redux-offline-crud-rest

Offline-first persistence for React Native web apps backed by CRUD-based operations over REST APIs

redux-offline-crud-rest is a set of factory helper functions that works as a client library for web services that offer a CRUD-like functionality over a REST API. It's design is heavily oriented to be used with redux-offline, but being written in vanilla Javascript and without external dependencies, it's possible to use it with plain redux or also with plain Javascript functions so far it support the same protocol.

In-wire data format

Data is transmitted as raw JSON objects in both directions for resources, and as JSON arrays for collections. Resources must have a server-side generated _id field that uniquely identify the resource inside its collection. CRUD operations are mapped to their most-alike HTTP method, it's said: Create -> POST, Read -> GET, Update -> PUT and Delete -> DELETE. As an extra feature, it also maps partial updates with the PATCH HTTP method, sending the diff data in raw JSON too, following the JSON Merge Patch format specification.

Install

npm install redux-offline-crud-rest

How to use it

redux-offline-crud-rest helper factories functions are splitted in three: actions, reducers and actionTypes.

actions

actions() function will return an namespace object with a function for each one of the possible CRUD operations:

• create(body, urlSuffix)
• read(id, ownId, urlSuffix)
• update(id, body, ownId, urlSuffix)
• patch(id, body, urlSuffix)
• delete(id, urlSuffix)

In all cases, id will be unique ID to identify a resource under the specified collection, and body will be a JSON object with the actual data to be stored for that resource except for patch() function, that it will be only the already calculated diff object between the old data and the new one. In all cases it will be returned an object to be given as input for the redux dispatch() function.

Required argument is the basePath of the collection where REST requests will be done, or alternatively an object defining several namespaces and their own configurations. An optional argument can be used to define both the redux dispatch() function so the returned namespace functions will directly call it instead of return an object to be passed to dispatch() manually, and the headers that will be added to all the requests on this namespace. You can also define the baseUrl in case it's different from the one where the client is served from.

const actions = require('./actions')

const baseType = 'path/resource'

const namespace = actions(baseType)

namespace.create({msg: 'hello world'})

You can also define functions both directly on the options object or using its resourceMethods object to define methods that will be called for a given resource, or for the full collection if an id is not provided. Calling them will send the arguments as a POST request, being the arguments defined on the provided body.

const namespace = actions('path', {foo(error, result){...}})

namespace.foo(1234, {msg: 'hello world'})  // => POST /path/1234/foo

reducers

Complementary to the actions factory, reducer generate a reducer function to process the CRUD operations for the provided basePath, both optimistic and the response given by the server (commiting the data on success, or doing rollback on it on failure). Optionally you can provide a childReducer() function to process child namespaces, and a onRollback() function to define what to do in case an operation went bad and operation needed to be undo (by default, just only print an error on the console).

const reducer = require('./reducer')

const namespace = reducer('path')

namespace(state, {})  // => state

actionTypes

This are generated and used internally by the actions and the reducers, so you would not need to use them explicitly except for some advanced usage, like manually dispatch()ing some action.

genActionTypes() function will return an object mapping all the possible CRUD operations related actions (requests, commits and rollbacks) with the actual redux action for the provided baseType.

const genActionTypes = require('./actionTypes')

const baseType = 'path/resource'

const actionTypes = genActionTypes(baseType)

actionTypes.create         // => 'path/resource#create'
actionTypes.update_commit  // => 'path/resource#update_commit'

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