CRUD Operation In Angular - Angular + Core 2.0 CRUD Operation

You can find all of my .NET Core posts here and the source code of my sample application here.

This post is Part Two of the articles on Angular 4 + Core 2.0 CRUD operations.

In my previous post (Part I), I explained how to do Database first in .NET Core 2.0 and we created Employee Web API using Database First approach. This, you can find here.

In this post, we will add different Angular component classes to perform the CRUD operation using an API that we created in this post and will show the details on UI as shown below.

Let us start.

Set routes for API methods

Our first task is to change the routes in API methods so that it would be easier for us to give the path to Angular component pages (Whole class here). For example:

[Route("~/api/GetAllEmployees")] // Add routes in all the methods
[HttpGet]
public IEnumerable GetEmployees() {
return _context.Employees;
}

Add Employee Folder

Add Employee folder on the ClientApp folder, as shown below.

Get Employees

Let us first add the code to get all employees and later, we will add the code for Add, Update, Delete.

For this, we will follow these steps.

Add EmployeeService TypeScript file
Add Employee HTML file
Add Employee component class
Add EmployeeComponent in the ApModule
Add Employee Management in the Navigation Menu

Add EmployeeService TypeScript file

We will add EmployeeService TypeScript file under Employee folder. Add the below code in the EmployeeService.ts class:

// Importing the libraries
import {
Injectable
} from "@angular/core";
import {
Http,
Response,
Headers
} from "@angular/http";
import "rxjs/add/operator/map";
import 'rxjs/add/operator/do'; // debug
import {
Observable
} from "rxjs/Observable";
import {
BehaviorSubject
} from 'rxjs/BehaviorSubject';
// To inject the dependancies in the service
@Injectable()
export class EmployeeService {
public employeeList: Observable < Employee[] > ;
private _employeeList: BehaviorSubject < Employee[] > ;
private baseUrl: string;
private dataStore: {
employeeList: Employee[];
};
//// Constructor to set the values
constructor(private http: Http) {
// Base URL for the API
this.baseUrl = '/api/';
this.dataStore = {
employeeList: []
};
this._employeeList = < BehaviorSubject < Employee[] >> new BehaviorSubject([]);
this.employeeList = this._employeeList.asObservable();
}
// Method to get all employees by calling /api/GetAllEmployees
getAll() {
this.http.get(`${this.baseUrl}GetAllEmployees`).map(response => response.json()).subscribe(data => {
this.dataStore.employeeList = data;
// Adding newly added Employee in the list
this._employeeList.next(Object.assign({}, this.dataStore).employeeList);
}, error => console.log('Could not load employee.'));
}
}

As you can see in the above code, we are getting all the employees by calling /api/GetAllEmployees.

Add Employee HTML file

Add the below HTML code to the file.

<div id="summary" class="section panel panel-primary">
<div class="panel-heading"> Employee Summary</div>
<div class="container">
<table class="table table-striped table-condensed">
<thead>
<tr>
<th>Name</th>
<th>Age</th>
<th>City</th>
<th>Country</th>
<th></th>
</tr>
<tr>
<th></th>
<th></th>
<th></th>
<th></th>
<th></th>
<th></th>
</tr>
</thead>
<tbody *ngFor="let item of employeeList | async">
<tr>
<td><input type="text" [(ngModel)]='item.empName' /></td>
<td><input type="text" [(ngModel)]='item.empAge' /></td>
<td><input type="text" [(ngModel)]='item.empCity' /></td>
<td><input type="text" [(ngModel)]='item.empCountry' /></td>
<td></td>
<td>
</tr>
</tbody>
</table>
</div>
</div>

Here, we have used,

ngFor to use for loop into the Employee list
Bound the Employee model from the component

Add Employee component class

Add the below code in the component class.

import {
Component,
OnInit
} from '@angular/core';
import 'rxjs/add/operator/catch';
import {
EmployeeService
} from "./employeeService";
import {
Observable
} from "rxjs/Observable";
import {
Employee
} from "./employeeService"
//Here we specified the provider as EmployeeService and html path which we will add later
@Component({
selector: 'employee',
providers: [EmployeeService],
templateUrl: './employee.component.html'
})
//After that add below code which will be used to get the data from the service
export class EmployeeComponent implements OnInit {
public employeeList: Observable < Employee[] > ;
showEditor = true;
myName: string;
employee: Employee;
constructor(private dataService: EmployeeService) {
this.employee = new Employee();
}
ngOnInit() {
// if you want to debug info just uncomment the console.log lines.
// console.log("You are in ngOnInit");
this.employeeList = this.dataService.employeeList;
this.dataService.getAll();
}
}

As you can see in the above code, we have specified that the application should call GetAll method of the service on init.

Add EmployeeComponent in the ApModule

Add EmployeeComponent to the class app.shared.module.ts, as shown below.

import {
NgModule
} from '@angular/core';
import {
CommonModule
} from '@angular/common';
import {
FormsModule
} from '@angular/forms';
import {
HttpModule
} from '@angular/http';
import {
RouterModule
} from '@angular/router';
import {
AppComponent
} from './components/app/app.component';
import {
NavMenuComponent
} from './components/navmenu/navmenu.component';
import {
HomeComponent
} from './components/home/home.component';
import {
FetchDataComponent
} from './components/fetchdata/fetchdata.component';
import {
CounterComponent
} from './components/counter/counter.component';
import {
EmployeeComponent
} from './components/Employee/employee.component'; // Added EmployeeComponent here
@NgModule({
declarations: [
AppComponent,
NavMenuComponent,
CounterComponent,
FetchDataComponent,
HomeComponent,
EmployeeComponent // Added EmployeeComponent here
],
imports: [
CommonModule,
HttpModule,
FormsModule,
RouterModule.forRoot([{
path: '',
redirectTo: 'home',
pathMatch: 'full'
}, {
path: 'employee',
component: EmployeeComponent
}, // Added EmployeeComponent here
{
path: 'home',
component: HomeComponent
}, {
path: 'counter',
component: CounterComponent
}, {
path: 'fetch-data',
component: FetchDataComponent
}, {
path: '**',
redirectTo: 'home'
}
])
]
})
export class AppModuleShared {}

Add Employee Management in the Navigation Menu

Update Navigation menu and add the Employee link as below.

<div class='main-nav'>
<div class='navbar navbar-inverse'>
<div class='navbar-header'> <button type='button' class='navbar-toggle' data-toggle='collapse' data-target='.navbar-collapse'>
<span class='sr-only'>Toggle navigation</span>
<span class='icon-bar'></span>
<span class='icon-bar'></span>
<span class='icon-bar'></span>
</button> <a class='navbar-brand' [routerLink]="['/home']">NeelAngular4CRUD</a></div>
<div class='clearfix'></div>
<div class='navbar-collapse collapse'>
<ul class='nav navbar-nav'>
<li [routerLinkActive]="['link-active']"> <a [routerLink]="['/employee']">
<span class='glyphicon glyphicon-employee'></span> Employee Management
</a></li>
<li [routerLinkActive]="['link-active']"> <a [routerLink]="['/home']">
<span class='glyphicon glyphicon-home'></span> Home
</a></li>
<li [routerLinkActive]="['link-active']"> <a [routerLink]="['/counter']">
<span class='glyphicon glyphicon-education'></span> Counter
</a></li>
<li [routerLinkActive]="['link-active']"> <a [routerLink]="['/fetch-data']">
<span class='glyphicon glyphicon-th-list'></span> Fetch data
</a></li>
</ul>
</div>
</div>
</div>