'dispatch' is not a function when argument to mapToDispatchToProps() in Redux

Question

I am a javascript/redux/react beginner building an small application with redux, react-redux, & react. For some reason when using mapDispatchToProps function in tandem with connect (react-redux binding) I receive a TypeError indicating that dispatch is not a function when I try to execute the resulting prop. When I call dispatch as a prop however (see the setAddr function in the provided code) it works.

I'm curious as to why this is, in the example TODO app in the redux docs the mapDispatchToProps method is setup the same way. When I console.log(dispatch) inside the function it says dispatch is type object. I could continue to use dispatch this way but I would feel better knowing why this is happening before I continue any further with redux. I am using webpack with babel-loaders to compile.

My Code:

import React, { PropTypes, Component } from 'react';
import { connect } from 'react-redux';
import { setAddresses } from '../actions.js';
import GeoCode from './geoCode.js';
import FlatButton from 'material-ui/lib/flat-button';

const Start = React.createClass({
    propTypes: {
        onSubmit: PropTypes.func.isRequired
    },

    setAddr: function(){
        this.props.dispatch(
            setAddresses({
                pickup: this.refs.pickup.state.address,
                dropoff: this.refs.dropoff.state.address
            })
        )   

    },

    render: function() {
        return (
            <div>
                <div className="row">
                    <div className="col-xs-6">
                        <GeoCode ref='pickup' />
                    </div>
                    <div className="col-xs-6">
                        <GeoCode ref='dropoff' />
                    </div>
                </div>
                <div className="row">
                    <div className="col-xs-6">
                        <FlatButton 
                            label='Does Not Work'
                            onClick={this.props.onSubmit({
                                pickup: this.refs.pickup.state.address,
                                dropoff: this.refs.dropoff.state.address
                            })} 
                            />
                    </div>
                    <div className="col-xs-6">
                        <FlatButton 
                            label='Works'
                            onClick={this.setAddr} 
                            />
                    </div>
                </div>
            </div>
        );
    }
})

const mapDispatchToProps = (dispatch) => {
    return {
        onSubmit: (data) => {
            dispatch(setAddresses(data))
        }
    }
}

const StartContainer = connect(mapDispatchToProps)(Start)

export default StartContainer

Cheers.

Answer 1

If you want to use mapDispatchToProps without a mapStateToProps just use null for the first argument.

export default connect(null, mapDispatchToProps)(Start)