CKEDITOR.plugins.add("cells", {
  icons: "insertcell",
  init: function(editor) {
    editor.addCommand("insertCellDialog", new CKEDITOR.dialogCommand("cellDialog"));

    CKEDITOR.dialog.add("cellDialog", "/assets/ckeditor/plugins/cells/dialogs/cells.js");

    editor.ui.addButton("InsertCell", {
      label: "Insert Cell",
      command: "insertCellDialog",
      icon: "/assets/ckeditor/plugins/cells/icons/insertcell.png",
    });
  },
});

CKEDITOR.dtd.$empty.cell = 1;
CKEDITOR.dtd.$nonEditable.cell = 1;
CKEDITOR.dtd.$object.cell = 1;