uswds/src/js/utils/behavior.js

Open source UI components and visual style guide for U.S. government websites

const assign = require('object-assign');
const forEach = require('array-foreach');
const Behavior = require('receptor/behavior');

/**
 * @name sequence
 * @param {...Function} seq an array of functions
 * @return { closure } callHooks
 */
// We use a named function here because we want it to inherit its lexical scope
// from the behavior props object, not from the module
const sequence = (...seq) => function callHooks(target = document.body) {
  forEach(seq, (method) => {
    if (typeof this[method] === 'function') {
      this[method].call(this, target);
    }
  });
};

/**
 * @name behavior
 * @param {object} events
 * @param {object?} props
 * @return {receptor.behavior}
 */
module.exports = (events, props) => Behavior(events, assign({
  on: sequence('init', 'add'),
  off: sequence('teardown', 'remove'),
}, props));