rxjs

Promise, which is resolveswhen the event is triggered. Then immediately remove the event listener. //Generate a Promise that listens only once for an eventvar oncepromise = (emitter, event) = return new Promise (resolve = { var handler = (... args) + = { Emitter.removeeventlistener (event, Handler); Resolve (... args); }; Emitter.addeventlistener (event, Handler); }); };This may seem a little inefficient, but it proves that WebSocket 's information reception can be implemented with our async

= () => {F (). Then ((t) => {Console.log (t);});};Testasync ();It's easy to see from snippets that Promise doesn't fix things, like having a lot of then methods, the whole piece of code is full of Promise methods, not the business logic itself, and every then method is a separate scope, and if you want to share data, It is necessary to expose some of the data to the outermost layer and assign a value within the then. However, Promise is very good for the encapsulation of asynchronous operations

Detailed description of the. Net Core + Angular2 environment, coreangular2 This article describes how to set up the. Net Core + Angular2 environment, as follows: Environment setup: 1) node. js version> 5.0, NPM version> 3.0, TypeScript version> 2.0 (the latest version is enough) 2) install NTVS 1.2 (node tools for vs) and TSVS dev 1.4 (TS for) 3) construct the package. json, tsconfig. json, and gulp. js files. 1. package. json { "name": "template.angular2", "version": "1.0.0", "licenses": [ {

Angular HTTP is to get and save data. The main purpose is to fetch data from my JSON file. Directly on the code bar:1. First introduce the Promise mode: (direct code)Heroes.json: 12345678 { NBSP;NBSP; "data" : [ NBSP;NBSP;NBSP;NBSP; {"id": 1, "name": " Windstorm "}, NBSP;NBSP;NBSP;NBSP; {" id ": 2," Name ":" Bombasto "}, NBSP;NBSP;NBSP;NBSP; {" ID ": 3," "Name": "Magneta"}, NBSP;NBSP;NBSP;NBSP; {"id": 4, "name": "Tornado"} NBSP;NBSP; } http is sur

Set up the. Net Core + Angular2 environment, coreangular2Environment setup: 1) node. js version> 5.0, NPM version> 3.0, TypeScript version> 2.0 (the latest version is enough) 2) install NTVS 1.2 (node tools for vs), TSVS dev 1.4 (TS for) 3) Build a package. json, tsconfig. json, gulp. js File 1. package. json { "name": "template.angular2", "version": "1.0.0", "licenses": [ { "type": "MIT", "url": "https://github.com/angular/angular.io/blob/master/LICENSE" } ], "dependencies"

lines of concurrent sending requests and sequential sending requests, avoid sending duplicate requests;Avoid sending duplicate requests to import ' Rxjs/add/operator/sharereplay '; const HttpGet = This.http . Get ("Assets/heroes.json") . Map ( data = _.values (data)) . Sharereplay (); so that even if you assign the HttpGet to another variable, or repeat the call, it will not be requested again.One way to send HTTP requests in parallel is to

:initializers is not allowed in ambient contexts.--The use of an initialization expression in the context of the environment is not allowed. What's the matter, for me this little white, only the internet search Help. In StackOverflow (https://stackoverflow.com/questions/43361702/ sample-webpack-angular4-application-throwing-errors/43442065) saw someone and I met the same problem, The accepted answer is that there is no problem with the 2.2.1 version of Typescript, and our Package.json file Types

']}) Export class Albumeditcomponent implements OnInit {private albumtypedata; Private file:file[]; Private Editalbumparam:editalbumparam=NewEditalbumparam (); Constructor (private api:apiservice, Private Router:router) {} ngoninit () {}//main implementation methods accept the file when it is modifiedFilechange (event) { This. File =Event.srcElement.files; } //Submit an eventSubmit () {//to submit parameters and files uniformly This. Api.editalbum ( This. Editalbumparam, This. file). Subs

", "@angular/http": "~2.1.1", "@angular/platform-browser": "~2.1.1", "@angular/platform-browser-dynamic": "~2.1.1", "@angular/router": "~3.1.1", "@angular/upgrade": "~2.1.1", "angular-in-memory-web-api": "~0.1.13", "core-js": "^2.4.1", "reflect-metadata": "^0.1.8", "rxjs": "5.0.0-beta.12", "systemjs": "0.19.39", "zone.js": "^0.6.25" }, "devDependencies": { "@types/core-js": "^0.9.34", "@types/node": "^6.0.45", "concurrently": "^3.0.0", "lite-server":

