zimejin

import { TestBed, tick, fakeAsync } from '@angular/core/testing';
import { UserAsyncComponent } from './user-async.component';
import { UserAsyncService } from './user-async.service';
import { Observable, Observer } from 'rxjs';

describe('User Async Component:', () => {
  beforeEach(async () => {
    TestBed.configureTestingModule({
      declarations: [UserAsyncComponent]
    });

zimejin

import { Observable, Observer } from 'rxjs';

export class UserAsyncService {
  user = { name: 'Mannie' };
  getUserDetails() {
    // Create an observables.
    const userObservables = Observable.create(
      (observer: Observer<{ name: string }>) => {
        setTimeout(() => {
          observer.next(this.user);

zimejin

import { async, TestBed } from '@angular/core/testing';

import { UserComponent } from './user.component';
import { UserService } from './user.service';

describe('UserComponent', () => {

  beforeEach(async(() => {
    TestBed.configureTestingModule({
      declarations: [UserComponent]

zimejin

export interface GoogleData {
  id: number;
  country: string;
  zipCode: string;
}

zimejin

import { Component, OnInit } from '@angular/core';
import { UserAsyncService } from './user-async.service';
import { Observable } from 'rxjs';

@Component({
  selector: 'app-user-async',
  templateUrl: './user-async.component.html',
  styleUrls: ['./user-async.component.scss'],
  providers: [UserAsyncService]
})

zimejin

import { Pipe, PipeTransform } from '@angular/core';

@Pipe({ name: 'excerpt' })
export class ExcerptPipe implements PipeTransform {
  transform(text: string, limit: number = 5) {
    if (text.length <= limit) {
      return text;
    }
    return text.substring(0, limit) + '...';
  }

zimejin

// Animal factory
const Animal = function(name){
    const animal = {};
    animal.name = name;
    animal.walk = function(){
        console.log(this.name + " walks");
    }
    return animal;
};

zimejin

// Using slice() to Remove value from beginning and end of string.
sliceString = function (value) {
    let result = value.slice(1, -1);
    return result;
}


// Using splice() method to changes the contents of an array by removing 
// or replacing existing elements and/or adding new elements
var months = ['Jan', 'March', 'April', 'June'];

zimejin

//emit value every 1s
const source = interval(1000);
const example = source.pipe(
  map(val => {
    if (val > 5) {
      //error will be picked up by retryWhen
      throw val;
    }
    return val;
  }),

zimejin

(focus)="myMethod()"  // An element has received focus
(blur)="myMethod()"   // An element has lost focus

(submit)="myMethod()"  // A submit button has been pressed

(scroll)="myMethod()"

(cut)="myMethod()"
(copy)="myMethod()"
(paste)="myMethod()"