Set cookie in from joomla plugin

Question

I want to display App download message(an image)to users browsing my site from Android device only. So i have developed a plugin to achieve this . Now i want to display this message only first time so, i need to set cookie. Here I'm checking if cookie is set first then don't display message else display message but condition is not working it is showing the message everytime.

<?php

defined('_JEXEC') or die;
jimport('joomla.plugin.plugin');

class plgsystemandroidmsg extends JPlugin {

    function onAfterRender() {
        $app = JFactory::getApplication();
        $htmlString = $app->getBody();
        if ($app->isAdmin()) {
            return;
        }
        $uri = JFactory::getURI();
        if (isset($_SERVER['HTTP_USER_AGENT'])) {
            $ua = strtolower($_SERVER['HTTP_USER_AGENT']);
            if (stripos($ua, 'android') !== false) {
                $cookieName = 'mymsgseen';
                $cookieValue = $app->input->cookie->get($cookieName);
                if ($cookieValue != null && $cookieValue == 1) {
                    $htmlString = 'cookie is set : ' . $cookieValue;
                    $app->setBody($htmlString);
                } else {
                    $cookieValue = 1;
                    $expire = time() + 60 * 60 * 24 * 30;
                    $app->input->cookie->set($cookieName, $cookieValue, $expire);
                    $htmlString = 'cookie is not set';
                    $app->setBody($htmlString);
                }
            }
        }
        return true;
    }

}

how can i achieve this? how to set and get cookies in joomla 3 ?

Answer 1

First of all you could first try to fit this code in your template. If may give you more flexibility there.

onAfterRender does not seem right for me to fiddle the content and to set cookies / read cookies.

Are you sure that your plugin is actually being called? Anyway, check your browser console to see the status.