Feature request for DGS Codegen: Allow interface generation for input types

[krutikavk]

Hi,

Similar to interfaces generation for data classes, having interface generation enabled for input types can be useful to extend functionality for input classes as well.

Use-case Walkthrough

Example of a use-case for interface type: https://github.com/krutikavk/sparseupdate-poc/tree/dynamic-proxy-no-intermediate

This design employs use of dynamic proxy to extend the functionality of any generic input class to identify presence of input arguments from client from a single object.

Consider the below schema and a sample class design:

type Query {
    show(id: ID!): Show
}

type Mutation {
    updateShow(input: UpdateShowInput!): Show
}

type Show  {
    id: ID!
    title: String
    releaseYear: Int
}

input UpdateShowInput {
    id: ID!
    releaseYear: Int 
    title: String
}

Design:

DGS Mutation can now use extended functionality proxyObject.isFieldSet(String fieldName) to identify if an input field is provided by the client. Instead of deducing the same information from 2 objects i.e. DGS data fetching environment and input argument, single proxy object holds persistent state for the mutation.

1. Data Fetcher in POC using above design
2. Generated classes including additional interface IUpdateShowInput for input type
3. Dynamic Proxy support classes

Happy to discuss further.

Thank you!

[krutikavk]

Hi @paulbakker @srinivasankavitha Can you possibly review the feature request and suggest if it's a good one to proceed with?