How to use the material-components-web.ripple function in material-components-web

var _ = require('underscore')
  , $ = require('jquery')
  , moment = require('moment')
  , MDCRipple = require('material-components-web').ripple.MDCRipple
  , MDCTextField = require('material-components-web').textField.MDCTextField;

module.exports = function observationNewsItem() {
  var directive = {
    restrict: "A",
    template:  require('./observation-feed.directive.html'),
    scope: {
      observation: '=observationNewsItem',
      event: '=event',
      form: '=selectedObservationForm'
    },
    controller: ObservationNewsItemController
  };

  return directive;
};

var _ = require('underscore')
  , $ = require('jquery')
  , moment = require('moment')
  , MDCRipple = require('material-components-web').ripple.MDCRipple
  , MDCTopAppBar = require('material-components-web').topAppBar.MDCTopAppBar
  , MDCTextField = require('material-components-web').textField.MDCTextField;

module.exports = function observationView() {
  var directive = {
    restrict: "E",
    template:  require('./observation-view.directive.html'),
    scope: {
      observation: '=observation',
      event: '=event'
    },
    controller: ObservationViewController
  };

  return directive;
};