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• iOS 5 Audio Alarms Don't Sound Without kAudioSessionProperty_OverrideCategoryMixWithOthers On

  - by coneybeare

  I have an audio app that is having some problems with the way iOS 5 has changed audio behaviors. When my app's audio is playing (AVAudioSessionCategoryPlayback), and a Clock.app alarm or timer is fired from the OS, the UIAlertView notification pops up, but without the audio alert. My application sound ducks fine to get out of the way of the audio alert, but the alarm app's audio alert does not sound. Naturally, tons of support requests poured in over the iOS 5 change. I have solved this temporarily by setting kAudioSessionProperty_OverrideCategoryMixWithOthers which lets the alarm audio come through, but there are a few very undesirable side-effects when doing this: Other app's audio can play with/over mine. The remote control events are not routed to my app, but to iPod.app. None of the above drawbacks are acceptable for my app's requirements. I have been hacking away at this for some time now but haven't been able to crack it. How can I setup my audio such that: My app's audio still uses the AVAudioSessionCategoryPlayback category for background audio. The Clock.app alarms still have their audio alerts make sound The app still responds to remote control notifications

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• iphone menu navigation with buttons help requested

  - by David

  Hi, I'm trying to program an iphone app that will have several different (sub)apps. Ideally, I want to know how to make the main menu for this app look and behave like the iphone's own app menu, but I can't figure it out. If any one knows a package or library that does this, please let me know. Plan B is to mock one using UIButtons, and here is where I'm having problems. Basically, when I press a button that should push a new view, it calls the push method, but I still see the top view. in the app delegate, I have something like: AppViewController *viewController; App1ViewController *app1ViewController; UINavigationController *navController; and in didFinishLaunching method, something like: viewController = [ [ AppViewController alloc ] initWithAppDelegate: self ]; app1ViewController = [ [App1ViewController alloc ] initWithAppDelegate: self ]; navController = [ [ UINavigationController alloc ] initWithRootViewController:viewController]; [window addSubview:viewController.view]; and 2 methods -(void)app1{[ navController pushViewController: app1ViewController animated:YES ];} -(void)back{[ navController popViewControllerAnimated:YES ];} then I have 2 viewcontrollers in AppViewController.h @interface AppViewController : UIViewController { UINavigationController *navController; UIButton *appbtn1, *appbtn2, *appbtn3, *appbtn4; } -(id)initWithAppDelegate:(id)appDelegate; @end @interface App1ViewController : UIViewController { UITextView *textView; UINavigationController *navController; } -(id)initWithAppDelegate:(id)appDelegate; @end and define a loadView for each viewcontroller. However, when I press the app1 button and the app1 method gets called, it says the view hasa been pushed, but my view remains the buttons view, i.e. the root view. If I press the button again, it tells me I can't repush the app1view, the one I can't see. Any ideas? I can post the full code if that helps. Thank you for your time.

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• Covariance and Contravariance type inference in C# 4.0

  - by devoured elysium

  When we define our interfaces in C# 4.0, we are allowed to mark each of the generic parameters as in or out. If we try to set a generic parameter as out and that'd lead to a problem, the compiler raises an error, not allowing us to do that. Question: If the compiler has ways of inferring what are valid uses for both covariance (out) and contravariance(in), why do we have to mark interfaces as such? Wouldn't it be enough to just let us define the interfaces as we always did, and when we tried to use them in our client code, raise an error if we tried to use them in an un-safe way? Example: interface MyInterface<out T> { T abracadabra(); } //works OK interface MyInterface2<in T> { T abracadabra(); } //compiler raises an error. //This makes me think that the compiler is cappable //of understanding what situations might generate //run-time problems and then prohibits them. Also, isn't it what Java does in the same situation? From what I recall, you just do something like IMyInterface<? extends whatever> myInterface; //covariance IMyInterface<? super whatever> myInterface2; //contravariance Or am I mixing things? Thanks

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• Take most significant 8 bytes of the MD5 hash of a string as a long (in Ruby)

