Manage subscriptions

- make use of the SubscriberSegment::status column to keep track of unsubscriptions
- unsubscribed segments now appear grayed out in the Subscribers listing
- added unsubscribed_at after segment names when editing a subscriber
- added date() method for Twig (uses WP's date format / date_offset)
- fixed typo in Form iframe export
- fixed unit test for Newsletters
- updated selection component (JSX) to allow more customization

lib/Twig/i18n.php

@@ -18,7 +18,13 @@ class i18n extends \Twig_Extension {
     // twig custom functions
     $twig_functions = array();
     // list of WP functions to map
-    $functions = array('localize', '__', '_n');
+    $functions = array(
+      'localize',
+      '__',
+      '_n',
+      'date',
+      'date_format'
+    );
 
     foreach($functions as $function) {
       $twig_functions[] = new \Twig_SimpleFunction(
@@ -57,6 +63,23 @@ class i18n extends \Twig_Extension {
     return call_user_func_array('_n', $this->setTextDomain($args));
   }
 
+  function date() {
+    $args = func_get_args();
+    $date = (isset($args[0])) ? $args[0] : null;
+    $date_format = (isset($args[1])) ? $args[1] : get_option('date_format');
+
+    if(empty($date)) return;
+
+    // check if it's an int passed as a string
+    if((string)(int)$date === $date) {
+      $date = (int)$date;
+    } else if(!is_int($date)) {
+      $date = strtotime($date);
+    }
+
+    return get_date_from_gmt(date('Y-m-d H:i:s', $date), $date_format);
+  }
+
   private function setTextDomain($args = array()) {
     // make sure that the last argument is our text domain
     if($args[count($args) - 1] !== $this->_text_domain) {