mediatr-ts
Version:
Mimic the famous MediatR csharp library see: (https://github.com/jbogard/MediatR)
247 lines • 11.7 kB
JavaScript
"use strict";
var __awaiter = (this && this.__awaiter) || function (thisArg, _arguments, P, generator) {
function adopt(value) { return value instanceof P ? value : new P(function (resolve) { resolve(value); }); }
return new (P || (P = Promise))(function (resolve, reject) {
function fulfilled(value) { try { step(generator.next(value)); } catch (e) { reject(e); } }
function rejected(value) { try { step(generator["throw"](value)); } catch (e) { reject(e); } }
function step(result) { result.done ? resolve(result.value) : adopt(result.value).then(fulfilled, rejected); }
step((generator = generator.apply(thisArg, _arguments || [])).next());
});
};
var __generator = (this && this.__generator) || function (thisArg, body) {
var _ = { label: 0, sent: function() { if (t[0] & 1) throw t[1]; return t[1]; }, trys: [], ops: [] }, f, y, t, g;
return g = { next: verb(0), "throw": verb(1), "return": verb(2) }, typeof Symbol === "function" && (g[Symbol.iterator] = function() { return this; }), g;
function verb(n) { return function (v) { return step([n, v]); }; }
function step(op) {
if (f) throw new TypeError("Generator is already executing.");
while (g && (g = 0, op[0] && (_ = 0)), _) try {
if (f = 1, y && (t = op[0] & 2 ? y["return"] : op[0] ? y["throw"] || ((t = y["return"]) && t.call(y), 0) : y.next) && !(t = t.call(y, op[1])).done) return t;
if (y = 0, t) op = [op[0] & 2, t.value];
switch (op[0]) {
case 0: case 1: t = op; break;
case 4: _.label++; return { value: op[1], done: false };
case 5: _.label++; y = op[1]; op = [0]; continue;
case 7: op = _.ops.pop(); _.trys.pop(); continue;
default:
if (!(t = _.trys, t = t.length > 0 && t[t.length - 1]) && (op[0] === 6 || op[0] === 2)) { _ = 0; continue; }
if (op[0] === 3 && (!t || (op[1] > t[0] && op[1] < t[3]))) { _.label = op[1]; break; }
if (op[0] === 6 && _.label < t[1]) { _.label = t[1]; t = op; break; }
if (t && _.label < t[2]) { _.label = t[2]; _.ops.push(op); break; }
if (t[2]) _.ops.pop();
_.trys.pop(); continue;
}
op = body.call(thisArg, _);
} catch (e) { op = [6, e]; y = 0; } finally { f = t = 0; }
if (op[0] & 5) throw op[1]; return { value: op[0] ? op[1] : void 0, done: true };
}
};
var __importDefault = (this && this.__importDefault) || function (mod) {
return (mod && mod.__esModule) ? mod : { "default": mod };
};
Object.defineProperty(exports, "__esModule", { value: true });
var index_js_1 = require("../models/mappings/index.js");
var instantiationResolver_js_1 = require("./instantiationResolver.js");
var publish_error_js_1 = __importDefault(require("../errors/publish-error.js"));
/**
* The mediator class.
* Sends request and publishes events.
*
* @export
* @class Mediator
* @implements {Mediator}
*/
var Mediator = /** @class */ (function () {
/**
* The constructor.
* If custom settings are provided, it uses the resolver from those settings;
* otherwise, it defaults to a new InstantiationResolver
*
* @param settings The custom settings
*/
function Mediator(settings) {
var resolver = (settings === null || settings === void 0 ? void 0 : settings.resolver) || new instantiationResolver_js_1.InstantiationResolver();
this._resolver = resolver;
this.registerTypesInResolver(resolver);
}
Object.defineProperty(Mediator.prototype, "notifications", {
/**
* Gets the notifications.
*/
get: function () {
return index_js_1.typeMappings.notifications;
},
enumerable: false,
configurable: true
});
Object.defineProperty(Mediator.prototype, "pipelineBehaviors", {
/**
* Gets the pipeline behaviors.
*/
get: function () {
return index_js_1.typeMappings.pipelineBehaviors;
},
enumerable: false,
configurable: true
});
/**
* This method registers types with a resolver.
* If custom settings are provided, it uses the resolver from those settings;
* otherwise, it defaults to a new InstantiationResolver where add method is not used
*
* @param resolver The resolver
*/
Mediator.prototype.registerTypesInResolver = function (resolver) {
for (var _i = 0, _a = index_js_1.typeMappings.notifications.getAll(); _i < _a.length; _i++) {
var mapping = _a[_i];
resolver.add(mapping.handlerClass);
}
for (var _b = 0, _c = index_js_1.typeMappings.requestHandlers.getAll(); _b < _c.length; _b++) {
var mapping = _c[_b];
resolver.add(mapping.handlerClass);
}
for (var _d = 0, _e = index_js_1.typeMappings.pipelineBehaviors.getAll(); _d < _e.length; _d++) {
var mapping = _e[_d];
resolver.add(mapping.behaviorClass);
}
};
/**
* Send a request to the mediator.