  - by Nate Murray

  Hey Friends, I'm trying to implement a java "hash" function in ruby. Here's the java side: import java.nio.charset.Charset; import java.security.MessageDigest; /** * @return most significant 8 bytes of the MD5 hash of the string, as a long */ protected long hash(String value) { byte[] md5hash; md5hash = md5Digest.digest(value.getBytes(Charset.forName("UTF8"))); long hash = 0L; for (int i = 0; i < 8; i++) { hash = hash << 8 | md5hash[i] & 0x00000000000000FFL; } return hash; } So far, my best guess in ruby is: # WRONG - doesn't work properly. #!/usr/bin/env ruby -wKU require 'digest/md5' require 'pp' md5hash = Digest::MD5.hexdigest("0").unpack("U*") pp md5hash hash = 0 0.upto(7) do |i| hash = hash << 8 | md5hash[i] & 0x00000000000000FF end pp hash Problem is, this ruby code doesn't match the java output. For reference, the above java code given these strings returns the corresponding long: "00038c53790ecedfeb2f83102e9115a522475d73" => -2059313900129568948 "0" => -3473083983811222033 "001211e8befc8ac22dd265ecaa77f8c227d0007f" => 3234260774580957018 Thoughts: I'm having problems getting the UTF8 bytes from the ruby string In ruby I'm using hexdigest, I suspect I should be using just digest instead The java code is taking the md5 of the UTF8 bytes whereas my ruby code is taking the bytes of the md5 (as hex) Any suggestions on how to get the exact same output in ruby?

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• Delphi 2009 dbExpress and Interbase: Unicode migration steps and risks?

  - by mjustin

  Currently, our database uses Win1252 as the only character encoding. We will have to support Unicode in the database tables soon, which means we have to perform this migration for four databases and around 80 Delphi applications which run in-house in a 24/7 environment. Are there recommendations for database migrations to UTF-8 (or UNICODE_FSS) for Delphi applications? Some questions listed below. Many thanks in advance for your answers! are there tools which help with the migration of the existing databases (sizes between 250 MB and 2 GB, no Blob fields), by dumping the data, recreating the database with UNICODE_FSS or UTF-8, and loading the data back? are there known problems with Delphi 2009, dbExpress and Interbase 7.5 related to Unicode character sets? would you recommend to upgrade the databases to Interbase 2009 first? (This upgrade is planned but does not have a high priority) can we simply migrate the database and Delphi will handle the Unicode character sets automatically, or will we have to change all character field types in every Datamodule (dfm and source code) too? which strategy would you recommend to work on the migration in parallel with the normal development and maintenance of the existing application? The application runs in-house so development and database administration is done internally. Update: one problem I found now is that there are two different persistent field types for Unicode and non Unicode character fields. For the existing database, dbExpress creates TStringField objects. For the Unicode database fields, dbExpress creates (or expects!) TWideStringField objects. This looks like a lot of work lies ahead. While we could try to avoid persistent fields (and add calculated fields at run time), Of course we would prefer a solution which does not require so many changes in existing units and DFM files.

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• Requiring library consumers reference additional assembly when using certain types

  - by Thomas G. Mayfield

  I have library code that uses ICSharpCode.SharpZipLib under the hood to make it easy to use ZIP files as data sources when running integration tests. As it stands, if I reference my library from another project, the other project will compile just fine, but when it accesses the code that uses SharpZipLib, I get an exception for it not finding the zip library: failed: System.IO.FileNotFoundException : Could not load file or assembly 'ICSharpCode.SharpZipLib, Version=0.85.5.452, Culture=neutral, PublicKeyToken=1b03e6acf1164f73' or one of its dependencies. The system cannot find the file specified. If the types in my library derived from a class in SharpZipLib, it'd generate a compile error CS0012. What other ways are there for triggering a CS0012, so that using code that requires SharpZipLib (but doesn't clearly indicate it) would cause consumer code to fail compilation? I've had similar problems in the past when I've used libraries like DeftTech.DuckTyping under the hood. I'd add my library code to a new project, start working, compile, run, and then suddenly hit an edge case that I'd used duck typing to get around and get a runtime error. What I'd most like is to have the same behavior as if I'd derived from a type in the 3rd-party library, so that a reference to my derived type generates a CS0012: The type 'type' is defined in an assembly that is not referenced. You must add a reference to assembly 'assembly'.

