title: React-Native Form Validation error ("this.validate is not a function")
body: <p>I get this this error when I click "this._onPressButton"  using the below code. Unable to figure out why this occurs or to find a solution. Thanks in advance.</p>
  
  <p><a href="https://i.stack.imgur.com/PoURi.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/PoURi.png" alt="Error"></a></p>
  
  <pre><code>import React, {Component}  from 'react';
  
  import {View, Text, TextInput, TouchableHighlight} from 'react-native';
  
  import ValidationComponent from 'react-native-form-validator';
  
  export default class FormTest extends ValidationComponent {
  
    constructor(props) {
      super(props);
      this.state = {name : "My name", email: "tibtib@gmail.com", number:"56", date: "2017-03-01"};
    }
  
    _onPressButton() {
      // Call ValidationComponent validate method
      this.validate({
        name: {minlength:3, maxlength:7, required: true},
        email: {email: true},
        number: {numbers: true},
        date: {date: 'YYYY-MM-DD'}
      });
    }
  
    render() {
        return (
          &lt;View&gt;
            &lt;TextInput ref="name" onChangeText={(name) =&gt; this.setState({name})} value={this.state.name} /&gt;
            &lt;TextInput ref="email" onChangeText={(email) =&gt; this.setState({email})} value={this.state.email} /&gt;
            &lt;TextInput ref="number" onChangeText={(number) =&gt; this.setState({number})} value={this.state.number} /&gt;
            &lt;TextInput ref="date" onChangeText={(date) =&gt; this.setState({date})} value={this.state.date} /&gt;
  
            &lt;TouchableHighlight onPress={this._onPressButton}&gt;
              &lt;Text&gt;Submit&lt;/Text&gt;
            &lt;/TouchableHighlight&gt;
  
            &lt;Text&gt;
              {this.getErrorMessages()}
            &lt;/Text&gt;
          &lt;/View&gt;
        );
    }
  
  }
  </code></pre>