Material UI Upload Button

UploadButton.js

import React, { PropTypes, Component } from 'react';
import FlatButton from 'material-ui/FlatButton';
import RaisedButton from 'material-ui/RaisedButton';

export default class UploadButton extends Component {
  static propTypes = {
    button: PropTypes.oneOf(['flat', 'raised']).isRequired,
    raised: PropTypes.bool,
    label: PropTypes.string.isRequired,
    disabled: PropTypes.bool,
    multiLabel: PropTypes.string,
    multiple: PropTypes.bool,
    inputName: PropTypes.string,
    inputRef: PropTypes.string,
    onChange: PropTypes.func,
    valueLink: PropTypes.object
  };

  constructor(props) {
    super(props);
    this.state = {
      fileName: this.props.label
    };
  };

  _getFileName = (event) => {
    if (event.target.files[0].name) {
      this.setState({
        fileName: `.../${event.target.files[0].name}`
      });
    }
    if (this.props.onChange) this.props.onChange(event);
  };

  _multipleHandler = (event) => {
    const multipleLabel = this.props.multiLabel || 'Files Selected';

    if (event.target.files.length > 0) {
      this.setState({
        fileName: `${event.target.files.length} ${multipleLabel}`
      });
    }
    if (this.props.onChange) this.props.onChange(event);
  };

  render() {
    const {
      button,
      label,
      multiLabel,
      multiple,
      inputName,
      inputRef,
      onChange,
      ...otherProps
    } = this.props;

    let inputElement;
    let currentLabel;

    const styles = {
      inputFile: {
        cursor: 'pointer',
        height: '100%',
        position: 'absolute',
        top: 0,
        right: 0,
        zIndex: 2,
        fontSize: 50,
        opacity: 0
      }
    };

    const inputProps = {
      style: styles.inputFile,
      ref: inputRef || 'input',
      name: inputName || 'input'
    };

    if (this.props.hasOwnProperty('valueLink')) {
      inputProps.valueLink = this.props.valueLink;
    }

    if (!this.props.disabled) {
      if (!multiple) {
        inputProps.onChange = this._getFileName;
      } else {
        inputProps.onChange = this._multipleHandler;
        inputProps.multiple = 'multiple';
      }
      inputElement = (
        <input type="file" {...inputProps} />
      );
    }

    currentLabel = this.state.fileName;

    let component;
    if (button === 'flat') {
      component = (
        <FlatButton {...otherProps}>
          {currentLabel}
          {inputElement}
        </FlatButton>
      );
    } else {
      component = (
        <RaisedButton {...otherProps}>
          {currentLabel}
          {inputElement}
        </RaisedButton>
      );
    }
    return (
      <span>
        {component}
      </span>
    );
  }
};