On Feb 16, 8:11 pm, soumik <[email protected]> wrote: > Thanks Marius and David for your suggestions. > I'll try that out. > > As to the problem itself, don't you think there should some kind of > exception generation to avoid the issue happening?
I still don't think there is a hang involved. Can you wrap your method call with a try/catch ? ... I have the feeling that a NPE (due to lack of proper S context) is thrown but because this is thrown on a different thread (as you'r inside a LiftActor) that is not shown anywhere. > > On Feb 16, 10:35 pm, Marius <[email protected]> wrote: > > > > > On Feb 16, 11:17 am, soumik <[email protected]> wrote: > > > > Hi Marius, > > > Thanks for the quick update. > > > The xhtml returned from the listFilesInDir() is actually sent as a > > > message to a display CometActor which renders the xhtml it receives > > > within a specific <div> tag. > > > So in essence we have these multiple feature threads running(the one > > > in question is intended to be a local file manager feature) which > > > generates xhtml for different functions which are then sent to this > > > one display CometActor which displays it. > > > So we intend to handle multi-feature tasking by running just the one > > > CometActor and not multiples of them which obviously is a problem for > > > lift(since the max no. of CometActors in a page is 2). > > > > But back to your explanation of the S context getting lost, I think I > > > understand what you mean regarding the session context. But does it > > > also apply for SHtml generator methods?? I mean, does SHtml generator > > > methods depend on the state of the session?? > > > Yes if you bind functions. Functions are kept per session. > > > > Another question I have is - even if SHtml generator methods fail to > > > co-relate the session, shouldn't SHtml generator methods return?? or > > > throw an exception? > > > No as SHtml should be used in the proper S context. That's why it is > > called [S]html. > > > > I don't know if you happened to use the exact same function in a > > > LiftActor object or not, but if you do that you'll see that the > > > function just doesn't return. > > > > Also, I don't intend to maintain state preservation. > > > You do not explicitly but as you are trying to bind functions (attach > > a scla function to a link, button etc) you need the proper context. > > > > I just want to > > > create a list of <a href> tags for all files which when clicked should > > > make an Ajax call to a specific function in the LiftActor thread which > > > processes the selection. Could you suggest some alternative way I > > > could go about this with the current architecture(1 comet actor for > > > display and individual feature-specific LiftActors sending xhtml to > > > CometActor for rendering)?? > > > Take Dave's advice. It is very good and leads to cleaner separation of > > concern. > > > > Thanks, > > > Soumik > > > > On Feb 16, 1:16 pm, Marius <[email protected]> wrote: > > > > > Well so you're using it from your own actor. I would not recommend > > > > this due to state preservation. I mean S context is very likely lost > > > > because your LiftActor is running on a different thread. What you need > > > > is to pass the LiftSession instance to your LiftActor say using some > > > > distinct message like: > > > > > case class Init(session: LiftSession) > > > > > then in your messageHandler > > > > > protected def messageHandler = { > > > > case FileManagerMsg(someMsg) => > > > > { > > > > S.initIfNotInitted(session) { > > > > var fileList = listFilesInDir("/Users/soumik/Movies/") > > > > Log.info("OUTPUT: " + fileList) > > > > } > > > > } > > > > > } > > > > > But I'm not sure from your code wht you do with the output of your > > > > listFilesInDir since that never gets to be rendered. > > > > > I strongly recommend using CometActor whenever you want to render > > > > something asynchronously. It does a lots of good things for you. > > > > > Br's, > > > > Marius > > > > > On Feb 16, 9:33 am, soumik <[email protected]> wrote: > > > > > > Hi Marius, > > > > > > Thanks for your response. I'm sorry for mis-communicating my problem > > > > > earlier. As you pointed out the problem doesn't occur when the call to > > > > > the function is made from a CometActor. > > > > > In my case too, it was not a CometActor. Rather, it was the LiftActor. > > > > > (Sometime back we had different CometActors for different feature > > > > > threads, now we have 1 single CometActor which takes care of the > > > > > display and different LiftActor threads which do the feature related > > > > > stuff. Hence the confusion on my part). > > > > > > Anyways, here's the relevant code: > > > > > ------------------------------------- > > > > > object TheVideoPlayerThread extends LiftActor > > > > > { > > > > > val threadName = "FileManager" > > > > > > def listFilesInDir(dirName:String): NodeSeq = > > > > > { > > > > > Log.info("Recursing for: " + dirName) > > > > > val files = (new