react-redux-getters

Provides an extra layer of ‘getters’ between your React components and the Redux store.
The getter returns the data from the store, if it’s there, otherwise it returns a stub and invokes the fetch action.
So the store is filled automatically.

Installation

yarn add react-redux-getters

Usage

Create getter

import { createGetter } from 'react-redux-getters'
import { updateSubjects, fetchSubjects } from 'actions/subjects'
export const getSubjects = createGetter({
  stateSelector: (state) => state.subjects,
  asyncFetcher: () => fetchSubjects(),
  stateUpdater: (data, dispatch) => dispatch(updateSubjects(data)),
})

Configure store

import { createStore, applyMiddleware } from 'redux'
import { gettersMiddleware } from 'react-redux-getters'
const store = createStore(
  reducers,
  applyMiddleware(gettersMiddleware, ...),
)

Component

import React, { Component } from 'react'
import PropTypes from 'prop-types'
import { connectGetters } from 'react-redux-getters'
import { getSubjects } from 'selectors/subjects'
class Subjects extends Component {
  static propTypes = {
    subjectsGetter: PropTypes.object.isRequired
  }
  render() {
    const { subjectsGetter } = this.props
    const { isSucceded, isPending, isFailure, error, data } = subjectsGetter
    if (isPending) {
      return (
        <LoadingRenderer ></LoadingRenderer>
      )
    }
    if (isFailure) {
      return (
        <ErrorRenderer error={error} ></ErrorRenderer>
      )
    }
    return (
      <DataRenderer data={data} ></DataRenderer>
    )
  }
}
const mapGettersToProps = (state) => ({
  subjectsGetter: getSubjects(state),
})
export default connectGetters(mapGettersToProps)(Subjects)

Done!

Your React component will be rerendered when the getter fetches the data and stores it in the Redux store.

Usage with reselect

Create selector with getter

import { createSelector } from 'reselect'
import { createGetter, composeGetters } from 'react-redux-getters'
import { getSubjects } from 'selectors/subjects'
import { getTeachers } from 'selectors/teachers'
export const getHumanitarianSubjects = createSelector(
  getSubjects,
  (subjectsGetter) => composeGetters(
    subjectsGetter,
    (subjects) => filterHumanitarianSubjects(subjects)
  )
)

Component (usage is the same as with a regular getter)

import React, { Component } from 'react'
import PropTypes from 'prop-types'
import { connectGetters } from 'react-redux-getters'
import { getHumanitarianSubjects } from 'selectors/subjects'
class HumanitarianSubjects extends Component {
  static propTypes = {
    humanitarianSubjectsGetter: PropTypes.object.isRequired
  }
  render() {
    const { humanitarianSubjectsGetter } = this.props
    const { isSucceded, isPending, isFailure, error, data } = humanitarianSubjectsGetter
    ...
  }
}
const mapGettersToProps = (state) => ({
  humanitarianSubjectsGetter: getHumanitarianSubjects(state),
})
export default connectGetters(mapGettersToProps)(HumanitarianSubjects)

More examples

Composing getters

import { createSelector } from 'reselect'
import { createGetter, composeGetters } from 'react-redux-getters'
import { getSubjects } from 'selectors/subjects'
import { getTeachers } from 'selectors/teachers'
export const getSubjectsAndTeachers = createSelector(
  getSubjects,
  getTeachers,
  (subjectsGetter, teachersGetter) => composeGetters(
    subjectsGetter,
    teachersGetter,
    (subjects, teachers) => ({ subjects, teachers })
  )
)

Using props

// Getter
import { createGetter } from 'react-redux-getters'
import { fetchTeacher, updateTeacher } from 'actions/teachers'
export const getTeacher = createGetter({
  stateSelector: (state, props) => state.teachers[props.teacherId],
  asyncFetcher: (dispatch, state, props) => fetchTeacher(props.teacherId),
  stateUpdater: (data, dispatch, state, props) => dispatch(updateTeacher(props.teacherId, data))
})
// Component
import React, { Component } from 'react'
import PropTypes from 'prop-types'
import { connectGetters } from 'react-redux-getters'
import { getTeacher } from 'selectors/teachers'
class Teacher extends Component {
  ...
}
const mapGettersToProps = (state, props) => ({
  teacherGetter: getTeacher(state, { teacherId: props.teacherId }),
})
export default connectGetters(mapGettersToProps)(Teacher)
// Using component
<Teacher teacherId={1} ></Teacher>

Composing getters without reselect

import { composeGetters } from 'react-redux-getters'
import { getSubjects } from 'actions/subjects'
export const getSubject = (state, props) => composeGetters(
  getSubjects(state),
  (subjects) => findSubjectById(subjects, props.subjectId)
)

API

import { createGetter, composeGetters } from 'react-redux-getters'
createGetter({
  stateSelector: (state, props) => dataFromState, // Required func – should return data from store state
  asyncFetcher: async (dispatch, state, props) => fetchedData, // Required async func – should return fetched data (Promise)
  stateUpdater: (data, dispatch, state, props) => {}, // Required func - should dispatch store update
  shouldFetch: (dataFromState, state, props) => isNil(dataFromState) // Optional func – condition that fetching is needed
})
composeGetters(
  ...getters, 
  composeData: (...gettersData) => newComposedData // Func – creates composed data from incoming getters data
)

License

MIT