bespoke/lib/bespoke.js

DIY Presentation Micro-Framework

var from = function(opts, plugins) {
  var parent = (opts.parent || opts).nodeType === 1 ? (opts.parent || opts) : document.querySelector(opts.parent || opts),
    slides = [].filter.call(typeof opts.slides === 'string' ? parent.querySelectorAll(opts.slides) : (opts.slides || parent.children), function(el) { return el.nodeName !== 'SCRIPT'; }),
    activeSlide = slides[0],
    listeners = {},

    activate = function(index, customData) {
      if (!slides[index]) {
        return;
      }

      fire('deactivate', createEventData(activeSlide, customData));
      activeSlide = slides[index];
      fire('activate', createEventData(activeSlide, customData));
    },

    slide = function(index, customData) {
      if (arguments.length) {
        fire('slide', createEventData(slides[index], customData)) && activate(index, customData);
      } else {
        return slides.indexOf(activeSlide);
      }
    },

    step = function(offset, customData) {
      var slideIndex = slides.indexOf(activeSlide) + offset;

      fire(offset > 0 ? 'next' : 'prev', createEventData(activeSlide, customData)) && activate(slideIndex, customData);
    },

    on = function(eventName, callback) {
      (listeners[eventName] || (listeners[eventName] = [])).push(callback);
      return off.bind(null, eventName, callback);
    },

    off = function(eventName, callback) {
      listeners[eventName] = (listeners[eventName] || []).filter(function(listener) { return listener !== callback; });
    },

    fire = function(eventName, eventData) {
      return (listeners[eventName] || [])
        .reduce(function(notCancelled, callback) {
          return notCancelled && callback(eventData) !== false;
        }, true);
    },

    createEventData = function(el, eventData) {
      eventData = eventData || {};
      eventData.index = slides.indexOf(el);
      eventData.slide = el;
      return eventData;
    },

    deck = {
      on: on,
      off: off,
      fire: fire,
      slide: slide,
      next: step.bind(null, 1),
      prev: step.bind(null, -1),
      parent: parent,
      slides: slides
    };

  (plugins || []).forEach(function(plugin) {
    plugin(deck);
  });

  activate(0);

  return deck;
};

module.exports = {
  from: from
};