April 23, 2012

jQuery URL Parser v2.0

======================

A jQuery plugin to parse urls and provide easy access to their attributes (such as the protocol, host, port etc), path segments, querystring parameters, fragment parameters and more.

The core parser functionality is based on the Regex URI parser by Steven Levithan.

Please note that version 2 is not backwards compatible with version 1.x of this plugin. v1.1 is still available for download should you need it for some reason.

This plugin requires jQuery to work. Tested on 1.4 and above but will probably work on older versions, too.

License: Available for use under a MIT-style license. If you need a different license for any reason please just let me know.

PLAIN JS VERSION: I've now created a branch of this that doesn't require jQuery. It has all the functionality of the jQuery version apart from the ability to retrieve and work with the URL of an specific element specified by a CSS selector. Grab it here: 'Plain JS' URL parser

Specifying the URL to parse

There are a few different ways to choose what URL to parse:

javascript var url = $.url(); // parse the current page URL var url = $.url('http://allmarkedup.com'); // pass in a URI as a string and parse that var url = $('#myElement').url(); // extract the URL from the selected element and parse that - will work on any element with a `src`, `href` or `action` attribute.

URL attributes

The .attr() method is used to return information on various parts of the URL. For example:

javascript var url = $.url('http://allmarkedup.com/folder/dir/index.html?item=value'); url.attr('protocol'); // returns 'http' url.attr('path'); // returns '/folder/dir/index.html'

The attributes available for querying are:

  • source - the whole url being parsed
  • protocol - eg. http, https, file, etc
  • host - eg. www.mydomain.com, localhost etc
  • port - eg. 80
  • relative - the relative path to the file including the querystring (eg. /folder/dir/index.html?item=value)
  • path - the path to the file (eg. /folder/dir/index.html)
  • directory - the directory part of the path (eg. /folder/dir/)
  • file - the basename of the file eg. index.html
  • query - the entire querystring if it exists, eg. item=value&item2=value2
  • fragment (also available as anchor) - the entire string after the # symbol

There are also a few more obscure ones available too if you want to dig about a bit ;-)

If you don't specify an attribute then this method will return an object literal with all the available attribute key:value pairs in it.

Query string parameters

The .param() method is used to return the values of querystring parameters.

Pass in a string to access that parameter's value:

javascript $.url('http://allmarkedup.com?sky=blue&grass=green').param('sky'); // returns 'blue'

If no argument is passed in it will return an object literal containing a key:value map of all the querystring parameters.

javascript $.url('http://allmarkedup.com?sky=blue&grass=green').param(); // returns { 'sky':'blue', 'grass':'green' }

Note that the .param() method will work on both ampersand-split and semicolon-split querystrings.

URL segments

The .segment() method is used to return values of individual segments from the URL's path.

Pass in an integer value to get the value of that segment - note however that the count is not zero-indexed like an array - i.e. .segment(1) returns the first segment, not the second one.

You can also pass in negative values, in which case it will count back from the end of the path rather than forwards from the start.

javascript var url = $.url('http://allmarkedup.com/folder/dir/example/index.html'); url.segment(1); // returns 'folder' url.segment(-2); // returns 'example' If no argument is passed in it will return an array of all the segments (which will be zero-indexed!).

javascript $.url('http://allmarkedup.com/folder/dir/example/index.html').segment(); // returns ['folder','dir','example','index.html']

Fragment parameters and/or segments

Some sites and apps also use the hash fragment to store querystring-style key value pairs (eg. http://test.com/#sky=blue&grass=green), or slash-delimited paths (eg. http://test.com/#/about/us/).

There are two methods available for extracting information from fragments of these types - .fparam() and .fsegment(), both of which behave indentically to their .param() and .segment() counterparts but act on the fragment rather than the main URL.

``` javascript $.url('http://test.com/#sky=blue&grass=green').fparam('grass'); // returns 'green'

$.url('http://test.com/#/about/us/').fsegment(1); // returns 'about' ```

Enabling strict mode

Internally this plugin uses Steven Levithan's excellent Regex URI parser, which has two modes - loose and strict. This plugin uses the loose mode by default (i.e. strict mode set to false), which deviates slightly from the specs but produces more intuitive results. If for some reason you prefer to use the strict parser and so be fully spec-compatible, then you can enable this when calling the plugin as follows:

javascript var url = $.url(true); // parse the current page URL in strict mode var url = $.url('http://allmarkedup.com',true); // pass in a URI as a string and parse that in strict mode var url = $('#myElement').url(true); // extract the URL from the selected element and parse that in strict mode

A note on improperly encoded URLs

If you attempt to use this plugin to parse a URL that has an invalid character encoding in it, it will throw a URIError Exception. This will happen if the URL has a percentage sign followed by either a non-numeric character or a numeric value of greater than 80 (i.e. 128 in decimal).

If there is a chance you may end up parsing a badly encoded URL you should probably wrap your calls to this plugin in a try/catch block to prevent this causing unforseen problems.

Thanks to steve78b for pointing this out.