kreepo

NodeJS implementation of Repository pattern

Insallation

npm install --save kreepo@latest

Usage

To use your first Repository just import module and call a factory method.

const kreepo = require('kreepo');
 
// create new repository
const dummyRepository = kreepo.createRepository();

All methods are thenable (return Promises), while construction process is synchronious.

const dummyRepository = kreepo.createRepository();
 
dummyRepository.set('key', 'value')
  .then(() => dummyRepository.get('key'))
  .then((result) => console.log(result));

Datasources

Repository pattern requires some kind of adapters for each data-layer platform to allow unified interface. Datasource classes implement those adapters.

Datasources are classes that incapsulate logic of direct data-layer communiation.

Many of general purpose datasources are provided with kreepo package.

// access datasource classes within a kreepo facade
const { InMemoryDatasource, JsonDatasource } = kreepo.datasource;
 
// create a Datasource that stores data in RAM
const ramDatasource = new InMemoryDatasource();
 
// create a Datasource that stores data in a JSON file
const jsonDatasource = new JsonDatasource('/tmp/test.json');
 
// create a Repository that access both Datasorses
const repository = bytebroket.createRepository({
  datasource: [ramDatasource, jsonDatasource],
});

API Reference

Repository

get(id)

Get an entity from a Repository.

@param {any} id -- identifier of entity to get

@return {Promise} -- resolves with a requested entity or null

Performs lookup over registered Datasources with respect ro readPriority of those.

Attempts to read data from a Datasource with a maximum readPriority.

Value is mapped with emtityFactory if the one is specified in constructor.

set(id, value)

Save entity within a Repository.

@param {any} id -- identifier of entity to save
@param {any} value -- value to be saved

@return {Promise} -- resolves with an identifier of saved entity or null if entity wasn't saved

Saves data to every WRITE_ALWAYS Datasource

Saves data to a single WRITE_FIRST Datasource with a maximum writePriority property

Skips NO_WRITE datasource

Saves data to cache instead of triggering Datasource directly when SYNC_ON_REQUEST or SYNC_ON_TIMEOUT sync strategy chosen.

delete(id)

Delete entity from a Repository.

@param {any} id -- identifier of entity to remove

@return {Promise} -- resolves with true if removal operation was performed and false if it wasn't

Removes data from each datasource except those that marked as NO_WRITE.

Saves data to cache instead of triggering Datasource directly when SYNC_ON_REQUEST or SYNC_ON_TIMEOUT sync strategy chosen.

getall()

List all keys that available all over the Datasources

@return {Promise} -- resolves with list of available keys

find(selector)

Search througth available keys using regular expression

@param {RegExp} selector -- regular xepression to test keys

@return {Promise} -- resolves with list of matching keys

mget(ids)

Get multiple entities from a Repository.

@param {Array} ids -- list of entity identifiers

@return {Promise} -- resolves with key-value mapping of ids to entities

Performs lookup over registered Datasources with respect ro readPriority of those.

Attempts to read data from a Datasource with a maximum readPriority.

Value is mapped with emtityFactory if the one is specified in constructor.

mset(payload)

Save multiple entities within a Repository.

@param {Object<id => value>} payload -- represents values that should be saved under id

@return {Promise} -- resolves with list of seted ids

Mitigates #set logic fluently

Use #set method directly if datasource have no #mset implemented

mdelete(ids)

Delete multiple entities from a Repository.

@param {Array} ids -- list of entity identifiers

@return {Promise} -- resolves with key-value mapping with id's and true, if value was removed

Removes data from each datasource except those that marked as NO_WRITE.

Saves data to cache instead of triggering Datasource directly when SYNC_ON_REQUEST or SYNC_ON_TIMEOUT sync strategy chosen.

sync()

TBD