intl/src/cldr.js

/* jslint esnext: true */

// Match these datetime components in a CLDR pattern, except those in single quotes
let expDTComponents = /(?:[Eec]{1,6}|G{1,5}|[Qq]{1,5}|(?:[yYur]+|U{1,5})|[ML]{1,5}|d{1,2}|D{1,3}|F{1}|[abB]{1,5}|[hkHK]{1,2}|w{1,2}|W{1}|m{1,2}|s{1,2}|[zZOvVxX]{1,4})(?=([^']*'[^']*')*[^']*$)/g;
// trim patterns after transformations
let expPatternTrimmer = /^[\s\uFEFF\xA0]+|[\s\uFEFF\xA0]+$/g;
// Skip over patterns with these datetime components because we don't have data
// to back them up:
// timezone, weekday, amoung others
let unwantedDTCs = /[rqQASjJgwWIQq]/; // xXVO were removed from this list in favor of computing matches with timeZoneName values but printing as empty string

let dtKeys = ["weekday", "era", "year", "month", "day", "weekday", "quarter"];
let tmKeys = ["hour", "minute", "second", "hour12", "timeZoneName"];

function isDateFormatOnly(obj) {
    for (let i = 0; i < tmKeys.length; i += 1) {
        if (obj.hasOwnProperty(tmKeys[i])) {
            return false;
        }
    }
    return true;
}

function isTimeFormatOnly(obj) {
    for (let i = 0; i < dtKeys.length; i += 1) {
        if (obj.hasOwnProperty(dtKeys[i])) {
            return false;
        }
    }
    return true;
}

function joinDateAndTimeFormats(dateFormatObj, timeFormatObj) {
    let o = { _: {} };
    for (let i = 0; i < dtKeys.length; i += 1) {
        if (dateFormatObj[dtKeys[i]]) {
            o[dtKeys[i]] = dateFormatObj[dtKeys[i]];
        }
        if (dateFormatObj._[dtKeys[i]]) {
            o._[dtKeys[i]] = dateFormatObj._[dtKeys[i]];
        }
    }
    for (let j = 0; j < tmKeys.length; j += 1) {
        if (timeFormatObj[tmKeys[j]]) {
            o[tmKeys[j]] = timeFormatObj[tmKeys[j]];
        }
        if (timeFormatObj._[tmKeys[j]]) {
            o._[tmKeys[j]] = timeFormatObj._[tmKeys[j]];
        }
    }
    return o;
}

function computeFinalPatterns(formatObj) {
    // From http://www.unicode.org/reports/tr35/tr35-dates.html#Date_Format_Patterns:
    //  'In patterns, two single quotes represents a literal single quote, either
    //   inside or outside single quotes. Text within single quotes is not
    //   interpreted in any way (except for two adjacent single quotes).'
    formatObj.pattern12 = formatObj.extendedPattern.replace(/'([^']*)'/g, ($0, literal) => {
        return literal ? literal : "'";
    });

    // pattern 12 is always the default. we can produce the 24 by removing {ampm}
    formatObj.pattern = formatObj.pattern12.replace('{ampm}', '').replace(expPatternTrimmer, '');
    return formatObj;
}

function expDTComponentsMeta($0, formatObj) {
    switch ($0.charAt(0)) {
        // --- Era
        case 'G':
            formatObj.era = [ 'short', 'short', 'short', 'long', 'narrow' ][$0.length-1];
            return '{era}';

        // --- Year
        case 'y':
        case 'Y':
        case 'u':
        case 'U':
        case 'r':
            formatObj.year = $0.length === 2 ? '2-digit' : 'numeric';
            return '{year}';

        // --- Quarter (not supported in this polyfill)
        case 'Q':
        case 'q':
            formatObj.quarter = [ 'numeric', '2-digit', 'short', 'long', 'narrow' ][$0.length-1];
            return '{quarter}';

