json-rules-engine/dist/engine.js at master · feenst/json-rules-engine · GitHub

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'use strict';

Object.defineProperty(exports, "__esModule", {

value: true

});

exports.FINISHED = exports.RUNNING = exports.READY = undefined;

var _fact = require('./fact');

var _fact2 = _interopRequireDefault(_fact);

var _rule = require('./rule');

var _rule2 = _interopRequireDefault(_rule);

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

var _operator2 = _interopRequireDefault(_operator);

var _almanac = require('./almanac');

var _almanac2 = _interopRequireDefault(_almanac);

var _events = require('events');

var _engineFacts = require('./engine-facts');

var _engineDefaultOperators = require('./engine-default-operators');

var _engineDefaultOperators2 = _interopRequireDefault(_engineDefaultOperators);

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"); } }

function _possibleConstructorReturn(self, call) { if (!self) { throw new ReferenceError("this hasn't been initialised - super() hasn't been called"); } return call && (typeof call === "object" || typeof call === "function") ? call : self; }

var debug = require('debug')('json-rules-engine');

var READY = exports.READY = 'READY';

var RUNNING = exports.RUNNING = 'RUNNING';

var FINISHED = exports.FINISHED = 'FINISHED';

var Engine = function (_EventEmitter) {

_inherits(Engine, _EventEmitter);

/**

* Returns a new Engine instance

* @param {Rule[]} rules - array of rules to initialize with

function Engine() {

var rules = arguments.length > 0 && arguments[0] !== undefined ? arguments[0] : [];

var options = arguments.length > 1 && arguments[1] !== undefined ? arguments[1] : {};

_classCallCheck(this, Engine);

var _this = _possibleConstructorReturn(this, (Engine.__proto__ || Object.getPrototypeOf(Engine)).call(this));

_this.rules = [];

_this.allowUndefinedFacts = options.allowUndefinedFacts || false;

_this.operators = new Map();

_this.facts = new Map();

_this.status = READY;

rules.map(function (r) {

return _this.addRule(r);

});

_engineDefaultOperators2.default.map(function (o) {

return _this.addOperator(o);

});

return _this;

}

/**

* Add a rule definition to the engine

* @param {object|Rule} properties - rule definition. can be JSON representation, or instance of Rule

* @param {integer} properties.priority (>1) - higher runs sooner.

* @param {Object} properties.event - event to fire when rule evaluates as successful

* @param {string} properties.event.type - name of event to emit

* @param {string} properties.event.params - parameters to pass to the event listener

* @param {Object} properties.conditions - conditions to evaluate when processing this rule

_createClass(Engine, [{

key: 'addRule',

value: function addRule(properties) {

if (!properties) throw new Error('Engine: addRule() requires options');

if (!properties.hasOwnProperty('conditions')) throw new Error('Engine: addRule() argument requires "conditions" property');

if (!properties.hasOwnProperty('event')) throw new Error('Engine: addRule() argument requires "event" property');

var rule = void 0;

if (properties instanceof _rule2.default) {

rule = properties;

} else {

rule = new _rule2.default(properties);

}

rule.setEngine(this);

this.rules.push(rule);

this.prioritizedRules = null;

return this;

}

/**

* Add a custom operator definition

* @param {string} operatorOrName - operator identifier within the condition; i.e. instead of 'equals', 'greaterThan', etc

* @param {function(factValue, jsonValue)} callback - the method to execute when the operator is encountered.

}, {

key: 'addOperator',

value: function addOperator(operatorOrName, cb) {

var operator = void 0;

if (operatorOrName instanceof _operator2.default) {

operator = operatorOrName;

} else {

operator = new _operator2.default(operatorOrName, cb);

}

debug('engine::addOperator name:' + operator.name);

this.operators.set(operator.name, operator);

}

/**

* Add a fact definition to the engine. Facts are called by rules as they are evaluated.

* @param {object|Fact} id - fact identifier or instance of Fact

* @param {function} definitionFunc - function to be called when computing the fact value for a given rule

* @param {Object} options - options to initialize the fact with. used when "id" is not a Fact instance

}, {

key: 'addFact',

value: function addFact(id, valueOrMethod, options) {

var factId = id;

var fact = void 0;

if (id instanceof _fact2.default) {

factId = id.id;

fact = id;

} else {

fact = new _fact2.default(id, valueOrMethod, options);

}

debug('engine::addFact id:' + factId);

this.facts.set(factId, fact);

return this;

}

/**

* Iterates over the engine rules, organizing them by highest -> lowest priority

* @return {Rule[][]} two dimensional array of Rules.

