@dwwoelfel/graphile-utils

graphile-utils

This package contains helpers for building plugins for GraphQL schemas utilising Graphile Engine, such as the one produced by PostGraphile.

Documentation is currently available here.

PRs to improve documentation are always welcome!

gql

Similar to the default export from graphql-tag, this export can be used to form tagged template literals that are useful when building schema extensions. gql in graphile-utils differs from graphql-tag in a number of ways, most notably: it can use interpolation to generate dynamically named fields and types, and it can embed raw values using the embed helper.

embed

Used to wrap a value to be included in a gql AST, e.g. for use in GraphQL directives.

makeExtendSchemaPlugin

Docs: https://www.graphile.org/postgraphile/make-extend-schema-plugin/

Enables you to add additonal types or extend existing types within your Graphile Engine GraphQL schema.

const {
  makeExtendSchemaPlugin,
  gql,
} = require('graphile-utils');

const MySchemaExtensionPlugin =
  makeExtendSchemaPlugin(
    build => ({
      typeDefs: gql`...`,
      resolvers: ...
    })
  );

module.exports = MySchemaExtensionPlugin;

e.g.:

makeExtendSchemaPlugin(build => ({
  typeDefs: gql`
    type Random {
      float: Float!
      number(min: Int!, max: Int!): Int!
    }
    extend type Query {
      random: Random
    }
  `,
  resolvers: {
    Query: {
      random() {
        return {};
      },
    },
    Random: {
      float() {
        return Math.random();
      },
      number(_parent, { min, max }) {
        return min + Math.floor(Math.random() * (max - min + 1));
      },
    },
  },
}));

makeAddInflectorsPlugin

Docs: https://www.graphile.org/postgraphile/make-add-inflectors-plugin/

If you don't like the default naming conventions that come with a Graphile Engine GraphQL schema then it's easy for you to override them using the inflector.

makeChangeNullabilityPlugin

Docs: https://www.graphile.org/postgraphile/make-change-nullability-plugin/

Use this plugin to override the nullability of fields in your GraphQL schema.

makeProcessSchemaPlugin

Docs: https://www.graphile.org/postgraphile/make-process-schema-plugin/

Enables you to process the schema after it's built, e.g. print it to a file, augment it with a third party library (e.g. graphql-shield), etc.

makeWrapResolversPlugin

Docs: https://www.graphile.org/postgraphile/make-wrap-resolvers-plugin/

Enables you to wrap the field resolvers in the generated GraphQL API, allowing you to take an action before or after the resolver, or even modify the resolver result.