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• Design: Website calling a webservice on the same machine

  - by Chris L

  More of a design/conceptual question. At work the decision was made to have our data access layer be called through webservices. So our website would call the webservices for any/all data to and from the database. Both the website & the webservices will be on the same machine(so no trip across the wire), but the database is on a separate machine(so that would require a trip across the wire regardless). This is all in-house, the website, webservice, and database are all within the same company(AFAIK, the webservices won't be reused by another other party). To the best of my knowledge: the website will open a port to the webservices, and the webservices will in turn open another port and go across the wire to the database server to get/submit the data. The trip across the wire can't be avoided, but I'm concerned about the webservices standing in the middle. I do agree there needs to be distinct layers between the functionality(such as business layer, data access layer, etc...), but this seems overly complex to me. I'm also sensing there will be some performance problems down the line. Seems to me it would be better to have the (DAL)assemblies referenced directly within the solution, thus negating the first port to port connection. Any thoughts(or links) both for and against this idea would be appreciated P.S. We're a .NET shop(migrating from vb to C# 3.5)

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• Sorting shell items like windows explorer

  - by Roy M Klever

  Hi, I am making a bread crumb bar in Delphi and having some problems regarding sorting the dropdown of the bread crumbs. Strangely enough, even Vista is not consequent when showing these items. I have tried many ways to figure out what is system folders, what is zip files and what is normal folders. It seems like an easy task but so far I have not found any good way of doing it. One way is to use TypeDisplayName from TSHFileinfo but these are localized names so I can not be sure they will be in correct order in every language. Here is the code I use to fill the menu: bool:= IsDesktop(SelectedPIDL); if bool then OleCheck(SHGetDesktopFolder(CurFolder)) else OleCheck(DesktopShellFolder.BindToObject(SelectedPIDL, nil, IID_IShellFolder, Pointer(CurFolder))); if CurFolder.EnumObjects(0, SHCONTF_FOLDERS, EnumIDList) = NOERROR then begin while EnumIDList.Next(1, CurPidl, Fetched) = S_OK do begin FName:= GetDisplayName(CurFolder, CurPidl, SHGDN_NORMAL); Text:= GetPIDLNameForAddressBar(CurFolder, CurPidl); if bool then Text:= PSpecialFolderItem(SpecialFolders[0]).Name + '\' + Text; if Text[Length(Text)] <> '\' then Text:= Text + '\'; NewPidl:= ConcatPIDLs(SelectedPIDL, CurPidl); SHGetFileInfo(PChar(NewPidl), 0, SFI, SizeOf(SFI), SHGFI_ATTRIBUTES or SHGFI_PIDL or SHGFI_SYSICONINDEX or SHGFI_TYPENAME); n:= SFI.dwAttributes; MenuList.Add(GetAttr(n) + FName); AddMenuItem(Text, FName, SFI.iIcon); CoTaskMemFree(CurPidl); CoTaskMemFree(NewPidl); end; end; CoTaskMemFree(SelectedPIDL); Any solution for how to get the correct sorting order? It is strange there is no way in dwAttributes of TSHFileInfo to tell if a folder is a system folder. Roy M Klever

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• Best pratice: How do I implement a list similar to Stackoverflow's Users List?

  - by André Pena

  Technologies involved: ASP.NET Web-forms Javascript (jQuery for instance) Case To make it clearer let's give the Stackoverflow Users list as an example. This list can be manipulated at client-side. I can search, page and so forth. So obviously we would need to call jQuery.ajax to retrieve the HTML of each page given a search. Alright. Now this leaves me with the first question: What is the best way to render the response for the jQuery.ajax at server-side? I can't use templates I suppose, so the most obvious solution I think is to create the HTML tags as server-controls and render them as the result of an ASHX request? Is this is best approach? Nice. That solved we have yet another problem: When the user first enters the Authors List the first list page should already come from the server completely rendered alright? Of course we could render the first page as well as an ajax call but I don't think it's better. This time I CAN use templates to render the list but this template couldn't be reused in case 1. What do I do? Now the final question: Now we have 2 rendering strategies: 1) Client and 2) Server. How do I reuse code for the 2 renderings? What are the best pratices for solving these problems?

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• Internet Explorer Warning when embedding Youtube on HTTPS site?

