Bi-Directional Adapter
Factory to create bi-directional adapters that can convert between two distinct data structures.
Using adapters helps to decouple systems which share common data structures and may need to alter them
independently without introducing conflicts in each other.
Why?
You have multiple services which each operate on a single shared resource but want to represent the data
differently in each service or want to isolate each service from data structure changes required by the other.
With bidirectional-adapter
you can define a simple entity which can be used to transform data between two formats.
const adapter = createAdapter<string, number>(
(stringValue) => parseInt(stringValue, 10),
(numericValue) => String(numericValue)
);
Example
import axios from 'axios';
import createAdapter from 'bidirectional-adapter';
const accountAdapter = createAdapter(
(dbAccount) => ({
id: dbAccount.user_id,
name: `${dbAccount.user.firstName} ${dbAccount.user.lastName}`,
email: dbAccount.user.email,
}),
(appAccount) => ({
user_id: appAcount.id,
user: {
firstName: appAccount.name.split(' ')[0],
lastName: appAccount.name.split(' ')[1],
},
email: appAccount.email,
})
);
const fetchAccount = (userID) => {
return axios.get(`/account/${userID}`).then((res) => accountAdapter.fromDB(res.data));
};
const updateAccount = (account) => {
return axios.post(`/account/${userID}`, accountAdapter.toDB(account));
};
Smart Adapter Example
import { createSmartMultiAdapter } from 'bidirectional-adapter';
interface DBModel {
x: number;
a: number;
b: string;
c1: boolean;
}
interface Model {
x: number;
ab: string;
c2: boolean;
}
type KeyMap = [['a' | 'b', 'ab'], ['c1', 'c2']];
const adapter = createSmartMultiAdapter<DBModel, Model, [], [], KeyMap>(
() => ({} as any),
() => ({} as any)
);
adapter.fromDB({ a: 1, b: 'a', c1: false, x: 1 });
adapter.fromDB({ a: 1, b: 'a', c1: false });
adapter.fromDB({ b: 'a', c1: false });
adapter.fromDB({ x: 1 });
adapter.fromDB({});
adapter.mapFromDB([{ a: 1, b: 'a', c1: false, x: 1 }]);
adapter.mapFromDB([{ a: 1, b: 'a', c1: false }]);
adapter.mapFromDB([{ b: 'a', c1: false }]);
adapter.mapFromDB([{ x: 1 }]);
adapter.mapFromDB([{}]);
adapter.toDB({ ab: '1', c2: false, x: 1 });
adapter.toDB({ ab: '1', x: 1 });
adapter.toDB({ c2: false });
adapter.toDB({ x: 1 });
adapter.toDB({});
adapter.mapToDB([{ ab: '1', c2: false, x: 1 }]);
adapter.mapToDB([{ ab: '1', x: 1 }]);
adapter.mapToDB([{ c2: false }]);
adapter.mapToDB([{ x: 1 }]);
adapter.mapToDB([{}]);
Installation
To use bidirectional-adapter
, install it as a dependency:
npm install bidirectional-adapter
yarn add bidirectional-adapter
This assumes that you’re using a package manager such as npm.
License
ISC