Typeorm automatically load relations when requested

[paales]

Hi @capaj! Thanks for forking and extending this! I'm trying to implement GraphQL with TypeORM, so far so good, the GraphQL part is working pretty nicely, but I am not sure how I should pass the right request to Typeorm, expecially while loading relationships and relations of relations:

So I have the following Graph:

I have the following resolver:

#Schema
@SchemaRoot()
class Schema {
  @Query({ type: Voorraad })
  async inventory(artikelnummer: string, @Context { dbConn }: IContext): Promise<Voorraad> {
    const result = await dbConn.manager
      .getRepository(Voorraad)
      .findOne({ where: { artikelnummer }, relations: ['onderdeelsoort'] })
    return result
  }
}

#Relation definition
@ManyToOne(() => Ondsoort, (ondsoort: Ondsoort) => ondsoort.voorraads, {
  onDelete: 'RESTRICT',
  onUpdate: 'RESTRICT',
})
@JoinColumn({ name: 'onderdeelsoort_id' })
@Field({ type: () => Ondsoort })
onderdeelsoort: Ondsoort | null

Now I manually have to provide the relation field here, but that is far from ideal.. Can the GrapHQL request be 'automatically converted' to a TypeORM request that automatically selects the right relations and relations of relations?

[capaj]

yes it can. We actually do exactly the same thing, but for objection on our @LeapLabs Looop api.
Although this functionality lies out of scope for decapi. Decapi's only job is to take arbitrary Typescript classes with methods as resolvers and generate a GQL schema.

What you need is to take TypeORM classes on input and generate decapi compatible resolvers for their relations. It would need to be developed as a separate plugin/library.
I will take a peek at it if I get some time, but no promises. I am quite busy ATM, so my delivery times are anywhere from month to half a year.

[paales]

I cobbled something together which extracts the right paths and adds them to TypeORM:

import getFieldNames from 'graphql-list-fields'

const RelationFields = Inject(({ info }) => {
  const stripDot = (path: string) =>
    path
      .split('.')
      .slice(0, path.split('.').length - 1)
      .join('.')

  let paths = getFieldNames(info).map(stripDot)

  const pathMap: Set<string> = new Set(paths.filter(_ => !!_))
  pathMap.forEach(path => pathMap.add(stripDot(path)))
  paths = [...pathMap].filter(v => !!v)

  return paths
})

async inventory(
  artikelnummer: string,
  @Context { dbConn }: IContext,
  // @ts-ignore
  @RelationFields relations,
): Promise<Voorraad> {
  return await dbConn.manager
    .getRepository(Voorraad)
    .findOne({ where: { artikelnummer }, relations })
}

The only thing I'm running into is that I can't seem to set the relations type properly? It seems that Inject always tries to return any..