@squarespace/controller

Squarespace Controller

Controller is a lightweight control assigner for DOM elements. Controller binds functions to elements, and does the management work of making sure they are relevant, handling lifecycle after asynchronous content load.

NOTICE: This code is licensed to you pursuant to Squarespace’s Developer Terms of Use. See license section below.

Basic Usage:

A controller function is associated with a string through the method register. The string can then be set as the data-controller attribute of an element in the DOM, in order to bind the controller to the element.

Inside the controller function, the DOM element is passed in as an argument.

HTML

<div data-controller="MyController"></div>

JavaScript

import controller from '@squarespace/controller';

function MyController(element) {
  const handleClick = () => {
    element.toggleClass('clicked');
  };
  element.addEventListener('click', handleClick);
}

controller.register('MyController', MyController);

Advanced Usage

Ajax

Controller also exports a method refresh. If you use Ajax loading on your site, refresh should be called whenever an asynchronous load occurs.

Controller functions can return an object with sync and destroy methods. When refresh is called, the Controller manager will take stock of DOM elements, run destroy on any elements that no longer exist on the page, run sync on elements that remain on the page, and run the controller function for elements that are newly added to the page.

Ajax Example

HTML

<div data-controller="MyController"></div>

JavaScript

const controller = require('@squarespace/controller');

function MyController(element) {
  const handleClick = () => {
    element.toggleClass('clicked');
  };
  element.addEventListener('click', handleClick);
  return {
    sync: () => {
      element.removeClass('clicked');
    },
    destroy: () => {
      element.removeEventListener('click', handleClick);
    }
  };
}

controller.register('MyController', MyController);

// Assuming this event is dispatched on ajax load
window.addEventListener('ajax:load', controller.refresh);

Using ES6

If you prefer to handle transpiling and polyfilling on your own, you can import ES6 from Controller:

import controller from '@squarespace/controller/src';

Alternately, Controller specifies a module property in package.json that points to the uncompiled src/index.js, so you may be able to simply import @squarespace/controller if you're using one of the following bundlers:

• Webpack 2
• Rollup

Reference

register(name, controller)

Register a function to a given name string, so that setting data-controller attribute to that string will bind that element to the controller function.

Params

• name string
• controller function

refresh()

Refresh all controllers. To be called after the DOM has been mutated.

License

Portions Copyright © 2016 Squarespace, Inc. This code is licensed to you pursuant to Squarespace’s Developer Terms of Use, available at http://developers.squarespace.com/developer-terms-of-use (the “Developer Terms”). You may only use this code on websites hosted by Squarespace, and in compliance with the Developer Terms. TO THE FULLEST EXTENT PERMITTED BY LAW, SQUARESPACE PROVIDES ITS CODE TO YOU ON AN “AS IS” BASIS WITHOUT WARRANTIES OF ANY KIND, EITHER EXPRESS OR IMPLIED.