graphql-cli-generate-schema

graphql-cli-generate-fragments [![npm]

Installation

npm i -g graphql-cli graphql-cli-generate-fragments

Usage

graphql generate-fragments

Generate Fragments for Graphql Schemas

Options:
  --dotenv         Path to .env file                                    [string]
  -p, --project    Project name                                         [string]
  --output, -o     Output folder                                        [string]
  --save, -s       Save settings to config file     [boolean] [default: "false"]
"false"]
  --generator, -g  Generate to 'js' or 'graphq'                 [string]
  --verbose        Show verbose output messages     [boolean] [default: "false"]
  -h, --help       Show help                                           [boolean]
  -v, --version    Show version number                                 [boolean]

Graphql Fragments Generation

Creates graphql fragments containing the fields for each type in the supplied schema.

The first time you use fragment generation in your project, you need to provide an output folder for your fragments, and the generator you want to use:

$ graphql generate-fragments -p database -o src/generated -g graphql --save
✔ Fragments for project database written to src/generated/database.fragments.js

This will also save the configuration in your .graphqlconfig file (see below).

Automating graphql generate-fragments

After you have set up fragment generation for all projects, you can simply run graphql generate-fragments without any parameters to process all projects:

$ graphql prepare
✔ Fragments for project app written to src/generated/app.fragments.graphql
✔ Fragments for project database written to src/generated/database.fragments.js

Fragments Usage and Examples

Generated Fragments

There are three types of fragments outputted by graphql-cli-generate-fragments.

Given the schema:

 
type User implements Node {
  id: ID!
  email: String!
  password: String!
  posts: [Post!]
}
 
type Post  {
  id: ID!
  createdAt: DateTime!
  updatedAt: DateTime!
  isPublished: Boolean!
  title: String!
  text: String!
  author: User!
}
 

The following fragments are generated:

 
fragment User on User {
  id
  email
  password
  posts {
    ...PostNoNesting
  }
}
 
fragment Post on Post {
  id
  createdAt
  updatedAt
  isPublished
  title
  text
  author {
    ...UserNoNesting
  }
}
 
fragment UserNoNesting on User {
  id
  email
  password
}
 
fragment PostNoNesting on Post {
  id
  createdAt
  updatedAt
  isPublished
  title
  text
}
 

Notice that we generate _NoNesting fragments, which do not include relations. Post and User would be recursive otherwise. If there is a recursive fragment you will receive a "Cannot spread fragment within itself" error.

Deeply Nested Fragments

When there is no recursive nesting of fragments it can be useful to include all related types queries. _DeepNesting fragments are generated for this use.

Given the following schema:

 
type User implements Node {
  id: ID!
  email: String!
  password: String!
  details: UserDetails!
}
 
type UserDetails {
  firstName: String!
  lastName: String!
  address: Address!
}
 
type Address {
  line1: String!
  line2: String
  county: String
  postcode: String!
}
 

The following is also generated:

 
fragment UserDeepNesting on User {
  id
  email
  password
  details {
    ...UserDetails
  }
}
 
fragment UserDetailsDeepNesting on UserDetails {
  firstName
  lastName
  address {
    ...Address
  }
}
 
fragment AddressDeepNesting on Address {
  line1
  line2
  county
  postcode
}
 

Use with Apollo Graphql Tag Loader

By using graphql-tag/loader with Webpack you can import fragments into .graphql files:

 
#import "../generated/app.fragments.graphql"
 
query CurrentUser {
  currentUser {
    ...User
  }
}
 

or into javascript

 
import { User } from "../generated/app.fragments.graphql"
 
const query = gql`
    query CurrentUser {
    currentUser {
      ...User
    }
  }
 
  ${User}
 

Use with JS

If you are unable to use Webpack - fragments can be generated to javascript models (see below)

 
import { User } from "../generated/app.fragments.js"
 
const query = gql`
    query CurrentUser {
    currentUser {
      ...User
    }
  }
 
  ${User}
 

Available generators

The following generators are provided:

Generator	Purpose
graphql	Generates fragments for all types in schema
js	Wraps the graphql and exports them for import in javascript

graphql-config extensions

To store the project configuration for fragment generation, graphql-cli-generate-fragments uses two extension keys in the graphql-config configuration file. These keys can be set manually, or using the --save parameter.

# ./.graphqlconfig.yml
projects:
  app:
    schemaPath: src/schema.graphql
    extensions:
      endpoints:
        default: 'http://localhost:4000'
+       prepare-bundle: 
+         src/generated/app.fragments.js
+         generator: js
  database:
    schemaPath: src/generated/prisma.graphql
    extensions:
      prisma: database/prisma.yml
+     generate-fragments:
+       output: src/generated/database.fragments.graphql
+       generator: graphql
 

License

This project is licensed under the MIT License - see the LICENSE.md file for details

Acknowledgments

• lachenmayer for graphql-fragment-codegen
• kbrandwijk/supergraphql for graphql-cli-prepare

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