How to submit a form in React Native

On the <input you need to add something like this, example:

<Input onChangeText={(text) => this.setState({username: text})} value={this.state.username}

And when you use the onPress function you just need to get the this.state.username and use it when you want. I don't usually do a function that handle the Login or something in other .js so you need to pass the this.state.username to the page that handles it.

What i usually do if I really need to pass something to other page is using GLOBALS, example:

// globals.js 
module.exports = {
  username: '',
};

And then to use the globals.js

// import the globals.js
GLOBAL = require('./globals');

<Input onChangeText={(text) => this_onButtonPressed(text) value={this.state.username}/>

_onButtonPressed(text){
  GLOBAL.username = this.state.username
  // call function that handles it
}

And then on the page that handles it you need to import it again and just use GLOBAL.username.

If you didn't understand it tell me I will try to explain it better, I need to know if you want to handle the login on a different .js or it can be on the .js that has the Form (its easier like this)