Retrieving the value that is not currently selected in a mat-select component

Question

Retrieving the value that is not currently selected in a mat-select component

In my mat-table, there is a mat-select component displayed like this:

<mat-select multiple placeholder="{{element.name}}" [(value)]="selectedCol" (selectionChange)="selectionChange($event)" [disabled]="!selection.isSelected(element.id)">
          <div *ngFor="let item of col">
            <div *ngIf="item.Id === element.id">
              <mat-option [value]="item.id"> 
                {{item.name}}
              </mat-option>
            </div>
          </div>
</mat-select>

I am trying to retrieve the value that was unselected so I can eliminate it from the list of selected values. Each row in my table is stored in one variable during "selectionChange".

angular typescript angular-material

Answer 1

Answer №1

When working with HTML

(updateSelection)="updateSelection($event)"

In the TypeScript file

updateSelection(event: MatSelectChange) {
      console.log(event.value)
}

The 'value' here is a list of objects stored in an array

Answer 2

When working with HTML

(updateSelection)="updateSelection($event)"

In the TypeScript file

updateSelection(event: MatSelectChange) {
      console.log(event.value)
}

The 'value' here is a list of objects stored in an array

Answer 3

Answer №2

To efficiently handle deselected values in my table, I aim to retrieve the value that was deselected and remove it from the list of selected values. Each row in my table is stored in a single variable on "selectionChange".

Why?? Angular simplifies this process for you. Utilize [(ngModel)] or a FormControl

<mat-form-field>
  <mat-select placeholder="Toppings" [(ngModel)]="toppings" multiple>
    <mat-option *ngFor="let topping of toppingList" [value]="topping">{{topping}}</mat-option>
  </mat-select>
</mat-form-field>
{{toppings|json}}

//in your .ts
toppings:any[]=[]

or

<mat-form-field>
  <mat-select placeholder="Toppings" [(formControl)]="toppings" multiple>
    <mat-option *ngFor="let topping of toppingList" [value]="topping">{{topping}}</mat-option>
  </mat-select>
</mat-form-field>
{{toppings.value|json}}
//in your .ts
  toppings = new FormControl();

Answer 4

To efficiently handle deselected values in my table, I aim to retrieve the value that was deselected and remove it from the list of selected values. Each row in my table is stored in a single variable on "selectionChange".

Why?? Angular simplifies this process for you. Utilize [(ngModel)] or a FormControl

<mat-form-field>
  <mat-select placeholder="Toppings" [(ngModel)]="toppings" multiple>
    <mat-option *ngFor="let topping of toppingList" [value]="topping">{{topping}}</mat-option>
  </mat-select>
</mat-form-field>
{{toppings|json}}

//in your .ts
toppings:any[]=[]

or

<mat-form-field>
  <mat-select placeholder="Toppings" [(formControl)]="toppings" multiple>
    <mat-option *ngFor="let topping of toppingList" [value]="topping">{{topping}}</mat-option>
  </mat-select>
</mat-form-field>
{{toppings.value|json}}
//in your .ts
  toppings = new FormControl();

Answer 5

Answer №3

After some troubleshooting, I was able to find a solution to my issue. It turns out that I required the deselected value due to having multiple mat-selects with the same ngModel/value. In order to overcome this challenge, I utilized the features of the SelectionModel Class.

Answer 6

After some troubleshooting, I was able to find a solution to my issue. It turns out that I required the deselected value due to having multiple mat-selects with the same ngModel/value. In order to overcome this challenge, I utilized the features of the SelectionModel Class.

Retrieving the value that is not currently selected in a mat-select component

Answer №1

Answer №2

Answer №3

Similar questions

Launching a nested route with a specific URL in Angular 5

Angular - Executing a function in one component from another

Encountered an unhandled promise rejection: TypeError - The Form is undefined in Angular 6 error

What steps can I take to prevent encountering a Typescript Error (TS2345) within the StatePropertyAccessor of the Microsoft Bot Framework while setting a property?

Angular 2 Array Filtering: Mastering the Art

Error message "Uncaught MatSnackBar provider error encountered while attempting to execute 'ng test' command"

In configuring the print settings, I specified margins to ensure proper formatting. However, I noticed that the margin adjustment only applies to the first page. I need

Issue with assigning objects to an array

Passing a click event to a reusable component in Angular 2 for enhanced functionality

Monitoring changes within the browser width with Angular 2 to automatically refresh the model

Is there a way to navigate directly to the code in a TypeScript type definitions index.d.ts file within Visual Studio Code?

How can a Firestore Timestamp object be correctly created within a rules test data set?

Access-Control-Allow-Methods does not allow the use of Method PUT in the preflight response, as stated by Firebase Cloud Functions

Receiving warnings during npm installation and encountering difficulties with fixing issues using npm audit fix

Implementing basic authentication with AWS Lambda and Application Load Balancer

switchMap: Triggering multiple requests simultaneously (2)

Is it required to double click checkboxes to uncheck them?

Transforming Angular application into a microfrontend architecture

The value stored within an object does not automatically refresh when using the useState hook

There seems to be an issue with the <mat-form-field> where normal input functions correctly, but encounters an error when trying to use mat