Change to allow formatTime to accept a format string. (#23)

* Default format string causes it to work as before
* New FFFF format supported for fractional second in 90k units
This commit is contained in:
Dolf Starreveld 2018-03-08 02:41:13 -08:00 committed by Scott Lamb
parent a03b98631a
commit 8a0bc4c401

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@ -53,13 +53,38 @@ function req(url) {
});
}
// Produces a human-readable but unambiguous format of the given timestamp:
// ISO-8601 plus an extra colon component after the seconds indicating the
// fractional time in 90,000ths of a second.
function formatTime(ts90k) {
const m = moment.tz(ts90k / 90, zone);
const frac = ts90k % 90000;
return m.format('YYYY-MM-DDTHH:mm:ss:' + String(100000 + frac).substr(1) + 'Z');
/**
* Format timestamp using a format string.
*
* The timestamp to be formatted is expected to be in units of 90,000 to a
* second (90k format).
*
* The format string should comply with what is accepted by moment.format,
* with one addition. A format pattern of FFFFF (5 Fs) can be used. This
* format pattern will be replaced with the fractional second part of the
* timestamp, still in 90k units. Thus if the timestamp was 89900 (which is
* almost a full second; 0.99888 seconds decimal), the output would be
* 89900, and NOT 0.99888. Only a pattern of five Fs is recognized and it
* will produce exactly a five position output! You cannot vary the number
* of Fs to produce less.
*
* The default format string was chosen to produce results identical to
* a previous version of this code that was hard-coded to produce that output.
*
* @param {Number} ts90k Timestamp in 90k units
* @param {String} format moment.format plus FFFFF pattern supported
* @return {String} Formatted timestamp
*/
function formatTime(ts90k, format = 'YYYY-MM-DDTHH:mm:ss:FFFFFZ') {
const ms = ts90k / 90.0;
const fracFmt = 'FFFFF';
let fracLoc = format.indexOf(fracFmt);
if (fracLoc != -1) {
const frac = ts90k % 90000;
format = format.substr(0, fracLoc) + String(100000 + frac).substr(1) +
format.substr(fracLoc + fracFmt.length);
}
return moment.tz(ms, zone).format(format);
}
function onSelectVideo(camera, range, recording) {