chrono-node
Version:
A natural language date parser in Javascript
48 lines (39 loc) • 1.81 kB
text/typescript
import { ParsingContext, Refiner } from "../../chrono";
import { ParsingResult } from "../../results";
const TIMEZONE_OFFSET_PATTERN = new RegExp("^\\s*(?:\\(?(?:GMT|UTC)\\s?)?([+-])(\\d{1,2})(?::?(\\d{2}))?\\)?", "i");
const TIMEZONE_OFFSET_SIGN_GROUP = 1;
const TIMEZONE_OFFSET_HOUR_OFFSET_GROUP = 2;
const TIMEZONE_OFFSET_MINUTE_OFFSET_GROUP = 3;
export default class ExtractTimezoneOffsetRefiner implements Refiner {
refine(context: ParsingContext, results: ParsingResult[]): ParsingResult[] {
results.forEach(function (result) {
if (result.start.isCertain("timezoneOffset")) {
return;
}
const suffix = context.text.substring(result.index + result.text.length);
const match = TIMEZONE_OFFSET_PATTERN.exec(suffix);
if (!match) {
return;
}
context.debug(() => {
console.log(`Extracting timezone: '${match[0]}' into : ${result}`);
});
const hourOffset = parseInt(match[TIMEZONE_OFFSET_HOUR_OFFSET_GROUP]);
const minuteOffset = parseInt(match[TIMEZONE_OFFSET_MINUTE_OFFSET_GROUP] || "0");
let timezoneOffset = hourOffset * 60 + minuteOffset;
// No timezones have offsets greater than 14 hours, so disregard this match
if (timezoneOffset > 14 * 60) {
return;
}
if (match[TIMEZONE_OFFSET_SIGN_GROUP] === "-") {
timezoneOffset = -timezoneOffset;
}
if (result.end != null) {
result.end.assign("timezoneOffset", timezoneOffset);
}
result.start.assign("timezoneOffset", timezoneOffset);
result.text += match[0];
});
return results;
}
}