README.md

GraphQL Lua

An Lua implementation of the GraphQL runtime.

Originally forked from this implementation. Thank you to bjornbytes and the tarantool team for the fantastic work on the runtime, up until this point.

• Prerequisites
• Usage

Prerequisites

When spinning up aos, you will need to specify the ao Module which includes the GraphQL parser and lua bindings.

# Spin up a aos-sqlite-graphql process with 1-gb memory limit
aos --module="Z6tG7HwtogBO3GlbIo8ZxIiCQIgqYqSpiCmgLImfe2c"

Usage

First, install the module using APM:

APM.install("@tilla/graphql")

Once installation has finished, you can require('@tilla/graphql.init') in order to build your GraphQL types, schema, and execution.

If you would like a turnkey GraphQL Server, you can use @tilla/graphql_server, which has OOTB aos integration.

local parse = require('@tilla/graphql.parse')
local schema = require('@tilla/graphql.schema')
local types = require('@tilla/graphql.types')
local validate = require('@tilla/graphql.validate')
local execute = require('@tilla/graphql.execute')

local Bob = {
  id = 'id-1',
  firstName = 'Bob',
  lastName = 'Ross',
  age = 52
}
local Jane = {
  id = 'id-2',
  firstName = 'Jane',
  lastName = 'Doe',
  age = 40
}
local John = {
  id = 'id-3',
  firstName = 'John',
  lastName = 'Locke',
  age = 44
}

-- Mock db
local db = { Bob, Jane, John }
-- Index by id
local dbById = {}
for k, v in ipairs(db) do dbById[v.id] = v end

local function findPersonById (id)
  return dbById[id]
end

--[[
  First define your types and resolvers

  Additional APIs:

  types.long
  types.list()
  types.enum()
  types.nonNull()
  types.nullable()
  types.scalar()
  types.inputObject()
]]

-- Create a type
local Person = types.object({
  name = 'Person',
  fields = {
    id = types.id.nonNull,
    firstName = types.string.nonNull,
    middleName = types.string,
    lastName = types.string.nonNull,
    age = types.int.nonNull
  }
})

-- Create a schema
local schema = schema.create({
  query = types.object({
    name = 'Query',
    fields = {
      person = {
        kind = Person,
        arguments = {
          id = types.id,
          defaultValue = 1
        },
        resolve = function(rootValue, arguments, contextValue, info)
          local findPersonById = contextValue.findPersonById
          return findPersonById(arguments.id)
        end
      }
    }
  })
})

--[[
  Now you can parse operations and execute your schema!
]]

-- Parse a query
local ast = parse [[
query GetPerson($id: ID) {
  person(id: $id) {
    firstName
    lastName
  }
}
]]

-- Validate a parsed query against a schema
validate(schema, ast)

-- Execution
local rootValue = {}
local contextValue = { findPersonById = findPersonById }
local variables = { id = 1 }
local operationName = nil

execute(schema, ast, rootValue, contextValue, variables, operationName)

--[[
{
  person = {
    firstName = 'Bob',
    lastName = 'Ross'
  }
}
]]