Use with Reducers

Handling actions dispatched by Redux promise middleware is simple by default.

const FOO_TYPE = 'FOO';
// Dispatch the action
const fooActionCreator = () => ({
type: FOO_TYPE
payload: Promise.resolve('foo')
});
// Handle the action
const fooReducer = (state = {}, action) => {
switch(action.type) {
case `${FOO_TYPE}_PENDING`:
return;
case `${FOO_TYPE}_FULFILLED`:
return {
isFulfilled: true,
data: action.payload
};
case `${FOO_TYPE}_REJECTED`:
return {
isRejected: true,
error: action.payload
};
default: return state;
}
}

Action Types

Optionally, the default promise suffixes can be imported from this module.

import { ActionType } from 'redux-promise-middleware';

This can be useful in your reducers to ensure types are more robust.

const FOO_PENDING = `FOO_${ActionType.Pending}`;
const FOO_FULFILLED = `FOO_${ActionType.Fulfilled}`;
const FOO_REJECTED = `FOO_${ActionType.Rejected}`;

Large Applications

In a large application with many async actions, having many reducers with this same structure can grow redundant.

To keep your reducers DRY, you might see value in using a solution like type-to-reducer.

import typeToReducer from 'type-to-reducer';
const BAR_TYPE = 'BAR';
// Dispatch the action
const barActionCreator = () => ({
type: BAR_TYPE
payload: Promise.resolve('bar')
});
// Handle the action
const barReducer = typeToReducer({
PENDING: () => ({
// ...
}),
REJECTED: (state, action) => ({
isRejected: true,
error: action.payload
}),
FULFILLED: (state, action) => ({
isFulfilled: true,
data: action.payload
})
}
}, {});