mat-select option to select all options
tosslePerOne(all){
if (this.allSelected.selected) {
this.allSelected.deselect();
return false;
}
if(this.searchUserForm.controls.userType.value.length==this.userTypeFilters.length)
this.allSelected.select();
}
toggleAllSelection() {
if (this.allSelected.selected) {
this.searchUserForm.controls.userType
.patchValue([...this.userTypeFilters.map(item => item.key), 0]);
} else {
this.searchUserForm.controls.userType.patchValue([]);
}
}
------------------- HTML-----------
<form [formGroup]="searchUserForm" fxFlex fxLayout="column" autocomplete="off" style="margin: 30px">
<mat-select placeholder="User Type" formControlName="userType" multiple>
<mat-option *ngFor="let filters of userTypeFilters" [value]="filters.key" (click)="tosslePerOne(allSelected.viewValue)">
{{filters.value}}
</mat-option>
<mat-option #allSelected (click)="toggleAllSelection()" [value]="0">All</mat-option>
</mat-select>
</form>