redux-validator

Action parameter validator middleware for redux

Installation

npm i redux-validator --save

How to use

Add middleware to your store

import Validator from 'redux-validator';

const validator = Validator();
const createStoreWithMiddleware = applyMiddleware(validator)(createStore);
const store = createStoreWithMiddleware(reducer);

If you use other middleware, apply redux-validator first to prevent unexpected errors.

import promise from 'redux-promise';
import Validator from 'redux-validator';

const validator = Validator();
const createStoreWithMiddleware = applyMiddleware(validator, promise)(createStore);
const store = createStoreWithMiddleware(reducer);

Add validators to your actions

const validAction = {
    type: ADD_TODO,
    payload: {
        text: 'Sample todo',
        complete: false
    },
    meta: {
        validator: {
            text: {
                func: (text, state, payload) => 0 <= text.length
                msg: 'Cannot add an empty todo'
            },
            complete: {
                func: (complete, state, payload) => typeof(complete) === "boolean"
                msg: 'Complete must be true or false'
            }
        }
    }
}

const result = dispatch(validAction); // validation success and dispatch completes

redux-validator is Flux Standard Action compatible.

The properties in action.payload are validated against the functions provided in the action.meta.validator map. If validation of any property fails, the dispatch is aborted and an object containing error information is returned.

const invalidAction = {
    type: ADD_TODO,
    payload: {
        text: ''
    },
    meta: {
        validator: {
            text: {
                func: (text, state, payload) => 0 <= text.length
                msg: 'Cannot add an empty todo'
            }
        }
    }
}

const result = dispatch(invalidAction); // dispatch aborted and error returned:
// result = {
//     err: 'validator',
//     msg: 'Cannot add an empty todo',
//     param: 'text',
//     id: 0
// }

Multiple validations may be defined for a single property. The property will be checked against all validators in the array in the order they are declared. The dispatch is aborted and the error returned on the first failing validation.

const action = {
    type: ADD_TODO,
    payload: {
        text: 'Write an awesome react app'
    },
    meta: {
        validator: {
            text: [
                {
                    func: (text, state, payload) => 0 <= text.length
                    msg: 'Cannot add an empty todo'
                },
                {
                    func: (text, state, payload) => text.length < 500
                    msg: 'Todo too long'
                }
            ]
        }
    }
}

Other Examples

Usage with redux-actions

It's very easy to integrate redux-validator with createAction from redux-actions:

import {createAction} from 'redux-actions';

const actionCreator = createAction('action2', payload => payload, () => ({
    validator: {
        payload: [ // if action.payload is not a map, use payload key to validate action.payload itself
            {
                func: (payload, state) => payload >= 0,
                msg: 'payload is less than 0'
            },
            {
                func: (payload, state) => payload < 100
            }
        ]
    }
}));

const result1 = dispath(actionCreator(-1));
const result2 = dispath(actionCreator(200));
// dispatchs would abort!
// result1 = {
//     err: 'validator',
//     msg: 'payload is less than 0',
//     param: 'payload',
//     id: 0
// }
// result2 = {
//     err: 'validator',
//     msg: '',
//     param: 'payload',
//     id: 1
// }

Async actions (thunk support)

import {createAction} from 'redux-actions';

const actionCreator = createAction('action2', payload => (
    {
        payload, // if you want a param to be validated, then return this param
        thunk: dispatch => {} // thunk would not be validated, and would be dispatched if validator all succeed
    }
), () => ({
    validator: {
        payload: [
            {
                func: (payload, state) => payload >= 0,
                msg: 'payload is less than 0'
            },
            {
                func: (payload, state) => payload < 100
            }
        ]
    }
}));

const result1 = dispath(actionCreator(-1));
const result2 = dispath(actionCreator(10));
// result1 would abort!
// result1 = {
//     err: 'validator',
//     msg: 'payload is less than 0',
//     param: 'payload',
//     id: 0
// }
// result2 would not abort, and it would continue to pass through thunk middleware
// result2 = thunk

API

Middleware Options

validatorKey

Override the default location for the validators in action objects (default is 'meta').

import Validator from 'redux-validator';

const validator = Validator({
    validatorKey: 'val' // validator should be put inside action.val
});

paramKey

Override the default location for the parmas in action objects (default is payload).

import Validator from 'redux-validator';

const validator = Validator({
    paramKey: 'val' // validator should be put inside action.val
});