In order to resolve a dependency, Angular’s DI uses type annotations. To make sure these types are preserved when transpiled to ES5, TypeScript emits metadata. In this lesson we’ll explore how the @Injectable decorator ensures metadata generation for…

When using provider string tokens, there’s a chance they collide with other third-party tokens. Angular has with the concept of opaque tokens, that allow us to make whatever token we use unique, so we don’t run into collision problems. In this lesson…

First, how to use a build in pipe: <div class="pipe-example"> <label>Uppercase Pipe: {{ message | uppercase }}</label> </div> <div class="pipe-example"> <label>Lowercase Pipe: {{ message | lowercase…

Angular 2 已经正式 Release 了,Thoughtram 已经发布了一系列的文档,对 Angular 2 的各个方面进行深入的阐释和说明. 我计划逐渐将这个系列翻译出来,以便对大家学习 Angular 2 提供一些方便. Getting Started Building a Zippy component in Angular 2 Developing a Tabs component in Angular 2 Angular 2 Template Syntax demystifi…

Dependecies aren’t always objects created by classes or factory functions. Sometimes, all we really want is inject a simple value, which can be a primitive, or maybe just a configuration object. For these cases, we can use value providers and in this…

When you use ngrx/store and you want to fire a service request. When it sucessfully return the response, you need to dispatch action to tell the store update. So one pattern can be considered to follow is: import {Http, Headers} from '@angular/http';…

一.原Http使用总结 使用方法 在根模块或核心模块引入HttpModule 即在AppModule或CoreModule中引入HttpModule: import { HttpModule } from '@angular/http'; @NgModule({ import: [ HttpModule ] // ... }) AppModule {} 在使用的地方注入Http服务 import { Http } from '@angular/http'; // ... constructor(…

一.路由守卫 当用户满足一定条件才被允许进入或者离开一个路由. 路由守卫场景: 只有当用户登录并拥有某些权限的时候才能进入某些路由. 一个由多个表单组成的向导,例如注册流程,用户只有在当前路由的组件中填写了满足要求的信息才可以导航到下一个路由. 当用户未执行保存操作而试图离开当前导航时提醒用户. Angular提供了一些钩子帮助控制进入或离开路由.这些钩子就是路由守卫,可以通过这些钩子实现上面场景. CanActivate: 处理导航到某路由的情况. CanDeactivate: 处理从当前路由…

目录 一. 划重点 二. Angular应用中的Http请求 三. 使用Rxjs构建Http请求结果的处理管道 3.1 基本示例 3.2 常见的操作符 四. 冷热Observable的两种典型场景 4.1 shareReplay与请求缓存 4.2 share与异步管道 五. 一点建议 本文是[Rxjs 响应式编程-第四章 构建完整的Web应用程序]这篇文章的学习笔记. 示例代码托管在:http://www.github.com/dashnowords/blogs 博客园地址:<大史住在大前端>…

Change the default Angular project Understanding it's purpose and limits Klaus KazlauskasFollow Nov 6, 2018 Angular's default project is nothing more than a string, set in angular.json, to say which project should run with ng commands without a defin…