I have the following TextInput Component:

```
<TextInput value={this.state.inputText}
  maxLength={1}
  onSubmitEditing={this.textHandler}
  onChangeText={(text) => this.setState({inputText: text})} />

```

When I change the input to '' and submit it (in the TextInput) I have the following error: *"Failed prop type: Invalid prop 'value' of type 'object' supplied to 'TextInput'"*

I tried deleting each callback and apparently, the error is throwed because of the 'onSubmitEditing'. 

```
textHandler = (text) => {

  if(text == '' || text == '-' ){
    text = '0';
  }

  this.setState({inputText: text});
}

```

How can I make the callback to be called only where text is a string and not an object?