Method _propagateChanges

src/material/select/select.ts:1281–1295

Emits change event to set the model value.

(fallbackValue?: any)

  /** Emits change event to set the model value. */
  private _propagateChanges(fallbackValue?: any): void {
    let valueToEmit: any;

    if (this.multiple) {
      valueToEmit = (this.selected as MatOption[]).map(option => option.value);
    } else {
      valueToEmit = this.selected ? (this.selected as MatOption).value : fallbackValue;
    }

    this._value = valueToEmit;
    this.valueChange.emit(valueToEmit);
    this._onChange(valueToEmit);
    this.selectionChange.emit(this._getChangeEvent(valueToEmit));
    this._changeDetectorRef.markForCheck();
  }

  /**
   * Highlights the selected item. If no option is selected, it will highlight