Angular: Issue encountered when accessing nested properties within an interface due to reading properties of undefined

Encountering difficulties with utilizing nested property interface.

//Food Interface (food.interface.ts)//

export interface Food {
 name: string;
 quantity?: string;
 description?: string;
 nutrients?: {
  calories?: number;
  protein?: number;
  carbs?: number;
  fats?: number;
 };
}

food.component.html

<input type="number" placeholder="Calories" [(ngModel)]="food.nutrients.calories" name="foodCalories" #calories="ngModel">

food.component.ts

import {Food} from '../../models/food/food.interface';
export class FoodComponent {

 food = {} as Food;

 constructor() {}

}

While accessing the first level properties works correctly, attempting to access the nutrients.(any property) results in 'undefined'.

Answer №1

When you create your meal, it comes with default values for all its properties, including the ingredients which are initialized as an empty object. However, if you have an optional property like spices, it will default to undefined unless explicitly set during initialization.

meal = { spices: {} } as Meal;

Answer №2

To ensure that you can access nutrients without it being undefined in the template, declare it as an empty object.

food = {} as Food;
this.food.nutrients = {};

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