        // --- Month
        case 'M':
        case 'L':
            formatObj.month = [ 'numeric', '2-digit', 'short', 'long', 'narrow' ][$0.length-1];
            return '{month}';

        // --- Week (not supported in this polyfill)
        case 'w':
            // week of the year
            formatObj.week = $0.length === 2 ? '2-digit' : 'numeric';
            return '{weekday}';
        case 'W':
            // week of the month
            formatObj.week = 'numeric';
            return '{weekday}';

        // --- Day
        case 'd':
            // day of the month
            formatObj.day = $0.length === 2 ? '2-digit' : 'numeric';
            return '{day}';
        case 'D': // day of the year
        case 'F': // day of the week
        case 'g':
            // 1..n: Modified Julian day
            formatObj.day = 'numeric';
            return '{day}';

        // --- Week Day
        case 'E':
            // day of the week
            formatObj.weekday = [ 'short', 'short', 'short', 'long', 'narrow', 'short' ][$0.length-1];
            return '{weekday}';
        case 'e':
            // local day of the week
            formatObj.weekday = [ 'numeric', '2-digit', 'short', 'long', 'narrow', 'short' ][$0.length-1];
            return '{weekday}';
        case 'c':
            // stand alone local day of the week
            formatObj.weekday = [ 'numeric', undefined, 'short', 'long', 'narrow', 'short' ][$0.length-1];
            return '{weekday}';

        // --- Period
        case 'a': // AM, PM
        case 'b': // am, pm, noon, midnight
        case 'B': // flexible day periods
            formatObj.hour12 = true;
            return '{ampm}';

        // --- Hour
        case 'h':
        case 'H':
            formatObj.hour = $0.length === 2 ? '2-digit' : 'numeric';
            return '{hour}';
        case 'k':
        case 'K':
            formatObj.hour12 = true; // 12-hour-cycle time formats (using h or K)
            formatObj.hour = $0.length === 2 ? '2-digit' : 'numeric';
            return '{hour}';

        // --- Minute
        case 'm':
            formatObj.minute = $0.length === 2 ? '2-digit' : 'numeric';
            return '{minute}';

        // --- Second
        case 's':
            formatObj.second = $0.length === 2 ? '2-digit' : 'numeric';
            return '{second}';
        case 'S':
        case 'A':
            formatObj.second = 'numeric';
            return '{second}';

        // --- Timezone
        case 'z': // 1..3, 4: specific non-location format
        case 'Z': // 1..3, 4, 5: The ISO8601 varios formats
        case 'O': // 1, 4: miliseconds in day short, long
        case 'v': // 1, 4: generic non-location format
        case 'V': // 1, 2, 3, 4: time zone ID or city
        case 'X': // 1, 2, 3, 4: The ISO8601 varios formats
        case 'x': // 1, 2, 3, 4: The ISO8601 varios formats
            // this polyfill only supports much, for now, we are just doing something dummy
            formatObj.timeZoneName = $0.length < 4 ? 'short' : 'long';
            return '{timeZoneName}';
    }
}


/**
 * Converts the CLDR availableFormats into the objects and patterns required by
 * the ECMAScript Internationalization API specification.
 */
export function createDateTimeFormat(skeleton, pattern) {
    // we ignore certain patterns that are unsupported to avoid this expensive op.
    if (unwantedDTCs.test(pattern))
        return undefined;

    let formatObj = {
        originalPattern: pattern,
        _: {},
    };

    // Replace the pattern string with the one required by the specification, whilst
    // at the same time evaluating it for the subsets and formats
    formatObj.extendedPattern = pattern.replace(expDTComponents, ($0) => {
        // See which symbol we're dealing with
        return expDTComponentsMeta($0, formatObj._);
    });

