wuchale/dist/compile.js

Protobuf-like i18n from plain code

const digitRange = ['0', '9'].map(d => d.charCodeAt(0));
function extractSpecial(msgStr, start) {
    const inPlaceHolder = msgStr[start] === '{';
    const inTag = msgStr[start] === '<';
    if (!inTag && !inPlaceHolder) {
        return [null, null, start];
    }
    let digits = '';
    let endChar = '';
    let inClose = false;
    let i = start + 1;
    const beginChar = msgStr[i];
    if (inTag && beginChar === '/') {
        inClose = true;
        i++;
    }
    while (i < msgStr.length) {
        const char = msgStr[i];
        const code = char.charCodeAt(0);
        if (code < digitRange[0] || code > digitRange[1]) {
            endChar = char;
            break;
        }
        digits += char;
        i++;
    }
    if (!digits) {
        return [null, null, start];
    }
    const n = Number(digits);
    if (inPlaceHolder) {
        if (endChar !== '}') {
            return [null, null, start];
        }
        return ['placeholder', n, i + 1];
    }
    if (endChar === '/' && msgStr[i + 1] === '>') {
        return ['selfclose', n, i + 2];
    }
    if (endChar != '>') {
        return [null, null, start];
    }
    if (inClose) {
        return ['close', n, i + 1];
    }
    return ['open', n, i + 1];
}
function compile(msgStr, start = 0, parentTag = null) {
    let curTxt = '';
    const compiled = [];
    let i = start;
    const len = msgStr.length;
    let currentOpenTag = null;
    while (i < len) {
        const char = msgStr[i];
        const [type, n, newI] = extractSpecial(msgStr, i);
        if (type === null) {
            curTxt += char;
            i++;
            continue;
        }
        if (curTxt) {
            compiled.push(curTxt);
            curTxt = '';
        }
        if (type === 'open') {
            currentOpenTag = n;
            const [subExt, newIc] = compile(msgStr, newI, n);
            compiled.push([n, ...subExt]);
            i = newIc;
            continue;
        }
        if (type === 'close') {
            if (currentOpenTag != null) {
                if (currentOpenTag != n) {
                    throw Error('Closing a different tag');
                }
                currentOpenTag = null;
            }
            else if (n === parentTag) {
                break;
            }
            else {
                throw Error('Closing a different tag');
            }
        }
        else if (type === 'selfclose') {
            compiled.push([n]);
        }
        else { // placeholder
            compiled.push(n);
        }
        i = newI;
    }
    if (curTxt) {
        compiled.push(curTxt);
    }
    return [compiled, i];
}
export function compileTranslation(msgStr, fallback) {
    if (!msgStr) {
        return fallback;
    }
    try {
        const [compiled] = compile(msgStr);
        if (compiled.length === 1 && typeof compiled[0] === 'string') {
            return compiled[0];
        }
        return compiled;
    }
    catch (err) {
        console.error(err);
        console.error(msgStr);
        return fallback;
    }
}