Override an existing service to extend its functionality

[AndyPelaez]

Hi,

I am attempting to extend the functionality of the ProductVariantService but haven't been successful. I've created a new plugin that includes a CustomVariantProductService extending the original one, which contains a log in the getSelectableStockService.

@Injectable()
export class CustomProductVariantService extends ProductVariantService {
override async getSaleableStockLevel(ctx: RequestContext, variant: ProductVariant): Promise<number> {
Logger.info('getSaleableStockLevel!', loggerCtx);
return super.getSaleableStockLevel(ctx, variant);
}}

I have also included the service in the providers(I know it should be placed in the original module but It is not possible without modifying the original module):

providers: [ { provide: ProductVariantService, useClass: CustomProductVariantService, } ],

I need to do this because I must modify how the stock of a product is obtained(In my case for products that will contain ingredients that set the stock of the product), and I haven't found any strategy that allows me to customize that.

Thanks in advance for any hints!
Best Regards

[michaelbromley]

Hi,

You are correct that providing a custom version of that service would need to be done in the core module in which it is currently declared, so not possible from a plugin.

So are you looking for some way that allows you to use arbitrary custom logic to calculate the stockOnHand for a variant? If so then yes, we don't currently have a strategy for that case. Can you give me an example (can be pseudo code) that illustrates the kind of thing you'd like to be able to do?