ts-fp-di-mikroorm
Use MikroORM Entities inside ts-fp-di State and achieve auto persistence in DB
Knowledge requirements
Basic knowledge of ts-fp-di and MikroORM
Get started
Firstly, need to wrap each life cycle of your backend application (each HTTP request/response, handle MQ message, ...) with ts-fp-di-mikroorm
Example of middleware for typical Koa application, where each HTTP request will be wrapped:
const orm = await MikroORM.init(
defineConfig({
/* DB config */
entities: [
/* init MikroORM Entities */
],
})
)
app.use(async (ctx, next) => {
await wrapTsFpDiMikroorm(orm, async () => {
return await next()
})
})Further, simply use ts-fp-di and MikroORM "as is" in code and auto persistence in DB will "magically" works 🪄
Only need to use em helper for MikroORM, which can help to consider context of appropriate life cycle
Example
import { wrap } from '@mikro-orm/core'
import { Entity, PrimaryKey, Property } from '@mikro-orm/decorators/legacy'
import { em, entityConstructor, onPersist, wrapTsFpDiMikroorm } from 'ts-fp-di-mikroorm'
import { dis, dic } from 'ts-fp-di'
@Entity()
class UserEntity {
constructor(entity: Partial<UserEntity>) {
// just little sugar, for avoiding boilerplate this.key = value
entityConstructor(this, entity)
}
@PrimaryKey()
id!: number
@Property()
name!: string
// service property for deleting Entity, see below
$forDelete?: boolean
}
const fetchUser = async (id: number) => {
// `em()` will return MikroORM Entity Manager for appropriate life cycle
// need use `em()` everywhere, when you want to use MikroORM API
return em().findOne(UserEntity, { id })
}
// diOnce, dic, diMap also supported
const $user = dis<UserEntity | null>((state, payload) =>
state ? wrap(state).assign(payload) : payload instanceof UserEntity ? payload : new UserEntity(payload)
)
// Entities can be placed in Array, Promise, Set, Map (as values) and fp-ts Some, Right
// Persistance for them will works
const $users = dic<UserEntity[]>()
// `wrapTsFpDiMikroorm` here just for example
// Need to use `wrapTsFpDiMikroorm` as middleware of your framework, see example above
await wrapTsFpDiMikroorm(orm, async () => {
// Mutate $user State for futher mutation
$user({ name: 'Vasya' })
// Optional hook, which will be called after DB persist
onPersist(async () => {
$user() // BTW, $user already contains `id`, because it's already persisted in DB
})
})
// By the way, user Vasya already persisted in DB!
await wrapTsFpDiMikroorm(orm, async () => {
$user(await fetchUser(1))
$user({ name: 'Petya' })
})
// user Vasya realized that he is Petya in DB now
await wrapTsFpDiMikroorm(orm, async () => {
$user({ id: 1, name: 'Petya', $forUpdate: true })
})
// if you know id, you can update entity without fetching
await wrapTsFpDiMikroorm(orm, async () => {
$user({ name: 'Petya', $forUpsert: true })
})
// upsert also works, Entity fetching will be happens on flush afterwards
await wrapTsFpDiMikroorm(orm, async () => {
$user(await fetchUser(1))
$user({ $noPersist: true })
})
// Persistance to DB ignored
await wrapTsFpDiMikroorm(orm, async () => {
$user(await fetchUser(1))
$user({ $forDelete: true })
})
// user Petya go away from DB
await wrapTsFpDiMikroorm(orm, async () => {
$users([
new UserEntity({ id: 1, name: 'Petya', $forUpdate: true }),
new UserEntity({ id: 2, name: 'Vasya', $forUpdate: true }),
new UserEntity({ id: 3, name: 'Kolya', $forUpdate: true }),
])
})
// all company will be persisted, despite the fact that they are in an Array