roundcube-easy-unsubscribe/easy_unsubscribe.php

<?php

class easy_unsubscribe extends rcube_plugin {

	public $task = 'mail';
	private $message_headers_done = false;
	private $unsubscribe_img;

	function init() {

		$rcmail = rcmail::get_instance();
		$layout = $rcmail->config->get('layout');

		$this->add_hook('message_headers_output', array($this, 'message_headers'));
		$this->add_hook('storage_init', array($this, 'storage_init'));
		
		$this->include_stylesheet('easy_unsubscribe.css');
		$this->include_script('easy_unsubscribe.js');

		$this->add_texts('localization/');

		$rcmail->output->add_label('easy_unsubscribe.confirm');

	}
	
	public function storage_init($p) {

		$p['fetch_headers'] = trim($p['fetch_headers'] . ' ' . strtoupper('List-Unsubscribe'));
		return $p;

	}
	
	public function message_headers($p) {		

		if($this->message_headers_done===false) {

			$this->message_headers_done = true;
			$ListUnsubscribe = $p['headers']->others['list-unsubscribe'];

			if (preg_match_all('/<(.+)>/mU', $ListUnsubscribe, $items, PREG_PATTERN_ORDER)) {

				foreach ( $items[1] as $uri ) {

					$this->unsubscribe_img .= '<a class="easy_unsubscribe_link tooltip-right" data-tooltip="' . $this->gettext('click_to_unsubscribe') . '" data-href="'. htmlentities($uri) .'" target="_blank" onclick="easy_unsubscribe_click(this);"><img src="plugins/easy_unsubscribe/icon.png" alt="' . $this->gettext('unsubscribe') . '" /></a>';
				
				}
			}

		}

		if(isset($p['output']['subject'])) {

			$p['output']['subject']['value'] = $p['output']['subject']['value'] . $this->unsubscribe_img;
			$p['output']['subject']['html'] = 1;

		}

		return $p;

	}

}