json-rules-engine/dist/operator-decorator.js

Rules Engine expressed in simple json

'use strict';

Object.defineProperty(exports, "__esModule", {
  value: true
});

var _createClass = 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); } } return function (Constructor, protoProps, staticProps) { if (protoProps) defineProperties(Constructor.prototype, protoProps); if (staticProps) defineProperties(Constructor, staticProps); return Constructor; }; }();

var _operator = require('./operator');

var _operator2 = _interopRequireDefault(_operator);

function _interopRequireDefault(obj) { return obj && obj.__esModule ? obj : { default: obj }; }

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

var OperatorDecorator = function () {
  /**
   * Constructor
   * @param {string}   name - decorator identifier
   * @param {function(factValue, jsonValue, next)} callback - callback that takes the next operator as a parameter
   * @param {function}  [factValueValidator] - optional validator for asserting the data type of the fact
   * @returns {OperatorDecorator} - instance
   */
  function OperatorDecorator(name, cb, factValueValidator) {
    _classCallCheck(this, OperatorDecorator);

    this.name = String(name);
    if (!name) throw new Error('Missing decorator name');
    if (typeof cb !== 'function') throw new Error('Missing decorator callback');
    this.cb = cb;
    this.factValueValidator = factValueValidator;
    if (!this.factValueValidator) this.factValueValidator = function () {
      return true;
    };
  }

  /**
   * Takes the fact result and compares it to the condition 'value', using the callback
   * @param   {Operator} operator - fact result
   * @returns {Operator} - whether the values pass the operator test
   */


  _createClass(OperatorDecorator, [{
    key: 'decorate',
    value: function decorate(operator) {
      var _this = this;

      var next = operator.evaluate.bind(operator);
      return new _operator2.default(this.name + ':' + operator.name, function (factValue, jsonValue) {
        return _this.cb(factValue, jsonValue, next);
      }, this.factValueValidator);
    }
  }]);

  return OperatorDecorator;
}();

exports.default = OperatorDecorator;