api.php

<?php
/**
 * Google URL API Class.
 * 
 * @package Google URL Shortener
 * @author Justin Kopepasah
 * @version 1.0.0
*/

class Google_URL_API {
	
	// Constructor
	function __construct( $key, $api_url = 'https://www.googleapis.com/urlshortener/v1/url' ) {
		// Keep the API Url
		$this->api_url = $api_url . '?key=' . $key;
	}
	
	// Shorten a URL
	function shorten( $url ) {
		// Send information along
		$response = $this->send( $url );
		
		// Return the result
		return isset( $response['id'] ) ? $response['id'] : false;
	}
	
	// Expand a URL
	function expand( $url ) {
		// Send information along
		$response = $this->send( $url, false );
		
		// Return the result
		return isset( $response['longUrl'] ) ? $response['longUrl'] : false;
	}
	
	// Send information to Google
	function send( $url, $shorten = true ) {
		// Create cURL
		$ch = curl_init();
		
		// If we're shortening a URL...
		if( $shorten ) {
			curl_setopt( $ch, CURLOPT_URL, $this->api_url );
			curl_setopt( $ch, CURLOPT_POST, 1 );
			curl_setopt( $ch, CURLOPT_POSTFIELDS, json_encode( array( "longUrl" => $url ) ) );
			curl_setopt( $ch, CURLOPT_HTTPHEADER, array( "Content-Type: application/json" ) );
		} else {
			curl_setopt( $ch, CURLOPT_URL, $this->api_url . '&shortUrl=' . $url );
		}
		
		curl_setopt( $ch, CURLOPT_RETURNTRANSFER, 1 );
		
		// Execute the post
		$result = curl_exec( $ch );
		
		// Close the connection
		curl_close( $ch );
		
		// Return the result
		return json_decode( $result, true );
	}
}