Add require notice (#33)

* Add require notice

* Added {order_discount} and {order_shipping} dynamic values to custom integration

* Add admin notice

Author: hasinur1997

conversion-tracking.php

@@ -76,7 +76,6 @@ public function __construct() {
         $this->init_classes();
 
         register_activation_hook( __FILE__, array( $this, 'activate' ) );
-
         do_action( 'wcct_loaded' );
     }
 
@@ -180,7 +179,7 @@ public function init_hooks() {
         add_action( 'plugins_loaded', array( $this, 'plugin_upgrades' ) );
         add_action( 'init', array( $this, 'localization_setup' ) );
         add_action( 'init', array( $this, 'init_tracker' ) );
-
+        add_action( 'admin_notices', array( $this, 'check_woocommerce_exist' ) );
         add_filter( 'plugin_action_links_' . plugin_basename( __FILE__ ), array( $this, 'plugin_action_links' ) );
     }
 
@@ -273,6 +272,20 @@ function plugin_action_links( $links ) {
 
         return $links;
     }
+    /**
+     * Check Woocommerce exist
+     *
+     * @return void
+     */
+    public function check_woocommerce_exist() {
+        if ( ! function_exists( 'WC' ) ) {
+            ?>
+                <div class="error notice is-dismissible">
+                    <p><?php _e( '<b>Woocommerce conversion tracking</b> requires <a target="_blank" href="https://wordpress.org/plugins/woocommerce/">Woocommerce</a>', 'woocommerce-conversion-tracking' );?></p>
+                </div>
+            <?php
+        }
+    }
 }
 
 function wcct_init() {