title: How to add a hidden field in dhtmlx scheduler lightbox
body: <p>I am trying to modify dhtmlx scheduler lightbox, i have added some new fields here, but now the problem i need a hidden field to it, and will pass the value through JavaScript. But dhtmlx scheduler do not have any field type hidden and i am unable to push any custom class or id there. I know there is a example which will create custom lightbox view <a href="https://docs.dhtmlx.com/scheduler/custom_details_form.html" rel="nofollow noreferrer">here</a>, but i do not want to use that just for one field.</p>
  
  <p>Here is My code : </p>
  
  <pre><code>function init() {
      var role = &lt;%= role %&gt; ;
      var custom_form = document.getElementById("custom_form");
      scheduler.config.lightbox.sections = [
          {   name: "Post on",type: "radio",map_to: "post_on",
              options: [
                  { key: "facebook", label: '&lt;i class="fa fa-facebook"&gt; &lt;/i&gt;' },
                  { key: "google", label: '&lt;i class="fa fa-google-plus"&gt; &lt;/i&gt;' },
                  { key: "twtter", label: '&lt;i class="fa fa-twitter"&gt; &lt;/i&gt;' }
              ]
          },
          { name: "files", height: 50, map_to: "files", type: "textarea", focus: true }, //This one need to be a hidden field with a unique class or id
          { name: "text", height: 50, map_to: "description", type: "textarea", focus: true },
          {   name: "Tags: ", type: "multiselect",map_to: "tags",
              options: [
                  { key: "funny", label: 'Funny' },
                  { key: "promotions", label: 'Promotions' },
                  { key: "Branding", label: 'Branding' },
              ]
          },
          {name: "time",height: 72,type: "time",map_to: "auto",},
      ];
      scheduler.config.first_hour = 0;
      scheduler.config.event_duration = (60 * 14) - 10;
      scheduler.config.auto_end_date = true;
      scheduler.config.include_end_by = true;
      scheduler.locale.labels.section_priority = 'Priority';
      // Adding custom button
      scheduler.config.buttons_left = ["dhx_save_btn", "dhx_cancel_btn", "add_file"];
      scheduler.locale.labels["add_file"] = "Add Files";
      scheduler.config.buttons_right = ["dhx_delete_btn", "select_file"]
      scheduler.locale.labels["select_file"] = "Select File";
      scheduler.attachEvent("onLightboxButton", function(button_id, node, e) {
          if (button_id == "add_file") showUploader();
          else if (button_id == "select_file") showFilemanager();
      });
      scheduler.config.xml_date = "%Y-%m-%d %H:%i";
      scheduler.init('scheduler_here', new Date(), "month");
      var user_id = &lt;%= locals.user_id %&gt; ;
      scheduler.templates.xml_date = function(value) { return new Date(value); };
      scheduler.load("/cdata?user_id=" + user_id, "json");
      var dp = new dataProcessor("/cdata?user_id=" + user_id);
      dp.init(scheduler);
      dp.setTransactionMode("POST", false);
      scheduler.templates.event_bar_text = function(text, start, end, event) {
          return "&lt;b&gt;" + end.post_on + "&lt;b&gt; &lt;i&gt;" + end.description + "&lt;/i&gt; " + end.tags;
      };
      scheduler.templates.event_bar_date = function() { return ""; };
  }
  </code></pre>
  
  <p>So is this possible to make the <code>files</code> field hidden and push a special class to it?</p>
  
  <p>Thanks in advance.</p>