, supporting Typescript, HTML, Angular Material Ngrx, RXJS, and Flex Layout. There are currently more than 2.2 million downloads and 172 angular code snippets. Angular V5 Snippets: Provides snippets of code for TYPESCRIPT, RxJS, HTML, and Docker files. There is currently a more than 2.7 million download volume. React Native/react/redux Snippets for Es6/es7: Provides a snippet of the ES6/ES7 syntax for

, OnInit} from ' @angular/core '; @Component ({ moduleid: __modulename, // fully resolved filename; defined at module loadtime selector: ' Contacts-header ' , ' Header.component.html ', styleurls: [' Header.component.css ']}) Export class Headercomponent Implements OnInit {}JSPM://If We decide to use JSPM, we use the Typescriptoptions configuration format in the Config.js file:Systemjs.config ({typescriptoptions: {module:"Commonjs", Emitdecoratormetadata:true, Experimentaldecorators:tru

Http clientforRoot()The configuration method requires a UserMemoryMockService instance to populate the data with the memory database. Edit app/service/user. restful. service. ts import {Injectable} from '@angular/core';import { Headers, Http } from '@angular/http';import 'rxjs/add/operator/toPromise';import { User } from '../model/User';import { Logger } from './logger.service';@Injectable()export class UserService { private USERURL = 'api/users';

Prepare angular 2 environment Ng-bootstrap is based on angular 2, so it is necessary to prepare the angular 2 environment first. Using Ng-bootstrap Download Ng-bootstrap Ng-bootstrap uses bootstrap 4.0 ALPHA2, so you need to download the bootstrap first and recommend the form of NPM package: NPM Install bootstrap@4.0.0-alpha.2--save Then download the ng-bootstrap and use the same form as NPM package: NPM Install @ng-bootstrap/ng-bootstrap--save Modify Systemjs.confi

We are now in five methods that modify an Immutable.map (). Set Update Delete Clear Merge //set ()varMap =Immutable.map ();varTodo ={ID:+NewDate (), Name:"Todo1", Content:"Learning immutable"}map=map.set (todo.id, Todo);varTask =Map.get (todo.id); Console.log (task.content);//"Learning immutable"//UpdatevarMap =Immutable.map ();varTodo ={ID:+NewDate (), Name:"Todo1", Content:"Learning immutable"}map=map.set (todo.id, Todo); Todo.content= "

Assignment operation symbol: =,+=,-=,*=,/=,%=,.= comparison operation symbol: >, 1. Recommended 10 articles about the PHP die () function Description: Assignment operation symbol: =,+=,-=,*=,/=,%=,.= comparison operation symbol: gt;, 2. Exclusive understanding: JavaScript Functional Programming Summary: JavaScript functional programming is a topic that has been around for a long time, but it seems to be getting hotter from the beginning of the 2016. This may be because the ES6 syntax is more f

Reactive Extensions for Javascript was born a few years ago, and it will be recognized by more developers as the release of the official version of ANGULAR2. The core provided by RXJS is the observable object, which is a combination of asynchronous and event programming using an observable data sequence. A similar asynchronous programming model is that Promise,promise is an asynchronous model based on state change, which cannot be modified once the st

Previous. NET core and ANGULAR2-1 used the dotnet template. I used it because I wanted to write a webapi, but I wrote the next one when I had some problems, so I wrote a branch test first. This time with node as the server--webpack-dev-server. Feel the demo is so easy!First, create a new project directory, here for F:\Visual Studio Code\app1Second, add the JSON configuration file under the project root: Package.json, Tsconfig.json, Typings.json{ "Name": "WebApplication", "Version": "0.0.0", "

With Redux-observable, we had the power of RxJS at our disposal-this means tasks that would otherwise is complicated an D imperative, become simple and declarative. In this lesson we'll respond to a action by queuing up 2 separate Ajax requests that'll execute sequentially. Then we'll group the results from both to an array and produce a single action from our epic that would save the data int o The Redux Store// Action = ' fetch_stories '= ' fetch_s

/common '; import {browseranimationsmodule} from' @angular/platform-browser/animations '; import {headercomponent} from'./header/header.component '; import {maincomponent} from'./main/main.component '; import {footercomponent} from'./footer/footer.component '; Import' Hammerjs '; Import' Rxjs/rx '; Import' Rxjs/add/operator/map '; import {sidenavcomponent} from'./sidenav/sidenav.component '; import {sharedm

Objective The core provided by RXJS is the observable object, which is a combination of asynchronous and event programming using observable data sequences.The asynchronous programming model that is similar to this is Promise,promise is an asynchronous model based on state change, which cannot be modified once the waiting state has entered a success or failure state, and the subscriber can only get a value when the state changes, while the observable