  - by pellepim

  Our application is run over HTTPS which rarely presents any problems for us. When it comes to youtube however, the fact that they do not present any content over SSL connections is giving us some head ache when trying to embed clips. Mostly because of Internet Explorers famous little warning message: "Do you want to view only the webpage content that was delivered securely? This page contains content that will not be delivered using a secure HTTPS ... etc" I've tried to solve this in several ways. The most promising one was to use the ProxyPass functionality in Apache to map to YouTube. Like this: ProxyPass: /youtube/ http://www.youtube.com ProxyPassReverse: /youtube/ http://www.youtube.com This gets rid of the annoying warning. However, the youtube SWF fails to start streaming The SWF i manage to load into the browser simply states : "An error occurred, please try again later". Potential solutions are perhaps: Download youtube FLV:s and serve them out of own domain (gah) Use custom FLV-player and stream only FLV:s from youtube over a https proxy? Update 10 March: I've tried to use Googles Youtube API for ActionScript to load a player. It looked promising at first and I was able to load a player through my https:// proxy. However, the SWF that is loaded contains loads of explicit calls to different non-ssl urls to create authentication links for the FLV-stream and for loading different crossdomain policies. It really seems like we're not supposed to access flv-streams directly. This makes it very hard to bypass the Internet Explorer warning, short of ripping out the FLV:s from youtube and serving them out of your own domain. There are solutions out there for downloading youtubes FLV:s. But that is not compliant with the Youtube terms of use and is really not an option for us.

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• How can I share variables between a base class and subclass in Perl?

  - by Jonathan

  I have a base class like this: package MyClass; use vars qw/$ME list of vars/; use Exporter; @ISA = qw/Exporter/; @EXPORT_OK = qw/ many variables & functions/; %EXPORT_TAGS = (all => \@EXPORT_OK ); sub my_method { } sub other_methods etc { } --- more code--- I want to subclass MyClass, but only for one method. package MySubclass; use MyClass; use vars qw/@ISA/; @ISA = 'MyClass'; sub my_method { --- new method } And I want to call this MySubclass like I would the original MyClass, and still have access to all of the variables and functions from Exporter. However I am having problems getting the Exporter variables from the original class, MyClass, to export correctly. Do I need to run Exporter again inside the subclass? That seems redundant and unclear. Example file: #!/usr/bin/perl use MySubclass /$ME/; -- rest of code But I get compile errors when I try to import the $ME variable. Any suggestions?

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• Why is Microsoft under-supporting or under-developping VBNET?

  - by Will Marcouiller

  I ran into a situation where the lack of some features has become somewhat frustrating while developping in VB.NET 2.0. Since my first day of programming, I've always been a C programmer, and still am. Naturally, I chose C# as my favorite .NET language. Recently, a customer of mine has obliged that all of his development projects which disregard SharePoint development have to be written in VB.NET 2.0, that is to avoid conflictual systems to come into some problems. That is a legitimate choice of his which I approve somehow, since he's running some old central systems and is slowly migrating toward latest technologies. As for me, I would have prefered to go with C#, but then, never having done much VB in my life, I see it as an opportunity to learn somethings new, how to handle this and that in VBNET, etc. Except that the syntax is really too verbose for me, which is a pain! I got used to it and that is fine. However, I recently wanted to use the InternalsVisibleToAttribute which I discovered lastly here on SO. But then, in addition to not being able to have lambda expression that returns no value, which I discovered months ago, today I learn that I can't use the attribute in VBNET! Here is what I have read in an article: [...] Sorry VB.Net developers, Microsoft is again shunning you guys and this attribute is NOT available to you.... :( And here is the link: InternalsVisibleTo: Testing internal methods in .Net 2.0 I have heard from Anders Hejlsberg mouth while watching a Webcast from his presentation of .NET 4.0 Framework that the VBNET team was working or has worked in collaboration with the C# team (Eric Lippert and others) in order to bring VBNET to offer the same features as C# offers. But then, I say to myself that the VBNET team has a huge step forward to make, if already in .NET 2.0, some of the most important features lacked! So my question is this: Why is Microsoft under-supporting or under-developping VBNET? Will VBNET ever be lacking the C# features?

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• How do you save images to a Blackberry device via HttpConnection?

  - by Kai

  My script fetches xml via httpConnection and saves to persistent store. No problems there. Then I loop through the saved data to compose a list of image url's to fetch via queue. Each of these requests calls the httpConnection thread as so ... public synchronized void run() { HttpConnection connection = (HttpConnection)Connector.open("http://www.somedomain.com/image1.jpg"); connection.setRequestMethod("GET"); String contentType = connection.getHeaderField("Content-type"); InputStream responseData = connection.openInputStream(); connection.close(); outputFinal(responseData, contentType); } public synchronized void outputFinal(InputStream result, String contentType) throws SAXException, ParserConfigurationException, IOException { if(contentType.startsWith("text/")) { // bunch of xml save code that works fine } else if(contentType.equals("image/png") || contentType.equals("image/jpeg") || contentType.equals("image/gif")) { // how to save images here? } else { //default } } What I can't find any good documentation on is how one would take the response data and save it to an image stored on the device. Maybe I just overlooked something very obvious. Any help is very appreciated. Thanks

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• .NET substitute dependent assemblies without recompiling?

