Demo for "Simplify Form Processing with Variable Variables and Lookup Arrays"

Multiple Form Handling Scripts vs. Switch/If...Else Statements vs. Lookup Arrays

A demonstration of how to use variable variables and lookup arrays by Jason Lengstorf.

Example 1 — Multiple Form Handling Scripts

In this example, each form directs to a separate form-handling script.

Processing File 1 (assets/inc/ex1-form1.php)

<?php

// Turn on error reporting so we can see if anything is going wrong
error_reporting(E_ALL);
ini_set('display_errors', 1);

// Make sure our faux-token was supplied
if( isset($_POST['token']) && $_POST['token']==='secret token goes here' )
{
    // Require the necessary class
    require_once 'class.copterlabs_account.inc.php';

    // Create a new instance of the class
    $account_obj = new CopterLabs_Account();

    // Handle the form submission
    $output = $account_obj->save_name();

    // For this example, just output some data about the form submission
    echo "<pre>Processing File: ", $_SERVER['PHP_SELF'],
            "\n\n<strong>Method Output:</strong>\n", $output, "</pre>\n",
            '<p><a href="../../">Go back</a></p>';
}
else
{
    die( 'Invalid form submission' );
}

Processing File 2 (assets/inc/ex1-form1.php)

<?php

// Turn on error reporting so we can see if anything is going wrong
error_reporting(E_ALL);
ini_set('display_errors', 1);

// Make sure our faux-token was supplied
if( isset($_POST['token']) && $_POST['token']==='secret token goes here' )
{
    // Require the necessary class
    require_once 'class.copterlabs_account.inc.php';

    // Create a new instance of the class
    $account_obj = new CopterLabs_Account();

    // Handle the form submission
    $output = $account_obj->save_email();

    // For this example, just output some data about the form submission
    echo "<pre>Processing File: ", $_SERVER['PHP_SELF'],
            "\n\n<strong>Method Output:</strong>\n", $output, "</pre>\n",
            '<p><a href="../../">Go back</a></p>';
}
else
{
    die( 'Invalid form submission' );
}

Processing File 3 (assets/inc/ex1-form1.php)

<?php

// Turn on error reporting so we can see if anything is going wrong
error_reporting(E_ALL);
ini_set('display_errors', 1);

// Make sure our faux-token was supplied
if( isset($_POST['token']) && $_POST['token']==='secret token goes here' )
{
    // Require the necessary class
    require_once 'class.copterlabs_account.inc.php';

    // Create a new instance of the class
    $account_obj = new CopterLabs_Account();

    // Handle the form submission
    $output = $account_obj->save_both();

    // For this example, just output some data about the form submission
    echo "<pre>Processing File: ", $_SERVER['PHP_SELF'],
            "\n\n<strong>Method Output:</strong>\n", $output, "</pre>\n",
            '<p><a href="../../">Go back</a></p>';
}
else
{
    die( 'Invalid form submission' );
}

Example 2 — Single Form Handling Script with a Switch

In this example, all forms direct to the same processing script, which uses a switch statement to determine what action should be taken.

Processing File (assets/inc/ex2-switch.php)

<?php

// Turn on error reporting so we can see if anything is going wrong
error_reporting(E_ALL);
ini_set('display_errors', 1);

// Make sure our faux-token was supplied
if( isset($_POST['token']) && $_POST['token']==='secret token goes here' )
{
    // Require the necessary class
    require_once 'class.copterlabs_account.inc.php';

    // Create a new instance of the class
    $account_obj = new CopterLabs_Account();

    // Sanitize the action
    $action = htmlentities($_POST['action'], ENT_QUOTES);

    // Use the new 'action' hidden input to determine what action to call
    switch( $action )
    {
        // Form 1 handling
        case 'update-name':
            $output = $account_obj->save_name();
            break;

        // Form 2 handling
        case 'update-email':
            $output = $account_obj->save_email();
            break;

        // Form 3 handling
        case 'update-both':
            $output = $account_obj->save_both();
            break;

        // If no valid action is found, something isn't right
        default:
            die( 'Unsupported action.' );
    }

    // For this example, just output some data about the form submission
    echo "<pre>Processing File: ", $_SERVER['PHP_SELF'],
            "\nAction: ", htmlentities($_POST['action'], ENT_QUOTES),
            "\n\n<strong>Method Output:</strong>\n", $output, "</pre>\n",
            '<p><a href="../../#ex2">Go back to example 2</a></p>';
}
else
{
    die( 'Invalid form submission' );
}

Example 3 — Single Form Handling Script with a Lookup Array

In this example, all forms direct to the same processing script, which uses a lookup array to determine what action should be taken.

Processing File (assets/inc/ex3-lookup-array.php)

<?php

// Turn on error reporting so we can see if anything is going wrong
error_reporting(E_ALL);
ini_set('display_errors', 1);

// Make sure our faux-token was supplied
if( isset($_POST['token']) && $_POST['token']==='secret token goes here' )
{
    // Require the necessary class
    require_once 'class.copterlabs_account.inc.php';

    // Create a new instance of the class
    $account_obj = new CopterLabs_Account();

    // Sanitize the action
    $action = htmlentities($_POST['action'], ENT_QUOTES);

    // Set up a lookup array to match actions to method names
    $lookup_array = array(
        'update-name' => 'save_name',
        'update-email' => 'save_email',
        'update-both' => 'save_both'
    );

    // Make sure the array key exists
    if( array_key_exists($action, $lookup_array) )
    {
        // Using variable variables, call the proper method and store the output
        $output = $account_obj->$lookup_array[$action]();
    }
    else
    {
        die( 'Unsupported action.' );
    }

    // For this example, just output some data about the form submission
    echo "<pre>Processing File: ", $_SERVER['PHP_SELF'],
            "\nAction: ", htmlentities($_POST['action'], ENT_QUOTES),
            "\n\n<strong>Method Output:</strong>\n", $output, "</pre>\n",
            '<p><a href="../../#ex3">Go back to example 3</a></p>';
}
else
{
    die( 'Invalid form submission' );
}