chowdown/dist/query/collection.js

A JavaScript library that allows for the quick transformation of DOM documents into useful formats.

"use strict";

function _typeof(obj) { if (typeof Symbol === "function" && typeof Symbol.iterator === "symbol") { _typeof = function _typeof(obj) { return typeof obj; }; } else { _typeof = function _typeof(obj) { return obj && typeof Symbol === "function" && obj.constructor === Symbol && obj !== Symbol.prototype ? "symbol" : typeof obj; }; } return _typeof(obj); }

function _classCallCheck(instance, Constructor) { if (!(instance instanceof Constructor)) { throw new TypeError("Cannot call a class as a function"); } }

function _defineProperties(target, props) { for (var i = 0; i < props.length; i++) { var descriptor = props[i]; descriptor.enumerable = descriptor.enumerable || false; descriptor.configurable = true; if ("value" in descriptor) descriptor.writable = true; Object.defineProperty(target, descriptor.key, descriptor); } }

function _createClass(Constructor, protoProps, staticProps) { if (protoProps) _defineProperties(Constructor.prototype, protoProps); if (staticProps) _defineProperties(Constructor, staticProps); return Constructor; }

function _possibleConstructorReturn(self, call) { if (call && (_typeof(call) === "object" || typeof call === "function")) { return call; } return _assertThisInitialized(self); }

function _assertThisInitialized(self) { if (self === void 0) { throw new ReferenceError("this hasn't been initialised - super() hasn't been called"); } return self; }

function _get(target, property, receiver) { if (typeof Reflect !== "undefined" && Reflect.get) { _get = Reflect.get; } else { _get = function _get(target, property, receiver) { var base = _superPropBase(target, property); if (!base) return; var desc = Object.getOwnPropertyDescriptor(base, property); if (desc.get) { return desc.get.call(receiver); } return desc.value; }; } return _get(target, property, receiver || target); }

function _superPropBase(object, property) { while (!Object.prototype.hasOwnProperty.call(object, property)) { object = _getPrototypeOf(object); if (object === null) break; } return object; }

function _getPrototypeOf(o) { _getPrototypeOf = Object.setPrototypeOf ? Object.getPrototypeOf : function _getPrototypeOf(o) { return o.__proto__ || Object.getPrototypeOf(o); }; return _getPrototypeOf(o); }

function _inherits(subClass, superClass) { if (typeof superClass !== "function" && superClass !== null) { throw new TypeError("Super expression must either be null or a function"); } subClass.prototype = Object.create(superClass && superClass.prototype, { constructor: { value: subClass, writable: true, configurable: true } }); if (superClass) _setPrototypeOf(subClass, superClass); }

function _setPrototypeOf(o, p) { _setPrototypeOf = Object.setPrototypeOf || function _setPrototypeOf(o, p) { o.__proto__ = p; return o; }; return _setPrototypeOf(o, p); }

var Promise = require('bluebird');

var Query = require('./');
/**
 * When executed, this query will return a promise resolving to
 * an array of values such that each value is the result of an inner query
 * executed on a child document.
 *
 * @class CollectionQuery
 * @extends Query
 */


var CollectionQuery =
/*#__PURE__*/
function (_Query) {
  _inherits(CollectionQuery, _Query);

  /**
   * Constructs a CollectionQuery given a selector for a list of child documents
   * and an inner query that describes a value to pick from each child document.
   * 
   * Also takes an object of additional configuration options.
   * 
   * @param  {string}   selector             The selector for the children in the document.
   * @param  {Query}    inner                A query representing what to pick from each child document.
   * @param  {object}   [options]            An object of further configuration options.
   * @param  {any}      [options.default=[]] The default value this query will resolve to if no child documents are found.
   * @param  {function} [options.filter]     A function used to filter the resulting array.
   */
  function CollectionQuery(selector, inner) {
    var options = arguments.length > 2 && arguments[2] !== undefined ? arguments[2] : {};

    _classCallCheck(this, CollectionQuery);

    options.inner = inner;
    return _possibleConstructorReturn(this, _getPrototypeOf(CollectionQuery).call(this, selector, options));
  }
  /**
   * Configures the CollectionQuery given an object of configuration options.
   * 
   * By default, the default value a CollectionQuery will resolve to is an empty array ([]).
   * 
   * The CollectionQuery supports a filter option. This is expected to be a function that
   * is called for every item in the array and where this function does not return
   * a truthy value, then the corresponding item is omitted.
   * 
   * @param  {object}   options              An object of further configuration options.
   * @param  {Query}    options.inner        The inner query representing what to pick from each child document.
   * @param  {any}      [options.default=[]] The default value this query will resolve to if no child documents are found.
   * @param  {function} [options.filter]     A function used to filter the resulting array.
   */


  _createClass(CollectionQuery, [{
    key: "configure",
    value: function configure(options) {
      var _this = this;

      _get(_getPrototypeOf(CollectionQuery.prototype), "configure", this).call(this, options);

      this.options.inner = Query.factory(this.options.inner);
      if (!this.options.hasOwnProperty('default')) this.options["default"] = [];
      if (this.options.hasOwnProperty('filter')) this.options.format.push(function (list) {
        return list.filter(_this.options.filter);
      });
    }
    /**
     * Locates the array of child documents in the given document and attempts to
     * execute the inner query on each one.
     * 
     * @param  {Document}       document  The document to locate the array of containers in.
     * @return {Promise<any>[]} An array of promises resolving to inner querys picked from each child document.
     */

  }, {
    key: "find",
    value: function find(document) {
      var _this2 = this;

      var children = document.children(this.options.selector);
      if (children !== undefined) return children.map(function (child) {
        return _this2.options.inner.on(child);
      });
    }
    /**
     * Given an array of promises, this method simply returns a promise that is
     * fulfilled when all promises in the array have been fulfilled.
     *   
     * @param  {Promise<any>[]} array An array of inner query promises.
     * @param  {Document}       document The document the children were retrieved from.
     * @return {Promise}        A promise that is fulfilled when all the items in the array are fulfilled.
     */

  }, {
    key: "build",
    value: function build(array, document) {
      return Promise.all(array);
    }
  }]);

  return CollectionQuery;
}(Query);

module.exports = CollectionQuery;