title: Onpress with conditional will not call a function
body: <p>I have some problem with <code>onPress</code> button function,
  if I create button and calling function directly it work well,
  but if I'm using conditional it will not call the function.  </p>
  
  <p>I already create 2 button below to simulate, button with title "submit normal" can call function and pass the property successfully, button with title "submit conditional" will not calling <code>this.makeRemoteRequest.bind(this);</code> but if you put alert it will react normally, nothing happen if calling a function.</p>
  
  <p></p>
  
  <pre><code>    &lt;Input
        containerStyle={{ width: '90%' }}
        placeholder="Predefined User ID"
        label="User ID"
        labelStyle={{ marginTop: 16 }}
        editable={false}
        value={this.state.userid}
        onChangeText={input_user_id =&gt; this.setState({ input_user_id })}
      /&gt;
  
      &lt;Input
        containerStyle={{ width: '90%' }}
        placeholder="Please fill services request notes here"
        label="Reason"
        labelStyle={{ marginTop: 16 }}
        onChangeText={input_services_detail =&gt; this.setState({ input_services_detail })}
      /&gt;
  
      &lt;Button
          title='Submit Conditional'
          onPress={() =&gt; {
            if (this.state.input_services_detail != null)
            {
              this.makeRemoteRequest.bind(this);
            }
            else
            {
              Alert.alert('Please fill the service detail first');
            }
          }}&gt;&lt;Text style={styles.buttonText}&gt;Submit Aset&lt;/Text&gt;
      &lt;/Button&gt;
  
      &lt;Button
          title='Submit Normal'
          onPress={this.makeRemoteRequest.bind(this)}&gt;&lt;Text style={styles.buttonText}&gt;Submit Aset&lt;/Text&gt;
      &lt;/Button&gt;
  
    &lt;/View&gt;
  </code></pre>
  
  <p>Expecting to call a function using conditional. Appreciate if somebody can brief me on this. Thanks before.</p>