parts.join("&");
	}

	// create an XML HTTP Request object
	xhr = new XMLHttpRequest();
	if (xhr) {
	// set a handler for changes in ready state
	xhr.onreadystatechange = function() {
	if (xhr.readyState == 4) {
	// check for HTTP status of OK
	if (xhr.status == 200) {
	try {
	callback(JSON.parse(xhr.responseText));
	}
	catch(e) {
	console.log(xhr.responseText); // for debug
	alert("AJAX request incomplete:\n" + e.toString());
	}
	}
	else {
	alert("AJAX request failed: " + xhr.status);
	}
	}
	};
	// open connection and send payload
	xhr.open("GET", url + "?" + data, true);
	xhr.send(null);
	}
	}

	/**
	* process the response, populating the form fields from the JSON data
	* @param {Object} response the JSON data parsed into an object
	*/
	function process_response(response) {
	var frm = document.getElementById("form-ajax");
	var i;

	console.dir(response); // for debug

	for (i in response) {
	if (i in frm.elements) {
	frm.elements[i].value = response[i];
	}
	}
	}

	}, false);

	</script>

	</head>

	<body>

	<form id="form-ajax" action="form-ajax.php">
	<label>ID:</label><input type="text" name="ID" /><br />
	<label>Name:</label><input type="text" name="Name" /><br />
	<label>Address:</label><input type="text" name="Address" /><br />
	<label>Phone:</label><input type="text" name="Phone" /><br />
	<label>Email:</label><input type="email" name="Email" /><br />
	<input type="submit" value="fill from db" />
	</form>

	</body>

	</html>