import React, { Component } from 'react';
        import  { TextInput } from 'react-native'
        class CustomTextInput extends Component {
           render() {
               return (
         <TextInput
        style={this.props.style}
        placeholder={this.props.placeholder}
        onChangeText = {this.props.onChangeText}
        value={this.props.value}
        onBlur={this.props.onBlur}
        onChange={this.props.onChange}
        onFocus={this.props.onFocus}
         />
      ); }}
     export default CustomTextInput;

export default class ParentComponent extends BaseInput {

     render (){
   return(
         <CustomTextInput
         ref="input"
     value={value}
      onBlur={this._onBlur}
      onFocus={this._onFocus}
      onChange={this._onChange}
        />)

       }

export default class BaseInput extends Component {
        componentWillReceiveProps(newProps) {

    const isFocused = this.refs.input.isFocused();
     if (!isFocused) {
     alert("hi")
         }
        }}