graphql.md

description
This page refers to the GraphQL JavaScript package

GraphQL

• http://github.com/graphql/graphql
• https://www.aizatto.com/notes/graphql

Directory Structure

src/graphql/Schema.ts
src/graphql/Mutation.ts
src/graphql/User.ts (GraphQLObjectType)
src/graphql/mutations/UserMutation.ts

Schema

Put edges in a "Viewer" GraphQLObjectType so that you can use it as the "root" object.

type Query {
  entries(order: String, sort: String, after: String, first: Int, before: String, last: Int): EntryConnection
  tags(after: String, first: Int, before: String, last: Int): TagConnection
  viewer: Viewer
}

type Viewer implements EntryConnectionInterface {
  entries(order: String, sort: String, after: String, first: Int, before: String, last: Int): EntryConnection
  tags(after: String, first: Int, before: String, last: Int): TagConnection
}

Resolvers

Naming:

• Postfix function names with Resolver
• Pass in all the args: root, args, context, info

{% code title="Entry.ts" %}

// For the connections
`query {
  entries(...) {
     edges...
  }
}`
export async function EntriesResolver(root, args, context, info);

`query {
  entry(...) { }
}`
export async function EntryResolver(root, args, context, info);

// My suggestion is put this function in the `Tag.ts` file.
// The goal is put all Resolvers that query the same database in the same file
`query {
  entry(...) {
    tags(...) { 
      edges...
    }
  }
}`
export async function EntryTagsResolver(root, args, context, info) {
  const row = await knex
    .from("tags")
    .where({
      tag.entryID: root.id,
    })
    .select();
    
  ...
}

{% endcode %}

export async function EntryResolver(
  root,
  args,
  context: Context,
  info
): Promise<any> {
  const userUUID = getUserUUIDFromContext(context);

  const where = {
    uuid: args.uuid,
    createdBy: userUUID
  };

  const row = await knex
    .from("users")
    .where(where)
    .limit(1)
    .select();
  return row.shift();
}

Bugs

Could not convert from GraphQL type String

When running relay-compiler I would get this error:

Could not convert from GraphQL type String

Environment: Lerna with multiple graphql packages installed

Solution specify resolutions in local package.json:

{% code title="package.json" %}

"resolutions": {
  "graphql": $your_version
}

{% endcode %}

Worse case, nuke your node_modules:

rm -rf \
  packages/your-package/node_modules/ \
  node_modules/ \
  yarn.lock