What is the best way to fill an array with specific dropdown values in Angular?

Question

What is the best way to fill an array with specific dropdown values in Angular?

My task is to dynamically populate an array with all selected values from a mat-select dropdown in Angular. The end goal is to generate an input field for each selected value, similar to the example shown below:

Image

I've been contemplating calling a method every time a value is selected, but I'm uncertain about the next steps... Here's what I have so far:

MyComponent.component.html

<mat-form-field>
  <mat-select placeholder="Products" [formControl]="products" multiple>
    <mat-option *ngFor="let product of productsList">{{ product }}</mat-option>
  </mat-select>
</mat-form-field>

MyComponent.component.ts

import { Component, OnInit } from '@angular/core';
import { FormControl } from '@angular/forms';

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

  products = new FormControl();
  productsList = ['Prod1', 'Prod2', 'Prod3', 'Prod4', 'Prod5', 'Prod6'];
  productsToReturn = [];

  constructor() { }

  ngOnInit() {
  }

  fillProductsToReturn(product){
    if(!this.productsToReturn.includes(product)){
      this.productsToReturn.push(product);
    }
  }
}

I'm looking for guidance on how to trigger a method within the HTML file to update the productsToReturn array. Any help would be greatly appreciated!

Thank you!

javascript bootstrap-4 angular-material

Answer 1

Answer №1

It's important to clarify when you need to access the selected objects.

If you require access upon form submission, such as when a button is clicked, you can simply use this.products.value to retrieve the selected options.

Alternatively, if you need access at the moment of selection, you can listen for the selectionChange() event.

<mat-select placeholder="Products" [formControl]="products" multiple (selectionChange)="onSelectionChange($event) >

In your TypeScript file, you can then access the selected options like this:

onSelectionChange(e){
    console.log(e.value); //or
    console.log(this.toppings.value);
}

Answer 2

It's important to clarify when you need to access the selected objects.

If you require access upon form submission, such as when a button is clicked, you can simply use this.products.value to retrieve the selected options.

Alternatively, if you need access at the moment of selection, you can listen for the selectionChange() event.

<mat-select placeholder="Products" [formControl]="products" multiple (selectionChange)="onSelectionChange($event) >

In your TypeScript file, you can then access the selected options like this:

onSelectionChange(e){
    console.log(e.value); //or
    console.log(this.toppings.value);
}

Answer 3

Answer №2

Instead of manually handling it, you can easily bind the value property of the mat-option to the current product string. This will automatically update your FormControl with the selected options.

Here's how you can set it up in your template:

<mat-form-field>
  <mat-select placeholder="Products" [formControl]="products" multiple>
    <mat-option *ngFor="let product of productsList" [value]="product">{{ product }}</mat-option>
  </mat-select>
</mat-form-field>

In your component, you can retrieve the selected options by accessing this.products.value.

If you need a working example, check out this minimal stackblitz demo. The selected values will be displayed next to the mat-select.

Answer 4

Instead of manually handling it, you can easily bind the value property of the mat-option to the current product string. This will automatically update your FormControl with the selected options.

Here's how you can set it up in your template:

<mat-form-field>
  <mat-select placeholder="Products" [formControl]="products" multiple>
    <mat-option *ngFor="let product of productsList" [value]="product">{{ product }}</mat-option>
  </mat-select>
</mat-form-field>

In your component, you can retrieve the selected options by accessing this.products.value.

If you need a working example, check out this minimal stackblitz demo. The selected values will be displayed next to the mat-select.

Answer 5

Answer №3

I successfully resolved my issue... After consulting with j4rey and implementing their suggestions, I made the necessary modifications.

Here is an excerpt from MyComponent.component.html:

<mat-form-field>
  <mat-select placeholder="Products" [formControl]="products" multiple>
    <mat-option *ngFor="let product of productsList" [value]="product" (onSelectionChange)="onSelectionChange(product)">{{ product }}</mat-option>
  </mat-select>
</mat-form-field>

<div class="row" *ngFor="let product of productsToReturn">
  <div class="col-4">
    <mat-form-field>
      <input matInput disabled="disabled" [value]="product">
    </mat-form-field>
  </div>
  <div class="col-2">
    <mat-form-field class="prod-qty">
      <input matInput step="1" value="1" min="1" type="number">
    </mat-form-field>
  </div>
</div>

This snippet is taken from MyComponent.component.ts:

import { Component, OnInit } from '@angular/core';
import { FormControl } from '@angular/forms';

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

  products = new FormControl();
  productsList = ['Prod1', 'Prod2', 'Prod3', 'Prod4', 'Prod5', 'Prod6'];
  productsToReturn = [];

  constructor() { }

  ngOnInit() { }

  onSelectionChange(product: string) {

    if (!this.productsToReturn.includes(product)) {
      this.productsToReturn.push(product);
    } else {
      let index = this.productsToReturn.indexOf(product);
      this.productsToReturn.splice(index, 1);
    }
  }
}

Answer 6

I successfully resolved my issue... After consulting with j4rey and implementing their suggestions, I made the necessary modifications.

Here is an excerpt from MyComponent.component.html:

<mat-form-field>
  <mat-select placeholder="Products" [formControl]="products" multiple>
    <mat-option *ngFor="let product of productsList" [value]="product" (onSelectionChange)="onSelectionChange(product)">{{ product }}</mat-option>
  </mat-select>
</mat-form-field>

<div class="row" *ngFor="let product of productsToReturn">
  <div class="col-4">
    <mat-form-field>
      <input matInput disabled="disabled" [value]="product">
    </mat-form-field>
  </div>
  <div class="col-2">
    <mat-form-field class="prod-qty">
      <input matInput step="1" value="1" min="1" type="number">
    </mat-form-field>
  </div>
</div>

This snippet is taken from MyComponent.component.ts:

import { Component, OnInit } from '@angular/core';
import { FormControl } from '@angular/forms';

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

  products = new FormControl();
  productsList = ['Prod1', 'Prod2', 'Prod3', 'Prod4', 'Prod5', 'Prod6'];
  productsToReturn = [];

  constructor() { }

  ngOnInit() { }

  onSelectionChange(product: string) {

    if (!this.productsToReturn.includes(product)) {
      this.productsToReturn.push(product);
    } else {
      let index = this.productsToReturn.indexOf(product);
      this.productsToReturn.splice(index, 1);
    }
  }
}

What is the best way to fill an array with specific dropdown values in Angular?

Answer №1

Answer №2

Answer №3

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