nodejs/doc/api/url.md

URL

Stability: 2 - Stable

This module has utilities for URL resolution and parsing. Call require('url') to use it.

URL Parsing

Parsed URL objects have some or all of the following fields, depending on whether or not they exist in the URL string. Any parts that are not in the URL string will not be in the parsed object. Examples are shown for the URL

'http://user:pass@host.com:8080/p/a/t/h?query=string#hash'

• href: The full URL that was originally parsed. Both the protocol and host are lowercased.

  Example: 'http://user:pass@host.com:8080/p/a/t/h?query=string#hash'

• protocol: The request protocol, lowercased.

  Example: 'http:'

• slashes: The protocol requires slashes after the colon.

  Example: true or false

• host: The full lowercased host portion of the URL, including port information.

  Example: 'host.com:8080'

• auth: The authentication information portion of a URL.

  Example: 'user:pass'

• hostname: Just the lowercased hostname portion of the host.

  Example: 'host.com'

• port: The port number portion of the host.

  Example: '8080'

• pathname: The path section of the URL, that comes after the host and before the query, including the initial slash if present. No decoding is performed.

  Example: '/p/a/t/h'

• search: The 'query string' portion of the URL, including the leading question mark.

  Example: '?query=string'

• path: Concatenation of pathname and search. No decoding is performed.

  Example: '/p/a/t/h?query=string'

• query: Either the 'params' portion of the query string, or a querystring-parsed object.

  Example: 'query=string' or {'query':'string'}

• hash: The 'fragment' portion of the URL including the pound-sign.

  Example: '#hash'

Escaped Characters

Spaces (' ') and the following characters will be automatically escaped in the properties of URL objects:

< > " ` \r \n \t { } | \ ^ '

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The following methods are provided by the URL module:

url.format(urlObj)

Take a parsed URL object, and return a formatted URL string.

Here's how the formatting process works:

• href will be ignored.
• path will be ignored.
• protocol is treated the same with or without the trailing : (colon).
  • The protocols http, https, ftp, gopher, file will be postfixed with :// (colon-slash-slash) as long as host/hostname are present.
  • All other protocols mailto, xmpp, aim, sftp, foo, etc will be postfixed with : (colon).
• slashes set to true if the protocol requires :// (colon-slash-slash)
  • Only needs to be set for protocols not previously listed as requiring slashes, such as mongodb://localhost:8000/, or if host/hostname are absent.
• auth will be used if present.
• hostname will only be used if host is absent.
• port will only be used if host is absent.
• host will be used in place of hostname and port.
• pathname is treated the same with or without the leading / (slash).
• query (object; see querystring) will only be used if search is absent.
• search will be used in place of query.
  • It is treated the same with or without the leading ? (question mark).
• hash is treated the same with or without the leading # (pound sign, anchor).

url.parse(urlStr[, parseQueryString][, slashesDenoteHost])

Take a URL string, and return an object.

Pass true as the second argument to also parse the query string using the querystring module. If true then the query property will always be assigned an object, and the search property will always be a (possibly empty) string. If false then the query property will not be parsed or decoded. Defaults to false.

Pass true as the third argument to treat //foo/bar as { host: 'foo', pathname: '/bar' } rather than { pathname: '//foo/bar' }. Defaults to false.

url.resolve(from, to)

Take a base URL, and a href URL, and resolve them as a browser would for an anchor tag. Examples:

url.resolve('/one/two/three', 'four')         // '/one/two/four'
url.resolve('http://example.com/', '/one')    // 'http://example.com/one'
url.resolve('http://example.com/one', '/two') // 'http://example.com/two'