* Each outer array element represents a single priority(integer). Inner array is

* all rules with that priority.

}, {

key: 'prioritizeRules',

value: function prioritizeRules() {

if (!this.prioritizedRules) {

var ruleSets = this.rules.reduce(function (sets, rule) {

var priority = rule.priority;

if (!sets[priority]) sets[priority] = [];

sets[priority].push(rule);

return sets;

}, {});

this.prioritizedRules = Object.keys(ruleSets).sort(function (a, b) {

return Number(a) > Number(b) ? -1 : 1; // order highest priority -> lowest

}).map(function (priority) {

return ruleSets[priority];

});

}

return this.prioritizedRules;

}

/**

* Stops the rules engine from running the next priority set of Rules. All remaining rules will be resolved as undefined,

* and no further events emitted. Since rules of the same priority are evaluated in parallel(not series), other rules of

* the same priority may still emit events, even though the engine is in a "finished" state.

* @return {Engine}

}, {

key: 'stop',

value: function stop() {

this.status = FINISHED;

return this;

}

/**

* Returns a fact by fact-id

* @param {string} factId - fact identifier

* @return {Fact} fact instance, or undefined if no such fact exists

}, {

key: 'getFact',

value: function getFact(factId) {

return this.facts.get(factId);

}

/**

* Runs an array of rules

* @param {Rule[]} array of rules to be evaluated

* @return {Promise} resolves when all rules in the array have been evaluated

}, {

key: 'evaluateRules',

value: function () {

var _ref = _asyncToGenerator(regeneratorRuntime.mark(function _callee(ruleArray, almanac) {

var _this2 = this;

return regeneratorRuntime.wrap(function _callee$(_context) {

while (1) {

switch (_context.prev = _context.next) {

case 0:

return _context.abrupt('return', Promise.all(ruleArray.map(function (rule) {

if (_this2.status !== RUNNING) {

debug('engine::run status:' + _this2.status + '; skipping remaining rules');

return;

}

return rule.evaluate(almanac).then(function (ruleResult) {

debug('engine::run ruleResult:' + ruleResult.result);

if (ruleResult.result) {

_this2.emit('success', rule.event, almanac, ruleResult);

_this2.emit(rule.event.type, rule.event.params, almanac, ruleResult);

almanac.factValue('success-events', { event: rule.event });

} else {

_this2.emit('failure', rule.event, almanac, ruleResult);

}

});

})));

case 1:

case 'end':

return _context.stop();

}

}, _callee, this);

}));

function evaluateRules(_x3, _x4) {

return _ref.apply(this, arguments);

}

return evaluateRules;

}()

/**

* Runs the rules engine

* @param {Object} runtimeFacts - fact values known at runtime

* @param {Object} runOptions - run options

* @return {Promise} resolves when the engine has completed running

}, {

key: 'run',

value: function () {

var _ref2 = _asyncToGenerator(regeneratorRuntime.mark(function _callee2() {

var _this3 = this;

var runtimeFacts = arguments.length > 0 && arguments[0] !== undefined ? arguments[0] : {};

var almanac, orderedSets, cursor;

return regeneratorRuntime.wrap(function _callee2$(_context2) {

while (1) {

switch (_context2.prev = _context2.next) {

case 0:

debug('engine::run started');

debug('engine::run runtimeFacts:', runtimeFacts);

runtimeFacts['success-events'] = new _fact2.default('success-events', (0, _engineFacts.SuccessEventFact)(), { cache: false });

this.status = RUNNING;

almanac = new _almanac2.default(this.facts, runtimeFacts);

orderedSets = this.prioritizeRules();

cursor = Promise.resolve();

// for each rule set, evaluate in parallel,

// before proceeding to the next priority set.

return _context2.abrupt('return', new Promise(function (resolve, reject) {

orderedSets.map(function (set) {

cursor = cursor.then(function () {

return _this3.evaluateRules(set, almanac);

}).catch(reject);

return cursor;

});

cursor.then(function () {

_this3.status = FINISHED;

debug('engine::run completed');

resolve(almanac.factValue('success-events'));

}).catch(reject);

}));

case 8:

case 'end':

return _context2.stop();

}

}, _callee2, this);

}));

function run() {

return _ref2.apply(this, arguments);

}

return run;

}()

}]);

return Engine;

}(_events.EventEmitter);

exports.default = Engine;

json-rules-engine/dist/engine.js at master · feenst/json-rules-engine · GitHub

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