about summary refs log tree commit diff
path: root/app/javascript/themes/glitch/components/relative_timestamp.js
blob: 51588e78ca1684aced5b58398a9b53b2f0cfe517 (plain) (blame)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
import React from 'react';
import { injectIntl, defineMessages } from 'react-intl';
import PropTypes from 'prop-types';

const messages = defineMessages({
  just_now: { id: 'relative_time.just_now', defaultMessage: 'now' },
  seconds: { id: 'relative_time.seconds', defaultMessage: '{number}s' },
  minutes: { id: 'relative_time.minutes', defaultMessage: '{number}m' },
  hours: { id: 'relative_time.hours', defaultMessage: '{number}h' },
  days: { id: 'relative_time.days', defaultMessage: '{number}d' },
});

const dateFormatOptions = {
  hour12: false,
  year: 'numeric',
  month: 'short',
  day: '2-digit',
  hour: '2-digit',
  minute: '2-digit',
};

const shortDateFormatOptions = {
  month: 'numeric',
  day: 'numeric',
};

const SECOND = 1000;
const MINUTE = 1000 * 60;
const HOUR   = 1000 * 60 * 60;
const DAY    = 1000 * 60 * 60 * 24;

const MAX_DELAY = 2147483647;

const selectUnits = delta => {
  const absDelta = Math.abs(delta);

  if (absDelta < MINUTE) {
    return 'second';
  } else if (absDelta < HOUR) {
    return 'minute';
  } else if (absDelta < DAY) {
    return 'hour';
  }

  return 'day';
};

const getUnitDelay = units => {
  switch (units) {
  case 'second':
    return SECOND;
  case 'minute':
    return MINUTE;
  case 'hour':
    return HOUR;
  case 'day':
    return DAY;
  default:
    return MAX_DELAY;
  }
};

@injectIntl
export default class RelativeTimestamp extends React.Component {

  static propTypes = {
    intl: PropTypes.object.isRequired,
    timestamp: PropTypes.string.isRequired,
  };

  state = {
    now: this.props.intl.now(),
  };

  shouldComponentUpdate (nextProps, nextState) {
    // As of right now the locale doesn't change without a new page load,
    // but we might as well check in case that ever changes.
    return this.props.timestamp !== nextProps.timestamp ||
      this.props.intl.locale !== nextProps.intl.locale ||
      this.state.now !== nextState.now;
  }

  componentWillReceiveProps (nextProps) {
    if (this.props.timestamp !== nextProps.timestamp) {
      this.setState({ now: this.props.intl.now() });
    }
  }

  componentDidMount () {
    this._scheduleNextUpdate(this.props, this.state);
  }

  componentWillUpdate (nextProps, nextState) {
    this._scheduleNextUpdate(nextProps, nextState);
  }

  componentWillUnmount () {
    clearTimeout(this._timer);
  }

  _scheduleNextUpdate (props, state) {
    clearTimeout(this._timer);

    const { timestamp }  = props;
    const delta          = (new Date(timestamp)).getTime() - state.now;
    const unitDelay      = getUnitDelay(selectUnits(delta));
    const unitRemainder  = Math.abs(delta % unitDelay);
    const updateInterval = 1000 * 10;
    const delay          = delta < 0 ? Math.max(updateInterval, unitDelay - unitRemainder) : Math.max(updateInterval, unitRemainder);

    this._timer = setTimeout(() => {
      this.setState({ now: this.props.intl.now() });
    }, delay);
  }

  render () {
    const { timestamp, intl } = this.props;

    const date  = new Date(timestamp);
    const delta = this.state.now - date.getTime();

    let relativeTime;

    if (delta < 10 * SECOND) {
      relativeTime = intl.formatMessage(messages.just_now);
    } else if (delta < 3 * DAY) {
      if (delta < MINUTE) {
        relativeTime = intl.formatMessage(messages.seconds, { number: Math.floor(delta / SECOND) });
      } else if (delta < HOUR) {
        relativeTime = intl.formatMessage(messages.minutes, { number: Math.floor(delta / MINUTE) });
      } else if (delta < DAY) {
        relativeTime = intl.formatMessage(messages.hours, { number: Math.floor(delta / HOUR) });
      } else {
        relativeTime = intl.formatMessage(messages.days, { number: Math.floor(delta / DAY) });
      }
    } else {
      relativeTime = intl.formatDate(date, shortDateFormatOptions);
    }

    return (
      <time dateTime={timestamp} title={intl.formatDate(date, dateFormatOptions)}>
        {relativeTime}
      </time>
    );
  }

}