Checkbox is checked and store it in my database with the help of Angular 5

There are two types of forms

1) Template Driven Forms

2) Model Drive Reactive Forms

The example below shows a template driven form. According to the example:

• A User model and a user service are used for storing data in the database.
• onFormSubmit() functions get the form instance once it gets submitted and you could verify for values.
• Once values are verified and assigned to model (User model) then call the service to save the value

Check the tutorial for clear information - Link

TS Component

 export class TemplateDrivenFormComponent { 
        user = new User();
        constructor(private userService: UserService) {
        }
        onFormSubmit(form: NgForm) {

           if(form.invalid){
              return;   
           }    

           this.user.isMarried = form.controls['married'].value;
           // assign other values and form the user object
           this.userService.createUser(this.user); // then call the service to store data
        }
}

HTML

<form #userForm="ngForm" (ngSubmit)="onFormSubmit(userForm)">
  <input type="checkbox" name="married" [ngModel]="user.isMarried">
  <button>Submit</button>
</form>

There you go. For simplicity we'll use a template driven form approach:

You simply bind a form with onSubmit (look at the form tag) and if you want you can add event on the checkbox as well:

Your index.component.html:

<div class="index-component-class">
  <form  (ngSubmit)="onSubmit()">
    <div class="billable">
      <div class="bilable-label">
        <label class="ct-form-label">Billable</label>
      </div>
      <div class="billable-checkbox">
        <input type="checkbox" [name]="billable" (change)="checkboxClicked()" [(ngModel)]="checkboxValue" />
      </div>
    </div>
  <button type="submit"  class="ct-submit"> Done</button>
  </form>
</div>

Your index.component.ts:

import {Component, OnDestroy, OnInit} from '@angular/core';
import {Subscription} from 'rxjs/Subscription';
import {MyHttpService}   from '../../../core/http/myHttp.service';

@Component({
  selector    : 'index-component',
  templateUrl : './index-component.html',
  styleUrls   : ['./index-component.scss'],
})
export class IndexComponent implements OnInit, OnDestroy {

  private sub   : Subscription;
  checkboxValue : boolean;

  constructor(private _myHttpService: MyHttpService) {
  }

  ngOnInit() {
    //Add some setup if you need..
  }

  onSubmit(){
   if(checkboxValue){
     //Go to server
     this._myHttpService.saveInDatabase().subscribe(params => {
       //Decide what you want to to..
     });
   }
  }


  checkboxClicked() {
    //Decide what you want to to..
  }

  ngOnDestroy() {
    this.sub.unsubscribe();
  }

}

HTML File

<div class="form-group">
    <label class="col-md-4">Hobbie</label>
    <table class="table">
      <tbody>
        <tr>
          <td *ngFor="let control of hobbiesArray.controls; let i = index">
            <input class="from-check-input" [formControl]="control" (change)="getSelectedHobbies()" type="checkbox" id="inlinecheckbox{{i}}">
            <label class="from-check-lable" for="inlinecheckbox{{i}}">{{studentHobbies[i]}}</label>
          </td>
        </tr>
      </tbody>
    </table>
  </div>
  <div class="alert alert-danger" *ngIf="studentHobbiesError && checkHobbiesTouched()">
    Atleast choose one
  </div>
<div class="form-group">
    <button (click)="addStudentInfo()" 
    [disabled]="angForm.pristine || angForm.invalid || studentHobbiesError"
    class="btn btn-primary">Add Student</button>
  </div>

Component File

const URL = 'http://localhost:4000/api/upload';

studentHobbies: Array<String> = ['Cricket', 'Reading', 'Football', 'Tenis'];
studentHobbiesError: Boolean = true;
constructor(private fb: FormBuilder, private http: HttpClient, private ss: StudentService) {
this.createForm();
}
createForm() {
this.angForm = this.fb.group({
  s_hobbie: this.addHobbies()
});
}
addHobbies() {
const hobbieArrays = this.studentHobbies.map(element => {
  return this.fb.control(false);
});
return this.fb.array(hobbieArrays);
}
get hobbiesArray() {
return <FormArray>this.angForm.get('s_hobbie');
}
getSelectedHobbies() {
this.selectedHobbies = [];
this.hobbiesArray.controls.forEach((control, i) => {
  if (control.value) {
    this.selectedHobbies.push(this.studentHobbies[i]);
  }
});
this.studentHobbiesError = this.selectedHobbies.length > 0 ? false : true;
}
checkHobbiesTouched() {
let flg = false;
this.hobbiesArray.controls.forEach((control) => {
  if (control.touched){
    flg = true;
  }
});
return flg;
}
addStudentInfo() {
const newHobbie = this.selectedHobbies;
this.ss.addStudent(newHobbie); 
}

Service File

uri = 'http://localhost:4000/student';
addStudent(s_hobbie) {
const obj = {
  s_hobbie: s_hobbie
};
console.log(obj);
this.http.post(`${this.uri}/add`, obj)
    .subscribe(res => this.router.navigate(['/student']));
}

Nodejs File

const express = require('express');
const app = express();
const studentRoutes = express.Router();

studentRoutes.route('/add').post(function (req, res) {
let student = new Student(req.body);
student.save()
    .then(student => {
       res.status(200).json({'student': 'student in added successfully'});
    })
    .catch(err => {
       res.status(400).send("unable to save to database");
    });
});