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  • What are the Open Source alternatives to WPF/XAML?

    - by Evan Plaice
    If we've learned anything from HTML/CSS it's that, declarative languages (like XML) work best to describe User Interfaces because: It's easy to build code preprocessors that can template the code effectively. The code is in a well defined well structured (ideally) format so it's easy to parse. The technology to effectively parse or crawl an XML based source file already exists. The UIs scripted code becomes much simpler and easier to understand. It simple enough that designers are able to design the interface themselves. Programmers suck at creating UIs so it should be made easy enough for designers. I recently took a look at the meat of a WPF application (ie. the XAML) and it looks surprisingly familiar to the declarative language style used in HTML. It's apparent to me that the current state of desktop UI development is largely fractionalized, otherwise there wouldn't be so much duplicated effort in the domain of graphical user interface design (IE. GTK, XUL, Qt, Winforms, WPF, etc). There are 45 GUI platforms for Python alone It's seems reasonable to me that there should be a general purpose, open source, standardized, platform independent, markup language for designing desktop GUIs. Much like what the W3C made HTML/CSS into. WPF, or more specifically XAML seems like a pretty likely step in the right direction. Now that the 'browser wars' are over should we look forward to a future of 'desktop gui wars?' Note: This topic is relatively subjective in the attempt to be 'future-thinking.' I think that desktop GUI development in its current state sucks ((really)hard) and, even though WPF is still in it's infancy, it presents a likely solution to the problem. Update: Thanks a lot for the info, keep it comin'. Here's are the options I've gathered from the comments and answers. GladeXML Editor: Glade Interface Designer OS Platforms: All GUI Platform: GTK+ Languages: C (libglade), C++, C# (Glade#), Python, Ada, Pike, Perl, PHP, Eiffel, Ruby XRC (XML Resource) Editors: wxGlade, XRCed, wxDesigner, DialogBlocks (non-free) OS Platforms: All GUI Platform: wxWidgets Languages: C++, Python (wxPython), Perl (wxPerl), .NET (wx.NET) XML based formats that are either not free, not cross-platform, or language specific XUL Editor: Any basic text editor OS Platforms: Any OS running a browser that supports XUL GUI Platform: Gecko Engine? Languages: C++, Python, Ruby as plugin languages not base languages Note: I'm not sure if XUL deserves mentioning in this list because it's less of a desktop GUI language and more of a make-webapps-run-on-the-desktop language. Plus, it requires a browser to run. IE, it's 'DHTML for the desktop.' CookSwing Editor: Eclipse via WindowBuilder, NetBeans 5.0 (non-free) via Swing GUI Builder aka Matisse OS Platforms: All GUI Platform: Java Languages: Java only XAML (Moonlight) Editor: MonoDevelop OS Platforms: Linux and other Unix/X11 based OSes only GUI Platforms: GTK+ Languages: .NET Note: XAML is not a pure Open Source format because Microsoft controls its terms of use including the right to change the terms at any time. Moonlight can not legally be made to run on Windows or Mac. In addition, the only platform that is exempt from legal action is Novell. See this for a full description of what I mean.

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  • Delphi - Why is my global variable "inacessible" when i debug

