Greenfinity bindings for NextJS

Scope

Bindings for NextJS.

A drop in replacement for more official bindings.

Next

Unofficial bindings for NextJs.

open GreenfinityNext.Next

NextAuth

Unofficial bindings for NextAuth.

open GreenfinityNext.NextAuth

Fetch

Utilities to use NextJs's Fetch.

open GreenfinityNext.Fetch

Errors

Utility module to define errors.

Protocol and Middleware

Works with the converters generated by spice / decco, to be used with NextJs.

Example for protocol in file GetAnswer.res:

open GreenfinityNext.Protocol

module Protocol = {
  let path = "/api/getAnswer"
  @spice
  type req = string
  @spice
  type resp = int
}

module Make = MakeProtocol(Protocol)
let make = Make.make

Example for a middleware that runs on the server, Mw_GetAnswer.res:

open GetAnswer

module Middleware = {
  include Protocol
  let processIt = async (question: Protocol.req, _: Content.Types.user): Protocol.resp =>
    switch question {
      | "How many Vogons does it take to change a lightbulb?" => 42
      | _ => 0
    }
}

module Default = MakeMiddleware(Middleware)
let default = Default.default

Api route imports the middleware, from file pages/api/getAnswer.js:

import Mw_GetTopicTypes from "../../src/api/get-topic-types/Mw_GetAnswer.bs.js";
export default function GetTopicTypes(req, res) {
  return Mw_GetTopicTypes(req, res);
}

Calling the api route from the client side,

let answer = await GetAnswer.make("How many Vogons does it take to change a lightbulb?")

Converter

Conversion between Rescript records and abstract objects in a type-safe way. One possible use case is to convert records to and from a database.

Example with one-on-one type conversion:

module Converter = GreenfinityTypeUtils.Make({
  @spice
  type t = myType
  let assignFromStorage = _ => Js.Obj.empty()
  let assignToStorage = _ => Js.Obj.empty()
})

open Converter

// converting a value to an abstract object
myValue->toStorage

// converting a value from an abstract object
o->fromStorage

There are variant to convert from a storage with nullable or optional objects:

// converting a value from a nullable abstract object
o->fromStorageNullable->Option.getExn

// converting a value from an optional abstract object
a[0]->fromStorageOptional->Option.getExn

Example with additional conversion. The dictionary returned will be assigned to the object after converting to (or before converting from) a record.

Storage_Converter.ResultField contains some conversion functions.

external toJs: 't => {..} = "%identity"

module Converter = Storage_Converter.Make({
  @spice
  type t = myType
  let assignFromStorage = topic =>
    {
      "topic_id": (topic->toJs)["topic_id"]->Storage_Converter.ResultField.int64,
    }->toJs
  let assignToStorage = topic =>
    {
      "topic_id": (topic->toJs)["topic_id"]->Storage_Converter.ResultField.int64,
    }->toJs
})

toJs is an annoyance and it's currently needed to make the abstract type less specific, avoiding a type error.