Tips for adding a "Select All" feature to a dropdown list?

Question

Tips for adding a "Select All" feature to a dropdown list?

Currently, I have a dropdown list with a filter for IN and OUT values. The functionality is working as expected:

<select class="form-select" style="max-width: 100px" [ngModel]="selectedBrand" (ngModelChange)="onChangeType($event)">
    <option [value]="'IN'">IN</option>
    <option [value]="'OUT'">OUT</option>
</select>

In my TypeScript file:

  public selectedBrand: any;
  public onChangeType(type: any) {
    this.selectedBrand = type;
    console.log(this.selectedBrand);

    this.filteredCustomer = this.customerTransferts.filter(
        (item) => item.type === this.selectedBrand
    );
    console.log(this.filteredCustomer);
  }

Now, I want to enhance the functionality by adding a SELECT ALL option to display all elements of either IN or OUT.

I'm seeking guidance on what modifications are needed in my code to achieve this.

Thank you in advance for your assistance.

javascript angular typescript

Answer 1

Answer №1

If you want to remove the filter, you can create a function like this:

resetFilter() {
    this.selectedBrand = '';
    this.filteredCustomer = this.customerTransferts
}

You can trigger this function with a button click or any other method you prefer.

Alternatively, you can add another option in your dropdown menu and handle it in the onChangeType method.

<select class="form-select" style="max-width: 100px" [ngModel]="selectedBrand" (ngModelChange)="onChangeType($event)">
    <option [value]="'ALL'">ALL</option>
    <option [value]="'IN'">IN</option>
    <option [value]="'OUT'">OUT</option>
</select>

public onChangeType(type: any) {
    if (type === 'ALL') {
      this.filteredCustomer = this.customerTransferts;
      return;
    }

    this.selectedBrand = type;
    console.log(this.selectedBrand);

    this.filteredCustomer = this.customerTransferts.filter(
        (item) => item.type === this.selectedBrand
    );
    console.log(this.filteredCustomer);
  }

It's recommended to use two-way binding for selectedBrand by changing ngModel to [(ngModel)].

<select class="form-select" style="max-width: 100px" [(ngModel)]="selectedBrand" (ngModelChange)="onChangeType($event)">

This way, the selectedBrand property will stay in sync automatically - both ways.

As a result, you can eliminate this.selectedBrand = type from the onChangeType() function.

public onChangeType(type: any) {
    if (type === 'ALL') {
      this.filteredCustomer = this.customerTransferts;
      return;
    }

    this.filteredCustomer = this.customerTransferts.filter(
        (item) => item.type === type
    );
  }

Answer 2

If you want to remove the filter, you can create a function like this:

resetFilter() {
    this.selectedBrand = '';
    this.filteredCustomer = this.customerTransferts
}

You can trigger this function with a button click or any other method you prefer.

Alternatively, you can add another option in your dropdown menu and handle it in the onChangeType method.

<select class="form-select" style="max-width: 100px" [ngModel]="selectedBrand" (ngModelChange)="onChangeType($event)">
    <option [value]="'ALL'">ALL</option>
    <option [value]="'IN'">IN</option>
    <option [value]="'OUT'">OUT</option>
</select>

public onChangeType(type: any) {
    if (type === 'ALL') {
      this.filteredCustomer = this.customerTransferts;
      return;
    }

    this.selectedBrand = type;
    console.log(this.selectedBrand);

    this.filteredCustomer = this.customerTransferts.filter(
        (item) => item.type === this.selectedBrand
    );
    console.log(this.filteredCustomer);
  }

It's recommended to use two-way binding for selectedBrand by changing ngModel to [(ngModel)].

<select class="form-select" style="max-width: 100px" [(ngModel)]="selectedBrand" (ngModelChange)="onChangeType($event)">

This way, the selectedBrand property will stay in sync automatically - both ways.

As a result, you can eliminate this.selectedBrand = type from the onChangeType() function.

public onChangeType(type: any) {
    if (type === 'ALL') {
      this.filteredCustomer = this.customerTransferts;
      return;
    }

    this.filteredCustomer = this.customerTransferts.filter(
        (item) => item.type === type
    );
  }

Tips for adding a "Select All" feature to a dropdown list?

Answer №1

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