Add linux cron option to settings

[MAILPOET-1538]

lib/Config/Menu.php

@@ -419,6 +419,7 @@ class Menu {
       'pages' => Pages::getAll(),
       'flags' => $flags,
       'current_user' => wp_get_current_user(),
+      'linux_cron_path' => dirname(dirname(__DIR__)),
       'hosts' => array(
         'web' => Hosts::getWebHosts(),
         'smtp' => Hosts::getSMTPHosts()

lib/Cron/CronTrigger.php

@@ -10,6 +10,7 @@ class CronTrigger {
   public static $available_methods = array(
     'mailpoet' => 'MailPoet',
     'wordpress' => 'WordPress',
+    'linux_cron' => 'Linux Cron',
     'none' => 'Disabled'
   );
   const DEFAULT_METHOD = 'WordPress';

views/settings.html

@@ -166,6 +166,16 @@
         toggleReCaptchaSettings();
         $('#settings_re_captcha_tokens_error').hide();
 
+        function toggleLinuxCronSettings() {
+          if ($('input[name="cron_trigger[method]"]:checked').val() === '<%= cron_trigger.linux_cron %>') {
+            $('#settings_linux_cron').show();
+          } else {
+            $('#settings_linux_cron').hide();
+          }
+        }
+        $('input[name="cron_trigger[method]"]').on('click', toggleLinuxCronSettings);
+        toggleLinuxCronSettings();
+
         // page preview
         $('.mailpoet_page_preview').on('click', function() {
           var selection = $(this).siblings('.mailpoet_page_selection');

views/settings/advanced.html

@@ -65,6 +65,35 @@
                  %>
           </label>
         </p>
+        <p>
+          <label>
+            <input
+              type="radio"
+              name="cron_trigger[method]"
+              value="<%= cron_trigger.linux_cron %>"
+            <% if (settings.cron_trigger.method == cron_trigger.linux_cron) %>
+            checked="checked"
+            <% endif %>
+            /><%= __("Server side cron (Linux cron)")
+            %>
+          </label>
+        </p>
+        <div id="settings_linux_cron">
+          <p>
+            <%= __("To use this option please add this command to your crontab:") %><br>
+            <input
+               value="php <%= linux_cron_path %>/mailpoet-cron.php"
+               class="large-text"
+               readonly
+            />
+          <p>
+            <%= __("With the frequency of running it every minute:") %><br>
+            <input
+               value="*/1 * * * *"
+               class="large-text"
+               readonly
+            />
+        </div>
       </td>
     </tr>
     <!-- roles and capabilities -->