foundation-sites/js/foundation.interchange.js

'use strict';

import $ from 'jquery';
import { MediaQuery } from './foundation.util.mediaQuery';
import { Plugin } from './foundation.plugin';
import { GetYoDigits } from './foundation.util.core';


/**
 * Interchange module.
 * @module foundation.interchange
 * @requires foundation.util.mediaQuery
 */

class Interchange extends Plugin {
  /**
   * Creates a new instance of Interchange.
   * @class
   * @name Interchange
   * @fires Interchange#init
   * @param {Object} element - jQuery object to add the trigger to.
   * @param {Object} options - Overrides to the default plugin settings.
   */
  _setup(element, options) {
    this.$element = element;
    this.options = $.extend({}, Interchange.defaults, options);
    this.rules = [];
    this.currentPath = '';
    this.className = 'Interchange'; // ie9 back compat

    this._init();
    this._events();
  }

  /**
   * Initializes the Interchange plugin and calls functions to get interchange functioning on load.
   * @function
   * @private
   */
  _init() {
    MediaQuery._init();

    var id = this.$element[0].id || GetYoDigits(6, 'interchange');
    this.$element.attr({
      'data-resize': id,
      'id': id
    });

    this._addBreakpoints();
    this._generateRules();
    this._reflow();
  }

  /**
   * Initializes events for Interchange.
   * @function
   * @private
   */
  _events() {
    this.$element.off('resizeme.zf.trigger').on('resizeme.zf.trigger', () => this._reflow());
  }

  /**
   * Calls necessary functions to update Interchange upon DOM change
   * @function
   * @private
   */
  _reflow() {
    var match;

    // Iterate through each rule, but only save the last match
    for (var i in this.rules) {
      if(this.rules.hasOwnProperty(i)) {
        var rule = this.rules[i];
        if (window.matchMedia(rule.query).matches) {
          match = rule;
        }
      }
    }

    if (match) {
      this.replace(match.path);
    }
  }

  /**
   * Gets the Foundation breakpoints and adds them to the Interchange.SPECIAL_QUERIES object.
   * @function
   * @private
   */
  _addBreakpoints() {
    for (var i in MediaQuery.queries) {
      if (MediaQuery.queries.hasOwnProperty(i)) {
        var query = MediaQuery.queries[i];
        Interchange.SPECIAL_QUERIES[query.name] = query.value;
      }
    }
  }

  /**
   * Checks the Interchange element for the provided media query + content pairings
   * @function
   * @private
   * @param {Object} element - jQuery object that is an Interchange instance
   * @returns {Array} scenarios - Array of objects that have 'mq' and 'path' keys with corresponding keys
   */
  _generateRules(element) {
    var rulesList = [];
    var rules;

    if (this.options.rules) {
      rules = this.options.rules;
    }
    else {
      rules = this.$element.data('interchange');
    }

    rules =  typeof rules === 'string' ? rules.match(/\[.*?\]/g) : rules;

    for (var i in rules) {
      if(rules.hasOwnProperty(i)) {
        var rule = rules[i].slice(1, -1).split(', ');
        var path = rule.slice(0, -1).join('');
        var query = rule[rule.length - 1];

        if (Interchange.SPECIAL_QUERIES[query]) {
          query = Interchange.SPECIAL_QUERIES[query];
        }

        rulesList.push({
          path: path,
          query: query
        });
      }
    }

    this.rules = rulesList;
  }

  /**
   * Update the `src` property of an image, or change the HTML of a container, to the specified path.
   * @function
   * @param {String} path - Path to the image or HTML partial.
   * @fires Interchange#replaced
   */
  replace(path) {
    if (this.currentPath === path) return;

    var _this = this,
        trigger = 'replaced.zf.interchange';

    // Replacing images
    if (this.$element[0].nodeName === 'IMG') {
      this.$element.attr('src', path).on('load', function() {
        _this.currentPath = path;
      })
      .trigger(trigger);
    }
    // Replacing background images
    else if (path.match(/\.(gif|jpg|jpeg|png|svg|tiff)([?#].*)?/i)) {
      path = path.replace(/\(/g, '%28').replace(/\)/g, '%29');
      this.$element.css({ 'background-image': 'url('+path+')' })
          .trigger(trigger);
    }
    // Replacing HTML
    else {
      $.get(path, function(response) {
        _this.$element.html(response)
             .trigger(trigger);
        $(response).foundation();
        _this.currentPath = path;
      });
    }

    /**
     * Fires when content in an Interchange element is done being loaded.
     * @event Interchange#replaced
     */
    // this.$element.trigger('replaced.zf.interchange');
  }

  /**
   * Destroys an instance of interchange.
   * @function
   */
  _destroy() {
    this.$element.off('resizeme.zf.trigger')
  }
}

/**
 * Default settings for plugin
 */
Interchange.defaults = {
  /**
   * Rules to be applied to Interchange elements. Set with the `data-interchange` array notation.
   * @option
   * @type {?array}
   * @default null
   */
  rules: null
};

Interchange.SPECIAL_QUERIES = {
  'landscape': 'screen and (orientation: landscape)',
  'portrait': 'screen and (orientation: portrait)',
  'retina': 'only screen and (-webkit-min-device-pixel-ratio: 2), only screen and (min--moz-device-pixel-ratio: 2), only screen and (-o-min-device-pixel-ratio: 2/1), only screen and (min-device-pixel-ratio: 2), only screen and (min-resolution: 192dpi), only screen and (min-resolution: 2dppx)'
};

export {Interchange};