README.md

redux-query

redux-query is a library for querying and managing network state in React/Redux applications.

With redux-query you can:

• Declare your network dependencies right next to your React components. Data is requested automatically when components mount. When components update and unmount, in-flight requests are automatically cancelled.
• Trigger server-side changes (mutations) by dispatching regular Redux actions.
• Have a consistent, minimal-boilerplate interface for all network-related state.
• Transform and normalize data to avoid duplicate state.
• Perform optimistic updates.
• Use with other Redux middleware libraries like redux-thunk and redux-saga.
• Debug network state and actions with Redux dev tools like redux-logger.

Getting Started

Install redux-query via npm:

$ npm install --save redux-query

Add the entitiesReducer and queriesReducer to your combined reducer.

Include the queryMiddleware in your store's applyMiddleware call. queryMiddleware requires two arguments: a selector (or function) that returns entities state, and a function for the queries state.

For example:

import { applyMiddleware, createStore, combineReducers } from 'redux';
import { entitiesReducer, queriesReducer, queryMiddleware } from 'redux-query';
import createLogger from 'redux-logger';

export const getQueries = (state) => state.queries;
export const getEntities = (state) => state.entities;

const reducer = combineReducers({
    entities: entitiesReducer,
    queries: queriesReducer,
});

const logger = createLogger();
const store = createStore(
    reducer,
    applyMiddleware(queryMiddleware(getQueries, getEntities), logger)
);

Dependencies

All dependencies are listed in package.json. Redux and React are peer dependencies. HTTP requests are made using superagent.

Usage and API

Requests and mutations

There are two types of queries with redux-query: "requests" and "mutations". Requests are for reading values from HTTP endpoints. Mutations are for HTTP endpoints that change network state – the "C", "U", and "D" in "CRUD".

Requests can be triggered from the connectRequest higher-order component or a requestAync action. Mutations are triggered by dispatching a mutateAsync action.

By default, requests are GETs and mutations are POSTS.

Query configs

Query configs are objects used to describe how redux-query should handle the request or mutation. Query config options differ slightly between requests and mutations

Request query config options

Name	Type	Required?	Description
url	string	yes	The URL for the HTTP request.
transform	function		Function that transforms the response data to an entities object where keys are entity IDs and values are entity data. Can be used to normalize data.
update	object	yes	Object where keys are entity IDs and values are update functions.
body	object		The request body.
force	boolean		Perform the request even if we've already successfully requested it.
queryKey	string		The identifier used to identify the query metadata in the queries reducer. If unprovided, the url and body fields are serialized to generate the query key.
meta	object		Various metadata for the query. Can be used to update other reducers when queries succeed or fail.
options	object		Options for the request. Set options.method to change the HTTP method.

Mutation query config options

Name	Type	Required?	Description
url	string	yes	The URL for the HTTP request.
transform	function		Function that transforms the response data to an entities object where keys are entity IDs and values are entity data. Can be used to normalize data.
update	object	yes	Object where keys are entity IDs and values are update functions.
optimisticUpdate	object		Object where keys are entity IDs and values are functions that provide the current entity value. The return values are used to update the entities store until the mutation finishes.
body	object		The HTTP request body.
queryKey	string		The identifier used to identify the query metadata in the queries reducer. If unprovided, the url and body fields are serialized to generate the query key.
options	object		Options for the request. Set options.method to change the HTTP method.

transform functions

transform functions let you process and normalize response data before it is passed to the update step. They have the following signature:

(responseJson: ?Object, responseText: string) => { [key: string]: any }

If your data is normalized on the server, you may not need to use this function.

update functions

update functions are responsible for reconciling response data with the existing entities reducer data for the given entity ID. They have the following signature:

(prevValue: any, transformedValue: any) => any

The prevValue is the whatever value is selected from the entities reducer for the respective entity ID. The returned value from this function will become the new value for the entity ID in the entities reducer.

optimisticUpdate functions

optimisticUpdate functions are just like update functions except they only pass the prevValue:

(prevValue: any) => any

connectRequest

Use the connectRequest higher-order component to declare network dependencies for a React component. connectRequest takes a function that transforms the component props to a request query config. Example usage:

import { connectRequest, querySelectors } from 'redux-query';

class Dashboard extends Component {
    ...
}

const DashboardContainer = connectRequest((props) => ({
    url: `/api/dashboard/${props.dashboardId}`,
    update: {
        chartsById: (prevCharts, dashboardCharts) => ({
            ...prevCharts,
            ...dashboardCharts,
        }),
        dashboardsById: (prevDashboards, dashboards) => ({
            ...prevDashboards,
            ...dashboards,
        }),
    },
}))(Dashboard);

const mapStateToProps = (state, props) => {
    return {
        dashboard: getDashboard(state, props),
    };
};

export default connect(mapStateToProps)(DashboardContainer);

connectRequest passes an extra prop to the child component: forceRequest. Calling this function will cause the request to be made again. This may be useful for polling or creating an interface to trigger refreshes.

mutateAsync

Dispatch mutateAsync Redux actions to trigger mutations. mutateAsync takes a mutation query config as its only argument. Example usage with a react-redux-connected component:

// src/queries/dashboard.js

export const createUpdateDashboardQuery = (dashboardId, newName) => ({
    url: `/api/${dashboardId}/update`,
    body: {
        name: newName,
    },
    update: {
        dashboardsById: (prevDashboardsById, newDashboardsById) => ({
            ...prevDashboardsById,
            ...newDashboardsById,
        }),
    },
});

// src/actions/dashboard.js

import { createUpdateDashboardQuery } from '../queries/dashboard';

export const updateDashboard = (dashboardId, newName) => {
    return mutateAsync(createUpdateDashboardQuery(dashboardId, newName));
};

// src/selectors/dashboard.js

export const getDashboard = (state, { dashboardId }) => {
    if (state.entities.dashboardsById) {
        return state.entities.dashboardsById[dashboardId];
    } else {
        return null;
    }
};

// src/components/Dashboard.jsx

import { connect } from 'react-redux';

import { updateDashboard } from '../actions/dashboard';
import { getDashboard } from '../selectors/dashboard';

class Dashboard extends Component {
    ...
}

const mapStateToProps = (state, props) => {
    return {
        dashboard: getDashboard(state, props),
    };
};

const mapDispatchToProps = (dispatch, props) => {
    return {
        changeName: (newName) => {
            dispatch(updateDashboard(props.dashboardId, newName));
        },
    };
};

export default connect(mapStateToProps, mapDispatchToProps)(Dashboard);

When dispatching a mutateAsync action, you can Promise-chain on the returned value from dispatch:

const mapDispatchToProps = (dispatch, props) => {
    return {
        changeName: (newName) => {
            dispatch(updateDashboard(props.dashboardId, newName)).then((result) => {
                if (result.status !== 200) {
                    dispatch(showUpdateDashboardFailedNotification(props.dashboardId));
                }
            });
        },
    };
};

requestAsync

Similarly to how mutations are triggered by dispatching mutateAsync actions, you can trigger requests by dispatching requestAsync actions with a request query config.

Example

A fork of the redux Async example is included. To run:

$ cd examples/async
$ npm install
$ npm run start