title: Passing an additional parameter with an onChange event
body: <p><strong>What I'm trying to do:</strong></p>
  
  <p>I am trying to pass a string from a child component to the handleChange function of a parent component.</p>
  
  <p><strong>What currently works:</strong></p>
  
  <p>I have a parent React JS class with the following method:</p>
  
  <pre><code>handleChange(event) {
  
      console.log(event.target.value);
  }
  </code></pre>
  
  <p>In the render function I have the following:</p>
  
  <pre><code>&lt;Child handleChange={this.handleChange.bind(this)} /&gt;
  </code></pre>
  
  <p>In the Child class I have:</p>
  
  <pre><code>&lt;fieldset onChange={this.props.handleChange}&gt;
      &lt;div&gt;Tag 1: &lt;input id="tag1" value={tags[0]} /&gt;&lt;/div&gt;
      &lt;div&gt;Tag 2: &lt;input id="tag2" value={tags[1]} /&gt;&lt;/div&gt;
      &lt;div&gt;Tag 3: &lt;input id="tag3" value={tags[2]} /&gt;&lt;/div&gt;
  &lt;/fieldset&gt;
  </code></pre>
  
  <p>This works fine.</p>
  
  <p><strong>What I am trying to do instead:</strong></p>
  
  <p>I am attempting to add a <code>section</code> parameter to the handleChange function as follows:</p>
  
  <pre><code>handleChange(section, event) {
      console.log(section);
      console.log(event.target.value);
  }
  </code></pre>
  
  <p>And in the Child class I have:</p>
  
  <pre><code>&lt;fieldset onChange={this.props.handleChange("tags")}&gt;
      &lt;div&gt;Tag 1: &lt;input id="tag1" value={tags[0]} /&gt;&lt;/div&gt;
      &lt;div&gt;Tag 2: &lt;input id="tag2" value={tags[1]} /&gt;&lt;/div&gt;
      &lt;div&gt;Tag 3: &lt;input id="tag3" value={tags[2]} /&gt;&lt;/div&gt;
  &lt;/fieldset&gt;
  </code></pre>
  
  <p>I now get the error:</p>
  
  <pre><code>Uncaught TypeError: Cannot read property 'target' of undefined
  </code></pre>
  
  <p>This error is being thrown in my second console.log statement.</p>
  
  <p>What am I doing wrong? </p>
  
  <p>Also, I am considering making the <code>section</code> parameter optional. If so, is there an easy way to do this? It seems like it might not be possible if the event parameter needs to be last.</p>