Image upload React component.

ImageInput.js

import React, { Component, PropTypes } from 'react';

export default class ImageInput extends Component {
  constructor(props) {
    super(props);
    this.state = {
      src: props.src ? props.src : null,
    }
    
    this.handleOnChange = this.handleOnChange.bind(this);
  }
  
  static propTypes = {
    src: PropTypes.string,
  }

  handleOnChange(e) {
    const file = e.target.files[0];

    // User opened up file upload and canceled
    if (file === undefined) {
      return;
    }

    const { onChange } = this.props;
    const reader = new FileReader();

    reader.onload = (e) => {
      this.setState({
        src: e.target.result
      });
      onChange(e.target.result);
    }

    reader.readAsDataURL(file);
  }

  render() {
    return (
      <div>
        <input
          type="file"
          accept=".jpg,.png"
          onChange={this.handleOnChange}
        />
        <div>
          <div>
            Upload an Image
          </div>
        </div>
        <img
          src={this.state.src}
        />
      </div>
    );
  }
};

This could also be made into a stateless component easily, by just relying on the src prop.