net/systemeD/halcyon/styleparser/NestedCSSLoader.as

   1 package net.systemeD.halcyon.styleparser {
   2
   3         /** A class permitting you to load CSS files containing '@import' rules, which will be
   4         *       automatically replaced with the contents of the file.
   5         *
   6         *   Typical usage:
   7         *
   8         *               cssLoader=new NestedCSSLoader();
   9         *               cssLoader.addEventListener(Event.COMPLETE, doParseCSS);
  10         *               cssLoader.load("potlatch.css");
  11         *
  12         *       doParseCSS can then access the CSS via event.target.css.
  13         */
  14
  15         import flash.events.*;
  16         import flash.net.URLLoader;
  17         import flash.net.URLLoaderDataFormat;
  18         import flash.net.URLRequest;
  19
  20         public class NestedCSSLoader extends EventDispatcher {
  21                 private var sourceCSS:String;
  22                 public var css:String;
  23                 private var url:String;
  24                 private var count:int;
  25
  26                 private static const IMPORT:RegExp=/@import\s*[^'"]*['"]([^'"]+)['"][^;]*;/g;           // '
  27
  28                 public function NestedCSSLoader() {
  29                 }
  30
  31                 public function load(url:String):void {
  32                         this.url=url;
  33                         var request:URLRequest=new URLRequest(url+"?d="+Math.random());
  34                         var loader:URLLoader = new URLLoader();
  35                         loader.dataFormat = URLLoaderDataFormat.TEXT;
  36                         loader.addEventListener(Event.COMPLETE, fileLoaded);
  37                         loader.addEventListener(SecurityErrorEvent.SECURITY_ERROR, fileError);
  38                         loader.addEventListener(IOErrorEvent.IO_ERROR, fileError);
  39                         loader.load(request);
  40                 }
  41
  42                 private function fileLoaded(event:Event):void {
  43                         sourceCSS=URLLoader(event.target).data;
  44                         css=sourceCSS;
  45                         count=0;
  46
  47                         var result:Object=IMPORT.exec(sourceCSS);
  48                         while (result!=null) {
  49                                 count++;
  50                                 replaceCSS(result[1],result[0]);
  51                                 result=IMPORT.exec(sourceCSS);
  52                         }
  53                         if (count==0) { fireComplete(); }
  54                 }
  55
  56                 private function replaceCSS(filename:String, toReplace:String):void {
  57                         var cssLoader:NestedCSSLoader=new NestedCSSLoader();
  58                         var replaceText:String=toReplace;
  59                         cssLoader.addEventListener(Event.COMPLETE, function(event:Event):void {
  60                                 css=css.replace(replaceText,event.target.css);
  61                                 decreaseCount();
  62                         });
  63                         cssLoader.load(filename+"?d="+Math.random());
  64                 }
  65
  66                 private function fileError(event:Event):void {
  67                         // just fire a complete event so we don't get an error dialogue
  68                         trace("Error while trying to load "+url);
  69                         fireComplete();
  70                 }
  71
  72                 private function decreaseCount():void {
  73                         count--; if (count>0) return;
  74                         fireComplete();
  75                 }
  76
  77                 private function fireComplete():void {
  78                         var event:Event=new Event(Event.COMPLETE);
  79                         dispatchEvent(event);
  80                 }
  81         }
  82 }