Vulcan/packages/vulcan-ui-bootstrap/lib/components/forms/Select.jsx

import React from 'react';
import { intlShape } from 'meteor/vulcan:i18n';
import Form from 'react-bootstrap/lib/Form';
import { Components, registerComponent } from 'meteor/vulcan:core';

// copied from vulcan:forms/utils.js to avoid extra dependency
const getFieldType = datatype => datatype && datatype[0].type;

const SelectComponent = ({ refFunction, inputProperties, datatype, ...properties }, { intl }) => {
  const noneOption = {
    label: intl.formatMessage({ id: 'forms.select_option' }),
    value: getFieldType(datatype) === String || getFieldType(datatype) === Number ? '' : null, // depending on field type, empty value can be '' or null
    disabled: true,
  };
  let otherOptions =
    Array.isArray(inputProperties.options) && inputProperties.options.length
      ? inputProperties.options
      : [];
  const options = [noneOption, ...otherOptions];
  return (
    <Components.FormItem {...inputProperties}>
      <Form.Control as="select" {...inputProperties} ref={refFunction}>
        {options.map((option, i) => (
          <option key={i} {...option}>{option.value}</option>
        ))}
      </Form.Control>
    </Components.FormItem>
  );
};

SelectComponent.contextTypes = {
  intl: intlShape,
};

registerComponent('FormComponentSelect', SelectComponent);