puyopuyotetr.is/app/javascript/mastodon/features/compose/components/search.js

import React from 'react';
import PropTypes from 'prop-types';
import { defineMessages, injectIntl } from 'react-intl';

const messages = defineMessages({
  placeholder: { id: 'search.placeholder', defaultMessage: 'Search' },
});

@injectIntl
export default class Search extends React.PureComponent {

  static propTypes = {
    value: PropTypes.string.isRequired,
    submitted: PropTypes.bool,
    onChange: PropTypes.func.isRequired,
    onSubmit: PropTypes.func.isRequired,
    onClear: PropTypes.func.isRequired,
    onShow: PropTypes.func.isRequired,
    intl: PropTypes.object.isRequired,
  };

  handleChange = (e) => {
    this.props.onChange(e.target.value);
  }

  handleClear = (e) => {
    e.preventDefault();

    if (this.props.value.length > 0 || this.props.submitted) {
      this.props.onClear();
    }
  }

  handleKeyDown = (e) => {
    if (e.key === 'Enter') {
      e.preventDefault();
      this.props.onSubmit();
    }
  }

  noop () {

  }

  handleFocus = () => {
    this.props.onShow();
  }

  render () {
    const { intl, value, submitted } = this.props;
    const hasValue = value.length > 0 || submitted;

    return (
      <div className='search'>
        <input
          className='search__input'
          type='text'
          placeholder={intl.formatMessage(messages.placeholder)}
          value={value}
          onChange={this.handleChange}
          onKeyUp={this.handleKeyDown}
          onFocus={this.handleFocus}
        />

        <div role='button' tabIndex='0' className='search__icon' onClick={this.handleClear}>
          <i className={`fa fa-search ${hasValue ? '' : 'active'}`} />
          <i aria-label={intl.formatMessage(messages.placeholder)} className={`fa fa-times-circle ${hasValue ? 'active' : ''}`} />
        </div>
      </div>
    );
  }

}