*
* @template T
* @param {RequestData<T>} request The request to send
* @returns {Promise<T>}
* @memberof Mediator
*/
Mediator.prototype.send = function (request) {
return __awaiter(this, void 0, void 0, function () {
var handler;
var _this = this;
return __generator(this, function (_a) {
handler = this.getRequiredHandlerForRequest(request);
return [2 /*return*/, this.wrapInPipelineBehaviorChainCalls(function () { return __awaiter(_this, void 0, void 0, function () { return __generator(this, function (_a) {
return [2 /*return*/, handler.handle(request)];
}); }); }, request)];
});
});
};
/**
* Wraps the given function in a chain of pipeline behavior calls.
*
* @param func The function to wrap
* @param request The request to send
* @returns The result of the action
* @memberof Mediator
* @private
*
*/
Mediator.prototype.wrapInPipelineBehaviorChainCalls = function (func, request) {
return __awaiter(this, void 0, void 0, function () {
var currentBehaviorIndex, behaviors, execBehavior, next;
var _this = this;
return __generator(this, function (_a) {
switch (_a.label) {
case 0:
currentBehaviorIndex = 0;
behaviors = index_js_1.typeMappings.pipelineBehaviors.getAll();
execBehavior = function (request, next) { return __awaiter(_this, void 0, void 0, function () {
var behaviorClass, nextBehaviorInChain;
return __generator(this, function (_a) {
switch (_a.label) {
case 0:
behaviorClass = behaviors[currentBehaviorIndex++].behaviorClass;
nextBehaviorInChain = this._resolver.resolve(behaviorClass);
return [4 /*yield*/, nextBehaviorInChain.handle(request, next)];
case 1: return [2 /*return*/, (_a.sent())];
}
});
}); };
next = function () { return __awaiter(_this, void 0, void 0, function () {
var areMoreBehaviorsNeedingProcessing;
return __generator(this, function (_a) {
switch (_a.label) {
case 0:
areMoreBehaviorsNeedingProcessing = currentBehaviorIndex < behaviors.length;
if (!areMoreBehaviorsNeedingProcessing) return [3 /*break*/, 2];
return [4 /*yield*/, execBehavior(request, next)];
case 1: return [2 /*return*/, _a.sent()]; // Process the behavior
case 2: return [4 /*yield*/, func()];
case 3: return [2 /*return*/, _a.sent()]; // Process the handler
}
});
}); };
return [4 /*yield*/, next()];
case 1: return [2 /*return*/, _a.sent()];
}
});
});
};
/**
* Get the handler for the given request
*
* @param {RequestData<TResult>} request The request
* @returns {RequestHandler<RequestData<TResult>, TResult>} The handler
* @private
* @memberof Mediator
*/
Mediator.prototype.getRequiredHandlerForRequest = function (request) {
var handlerClasses = index_js_1.typeMappings.requestHandlers.getAll(request.constructor);
var handler = this._resolver.resolve(handlerClasses[0].handlerClass);
return handler;
};
/**
* Publish a new message
*
* @param {Notification} message The message to publish
* @returns {Promise<void>}
* @memberof Mediator
*/
Mediator.prototype.publish = function (message) {
return __awaiter(this, void 0, void 0, function () {
var events, results;
var _this = this;
return __generator(this, function (_a) {
switch (_a.label) {
case 0:
events = index_js_1.typeMappings.notifications.getAll(message.constructor);
return [4 /*yield*/, Promise.allSettled(events.map(function (p) { return __awaiter(_this, void 0, void 0, function () {
var handler;
return __generator(this, function (_a) {
handler = this._resolver.resolve(p.handlerClass);
return [2 /*return*/, handler.handle(message)];
});
}); }))];
case 1:
results = _a.sent();
if (results.some(function (r) { return r.status === "rejected"; }))
throw new publish_error_js_1.default("Error publishing notification", results);
return [2 /*return*/];
}
});
});
};
/**
* @description - Manually register a handler without {@requestHandler()}
* @type
* @param {RequestDataClass<T>} request - request class
* @param {RequestHandlerClass<RequestData<unknown>, unknown>} handler - request handler class
* @memberof Mediator
*/
Mediator.prototype.registerHandler = function (request, handler) {
index_js_1.typeMappings.requestHandlers.throwIfExistingTypeMappings(request);
// check if handler in resolver
try {
this._resolver.resolve(handler);
}
catch (error) {
// adds handler to resolver, since it wont added in constructing phase
this._resolver.add(handler);
}
index_js_1.typeMappings.requestHandlers.add({
requestClass: request,
handlerClass: handler,
});
};
return Mediator;
}());
exports.default = Mediator;
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