    // Match the skeleton string with the one required by the specification
    // this implementation is based on the Date Field Symbol Table:
    // http://unicode.org/reports/tr35/tr35-dates.html#Date_Field_Symbol_Table
    // Note: we are adding extra data to the formatObject even though this polyfill
    //       might not support it.
    skeleton.replace(expDTComponents, ($0) => {
        // See which symbol we're dealing with
        return expDTComponentsMeta($0, formatObj);
    });

    return computeFinalPatterns(formatObj);
}

/**
 * Processes DateTime formats from CLDR to an easier-to-parse format.
 * the result of this operation should be cached the first time a particular
 * calendar is analyzed.
 *
 * The specification requires we support at least the following subsets of
 * date/time components:
 *
 *   - 'weekday', 'year', 'month', 'day', 'hour', 'minute', 'second'
 *   - 'weekday', 'year', 'month', 'day'
 *   - 'year', 'month', 'day'
 *   - 'year', 'month'
 *   - 'month', 'day'
 *   - 'hour', 'minute', 'second'
 *   - 'hour', 'minute'
 *
 * We need to cherry pick at least these subsets from the CLDR data and convert
 * them into the pattern objects used in the ECMA-402 API.
 */
export function createDateTimeFormats(formats) {
    let availableFormats = formats.availableFormats;
    let timeFormats = formats.timeFormats;
    let dateFormats = formats.dateFormats;
    let result = [];
    let skeleton, pattern, computed, i, j;
    let timeRelatedFormats = [];
    let dateRelatedFormats = [];

    // Map available (custom) formats into a pattern for createDateTimeFormats
    for (skeleton in availableFormats) {
        if (availableFormats.hasOwnProperty(skeleton)) {
            pattern = availableFormats[skeleton];
            computed = createDateTimeFormat(skeleton, pattern);
            if (computed) {
                result.push(computed);
                // in some cases, the format is only displaying date specific props
                // or time specific props, in which case we need to also produce the
                // combined formats.
                if (isDateFormatOnly(computed)) {
                    dateRelatedFormats.push(computed);
                } else if (isTimeFormatOnly(computed)) {
                    timeRelatedFormats.push(computed);
                }
            }
        }
    }

    // Map time formats into a pattern for createDateTimeFormats
    for (skeleton in timeFormats) {
        if (timeFormats.hasOwnProperty(skeleton)) {
            pattern = timeFormats[skeleton];
            computed = createDateTimeFormat(skeleton, pattern);
            if (computed) {
                result.push(computed);
                timeRelatedFormats.push(computed);
            }
        }
    }

    // Map date formats into a pattern for createDateTimeFormats
    for (skeleton in dateFormats) {
        if (dateFormats.hasOwnProperty(skeleton)) {
            pattern = dateFormats[skeleton];
            computed = createDateTimeFormat(skeleton, pattern);
            if (computed) {
                result.push(computed);
                dateRelatedFormats.push(computed);
            }
        }
    }

    // combine custom time and custom date formats when they are orthogonals to complete the
    // formats supported by CLDR.
    // This Algo is based on section "Missing Skeleton Fields" from:
    // http://unicode.org/reports/tr35/tr35-dates.html#availableFormats_appendItems
    for (i = 0; i < timeRelatedFormats.length; i += 1) {
        for (j = 0; j < dateRelatedFormats.length; j += 1) {
            if (dateRelatedFormats[j].month === 'long') {
                pattern = dateRelatedFormats[j].weekday ? formats.full : formats.long;
            } else if (dateRelatedFormats[j].month === 'short') {
                pattern = formats.medium;
            } else {
                pattern = formats.short;
            }
            computed = joinDateAndTimeFormats(dateRelatedFormats[j], timeRelatedFormats[i]);
            computed.originalPattern = pattern;
            computed.extendedPattern = pattern
                .replace('{0}', timeRelatedFormats[i].extendedPattern)
                .replace('{1}', dateRelatedFormats[j].extendedPattern)
                .replace(/^[,\s]+|[,\s]+$/gi, '');
            result.push(computeFinalPatterns(computed));
        }
    }

    return result;
}