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Version: 2.x

Change a resolver behavior

As an example, we will change the way the Product meta_description field value is generated.

Create dedicated GraphQL module​

First, you have to create a GraphQL module. For that, you can follow the process detailed in the Create a new GraphQL module. Don't forget to also to register the module in Front-Commerce.

For this example, the ProductMetaDescription module containing:

src/server/modules/productmetadescription/index.js
export default {
  namespace: "ProductMetaDescription",
};

Set the module dependency​

Before being able to inject you custom resolver logic, you first need to find the module that defines the resolver for the field. In our example, the Product meta_description is resolved by the resolver provided by the Magento2/Catalog/Products module. As a result, the Magento2/Catalog/Products module must be added as a dependency of our custom module:

src/server/modules/productmetadescription/index.js
export default {
  namespace: "ProductMetaDescription",
  dependencies: ["Magento2/Catalog/Products"],
};

Implement your custom resolver logic​

Our custom module can now provide a resolver with a custom logic.

src/server/modules/productmetadescription/index.js
import resolvers from "./resolvers";

export default {
  namespace: "ChangeResolverBehavior",
  dependencies: ["Magento2/Catalog/Products"],
  resolvers,
};

And the resolver could look like:

src/server/modules/productmetadescription/resolvers.js
export default {
  Product: {
    meta_description: (product) => {
      // your implementation here
      return "my custom description";
    },
  },
};

This custom resolver will now be merged with the existing ones and the meta_description will be resolved with our custom implementation instead of the default one.