gistfile1.js

// Potentially part of the jQuery urlInternal plugin

(function($){
  
  // Method: jQuery.isUrlFragment
  // 
  // Test whether or not a URL is a fragment. The URL can either begin with #
  // or be a partial URL or full URI, that when navigated to, only changes the
  // document.location.hash.
  // 
  // Usage:
  // 
  // > jQuery.isUrlFragment( url );
  // 
  // Arguments:
  // 
  //   url - (String) a URL to test the fragment-ness of.
  // 
  // Returns:
  // 
  //  (Boolean) true if the URL is a fragment, false otherwise.
  
  $.isUrlFragment = function( url ) {
    var loc = document.location,
      loc_fragbase = loc.href.replace( /#.*$/, '' ) + '#',
      loc_hostbase = loc_fragbase.replace( /^(https?:\/\/.*?\/).*$/, '$1' ),
      url_fragbase = url.replace( /#.*$/, '' ) + '#';
    
    // url is just a fragment
    return url.indexOf( '#' ) === 0
      
      // url is absolute
      || url.indexOf( loc_fragbase ) === 0
      
      // url is relative, beginning with '/'
      || url.indexOf( '/' ) === 0 && loc_hostbase + url_fragbase.slice( 1 ) === loc_fragbase
      
      // url is relative, but doesn't begin with '/' (this is very inefficient, but easy)
      || $('<a href="' + url + '"/>')[0].href.indexOf( loc_fragbase ) === 0;
  };

})(jQuery);