query-string.js

/*!
	query-string
	Parse and stringify URL query strings
	https://github.com/sindresorhus/query-string
	by Sindre Sorhus
	MIT License
	*/
'use strict';

export const queryParse = function (str) {
	if (typeof str !== 'string') {
		return {};
	}

	str = str.trim().replace(/^\?/, '');

	if (!str) {
		return {};
	}

	return str.trim().split('&').reduce(function (ret, param) {
		var parts = param.replace(/\+/g, ' ').split('=');
		var key = parts[0];
		var val = parts[1];

		key = decodeURIComponent(key);
		// missing `=` should be `null`:
		// http://w3.org/TR/2012/WD-url-20120524/#collect-url-parameters
		val = val === undefined ? null : decodeURIComponent(val);

		if (!ret.hasOwnProperty(key)) {
			ret[key] = val;
		} else if (Array.isArray(ret[key])) {
			ret[key].push(val);
		} else {
			ret[key] = [ret[key], val];
		}

		return ret;
	}, {});
};

export const queryStringify = function (obj) {
	return obj ? Object.keys(obj).map(function (key) {
		var val = obj[key];

		if (Array.isArray(val)) {
			return val.map(function (val2) {
				return encodeURIComponent(key) + '=' + encodeURIComponent(val2);
			}).join('&');
		}

		return encodeURIComponent(key) + '=' + encodeURIComponent(val);
	}).join('&') : '';
};

export const queryPush = function (key, new_value) {
	var params = queryParse(location.search);
	params[key] = new_value;
	var new_params_string = queryStringify(params)
	history.pushState({}, "", window.location.pathname + '?' + new_params_string);
}