Dropdown | Deprecate autoDisplayFirst property

[cetincakiroglu]

• autoDisplayFirst property will be removed in the future because of the maintenance time cost and model value collisions.

• Instead of the autoDisplayFirst, users can set the value by the model value as shown below.

// component.html
<p-dropdown [options]="cities" [(ngModel)]="selectedCity" optionLabel="name" placeholder="Select a City"></p-dropdown>


// component.ts
    cities: City[];

    selectedCity: City | undefined;

    ngOnInit() {
        this.cities = [
            { name: 'New York', code: 'NY' },
            { name: 'Rome', code: 'RM' },
            { name: 'London', code: 'LDN' },
            { name: 'Istanbul', code: 'IST' },
            { name: 'Paris', code: 'PRS' }
        ];
        this.selectedCity = this.cities[0] // same output with the autoDisplayFirst property, therefore it's not needed.
    }

[alexnoise79]

it's a pity cause scenario like this cannot be used anymore, and they were very useful

<p-dropdown [options]="cities" ngModel optionLabel="name" (ngModelChange)="doThis($event)></p-dropdown>

[PeterHewat]

Documentation needs updating: https://primeng.org/dropdown#api.dropdown.props.autoDisplayFirst

[ArturJarosz]

Isn't ngModel deprecated as well here as well?

[AlbaSS18]

And if I don't want to select any value, what value should I set? Null or undefined?

[majkers]

It's a really bad change. What if we want to force user to select an item (so we don't want to select firs item) and option list is taken from service? We have to either spread it (option list) with empty|null value and label or use empty string as placeholder now...

[digitalcraftco]

What about async as options now? #14190 (comment)