graphql-pick

Build dynamic GraphQL queries from your schema using a list of paths e.g. ["path.to.field", "path.to.another.field"].

Given the schema

# schema.graphql
type User {
  name: String!
}

type Query {
  currentUser: User!
}

Lookup currentUser's name:

// index.js
import { print } from "graphql"

const query = pick(["currentUser.name"])

console.log(print(query))

// output
"query currentUser_query {
  currentUser {
    name
  }
}"

Motivation

There are times when you may not be able to predict you application's data requirements at build time. For example when it depends on a piece of state.

While you can construct query strings by hand, this method is error prone and cumbersome to maintain. Alternatively you could use GraphQL directives, but for the complex cases, graphql-pick takes center stage.

graphql-pick provides a robust method for query document generation. By traversing your schema, it guarantees that any output you generate is valid on the server.

Usage

Quick start

Assuming you have a schema of the form:

type User {
  name: String!
}

type Query {
  currentUser: User!
}

at the root of your application, initialize graphql-pick.

import { initPick } from 'graphql-pick'

initPick(schema)

Then in your components, use pick to generate queries

import pick from 'graphql-pick'

const query = pick(["currentUser.name"])

With Fragments

If you wish to attach static fragment definitions to your queries, load them in during initialization.

import { initPick } from 'graphql-pick'
import userNameFragment from './fragment.userNameFragment.graphql'

initPick(schema, { fragments: [userNameFragment] })

Then in your components, include the fragment name in your path.

import pick, { wrapFragment } from 'graphql-pick'

// directly
const query = pick(["currentUser.__fragment_userNameFragment"])
// with utility
const theSameQuery = pick([`currentUser.${wrapFragment("userNameFragment")}`])

With Aliases

import pick, { wrapAlias } from 'graphql-pick'

// directly
const query = pick(["currentUser.__alias_fullname_name"])
// with utility
const theSameQuery = pick([`currentUser.${wrapAlias("fullname", "name")}`])

Acknowledgements

This package was developed with reference to graphql-tools. The original project is licensed under the MIT license.