nwjs/nw.js · error · TypeError

Must set 'title' or 'icon' field in option

Error message

Must set 'title' or 'icon' field in option

What it means

Thrown by the Tray constructor when option is an object but has neither a 'title' nor an 'icon' property. At least one of these must be present because the native Tray requires something to display (text or image). Both are checked via hasOwnProperty, so inherited properties do not count.

Source

Thrown at src/resources/api_nw_tray.js:29

  var tray = trayEvents.objs[id];
  if (!tray)
    return;
  var args = Array.prototype.slice.call(arguments, 1);
  args.unshift('click');
  tray.emit.apply(tray, args);
});

function Tray(option) {
  if (!(this instanceof Tray)) {
    return new Tray(option);
  }
  EventEmitter.apply(this);

  if (typeof option != 'object')
    throw new TypeError('Invalid option.');

  if (!option.hasOwnProperty('title') && !option.hasOwnProperty('icon'))
    throw new TypeError("Must set 'title' or 'icon' field in option");

  if (!option.hasOwnProperty('title'))
    option.title = '';
  else
    option.title = String(option.title);

  if (option.hasOwnProperty('icon')) {
    option.shadowIcon = String(option.icon);
    option.icon = nwNative.getAbsolutePath(option.icon);
  }

  if (option.hasOwnProperty('alticon')) {
    option.shadowAlticon = String(option.alticon);
    option.alticon = nwNative.getAbsolutePath(option.alticon);
  }

  if (option.hasOwnProperty('iconsAreTemplates'))
    option.iconsAreTemplates = Boolean(option.iconsAreTemplates);

View on GitHub (pinned to e15da848e9)

Solutions

1. Include at least one of title or icon in the initial options: { title: '' } is acceptable (empty title) if you plan to set an icon immediately after.
2. Default to a title or icon path in your config loader before constructing the Tray.

Example fix

// before
new nw.Tray({ tooltip: 'My App', click: handler });
// after
new nw.Tray({ title: 'My App', tooltip: 'My App', click: handler });

if (!option || (!('title' in option) && !('icon' in option))) {
  throw new TypeError("Tray option must include 'title' or 'icon'");
}

function hasTrayTitleOrIcon(o) { return !!o && (o.hasOwnProperty('title') || o.hasOwnProperty('icon')); }

When it happens

Trigger: new nw.Tray({ tooltip: 'x' }) (only tooltip); new nw.Tray({}) (empty object); new nw.Tray({ click: fn }) (only a click handler).

Common situations: Building the options object from optional config where both title and icon ended up unset; intending to set the icon later via the setter but the constructor still requires one upfront; spreading a partial config.

Related errors

• A normal MenuItem must have a label
• Shortcut requires 'key' to specify key combinations.
• Must set 'title' or 'icon' field in option
• Shortcut requires 'key' to specify key combinations.
• Invalid option.

AI-assisted analysis of nwjs/nw.js@e15da848e9 (2026-08-13). Data as JSON: /api/errors/1d6908f8235f7303. Report an issue: GitHub.