[PHP] Refactoring a script to use functions in order to make it a little more maintainable over the course of time.

00-original-script.php

<?php

if ( empty( $_GET['data'] ) ) {
  
  echo "-1";
  die;

}

$query_string = '';
$url     = '' . '?' . $query_string;
$result  = file_get_contents( $url );

echo ( 'request completed successfully' == $result ) ? "success" : "failure";
die;

01-refactored-script.php

<?php

/**
 * @param    string    $url    The URL to which we're making the request.
 * @return   string    $output The result of the request.
 */
function get_request_response ( $url ) {

    /* If cURL is installed, then use it to make the request with the specified URL.
     * If not, then fallback to file_get_contents and return the response.
     */
     
    return $output

}

/**
 * @return   bool    $is_valid    True if the data is valid; otherwise, false.
 */
function data_is_valid() {

	$is_valid = true;

	// Check to see if arguments in the $_GET collection are set

	return $is_valid;

}

if ( data_is_valid() ) {

	// 1. Define the query string parameters here.
	$query_string = '';
	
	// 2. Define the URL to which you're going to be making the request.
	$url     = '';
	
	// 3. Add the query string parameters to the URL
	$url .= '?' . $query_string;
	
	// 4. Now get the result and echo it to the client
	$result  = get_request_response( $url );
	echo ( 'request completed successfully' == $result ) ? "success" : "failure";
	
	die;

}