url-parse

What is url-parse?

The url-parse package is a robust tool for parsing URLs in Node.js and browser environments. It provides a convenient way to break down a URL into its components, such as protocol, host, path, query parameters, and hash. This package is useful for applications that need to manipulate or extract information from URLs.

What are url-parse's main functionalities?

Parsing URL

This feature allows you to parse a full URL into its constituent parts, including protocol, username, password, host, port, pathname, query, and hash. The second parameter set to true parses the query string into an object.

const parse = require('url-parse');
const url = parse('http://username:[e-mail]:8080/p/a/t/h?query=string#hash', true);
console.log(url.protocol); // 'http:'
console.log(url.host); // 'host.com:8080'

Manipulating Query Strings

This feature demonstrates how to manipulate query strings. After parsing the URL with the query string parsing option enabled, you can easily add, modify, or delete query parameters and then serialize the URL back to a string.

const parse = require('url-parse');
const url = parse('http://example.com?foo=bar', true);
url.query.newParam = 'newValue';
console.log(url.toString()); // 'http://example.com/?foo=bar&newParam=newValue'

Relative URL Resolution

This feature shows how to resolve relative URLs against a base URL. By parsing both the base and relative URLs, you can combine their components to form a new, resolved URL.

const parse = require('url-parse');
const baseUrl = parse('http://example.com/directory/');
const relativeUrl = parse('another/directory', true);
const resolvedUrl = baseUrl.set('pathname', baseUrl.pathname + relativeUrl.pathname);
console.log(resolvedUrl.toString()); // 'http://example.com/directory/another/directory'

Other packages similar to url-parse

whatwg-url

This package implements the URL standard as specified by the WHATWG (Web Hypertext Application Technology Working Group). It offers more comprehensive support for the URL standard than url-parse, including features like URLSearchParams. However, it might be more complex to use for simple URL parsing and manipulation tasks.

README

url-parse

url-parse was created in 2014 when the WHATWG URL API was not available in Node.js and the URL interface was supported only in some browsers. Today this is no longer true. The URL interface is available in all supported Node.js release lines and basically all browsers. Consider using it for better security and accuracy.

The url-parse method exposes two different API interfaces. The url interface that you know from Node.js and the new URL interface that is available in the latest browsers.

In version 0.1 we moved from a DOM based parsing solution, using the <a> element, to a full Regular Expression solution. The main reason for this was to make the URL parser available in different JavaScript environments as you don't always have access to the DOM. An example of such environment is the Worker interface. The RegExp based solution didn't work well as it required a lot of lookups causing major problems in FireFox. In version 1.0.0 we ditched the RegExp based solution in favor of a pure string parsing solution which chops up the URL into smaller pieces. This module still has a really small footprint as it has been designed to be used on the client side.

In addition to URL parsing we also expose the bundled querystringify module.

Installation

This module is designed to be used using either browserify or Node.js it's released in the public npm registry and can be installed using:

npm install url-parse

Usage

All examples assume that this library is bootstrapped using:

'use strict';

var Url = require('url-parse');

To parse an URL simply call the URL method with the URL that needs to be transformed into an object.

var url = new Url('https://github.com/foo/bar');

The new keyword is optional but it will save you an extra function invocation. The constructor takes the following arguments:

• url (String): A string representing an absolute or relative URL.
• baseURL (Object | String): An object or string representing the base URL to use in case url is a relative URL. This argument is optional and defaults to location in the browser.
• parser (Boolean | Function): This argument is optional and specifies how to parse the query string. By default it is false so the query string is not parsed. If you pass true the query string is parsed using the embedded querystringify module. If you pass a function the query string will be parsed using this function.

As said above we also support the Node.js interface so you can also use the library in this way:

'use strict';

var parse = require('url-parse')
  , url = parse('https://github.com/foo/bar', true);

The returned url instance contains the following properties:

• protocol: The protocol scheme of the URL (e.g. http:).
• slashes: A boolean which indicates whether the protocol is followed by two forward slashes (//).
• auth: Authentication information portion (e.g. username:password).
• username: Username of basic authentication.
• password: Password of basic authentication.
• host: Host name with port number. The hostname might be invalid.
• hostname: Host name without port number. This might be an invalid hostname.
• port: Optional port number.
• pathname: URL path.
• query: Parsed object containing query string, unless parsing is set to false.
• hash: The "fragment" portion of the URL including the pound-sign (#).
• href: The full URL.
• origin: The origin of the URL.

Note that when url-parse is used in a browser environment, it will default to using the browser's current window location as the base URL when parsing all inputs. To parse an input independently of the browser's current URL (e.g. for functionality parity with the library in a Node environment), pass an empty location object as the second parameter:

var parse = require('url-parse');
parse('hostname', {});

Url.set(key, value)

A simple helper function to change parts of the URL and propagating it through all properties. When you set a new host you want the same value to be applied to port if has a different port number, hostname so it has a correct name again and href so you have a complete URL.

var parsed = parse('http://google.com/parse-things');

parsed.set('hostname', 'yahoo.com');
console.log(parsed.href); // http://yahoo.com/parse-things

It's aware of default ports so you cannot set a port 80 on an URL which has http as protocol.

Url.toString()

The returned url object comes with a custom toString method which will generate a full URL again when called. The method accepts an extra function which will stringify the query string for you. If you don't supply a function we will use our default method.

var location = url.toString(); // http://example.com/whatever/?qs=32

You would rarely need to use this method as the full URL is also available as href property. If you are using the URL.set method to make changes, this will automatically update.

Testing

The testing of this module is done in 3 different ways:

1. We have unit tests that run under Node.js. You can run these tests with the npm test command.
2. Code coverage can be run manually using npm run coverage.
3. For browser testing we use Sauce Labs and zuul. You can run browser tests using the npm run test-browser command.

License

MIT