{"id":264,"date":"2011-02-11T15:42:28","date_gmt":"2011-02-11T13:42:28","guid":{"rendered":"http:\/\/blog.ansuz.nl\/?p=264"},"modified":"2011-02-11T15:43:34","modified_gmt":"2011-02-11T13:43:34","slug":"flex-ftp-abort","status":"publish","type":"post","link":"http:\/\/blog.ansuz.nl\/index.php\/2011\/02\/11\/flex-ftp-abort\/","title":{"rendered":"Flex FTP Abort"},"content":{"rendered":"

To properly close a transfer to the FTP server, you need to send an Abort command (see http:\/\/www.w3.org\/Protocols\/rfc959\/4_FileTransfer.html<\/a> (ABORT) ). Flex FTP<\/a> doesn’t support this so I added some functionality to be able to send an abort.<\/p>\n

First I added the Abort command to the Commands class:<\/p>\n

\n\n\t\t
\n\n\t\t
\n\t\t\t\t\t\t< View plain text<\/span> ><\/a>\n\t\t\t\t\t<\/div>\n\n\t\t
code<\/div>\n\n\t\t\n\t\t
\n\n\t<\/div>\n\t\n\t
\n\t\t
  1. public static const ABOR:String = "ABOR";<\/div><\/li>\n<\/ol>\t<\/div>\n\n<\/div>\n\n

    After that I added a new invoker to the invokers package, AbortInv<\/a>.<\/p>\n

    The FTPInvoker class required a new public method to support the Abort command, which can be overridden by the specific implementations. In FTPInvoker I added an abort method like this:<\/p>\n

    \n\n\t\t
    \n\n\t\t
    \n\t\t\t\t\t\t< View plain text<\/span> ><\/a>\n\t\t\t\t\t<\/div>\n\n\t\t
    code<\/div>\n\n\t\t\n\t\t
    \n\n\t<\/div>\n\t\n\t
    \n\t\t
    1. \/**<\/div><\/li>\n
    2. * Stops this Invoker from executing.<\/div><\/li>\n
    3. *\/<\/div><\/li>\n
    4. public function abort():void {<\/div><\/li>\n
    5. \/\/ Some Invokers just don't need to do anything.<\/div><\/li>\n
    6. finalize();<\/div><\/li>\n
    7. }<\/div><\/li>\n<\/ol>\t<\/div>\n\n<\/div>\n\n

      There was only one invoker where I had to override the abort method to get things working correctly and that was the UploadInv class. Here I added the following code:<\/p>\n

      \n\n\t\t
      \n\n\t\t
      \n\t\t\t\t\t\t< View plain text<\/span> ><\/a>\n\t\t\t\t\t<\/div>\n\n\t\t
      code<\/div>\n\n\t\t\n\t\t
      \n\n\t<\/div>\n\t\n\t
      \n\t\t
      1. \/**<\/div><\/li>\n
      2. * @inheritDoc<\/div><\/li>\n
      3. *\/<\/div><\/li>\n
      4. override public function abort():void {<\/div><\/li>\n
      5. super.abort();<\/div><\/li>\n
      6.  <\/div><\/li>\n
      7. if(interval) clearInterval(interval);<\/div><\/li>\n
      8. if(sourceFile) sourceFile.close();<\/div><\/li>\n
      9. if(passiveSocket &amp;&amp; passiveSocket.connected) passiveSocket.close();<\/div><\/li>\n
      10. }<\/div><\/li>\n<\/ol>\t<\/div>\n\n<\/div>\n\n

        After that it was a matter of updating the FTPClient class with an abort method to get the circle complete.<\/p>\n

        \n\n\t\t
        \n\n\t\t
        \n\t\t\t\t\t\t< View plain text<\/span> ><\/a>\n\t\t\t\t\t<\/div>\n\n\t\t
        code<\/div>\n\n\t\t\n\t\t
        \n\n\t<\/div>\n\t\n\t
        \n\t\t
        1. \/**<\/div><\/li>\n
        2. * Aborts the previous FTP command.<\/div><\/li>\n
        3. *\/<\/div><\/li>\n
        4. public function abort():void {<\/div><\/li>\n
        5. if(currentProcess) {<\/div><\/li>\n
        6. if(currentProcess is UploadInv) {<\/div><\/li>\n
        7. swallowNextResponse = true;<\/div><\/li>\n
        8. }<\/div><\/li>\n
        9. currentProcess.abort();<\/div><\/li>\n
        10. currentProcess = null;<\/div><\/li>\n
        11. }<\/div><\/li>\n
        12.  <\/div><\/li>\n
        13. invoke( new AbortInv(this) );<\/div><\/li>\n
        14. }<\/div><\/li>\n<\/ol>\t<\/div>\n\n<\/div>\n\n

          Unfortunately I also had to update handleData method in the FTPClient class a little bit, because aborting an upload would result into 2 (or more) resonses at once from the FTP server.
          \nMy handleData method now looks like this:<\/p>\n

          \n\n\t\t
          \n\n\t\t
          \n\t\t\t\t\t\t< View plain text<\/span> ><\/a>\n\t\t\t\t\t<\/div>\n\n\t\t
          code<\/div>\n\n\t\t\n\t\t
          \n\n\t<\/div>\n\t\n\t
          \n\t\t
          1. private function handleData (pEvt:ProgressEvent):void<\/div><\/li>\n
          2. {<\/div><\/li>\n
          3. processing = false;<\/div><\/li>\n
          4. var response:String = ctrlSocket.readUTFBytes(ctrlSocket.bytesAvailable);<\/div><\/li>\n
          5. var responseList:Array = response.split("\\n");<\/div><\/li>\n
          6. \/\/ Apparently we always get a linebreak with a response...<\/div><\/li>\n
          7. responseList.pop();<\/div><\/li>\n
          8.  <\/div><\/li>\n
          9. var eventList:Array = new Array();<\/div><\/li>\n
          10. var evt:FTPEvent;<\/div><\/li>\n
          11. for(var i:int = 0; i &lt; responseList.length; i++) {<\/div><\/li>\n
          12. evt = new FTPEvent(FTPEvent.RESPONSE);<\/div><\/li>\n
          13. evt.response = FTPResponse.parseResponse(responseList[i]);<\/div><\/li>\n
          14. eventList.push(evt);<\/div><\/li>\n
          15. if (FTPClient.DEBUG) trace("-&gt;" + evt.response.code+" "+evt.response.message);<\/div><\/li>\n
          16. }<\/div><\/li>\n
          17.  <\/div><\/li>\n
          18. if(swallowNextResponse) {<\/div><\/li>\n
          19. if (FTPClient.DEBUG) trace(" - ignoring this response...");<\/div><\/li>\n
          20. swallowNextResponse = false;<\/div><\/li>\n
          21. responseList.shift();<\/div><\/li>\n
          22. }<\/div><\/li>\n
          23.  <\/div><\/li>\n
          24. if(responseList.length &gt; 0) {<\/div><\/li>\n
          25. for(var k:int = 0; k &lt; responseList.length; k++) {<\/div><\/li>\n
          26. dispatchEvent(eventList[k]);<\/div><\/li>\n
          27. }<\/div><\/li>\n
          28. }<\/div><\/li>\n
          29. }<\/div><\/li>\n<\/ol>\t<\/div>\n\n<\/div>\n\n

            Links<\/strong><\/p>\n