  - by RK

  I have a question about how the .NET framework (2.0) resolves dependent assemblies. We're currently involved in a bit of a rewrite of a large ASP.NET application and various satellite executables. There are also some nagging problems with our foundation classes that we developed a new API to solve. So far this is a normal, albeit wide-reaching, update. Our heirarchy is: ASP.NET (aspx) business logic (DLLs) foundation classes (DLLs) So ASP.NET doesn't throw a fit, some of the DLLs (specifically the foundation classes) have a redirection layer that contains the old namespaces/functions and forwards them to the new API. When we replaced the DLLs, ASP.NET picked them up fine (probably because it triggered a recompile). Precompiled applications don't though, even though the same namespaces and classes are in both sets of DLLs. Even when the file is renamed, it complains about the assemblyname attribute being different (which it has to be by necessity). I know you can redirect to differnet versions of the same assembly, but is there any way to direct to a completely different assembly? The alternatives are to recompile the applications (don't really want to because the applications themselves haven't changed) or recompile the old foundation DLL with stubs refering to the new foundation DLL (the new dummy DLL is file system clutter).

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• Versioned RDF store

  - by Mat

  Let me try rephrasing this: I am looking for a robust RDF store or library with the following features: Named graphs, or some other form of reification. Version tracking (probably at the named graph level). Privacy between groups of users, either at named graph or triple level. Human-readable data input and output, e.g. TriG parser and serialiser. I've played with Jena, Sesame, Boca, RDFLib, Redland and one or two others some time ago but each had its problems. Have any improved in the above areas recently? Can anything else do what I want, or is RDF not yet ready for prime-time? Reading around the subject a bit more, I've found that: Jena, nothing further Sesame, nothing further Boca does not appear to be maintained any more and seems only really designed for DB2. OpenAnzo, an open-source fork, appears more promising. RDFLib, nothing further Redland, nothing further Talis Platform appears to support changesets (wiki page and reference in Kniblet Tutorial Part 5) but it's a hosted-only service. Still may look into it though. SemVersion sounded promising, but appears to be stale.

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• How to propagate .java file change to .class under eclipse, tomcat & stripes

  - by BigBourin

  Hi, i'm new to java and i got some problems. i'm developping a web application using the framework stripes on tomcat 6.0. I'm working with eclipse EE on windows. i successfully managed to get the stripes example application (called Bugzooky) up and running on my tomcat server. I imported the .war file and stripes libs in Eclipse. Here is the stripes archive containing the examples and libs But now i'm trying to change the example source files to learn how does it work. but whatever the modification made to the source files "WebContent/WEB-INF/src/*.java", nothing change! even after restarting the server. i noticed that the classes are compiled into .class files in the "ImportedClasses" folder, and tomcat always use these files, they are never updated, and if i removed one of them, the application just don't start. it look like my source files don't exists! I also tried to build my webapp from scratch, but when i tried to use the features used in the example files (like SecurityFilter.java): import javax.servlet.Filter; import javax.servlet.FilterChain; import javax.servlet.FilterConfig; import ... It ends up with plenty of: the import javax.servlet.Filter cannot be resolved I checked the Librairies and it look like i'm using exactly the same as the example. It's probably something i didn't understood about java but i googled 100 times yesterday, and i can't find the solution (i probably didn't search the right place because i don't really understand my problem). I hope you'll be able to help me.

