Converts product links to the Amazon Smile domain, generated by the Amazon Auto Links WordPress plugin.

amazon-auto-links-product-link-to-smile.php

<?php
/**
 *	Plugin Name:    Amazon Auto Links - Product Link to Amazon Smile
 *	Plugin URI:     http://en.michaeluno.jp/amazon-auto-links
 *	Description:    Converts product links to the Amazon Smile domain 
 *	Author URI:     http://michaeluno.jp
 *	Version:        0.0.1
 *  Author:         Michael Uno
 */
 

new AmazonAutoLinks_AmazonSmileProductLinks;

class AmazonAutoLinks_AmazonSmileProductLinks {
    
    public function __construct() {
        add_filter( 'aal_filter_product_link', array( $this, '_getProductLinkModified' ), 10, 4 );
    }

    public function _getProductLinkModified( $sURL, $sRawURL, $sASIN, $aUnitOptions ) {
        return str_replace(
            "://www.amazon.",   // search
            "://smile.amazon.", // replace
            $sURL               // subject
        );
    }   
    
}