title: React - State Update value only of Particular key
body: <p>I'm trying to experiment with React, I have a issue of updating state values of a particular key.</p>
  
  <p>Here is my state</p>
  
  <pre><code>this.state = {
          connections : {
              facebook : "http://facebook.com",
              flickr : null,
              foursquare : null,
              googleplus : null,
              id : 0,
              instagram : "http://instagram.com/",
              openstreetmap : null,
              pinterest : null,
              place_id : 1,
              tomtom : null,
              tripadvisor : null,
              twitter : "http://twitter.com",
              vimeo : null,
              wikipedia : null,
              yelp : null,
              youtube : null
          },
          contact : {
  
          }
      }
  </code></pre>
  
  <p>I'm calling a external component and sending parameters to it.</p>
  
  <pre><code>&lt;Connection type="Facebook" icon={facebookIcon} placeholder="Add Facebook Link" name="facebook" value={this.state.connections.facebook} onChange={this.handleChange.bind(this)}/&gt;
  &lt;Connection type="Twitter" icon={twitterIcon} placeholder="Add Twitter Link" name="twitter" value={this.state.connections.twitter} onChange={this.handleChange.bind(this)}/&gt;
  &lt;Connection type="Instagram" icon={instagramIcon} placeholder="Add Instagram Link" name="instagram" value={this.state.connections.instagram} onChange={this.handleChange.bind(this)}/&gt;
  </code></pre>
  
  <p>Component in external file: </p>
  
  <pre><code>&lt;input type="text" name={this.props.name} placeholder={this.state.placeholder} value={this.props.value} onChange={this.props.onChange} /&gt;
  </code></pre>
  
  <p>On change of value in textbox,</p>
  
  <pre><code>handleChange(e) {        
      this.setState({
          connections : {[e.target.name]: e.target.value}
      })
  }
  </code></pre>
  
  <p>While I try to change any field values, it sets the rest 2 with empty. For example, if I try to edit textbox of Facebook, it sets Twitter and Instagram values to empty. </p>
  
  <p>May I know what I'm doing wrong in setting handleChange? I'm sure its something wrong with <strong>this.setState</strong>, but not sure how to target particular key value.</p>