sangria-graphql/sangria

Schema transformation

Open

#418 opened on Nov 12, 2018

View on GitHub
 (4 comments) (0 reactions) (0 assignees)Scala (1,961 stars) (219 forks)batch import
featurehelp wanted

Description

The idea is to provide an easy and convenient way to transform existing schema. Since all types are cross-referenced within the schema, the whole schema needs to be re-created in a similar way as in the AST materializer where it re-creates existing types with the help of the builder.

In this case a dedicated builder might be useful as a low-level implementation detail. But it also would be nice to have a high-level DSL. Here is just an idea of how it might look like:

val newSchema =
  schema
    .mapObjectType("Book", _.rename("Publication"))
    .mapOutputTypes(_.filterFileds(field ⇒ !field.tags.contains(Preview)))

Contributor guide

Tech stack
scalagraphql
Domain
api
Issue type
feature
DifficultyEstimated implementation difficulty for a new contributor, from 1 for very small changes to 5 for expert-level work.
3
Estimated timeA rough time range for an experienced contributor to investigate, implement, test, and prepare a pull request.
3-5 days
Activity statusHow available the issue appears right now: fresh, active, stale, blocked, or waiting on maintainer input.
stale
ClarityHow clearly the issue explains the expected change, acceptance criteria, and next step.
clear
Prerequisites
ScalaGraphQL schemaSangria library internals
Newbie friendlinessA 1-100 score estimating how approachable this issue is for first-time contributors.
45
Research direction
Examine the existing `AstSchemaMaterializer.scala` for the approach of recreating types. Investigate how a dedicated builder can be designed to traverse and transform schema types. Consider implementing a high level DSL similar to the example provided, starting with a simple rename or field filter. Look at how types are cross referenced and ensure the transformation preserves references.