namespace

Provides an API for creating namespaces for any given objects, which effectively may be used for creating fields that are not part of objects public API.

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let { ns } = require('api-utils/namespace');
let aNamespace = ns();
 
aNamespace(publicAPI).secret = secret;

One namespace may be used with multiple objects:

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let { ns } = require('api-utils/namespace');
let dom = ns();
 
function View(element) {
  let view = Object.create(View.prototype);
  dom(view).element = element;
  // ....
}
View.prototype.destroy = function destroy() {
  let { element } = dom(this);
  element.parentNode.removeChild(element);
  // ...
};
// ...
exports.View = View;
// ...

Also, multiple namespaces can be used with one object:

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// ./widget.js
 
let { Cu } = require('chrome');
let { ns } = require('api-utils/namespace');
let { View } = require('./view');
 
// Note this is completely independent from View's internal Namespace object.
let sandboxes = ns();
 
function Widget(options) {
  let { element, contentScript } = options;
  let widget = Object.create(Widget.prototype);
  View.call(widget, options.element);
  sandboxes(widget).sandbox = Cu.Sandbox(element.ownerDocument.defaultView);
  // ...
}
Widget.prototype = Object.create(View.prototype);
Widget.prototype.postMessage = function postMessage(message) {
  let { sandbox } = sandboxes(this);
  sandbox.postMessage(JSON.stringify(JSON.parse(message)));
  ...
};
Widget.prototype.destroy = function destroy() {
  View.prototype.destroy.call(this);
  // ...
  delete sandboxes(this).sandbox;
};
exports.Widget = Widget;

In addition access to the namespace can be shared with other code by just handing them a namespace accessor function.

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let { dom } = require('./view');
Widget.prototype.setInnerHTML = function setInnerHTML(html) {
  dom(this).element.innerHTML = String(html);
};