automatic-analytics-trigger/dist/automatic-analytics-trigger.js

Automatically trigger events and mutations for analytics

'use strict';

var defaultConfig = {
  mutations: ['show'],
  events: ['click'],
  target: document.documentElement || document.body,
  maxAncestorsChecks: 5,
};

const DATASET = 'data-analytics';

class EventListener {
  constructor(events, target, dispatcheEvent, finder) {
    this.target = target;
    this.events = events;
    this.dispatcheEvent = dispatcheEvent;
    this.listeners = {};
    this.finder = finder;
  }

  registerEventsListeners() {
    for (const event of this.events) {
      this.listeners[event] = e => this._eventHandler(e, `${DATASET}-${event}`);

      this.target.addEventListener(event, this.listeners[event], false);
    }
  }

  removeEventsListeners() {
    for (const event of this.events) {
      this.target.removeEventListener(event, this.listeners[event], false);
    }
  }

  _eventHandler(event, datasetEvent) {
    const markedElement = this.finder.firstWithAttribute(event, datasetEvent);

    if (markedElement == undefined) return;

    this.dispatcheEvent(markedElement);
  }
}

class EventElementFinder {
  constructor(maxAncestorsChecks = 0) {
    this.maxAncestorsChecks = maxAncestorsChecks;
  }

  firstWithAttribute(event, attribute) {
    let elements = event.composedPath();

    elements = this._removeWindowAndDocumentFromList(elements);

    elements = this._applyLimitIfNecessary(elements);

    return elements.find(element => element.hasAttribute(attribute));
  }

  _removeWindowAndDocumentFromList(elements) {
    return elements.slice(0, elements.length - 2);
  }

  _applyLimitIfNecessary(elements) {
    if (this._notNecessaryApplyLimit(this.maxAncestorsChecks)) {
      return elements;
    }

    return elements.slice(0, this.maxAncestorsChecks);
  }

  _notNecessaryApplyLimit(elements) {
    return this.maxAncestorsChecks == 0 || elements.length <= this.maxAncestorsChecks;
  }
}

const DATASET$1 = 'data-analytics';

class MutationListener {
  constructor(mutations, target, dispatcheEvent) {
    this.target = target;
    this.mutations = mutations;
    this.dispatcheEvent = dispatcheEvent;
  }

  registerMutationsListeners() {
    this.observer = new MutationObserver(this._mutationHandler.bind(this));
    this.observer.observe(this.target, {
      attributes: true,
      childList: true,
      subtree: true,
      attributeFilter: ['style'],
    });
  }

  removeMutationsListeners() {
    if (this.observer) {
      this.observer.disconnect();
      this.observer = null;
    }
  }

  _mutationHandler(mutations) {
    for (let mutation of mutations) {
      this._checkShowAttributes(mutation);
      this._checkShowAddedNodes(mutation);
    }
  }

  _checkShowAttributes(mutation) {
    if (mutation.type === 'attributes' && isShowEvent(mutation.target) && mutation.attributeName === 'style') {
      if (isVisibleElement(mutation.target)) this.dispatcheEvent(mutation.target);
    }
  }

  _checkShowAddedNodes(mutation) {
    if (mutation.type === 'childList' && mutation.addedNodes.length > 0) {
      for (let node of mutation.addedNodes) {
        if (isShowEvent(node) && isVisibleElement(node)) this.dispatcheEvent(node);
      }
    }
  }
}

const isShowEvent = node => node.dataset && node.hasAttribute([`${DATASET$1}-show`]);

const isVisibleElement = element => element.style.display != 'none' && element.style.visibility != 'hidden';

class AutomaticAnalyticsTrigger {
  constructor(callback, customConfig) {
    const config = { ...defaultConfig, ...customConfig };

    this.callback = callback;
    this.target = config.target;
    this.events = config.events;
    this.mutations = config.mutations;
    this.maxAncestorsChecks = config.maxAncestorsChecks;

    this.finder = new EventElementFinder(this.maxAncestorsChecks);

    this._dispatcheEventData = this._dispatcheEventData.bind(this);
  }

  init() {
    if (this.events) {
      this.eventListener = new EventListener(this.events, this.target, this._dispatcheEventData, this.finder);
      this.eventListener.registerEventsListeners();
    }

    if (this.mutations) {
      this.mutationListener = new MutationListener(this.mutations, this.target, this._dispatcheEventData);
      this.mutationListener.registerMutationsListeners();
    }
  }

  close() {
    if (this.events) this.eventListener.removeEventsListeners();
    if (this.mutations) this.mutationListener.removeMutationsListeners();
  }

  _dispatcheEventData(target) {
    const eventData = this._getEventDataFromDataAttributes(target.dataset);
    this.callback(eventData);
  }

  _getEventDataFromDataAttributes(dataset) {
    const dimensions = Object.keys(dataset)
      .filter(key => key.includes('analyticsDimension'))
      .reduce((obj, key) => {
        obj[key.replace('analyticsDimension', 'dimension')] = dataset[key];
        return obj;
      }, {});

    return {
      ...(dataset.analyticsEvent && { event: dataset.analyticsEvent }),
      ...(dataset.analyticsEventCategory && { eventCategory: dataset.analyticsEventCategory }),
      ...(dataset.analyticsEventAction && { eventAction: dataset.analyticsEventAction }),
      ...(dataset.analyticsEventLabel && { eventLabel: dataset.analyticsEventLabel }),
      ...(dataset.analyticsEventValue && { eventValue: dataset.analyticsEventValue }),
      ...(dataset.analyticsScreenName && { screenName: dataset.analyticsScreenName }),
      ...(Object.keys(dimensions).length > 0 && { eventDimensions: dimensions }),
    };
  }
}

module.exports = AutomaticAnalyticsTrigger;