java.io.File(dirName)).listFiles > > > > > > def showFile1() = "AAA" > > > > > > <li class="fileElem" id="dir">{dirName}</li> > > > > > <ul> > > > > > {files.flatMap(f => { > > > > > if (f.isDirectory()) > > > > > { > > > > > Log.info("Directory: " + f.toString) > > > > > listFilesInDir(f.toString) > > > > > } > > > > > else > > > > > { > > > > > Log.info("Regular file: " + f.getName) > > > > > <li class="fileElem" id="regfile"> > > > > > {SHtml.link("", () => showFile1, > > > > > Text(f.getName)) } //This is the line causing the > > > > > issue > > > > > </li> > > > > > } > > > > > } > > > > > )} > > > > > </ul> > > > > > } > > > > > > protected def messageHandler = { > > > > > case FileManagerMsg(someMsg) => > > > > > { > > > > > var fileList = listFilesInDir("/Users/soumik/Movies/") > > > > > Log.info("OUTPUT: " + fileList) > > > > > } > > > > > } > > > > > ------------------------------------- > > > > > (I've omitted some of code in this thread which are not related to the > > > > > file listing functionality.) > > > > > The problem I see is as soon as I encounter the first file in the > > > > > directory specified, it prints - "Regular file: <filename>", but after > > > > > that I don't see the log - "OUTPUT - ...". The function never returns. > > > > > Same function works perfectly in a CometActor and I see the nodeseq of > > > > > files in <li> tags to be rendered. > > > > > Also in the same method in my LiftActor object, if I replace the line: > > > > > {SHtml.link("", () => showFile1, Text(f.getName)) } > > > > > with just > > > > > {f.getName} > > > > > I see the function return and print the log "OUTPUT - .." with the > > > > > list of all the files as <li> entries. > > > > > > I'm sorry I couldn't give a more concrete example which you could run > > > > > and reproduce the issue. I'll appreciate if you could just give this > > > > > function a try from any LiftActor object and check the output on > > > > > console. > > > > > Also, I'm still on 1.1-SNAPSHOT. I've a fairly big codebase, so not > > > > > sure if migrating to 2.0-SNAPSHOT will cause any other issues, > > > > > particularly with jquery(i'm using lot of jquery plugins dependent on > > > > > 1.3.2, not sure if all of them works nicely with 1.4). > > > > > > Thanks, > > > > > Soumik > > > > > > On Feb 15, 11:22 pm, Marius <[email protected]> wrote: > > > > > > > I don't think the cause is in SHtml. I tried your code from a > > > > > > snippet > > > > > > and from a Comet actor and there was no lock whatsoever. But I did > > > > > > use > > > > > > lift 2.0-SNAPSHOT. can you try with 2.0-SNAPSHOT ? > > > > > > > Br's, > > > > > > Marius > > > > > > > On 15 feb., 15:20, soumik <[email protected]> wrote: > > > > > > > > Hi, > > > > > > > I'm using 1.1-SNAPSHOT lift release and am experiencing strange > > > > > > > behaviour when trying to output a NodeSeq formed from nested > > > > > > > NodeSeq & > > > > > > > Scala code. > > > > > > > > To highlight the problem let me show you the code I'm trying to > > > > > > > execute: > > > > > > > ----------------------------------- > > > > > > > def listFilesInDir(dirName:String): NodeSeq = > > > > > > > { > > > > > > > Log.info("Recursing for: " + dirName) > > > > > > > val files = (new java.io.File(dirName)).listFiles > > > > > > > > def playFile1() = "AAA" > > > > > > > > <li class="fileElem" id="dir">{dirName}</li> > > > > > > > <ul> > > > > > > > {files.flatMap(f => { > > > > > > > if (f.isDirectory()) > > > > > > > { > > > > > > > Log.info("Directory: " + f.toString) > > > > > > > listFilesInDir(f.toString) > > > > > > > <span></span> > > > > > > > } > > > > > > > else > > > > > > > { > > > > > > > Log.info("Regular file: " + f.getName) > > > > > > > <li class="fileElem" id="regfile"> > > > > > > > {SHtml.link("", () => playFile1, > > > > > > > Text("Something")) } /* Problem in this line */ > > > > > > > </li> > > > > > > > } > > > > > > > } > > > > > > > )} > > > > > > > </ul> > > > > > > > ----------------------------------- > > > > > > > I'm trying to render the output of the above function in a comet > > > > > > > actor. The problem i see is with the highlighted line of code. > > > > > > > When > > > > > > > the execution reaches this line of code, it gets stuck; the > > > > > > > function > > > > > > > doesn't return and i don't get a NodeSeq to render. > > > > > > > However, for some reason if I change the highlighted line of code > > > > > > > to > > > > > > > say: > > > > > > > {f.getName} > > > > > > > I get the proper NodeSeq which lists all the files in the > > > > > > > directory. > > > > > > > > Seems to me that the SHtml class functions are encountering an > > > > > > > error > > ... > > read more » -- You received this message because you are subscribed to the Google Groups "Lift" group. To post to this group, send email to [email protected]. To unsubscribe from this group, send email to [email protected]. For more options, visit this group at http://groups.google.com/group/liftweb?hl=en.
