Basic PHP Geocoding Example using PostCoder Web. Find out more at - http://developers.alliescomputing.com/postcoder-web-api/geocoding/position

geocoding.php

<?php
	// Check if POST request has been made
	if($_SERVER['REQUEST_METHOD'] === 'POST') {
	
		// Basic validation on the postcode field
		if(array_key_exists('postcode', $_POST) and !empty($_POST['postcode'])) {

			// Insert your PostCoder Web API Key here 
			// Sign up for free at www.alliescomputing.com/postcoder/sign-up
			$pcw_api_key = "YOUR-API-KEY-HERE";
	
			// URL we are calling with API key and url encoded postcode
			$pcw_geocode_url = "http://ws.postcoder.com/pcw/". $pcw_api_key ."/position/uk/" . rawurlencode($_POST['postcode']);
		
			// Get and JSON decode the response from the service
			$response = json_decode(file_get_contents($pcw_geocode_url));
			
			// Make sure the repsonse isn't empty
			if(!empty($response)) {
			
				// Dislay co-ordinates
				echo "<p>Co-ordinates for <strong>" . $_POST['postcode'] . "</strong></p>";
				echo "<p>Latitude: ".$response[0]->latitude."<br>Longitude: ".$response[0]->longitude."<br>Easting: ".$response[0]->grideasting."<br>Northing: ".$response[0]->gridnorthing."</p>";
			
			} else {
			
				// Display error message
				echo "<p><strong>" . $_POST['postcode'] . "</strong> - could not be found</p>";
			
			}
	
		}
	
	}

	// Basic POST submit form HTML below

?>
<form action="geocoding.php" method="post">

	<fieldset>
		<label for="postcode">Postcode:</label>
		<input type="text" name="postcode" id="postcode">
	</fieldset>

	<input type="submit" value="Geocode">

</form>