javascript - How to programmatically change the selected option in an html select tag - Stack Overflow

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I have a select group in my html to select a price range with. The user can select a range, and then filter the results based on the selection. This works fine, however the user can also reset the results from a totally different place (a search box). I need to change the selection that is actually displayed in the select box so I can reset it to "show all" so that it doesn't look like it is still filtered by price range when the user has actually reset the results from the search box.

I'm able to change the actual value that is selected via the following:

document.getElementById("selectedPriceRange").setAttribute("value","0")

This does actually change the value held in the select box, but the box itself still displays whichever option was last selected.

How can I get the text that is shown in the select box to change without physically selecting another option?

Here's my select box:

<select #priceRangeOptions class="custom-select" id="inputGroupSelect01">
     <option *ngFor="let priceRange of priceRangeOptions; let i=index"
     id="selectedPriceRange" [value]="i">{{priceRange}}</option>
</select>

I have a select group in my html to select a price range with. The user can select a range, and then filter the results based on the selection. This works fine, however the user can also reset the results from a totally different place (a search box). I need to change the selection that is actually displayed in the select box so I can reset it to "show all" so that it doesn't look like it is still filtered by price range when the user has actually reset the results from the search box.

I'm able to change the actual value that is selected via the following:

document.getElementById("selectedPriceRange").setAttribute("value","0")

This does actually change the value held in the select box, but the box itself still displays whichever option was last selected.

How can I get the text that is shown in the select box to change without physically selecting another option?

Here's my select box:

<select #priceRangeOptions class="custom-select" id="inputGroupSelect01">
     <option *ngFor="let priceRange of priceRangeOptions; let i=index"
     id="selectedPriceRange" [value]="i">{{priceRange}}</option>
</select>

• javascript
• html
• angular
• html-select

Share Improve this question Follow asked Jul 2, 2019 at 23:17 KatKat 1,56411 gold badge1212 silver badges1414 bronze badges

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3 Answers 3

Sorted by: Reset to default 5

Don't use Javascript to query the DOM / set values

Also, from what you posted you don't need an index (although maybe you do)

Instead, you can do this:

<select #priceRangeOptions class="custom-select" id="inputGroupSelect01" [(ngModel)]="option">
     <option *ngFor="let option of options;"
     id="selectedOption" [value]="option">{{option}}</option>
 </select>

<button type="button" (click)="setHotDog()">Choose the hotdog</button>

The [()] syntax denotes two way binding.

As a proof of concept, this typescript sets the model value:

export class AppComponent  {
  name = 'Angular';
  option: string;
  options: string[] = ['One', 'Another Choice','Wow, A Hotdog?'];

  setHotDog(){
    this.option = this.options[2];
  }
}

This would be the Angular way, and the correct approach

on select all you have to do is to set ngModel attribute and then you can change variable value to set value.

<select #priceRangeOptions [(ngModel)]="selectedValue" class="custom-select" id="inputGroupSelect01">
 <option *ngFor="let priceRange of priceRangeOptions; let i=index"
 id="selectedPriceRange" [value]="i">{{priceRange}}</option>
</select>

selectedValue = 'my selected value.';

or you can use javascript to do that

document.getElementById('inputGroupSelect01').value = "value";

To offer an alternative that is still the Angular way. ReactiveForms!

Template

<form [formGroup]="form">
    <select
      #selectDropdown
      formControlName="dropdown"
      (change)="onChange(selectDropdown.value)"
    >
      <option *ngFor="let option of options">
        {{ option }}
      </option>
    </select>
</form>

Component

@Component({
    ..ponent meta
})
export class MyComponent implements OnInit {

form: FormGroup;

constructor(private fb: FormBuilder) {}

  ngOnInit(): void {
    this.form = this.fb.group({
      formOption: ['initial value'], // Sets initial value for select options
    });
  }

  onChange(selectedValue: string) {
    // Do something with the selected value
  }
}

You can totally hook into the form and watch for valueChanges this.form.get('formOption').valueChanges.subscribe({next: (value) => //do something with value }) or you can use a template variable like I have to grab the value. Either or. The Form, for me, helped set the initial value while giving me the flexibility to do what I want once the user changes the value. Hope this is helpful to someone :)

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