title: Programmatically change Redux-Form Field value
body: <p>When I use <code>redux-form</code> v7, I find there is no way to set the field value. Now in my <code>form</code>, I have two <code>select</code> component. The second's value will be clear when the first <code>select</code> component value changed.</p>
  
  <p>In class render:</p>
  
  <pre><code>&lt;div className={classNames(style.line, style.largeLine)}&gt;
    &lt;div className={style.lable}&gt;site:&lt;/div&gt;
    &lt;div className={style.content}&gt;
      &lt;Field
        name="site"
        options={sites}
        clearable={false}
        component={this.renderSelectField}
        validate={[required]}
      /&gt;
    &lt;/div&gt;
  &lt;/div&gt;
  
  &lt;div className={classNames(style.line, style.largeLine)}&gt;
    &lt;div className={style.lable}&gt;net:&lt;/div&gt;
    &lt;div className={style.content}&gt;
      &lt;Field
        name="net"
        options={nets}
        clearable={false}
        component={this.renderSelectField}
        validate={[required]}
        warning={warnings.net}
      /&gt;
    &lt;/div&gt;
  &lt;/div&gt;
  </code></pre>
  
  <p>Now I add the <code>select</code> change hook, and how can I change the other <code>select</code> value</p>
  
  <pre><code>renderSelectField = props =&gt; {
    const {
      input,
      type,
      meta: { touched, error },
      ...others
    } = props
    const { onChange } = input
    const _onChange = value =&gt; {
      onChange(value)
      this.handleSelectChange({ value, type: input.name })
    }
    return (
      &lt;CHSelect 
        error={touched &amp;&amp; error}
        {...input}
        {...others}
        onChange={_onChange}
        onBlur={null}
      /&gt;
    )
  }
  </code></pre>