AS3 complex string replacements with Regular Expressions (RegExp)

gistfile1.as

  /**
   * Use regular expressions to easily replace tokens within specific patterns
   * Here we are using SWFAddress with deep linking to update the browser fragment
   */

  var url1     : String = "http://www.test.com/ria.html#/user/100083?view=13432&filter=all&layout=horizontal"
  var url2     : String = "http://www.test.com/ria.html#/user/100083&filter=all/edit"

  // Here we want to update [with filter value above] only the section filter=xxx; 
  // without affecting any other part of the fragment... 

  var pattern  : RegExp = /filter=(user|critical|all)/gi;

  // Current filter value 

  var filter   : String = "user"

  trace ( url1.replace( pattern, supplant("filter={0}",[filter] ) )  )
  trace ( url2.replace( pattern, supplant("filter={0}",[filter] ) )  )

  // output url1 == `http://www.test.com/ria.html#/user/100083?view=13432&filter=user&layout=horizontal`
  // output url1 == `http://www.test.com/ria.html#/user/100083&filter=user/edit`