MailChimp webhooks for WordPress

webhooks_action.php

<?php
function mcwh_action_webhook() {

	$mcwh_settings = get_option( 'mcwh_settings' );

	mcwh_log('==================[ Incoming Request ]==================');

	// mcwh_log('Full _REQUEST dump:\n'.print_r($_REQUEST,true)); 
	
	if ( empty($_POST) ) {
		mcwh_log('No request details found.');
		die('No request details found.');
	}

	if ( !isset($_GET['key']) ){
    	mcwh_log('FAILED! No security key specified, ignoring request'); 
    	
	} elseif ($_GET['key'] != $mcwh_settings['webhook_key']) {
	
    	mcwh_log('FAILED: Security key specified, but not correct');
    	// mcwh_log("\t".'Wanted: "'.$webhook_key.'", but received "'.$_GET['key'].'"');
    	
	} else {
    
    		//process the request
    		mcwh_log('Processing a "'.$_POST['type'].'" request for email address ' . $_POST['data']['email'] . '...');
    	
		switch($_POST['type']){
			case 'subscribe'  : mcwh_subscribe($_POST['data']);   break;
			case 'unsubscribe': mcwh_unsubscribe($_POST['data']); break;
			case 'cleaned'    : mcwh_cleaned($_POST['data']);     break;
			case 'upemail'    : mcwh_upemail($_POST['data']);     break;
			case 'profile'    : mcwh_profile($_POST['data']);     break;
			default:
				mcwh_log('Request type "'.$_POST['type'].'" unknown, ignoring.');
		}

	}
	
	mcwh_log('Finished processing request.');		

}
?>

webhooks_intercept.php

<?php
function mcwh_parse_request( &$wp )
{
   
    	if ( array_key_exists( 'webhook', $wp->query_vars ) ) {
        
        	mcwh_action_webhook();
        
        	exit();
    	}
    
}
?>

webhooks_setup.php

<?php
function mcwh_endpoint(){

	// access webhook at url such as http://[your site]/webhook
    	add_rewrite_rule( 'webhook' , 'index.php?webhook=1', 'top' );
    	add_rewrite_tag( '%webhook%' , '([^&]+)' );

}
?>

webhooks_subscribe.php

<?php
function mcwh_subscribe($data){

	$mcwh_settings = get_option( 'mcwh_settings' );

	$user_email = $data['email'];

	/* get existing user record */
    	$thisuser = get_user_by( 'email', $user_email );

   	/* if new user... */
    	if ( $thisuser === false ) 
    	
    		/* if hard_subscribe then create new user record */
    		if ( $mcwh_settings['hard_subscribe'] ) {

    			$userdata = array(
    				'user_pass' 	=> wp_generate_password( $length=12, $include_standard_special_chars=false ),
    				'user_login' 	=> $data['id'],
    				'user_email' 	=> $user_email,
    				'first_name' 	=> $data['merges']['FNAME'],
    				'last_name' 	=> $data['merges']['LNAME'],
    				'role' 		=> 'subscriber'
    			);
    		
    			$user_id = wp_insert_user( $userdata );
    
    			if ( !is_wp_error( $user_id ) ) {
    		
    				mcwh_log( 'SUBSCRIBE: Created new user [ ' . $user_email . ' ]' );
    			
    			} else {
    		
    				mcwh_log( 'SUBSCRIBE: FAILED! Problem encountered trying to create new user [ ' . $user_email . ' ]' );
    				return;
    			}
    			
    		} else {
    			
    			/* if no user found and not creating accounts then exit */
    			mcwh_log( 'SUBSCRIBE: FAILED! No user found with this email address and hard_(un)subscribe is false' );
    			return;

    	} else {

    		mcwh_log( 'SUBSCRIBE: Existing user found with this email address  ' . $user_email );
    		$user_id = $thisuser->ID;
	}

	/* update the user meta regardless - if hard_unsubscribe just won't be shown on the user profile */
	$subscribed = update_user_meta( $user_id, '_newsletter_subscriber', 1, 0 );
	
	mcwh_log( 'SUBSCRIBE: ' . ( $subscribed ? 'SUCCESS! User subscribed' : 'FAILED! User already subscribed' ) );  
}
?>

webhooks_unsubscribe.php

<?php
function mcwh_unsubscribe($data){

	$mcwh_settings = get_option( 'mcwh_settings' );
	
	$user_email = $data['email'];

	/* get existing user */
    	$thisuser = get_user_by( 'email', $user_email );
    
	/* if user exists then unsubscribe */
    	if( $thisuser ) {
    	
    		/* if hard unsubscribe then delete the user */
    		if ( $mcwh_settings['hard_unsubscribe'] ) {
    
    			/* have to include this file to get access to wp_delete_user function */
    			require_once(ABSPATH.'wp-admin/includes/user.php' );
    
    			wp_delete_user( $thisuser->ID );

    			mcwh_log( 'UNSUBSCRIBE: SUCCESS! ' . $user_email . ' deleted (hard unsubscribe) ');
    		
    		} else {
    		
    			/* soft unsubscribe - just change _newsletter_subscriber meta to 0 */
    			$unsubscribed = update_user_meta( $thisuser->ID, '_newsletter_subscriber', 0, 1 );
			mcwh_log( 'UNSUBSCRIBE: ' . ( $unsubscribed ? 'SUCCESS! User unsubscribed' : 'FAILED: User already unsubscribed' ) );  
    		
    		}
    
    	} else {
    
    		mcwh_log ( 'UNSUBSCRIBE: FAILED! User with email address ' . $user_email . ' does not exist. Cannot unsubscribe.' );
    	}
    	
}
?>

webhooks_userprofile.php

<?php

/* add hooks for showing _newsletter_subscriber value in profile */
add_action( 'show_user_profile', 'mcwh_show_user_profile' );
add_action( 'edit_user_profile', 'mcwh_show_user_profile' );
	
function mcwh_show_user_profile( $user ) { 

	$subscribed = get_user_meta( $user->ID, '_newsletter_subscriber', true );

	echo '<h3>MailChimp Newsletter</h3>
    		<table class="form-table">
        		<tr>
            			<th><label for="_newsletter_subscriber">Current Subscriber</label></th>
             			<td>';
	echo '<input type="checkbox" name="_newsletter_subscriber" id="_newsletter_subscriber" ';
	echo $subscribed ? "checked" : ""; 
	echo ' disabled/><br />
                			<span class="description">Is this user subscribed to the MailChimp newsletter?</span>
            			</td>
        		</tr>
    		</table>';
    
}

?>