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• Synchronizing ASP.NET MVC action methods with ReaderWriterLockSlim

  - by James D

  Any obvious issues/problems/gotchas with synchronizing access (in an ASP.NET MVC blogging engine) to a shared object model (NHibernate, but it could be anything) at the Controller/Action level via ReaderWriterLockSlim? (Assume the object model is very large and expensive to build per-request, so we need to share it among requests.) Here's how a typical "Read Post" action would look. Enter the read lock, do some work, exit the read lock. public ActionResult ReadPost(int id) { // ReaderWriterLockSlim allows multiple concurrent writes; this method // only blocks in the unlikely event that some other client is currently // writing to the model, which would only happen if a comment were being // submitted or a new post were being saved. _lock.EnterReadLock(); try { // Access the model, fetch the post with specificied id // Pseudocode, etc. Post p = TheObjectModel.GetPostByID(id); ActionResult ar = View(p); return ar; } finally { // Under all code paths, we must release the read lock _lock.ExitReadLock(); } } Meanwhile, if a user submits a comment or an author authors a new post, they're going to need write access to the model, which is done roughly like so: [AcceptVerbs(HttpVerbs.Post)] public ActionResult SaveComment(/* some posted data */) { // try/finally omitted for brevity _lock.EnterWriteLock(); // Save the comment to the DB, update the model to include the comment, etc. _lock.ExitWriteLock(); } Of course, this could also be done by tagging those action methods with some sort of "synchronized" attribute... but however you do it, my question is is this a bad idea? ps. ReaderWriterLockSlim is optimized for multiple concurrent reads, and only blocks if the write lock is held. Since writes are so infrequent (1000s or 10,000s or 100,000s of reads for every 1 write), and since they're of such a short duration, the effect is that the model is synchronized , and almost nobody ever locks, and if they do, it's not for very long.

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• What are the specific names for these OLE controls?

  - by Kris

  I have been working on making a block of code that would enable me to input values into a worksheet, as well as an MSgraph object. I have succeeded in this, but this has just presented me with a new set of problems: What are the control names for changing the visible size as well as the focus of a worksheet? What are the control names for changing/making background colours and borders? How do I create and define new worksheets and MSGraph objects inside the document? My example code so far: Option Explicit Dim objWord 'Word application object Dim objIShape 'Inline shapes object Dim objOLE 'OLE object Set objWord=CreateObject("Word.Application") objWord.Application.Documents.Open("C:\birdy.doc") objWord.Visible=True Set objIShape = objWord.ActiveDocument.InlineShapes Function count_filled_spaces(intOLENo, strRange) 'Activates the the inline shape by number(intOLENo) and defines it as the OLE object objIShape(intOLENo).OLEFormat.Activate Set objOLE = objIShape(intOLENo).OLEFormat.Object 'Detects the ClassType of the inline shape and uses a class specific counter to count which datafields have data Dim strClass, i, p, intSheetno intSheetno = 1 strClass = objIShape(intOLENo).OLEFormat.ClassType i = 0 If Left(strClass, 8) = "MSGraph." then For Each p In objOLE.Application.DataSheet.Range(strRange) If p <> "" Then i = i+1 End If Next ElseIf Left(strClass, 6) = "Excel." then For Each p In objOLE.Worksheets(intSheetno).Range(strRange) If p <> "" Then i = i+1 End If Next objOLE.Worksheets(intSheetno).Range("B" & i+1) = objOLE.Worksheets(intSheetno).Range("B" & i) End if count_filled_spaces = i End Function Dim strRange strRange = InputBox("Lol", "do eeet", "B1:B10") wscript.echo count_filled_spaces(2, strRange) 'objWord.Application.Documents.Save 'objWord.Application.Documents.Close 'objWord.Application.Quit WScript.Quit(0)

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• IUsable: controlling resources in a better way than IDisposable

  - by Ilya Ryzhenkov

  I wish we have "Usable" pattern in C#, when code block of using construct would be passed to a function as delegate: class Usable : IUsable { public void Use(Action action) // implements IUsable { // acquire resources action(); // release resources } } and in user code: using (new Usable()) { // this code block is converted to delegate and passed to Use method above } Pros: Controlled execution, exceptions The fact of using "Usable" is visible in call stack Cons: Cost of delegate Do you think it is feasible and useful, and if it doesn't have any problems from the language point of view? Are there any pitfalls you can see? EDIT: David Schmitt proposed the following using(new Usable(delegate() { // actions here }) {} It can work in the sample scenario like that, but usually you have resource already allocated and want it to look like this: using (Repository.GlobalResource) { // actions here } Where GlobalResource (yes, I know global resources are bad) implements IUsable. You can rewrite is as short as Repository.GlobalResource.Use(() => { // actions here }); But it looks a little bit weird (and more weird if you implement interface explicitly), and this is so often case in various flavours, that I thought it deserve to be new syntactic sugar in a language.

