Improving the process of class initialization in Angular 4 using TypeScript

Is there a more efficient method to initialize an inner class within an outer class in Angular 4?

Suppose we have an outer class named ProductsModel that includes ProductsListModel. We need to send the ProductId string array as part of a server-side request. The code below works properly when initializing the inner class inside the outer class.

If not initialized:

export class ProductsModel {
        productList: ProductListModel;
}

However, attempting this resulted in the following error message:

Cannot set property ProductId to be undefined.

Therefore, I initialized it as shown below, which functions as intended. Is there a better way to do this initialization?

Outer Class:

export class ProductsModel{
productList = new ProductListModel();
}


export class ProductListModel{
ProductId: string[];
}

-- app.component.ts

export class AppComponent {

// Initialize outer class here:

products = new ProductsModel();

Inside this subscribe block:


DetailsByProductID(){
this.products.productList.ProductId = ['8901', '8902'];
// pass the model object here 

this.ProductService.fetchByPID(this.products).subscribe(response => console.log(response));
}
}

Answer №1

To ensure smooth initialization, it's best to handle it within the component itself while maintaining your classes with their properties intact.

The error message you are encountering, "Cannot set property of ProductId be undefined," is most likely due to the null value of the product.

You can address this issue by performing the initialization directly within your component, similar to how you did it within the class.

products = new ProductsModel();

this.products.productList = new ProductListModel();

this.products.productList.ProductId = ['8901','8902'];

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