utilja/util.js

util for js

/*
* Copyright (c) JinLiwei 2022-present
*/

/**
 *
 * @param obj obj traversed
 * @param objContainer objContainer containing obj
 * @param key key for obj
 * @param level obj level relative to root
 * @param nullCallback called when obj is null or undefined
 * @param arrayCallback called when obj is array
 * @param objCallback called when obj is object
 * @param primitiveCallback called when obj is primitive
 */
function traverse(obj, objContainer, key, level, {nullCallback, arrayCallback, objCallback, primitiveCallback}) {
    if (obj === null || obj === undefined) {
        if (typeof nullCallback === 'function') {
            nullCallback(obj, objContainer, key, level);
        }
        return;
    }
    if (Array.isArray(obj)) {
        if (typeof arrayCallback === 'function') {
            arrayCallback(obj, objContainer, key, level);
        }
        for (let i = 0; i < obj.length; i++) {
            traverse(obj[i], obj, i, level + 1, {nullCallback, arrayCallback, objCallback, primitiveCallback});
        }
        return;
    }
    if (typeof obj === 'object') {
        if (typeof objCallback === 'function') {
            objCallback(obj, objContainer, key, level);
        }
        let keys = Object.keys(obj);
        if (keys) {
            keys.forEach(itemKey => {
                traverse(obj[itemKey], obj, itemKey, level + 1, {
                    nullCallback,
                    arrayCallback,
                    objCallback,
                    primitiveCallback
                });
            });
        }
        return;
    }
    if (typeof primitiveCallback === 'function') {
        primitiveCallback(obj, objContainer, key, level);
    }
}

module.exports = {
    traverse
}