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• Functional way to get a matrix from text

  - by Elazar Leibovich

  I'm trying to solve some Google Code Jam problems, where an input matrix is typically given in this form: 2 3 #matrix dimensions 1 2 3 4 5 6 7 8 9 # all 3 elements in the first row 2 3 4 5 6 7 8 9 0 # each element is composed of three integers where each element of the matrix is composed of, say, three integers. So this example should be converted to #!scala Array( Array(A(1,2,3),A(4,5,6),A(7,8,9), Array(A(2,3,4),A(5,6,7),A(8,9,0), ) An imperative solution would be of the form #!python input = """2 3 1 2 3 4 5 6 7 8 9 2 3 4 5 6 7 8 9 0 """ lines = input.split('\n') print lines[0] m,n = (int(x) for x in lines[0].split()) array = [] row = [] A = [] for line in lines[1:]: for elt in line.split(): A.append(elt) if len(A)== 3: row.append(A) A = [] array.append(row) row = [] from pprint import pprint pprint(array) A functional solution I've thought of is #!scala def splitList[A](l:List[A],i:Int):List[List[A]] = { if (l.isEmpty) return List[List[A]]() val (head,tail) = l.splitAt(i) return head :: splitList(tail,i) } def readMatrix(src:Iterator[String]):Array[Array[TrafficLight]] = { val Array(x,y) = src.next.split(" +").map(_.trim.toInt) val mat = src.take(x).toList.map(_.split(" "). map(_.trim.toInt)). map(a => splitList(a.toList,3). map(b => TrafficLight(b(0),b(1),b(2)) ).toArray ).toArray return mat } But I really feel it's the wrong way to go because: I'm using the functional List structure for each line, and then convert it to an array. The whole code seems much less efficeint I find it longer less elegant and much less readable than the python solution. It is harder to which of the map functions operates on what, as they all use the same semantics. What is the right functional way to do that?

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• FileNotFoundException, although the XML file should be deployed

  - by Bernhard V

  Hi, I've got problems starting my WAR application on a local JBoss. After two other EARs are deployed and the TomcatDeployer begins deploying the WAR, I'm getting the following error message: 2010-04-28 10:01:56,605 ERROR [org.jboss.ejb.plugins.LogInterceptor] [] [main] EJBException in method: public abstract at.sozvers.stp.zpv.ejb.lea.rwsuc.EJBLeaRegelwerkSuchenRemote at.sozvers.stp.zpv.ejb.lea.rwsuc.EJBLeaRegelwerkSuchenHome.create() throws javax.ejb.CreateException,java.rmi.RemoteException, causedBy: javax.ejb.EJBException: org.springframework.beans.factory.access.BootstrapException: Unable to initialize group definition. Group resource name [classpath*:applicationContext.xml], factory key [contextService]; nested exception is org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'contextService' defined in URL [jar:file:/C:/ta30/nutzb/jboss-4.2.3.GA.ZPV/server/default/deploy/deploy.last/zpv-app-web-frontend-1.0-SNAPSHOT.war/WEB-INF/lib/zpv-comp-ejb-modules-1.0-SNAPSHOT-client.jar!/applicationContext.xml]: Instantiation of bean failed; nested exception is org.springframework.beans.BeanInstantiationException: Could not instantiate bean class [org.springframework.context.support.ClassPathXmlApplicationContext]: Constructor threw exception; nested exception is org.springframework.beans.factory.BeanDefinitionStoreException: IOException parsing XML document from class path resource [at/sozvers/stp/zpv/dao/ContextBasic.xml]; nested exception is java.io.FileNotFoundException: class path resource [at/sozvers/stp/zpv/dao/ContextBasic.xml] cannot be opened because it does not exist The sad thing is that the resource at/sozvers/stp/zpv/dao/ContextBasic.xml actually is placed in a JAR in one of my EAR files which should be deployed before the WAR. And at least I get a message that the deployment of the EAR has been successful. I also looked into the JAR with my file archiver and the ContextBasic.xml is indeed there at the right place. Is there a way for me to get sure that the JAR, not the EAR as a whole, is really deployed to the JBoss? I'm already starting to lose my head about this issue. Thank you. Bernhard

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• How I can fix this code to allow my AVR to talk over serial port?

