In React ES6, why does the input field lose focus after typing a character?

Question

In my component below, the input field loses focus after typing a character. While using Chrome's Inspector, it looks like the whole form is being re-rendered instead of just the value attribute of the input field when typing.

I get no errors from either eslint nor Chrome Inspector.

Submitting the form itself works as does the actual input field when it is located either in the render's return or while being imported as a separate component but not in how I have it coded below.

Why is this so?

Main Page Component

import React, { Component, PropTypes } from 'react';
import { connect } from 'react-redux';
import { bindActionCreators } from 'redux';
import * as actionPost from '../redux/action/actionPost';
import InputText from './form/InputText';
import InputSubmit from './form/InputSubmit';

class _PostSingle extends Component {
    constructor(props, context) {
        super(props, context);
        this.state = {
            post: {
                title: '',
            },
        };
        this.onChange = this.onChange.bind(this);
        this.onSubmit = this.onSubmit.bind(this);
    }
    onChange(event) {
        this.setState({
            post: {
                title: event.target.value,
            },
        });
    }
    onSubmit(event) {
        event.preventDefault();
        this.props.actions.postCreate(this.state.post);
        this.setState({
            post: {
                title: '',
            },
        });
    }
    render() {
        const onChange = this.onChange;
        const onSubmit = this.onSubmit;
        const valueTitle = this.state.post.title;
        const FormPostSingle = () => (
            <form onSubmit={onSubmit}>
                <InputText name="title" label="Title" placeholder="Enter a title" onChange={onChange} value={valueTitle} />
                <InputSubmit name="Save" />
            </form>
        );
        return (
            <main id="main" role="main">
                <div className="container-fluid">
                    <FormPostSingle />
                </div>
            </main>
        );
    }
}

_PostSingle.propTypes = {
    actions: PropTypes.objectOf(PropTypes.func).isRequired,
};

function mapStateToProps(state) {
    return {
        posts: state.posts,
    };
}

function mapDispatchToProps(dispatch) {
    return {
        actions: bindActionCreators(actionPost, dispatch),
    };
}

export default connect(mapStateToProps, mapDispatchToProps)(_PostSingle);

Text Input Component

import React, { PropTypes } from 'react';

const InputText = ({ name, label, placeholder, onChange, value, error }) => {
    const fieldClass = 'form-control input-lg';
    let wrapperClass = 'form-group';
    if (error && error.length > 0) {
        wrapperClass += ' has-error';
    }
    return (
        <div className={wrapperClass}>
            <label htmlFor={name} className="sr-only">{label}</label>
            <input type="text" id={name} name={name} placeholder={placeholder} onChange={onChange} value={value} className={fieldClass} />
            {error &&
                <div className="alert alert-danger">{error}</div>
            }
        </div>
    );
};

InputText.propTypes = {
    name: PropTypes.string.isRequired,
    label: PropTypes.string.isRequired,
    placeholder: PropTypes.string.isRequired,
    onChange: PropTypes.func.isRequired,
    value: PropTypes.string,
    error: PropTypes.string,
};

InputText.defaultProps = {
    value: null,
    error: null,
};

export default InputText;

Submit Button Component

import React, { PropTypes } from 'react';

const InputSubmit = ({ name }) => {
    const fieldClass = 'btn btn-primary btn-lg';
    return (
        <input type="submit" value={name} className={fieldClass} />
    );
};

InputSubmit.propTypes = {
    name: PropTypes.string,
};

InputSubmit.defaultProps = {
    name: 'Submit',
};

export default InputSubmit;

Answer 1

it is because you are rendering the form in a function inside render().

Every time your state/prop change, the function returns a new form. it caused you to lose focus.

Try putting what's inside the function into your render directly.

       <main id="main" role="main">
            <div className="container-fluid">
                <FormPostSingle />
            </div>
        </main>

====>

       <main id="main" role="main">
            <div className="container-fluid">
                <form onSubmit={onSubmit}>
                    <InputText name="title" label="Title" placeholder="Enter a title" onChange={onChange} value={valueTitle} />
                    <InputSubmit name="Save" />
                </form>
            </div>
        </main>