How to access multiple checkbox values in Angular 4/5

Question

I want to get the values from my checkboxes but I can only get true or false.

Here is my template:

<h4>Categories</h4>
<div class="form-check" *ngFor="let cat of categories$|async">
    <input class="form-check-input" [(ngModel)]="cat.id" name="{{ cat.name }}" type="checkbox" id="{{cat.name}}">
    <label class="form-check-label" for="{{cat.name}}">
        {{cat.name}}
    </label>
</div>

Here is my component

this.categories$ = this.storeService.getAllCategories().pipe(
    map(result => (result as any).data),
    tap(r => console.log(r))
)

My component basically gets a list of the categories from an external api

You mean, when you check the checkbox with "Tom Ford", you should get "Tom Ford" as value, not `true` or `false`? — Basavaraj Bhusani, May 04 '18 at 11:04
I want my data to be like so brand: Tom Ford or the id of the brand — , May 04 '18 at 11:10
Since `checkbox` takes Boolean value to be checked or un-checked. So you cant make checkbox to have "name" as value. You can make use of `{change)` method which triggers on check change, to do necessary stuffs. — Basavaraj Bhusani, May 04 '18 at 11:17

Pardeep Jain · Answer 1 · 2020-09-25T05:19:46.740

20

You can simply use the change event to get an event when the checkbox clicked like below -

<div class="form-check" *ngFor="let cat of categories">
    <input class="form-check-input" (change)="onChange(cat.name, $event.target.checked)"name="{{ cat.name }}" type="checkbox" id="{{cat.name}}">
    <label class="form-check-label" for="{{cat.name}}">
        {{cat.name}}
    </label>
</div>

onChange(email:string, isChecked: boolean) {
      if(isChecked) {
        this.emailFormArray.push(email);
      } else {
        let index = this.emailFormArray.indexOf(email);
        this.emailFormArray.splice(index,1);
      }
  }

Update

In case of check all checkboxes you can loop over them -

    et checkBoxes = document.querySelectorAll('.form-check-input');
    checkBoxes.forEach(ele => ele.click())

working example

edited Sep 25 '20 at 05:19

answered May 04 '18 at 11:37

Pardeep Jain

78,495
36
155
210

Your example works but I am not seeing the checkboxes in my view? – May 04 '18 at 11:53
Just the binding properly in your view and try to print the json in view part using `|json` pipe – Pardeep Jain May 04 '18 at 12:29
how do I select all checkbox at once ? – Santosh Sep 24 '20 at 15:32
1

@Santosh please check the updated answer and Stackblitz example – Pardeep Jain Sep 25 '20 at 05:20
@PardeepJain, we should avoid use querySelectorAll in Angular (if it's unnecesary). Angular works relation model (variables in .ts) with view (the .html). So the "angular way" is use [(ngModel)] or Reactive Forms, see my answer – Eliseo Sep 25 '20 at 06:24
@Eliseo true that. We should not leave angular boundary if not necesary – Pardeep Jain Sep 25 '20 at 09:23

Srinivasan K K · Accepted Answer · 2018-05-04T11:46:49.953

10

You can use change event with checkbox control like below,

<div class="form-check" *ngFor="let cat of categories$|async">
    <input class="form-check-input" [(ngModel)]="cat.id" name="{{ cat.name }}" type="checkbox" id="{{cat.name}}" (change)="onChangeCategory($event, cat)">
    <label class="form-check-label" for="{{cat.name}}">
        {{cat.name}}
    </label>
</div>

From component.ts file,

    tempArr: any = { "brands": [] };

    onChangeCategory(event, cat: any){ // Use appropriate model type instead of any
      this.tempArr.brands.push(cat.name);

    }

edited May 04 '18 at 11:46

answered May 04 '18 at 11:16

Srinivasan K K

408
4
10

1

What I really want is an array of like: { "brands":[ "Tom Ford", "Rolex" ] } – May 04 '18 at 11:28
Thanks this is just what I was looking for I am using indexOf to not add duplicates – May 04 '18 at 13:16
what if I want all checkbox in false at begin? – Marlaurita Jul 18 '18 at 22:09

Eliseo · Answer 3 · 2020-09-25T06:25:37.223

it's unnecesary use event change and use auxiliar variable to store the array. You can simply use a getter to get the value

If we use as [(ngModel)] 'cat.isChecked'

<div class="form-check" *ngFor="let cat of categories">
    <input class="form-check-input" [(ngModel)]="cat.isChecked" name="{{ cat.name }}" type="checkbox" id="{{cat.name}}">
    <label class="form-check-label" for="{{cat.name}}">
        {{cat.name}}
    </label>
</div>

We can has some like:

get values()
{
    return this.categories.filter(x=>x.isChecked).map(x=>x.id)
}

If we need a "check all" we can use

<input #checkAll type="checkbox" (change)="selectAll(checkAll.checked)">

  selectAll(checked:any)
  {
    this.categories.forEach(x=>x.isChecked=checked)
  }

See the stackblitz

Good approach you are using in the answer. – Pardeep Jain Sep 25 '20 at 09:22 — Pardeep Jain, Sep 25 '20 at 09:22

score 0 · Answer 4 · answered May 04 '18 at 11:06

0

You want to get values from checkboxes. Checkbox represents a boolean. So getting true and false is what you should get.

answered May 04 '18 at 11:06

pbialy

904
11
22

score 0 · Answer 5 · answered Apr 18 '20 at 07:17

Check this Angular Typescript example link

Update HTML template

  <ul class="checkbox-items">
    <li *ngFor="let item of checkboxesDataList">
      <input type="checkbox" [(ngModel)]="item.isChecked" (change)="changeSelection()">{{item.label}}
    </li>
  </ul>

Component Class

  checkboxesDataList = [
    {
      id: 'C001',
      label: 'Photography',
      isChecked: true
    },
    {
      id: 'C002',
      label: 'Writing',
      isChecked: true
    },
    {
      id: 'C003',
      label: 'Painting',
      isChecked: true
    },
    {
      id: 'C004',
      label: 'Knitting',
      isChecked: false
    },
    {
      id: 'C004',
      label: 'Dancing',
      isChecked: false
    },
    {
      id: 'C005',
      label: 'Gardening',
      isChecked: true
    },
    {
      id: 'C006',
      label: 'Drawing',
      isChecked: true
    },
    {
      id: 'C007',
      label: 'Gyming',
      isChecked: false
    },
    {
      id: 'C008',
      label: 'Cooking',
      isChecked: true
    },
    {
      id: 'C009',
      label: 'Scrapbooking',
      isChecked: false
    },
    {
      id: 'C010',
      label: 'Origami',
      isChecked: false
    }
  ]


  // Selected item
  fetchSelectedItems() {
    this.selectedItemsList = this.checkboxesDataList.filter((value, index) => {
      return value.isChecked
    });
  }

  // IDs of selected item
  fetchCheckedIDs() {
    this.checkedIDs = []
    this.checkboxesDataList.forEach((value, index) => {
      if (value.isChecked) {
        this.checkedIDs.push(value.id);
      }
    });
  }

How to access multiple checkbox values in Angular 4/5

5 Answers5

Update

working example

Linked