  - by samoz

  Hi guys, I've been pulling my hair out lately trying to get an ATmega162 on my STK200 to talk to my computer over RS232. I checked and made sure that the STK200 contains a MAX202CPE chip. I've configured the chip to use its internal 8MHz clock and divided it by 8. I've tried to copy the code out of the data sheet (and made changes where the compiler complained), but to no avail. My code is below, could someone please help me fix the problems that I'm having? I've confirmed that my serial port works on other devices and is not faulty. Thanks! #include <avr/io.h> #include <avr/iom162.h> #define BAUDRATE 4800 void USART_Init(unsigned int baud) { UBRR0H = (unsigned char)(baud >> 8); UBRR0L = (unsigned char)baud; UCSR0B = (1 << RXEN0) | (1 << TXEN0); UCSR0C = (1 << URSEL0) | (1 << USBS0) | (3 << UCSZ00); } void USART_Transmit(unsigned char data) { while(!(UCSR0A & (1 << UDRE0))); UDR0 = data; } unsigned char USART_Receive() { while(!(UCSR0A & (1 << RXC0))); return UDR0; } int main() { USART_Init(BAUDRATE); unsigned char data; // all are 1, all as output DDRB = 0xFF; while(1) { data = USART_Receive(); PORTB = data; USART_Transmit(data); } }

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• NIS password mapping question

  - by papoyan

  I have NIS server with user "techsupport", which has uid/gid = 517 I've configured NIS and NFS on that server, as well as NFS/NIS client on the remote web server. Now I need to techsupport user to be able to login to web server using techsupport username, but HAVE root privileges. I need this, so I can easily track, which support agent doing what on the web server. Everything works fine, when from NIS server, I ssh to the web server with tech support user nisserver# ssh [email protected] I can authenticate against the NIS server just fine, and my home directory that is on NIS server, get's mounted on web server just fine. The Only two problems I have are : my GID on web server is webserver# id uid=517(techsupport) gid=517(client_jonny) groups=517(client_jonny) (as you can see, that it picked up gid of a client that exists on the web server, since it's same number) I need to make sure, that my "techsupport" user has ROOT privileges. How can I achieve this? I remember that I've seen identical results elsewhere, but LDAP was used, is there a way to achieve this with NIS/NFS setup? Thank you in advance,

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• CSRF Protection in AJAX Requests using MVC2

  - by mnemosyn

  The page I'm building depends heavily on AJAX. Basically, there is just one "page" and every data transfer is handled via AJAX. Since overoptimistic caching on the browser side leads to strange problems (data not reloaded), I have to perform all requests (also reads) using POST - that forces a reload. Now I want to prevent the page against CSRF. With form submission, using Html.AntiForgeryToken() works neatly, but in AJAX-request, I guess I will have to append the token manually? Is there anything out-of-the box available? My current attempt looks like this: I'd love to reuse the existing magic. However, HtmlHelper.GetAntiForgeryTokenAndSetCookie is private and I don't want to hack around in MVC. The other option is to write an extension like public static string PlainAntiForgeryToken(this HtmlHelper helper) { // extract the actual field value from the hidden input return helper.AntiForgeryToken().DoSomeHackyStringActions(); } which is somewhat hacky and leaves the bigger problem unsolved: How to verify that token? The default verification implementation is internal and hard-coded against using form fields. I tried to write a slightly modified ValidateAntiForgeryTokenAttribute, but it uses an AntiForgeryDataSerializer which is private and I really didn't want to copy that, too. At this point it seems to be easier to come up with a homegrown solution, but that is really duplicate code. Any suggestions how to do this the smart way? Am I missing something completely obvious?

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• How to protect/monitor your site from crawling by malicious user

  - by deathy

  Situation: Site with content protected by username/password (not all controlled since they can be trial/test users) a normal search engine can't get at it because of username/password restrictions a malicious user can still login and pass the session cookie to a "wget -r" or something else. The question would be what is the best solution to monitor such activity and respond to it (considering the site policy is no-crawling/scraping allowed) I can think of some options: Set up some traffic monitoring solution to limit the number of requests for a given user/IP. Related to the first point: Automatically block some user-agents (Evil :)) Set up a hidden link that when accessed logs out the user and disables his account. (Presumably this would not be accessed by a normal user since he wouldn't see it to click it, but a bot will crawl all links.) For point 1. do you know of a good already-implemented solution? Any experiences with it? One problem would be that some false positives might show up for very active but human users. For point 3: do you think this is really evil? Or do you see any possible problems with it? Also accepting other suggestions.

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