Вопрос по поводу setState() в react

class Input extends React.Component { 
 
    constructor(props) { 
        super(props); 
        this.state = {isValid: false}; 
        this.inputValueChanged = this.inputValueChanged.bind(this); 
    } 
 
    inputValueChanged(e) { 
        var txt = e.target.value; 
        this.state.isValid = txt.length >= 3; 
        this.state.text = txt; 
        this.props.checkToUnblockSubmit(); 
    } 
 
    render() { 
        return React.createElement('input', { 
            className: "form-control", 
            onChange: this.inputValueChanged, 
            placeholder: this.props.placeholder, 
            type: this.props.type, 
            style: {borderColor: this.state.isValid ? "green" : "red"} 
        }, null); 
    } 
} 
 
 
class Form extends React.Component { 
 
    constructor(props) { 
        super(props); 
        this.state = {repeatIsValid: false, allInputsValid: false}; 
        this.checkToUnblockSubmit = this.checkToUnblockSubmit.bind(this); 
        this.saveRepeatValue = this.saveRepeatValue.bind(this); 
        this.send = this.send.bind(this); 
    } 
 
    checkToUnblockSubmit() { 
        this.state.repeatIsValid = this.refs.password.state.isValid && (this.refs.password.state.text === this.state.repeatText); 
        this.state.allInputsValid = this.refs.login.state.isValid && this.refs.password.state.isValid && this.state.repeatIsValid; 
        this.setState(); 
    } 
 
    saveRepeatValue(e) { 
        this.state.repeatText = e.target.value; 
        this.checkToUnblockSubmit(); 
    } 
 
    send() { 
       console.log("здесь мы отправляем"); 
    } 
 
    render() { 
        return ( 
            React.createElement('div', null, 
 
                React.createElement('div', {className: "form-group"}, 
                    React.createElement(Input, { 
                        type: "text", 
                        ref: "login", 
                        placeholder: "логин", 
                        checkToUnblockSubmit: this.checkToUnblockSubmit 
                    }, null)), 
 
                React.createElement('div', {className: "form-group"}, 
                    React.createElement(Input, { 
                        type: "password", 
                        ref: "password", 
                        placeholder: "пароль", 
                        checkToUnblockSubmit: this.checkToUnblockSubmit 
                    }, null)), 
 
                React.createElement('div', {className: "form-group"}, 
                    React.createElement('input', { 
                        type: "password", 
                        ref: "repeat", 
                        className: "form-control", 
                        placeholder: "повторить пароль", 
                        style: {borderColor: this.state.repeatIsValid ? "green" : "red"}, 
                        onChange: this.saveRepeatValue 
                    }, null)), 
 
                React.createElement('div', {className: "form-group"}, 
                    React.createElement('button', {                         
                        className: this.state.allInputsValid ? "btn btn-success" : "btn btn-danger", 
                        disabled: !this.state.allInputsValid, 
                        onClick: this.send 
                    }, 'отправить'))                     
            ) 
        ) 
    } 
} 
 
ReactDOM.render( 
    React.createElement(Form, null, null), 
    document.getElementById('container') 
);

<link href="https://maxcdn.bootstrapcdn.com/bootstrap/3.3.7/css/bootstrap.min.css" rel="stylesheet"/> 
<script src="https://cdnjs.cloudflare.com/ajax/libs/react/15.1.0/react.min.js"></script> 
<script src="https://cdnjs.cloudflare.com/ajax/libs/react/15.1.0/react-dom.min.js"></script> 
 
<div id="container"></div>