    - by Antoine Lpy
    I'm building an application that contains around 30 Forms. I need to manage sessions, so I would like to have a global LoggedInUser variable accessible from all forms. I read "David Heffernan"'s post about global variables, and how to avoid them but I thought it would be easier to have a global User variable rather than 30 forms having their own User variable. So i have a unit : GlobalVars unit GlobalVars; interface uses User; // I defined my TUser class in a unit called User var LoggedInUser: TUser; implementation initialization LoggedInUser:= TUser.Create; finalization LoggedInUser.Free; end. Then in my LoginForm's LoginBtnClick procedure I do : unit FormLogin; interface uses [...],User; type TForm1 = class(TForm) [...] procedure LoginBtnClick(Sender: TObject); private { Déclarations privées } public end; var Form1: TForm1; AureliusConnection : IDBConnection; implementation {$R *.fmx} uses [...]GlobalVars; procedure TForm1.LoginBtnClick(Sender: TObject); var Manager : TObjectManager; MyCriteria: TCriteria<TUser>; u : TUser; begin Manager := TObjectManageR.Create(AureliusConnection); MyCriteria :=Manager.Find<TUtilisateur> .Add(TExpression.Eq('login',LoginEdit.Text)) .Add(TExpression.Eq('password',PasswordEdit.Text)); u := MyCriteria.UniqueResult; if u = nil then MessageDlg('Login ou mot de passe incorrect',TMsgDlgType.mtError,[TMsgDlgBtn.mbOK],0) else begin LoggedInUser:=u; //Here I assign my local User data to my global User variable Form1.Destroy; A00Form.visible:=true; end; Manager.Free; end; Then in another form I would like to access this LoggedInUser object in the Menu1BtnClick procedure : Unit C01_Deviations; interface uses System.SysUtils, System.Types, System.UITypes, System.Classes, System.Variants, FMX.Types, FMX.Graphics, FMX.Controls, FMX.Forms, FMX.Dialogs, FMX.StdCtrls, FMX.ListView.Types, FMX.ListView, FMX.Objects, FMX.Layouts, FMX.Edit, FMX.Ani; type TC01Form = class(TForm) [...] Menu1Btn: TButton; [...] procedure Menu1BtnClick(Sender: TObject); private { Déclarations privées } public { Déclarations publiques } end; var C01Form: TC01Form; implementation uses [...]User,GlobalVars; {$R *.fmx} procedure TC01Form.Menu1BtnClick(Sender: TObject); var Assoc : TUtilisateur_FonctionManagement; ValidationOK : Boolean; util : TUser; begin ValidationOK := False; util := GlobalVars.LoggedInUser; // Here i created a local user variable for debug purposes as I thought it would permit me to see the user data. But i get "Inaccessible Value" as its value util.Nom:='test'; for Assoc in util.FonctionManagement do // Here is were my initial " access violation" error occurs begin if Assoc.FonctionManagement.Libelle = 'Reponsable équipe HACCP' then begin ValidationOK := True; break; end; end; [...] end; When I debug I see "Inaccessible Value" in the value column of my user. Do you have any idea why ? I tried to put an integer in this GlobalVar unit, and i was able to set its value from my login form and read it from my other form.. I guess I could store the user's id, which is an integer, and then retrieve the user from the database using its id. But it seems really unefficient.

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  • Passing Variables between views / view controllers

    - by Dan
    Hi I'm new to ObjectiveC / IPhoneSDK and I'm informally trying to study it on my own. What I'm basically trying to do is from one view there are 12 zodiac signs. When a user clicks one, it proceeds to the second view (with animation) and loads the name of the zodiac sign it clicked in a UILabel, that's it. Here are my codes: Lovescopes = 1st page Horoscopes = 2nd page Lovescopes4AppDelegate.h #import <UIKit/UIKit.h> #import "HoroscopesViewController.h" #import "Lovescopes4AppDelegate.h" @class Lovescopes4ViewController; @interface Lovescopes4AppDelegate : NSObject <UIApplicationDelegate> { UIWindow *window; Lovescopes4ViewController *viewController; HoroscopesViewController *horoscopesViewController; } -(void)loadHoroscope; -(void)loadMainPage; @property (nonatomic, retain) IBOutlet UIWindow *window; @property (nonatomic, retain) IBOutlet Lovescopes4ViewController *viewController; @property (nonatomic, retain) HoroscopesViewController *horoscopesViewController; @end Lovescopes4AppDelegate.m #import "Lovescopes4AppDelegate.h" #import "Lovescopes4ViewController.h" @implementation Lovescopes4AppDelegate @synthesize window; @synthesize viewController; @synthesize horoscopesViewController; -(void)loadHoroscope { HoroscopesViewController *aHoroscopeViewController = [[HoroscopesViewController alloc] initWithNibName:@"HoroscopesViewController" bundle:nil]; [self setHoroscopesViewController:aHoroscopeViewController]; [aHoroscopeViewController release]; [UIView beginAnimations:nil context:NULL]; [UIView setAnimationDuration:0.5]; [UIView setAnimationTransition:UIViewAnimationTransitionFlipFromLeft forView:window cache:YES]; [viewController.view removeFromSuperview]; [self.window addSubview:[horoscopesViewController view]]; [UIView commitAnimations]; } -(void)loadMainPage { [UIView beginAnimations:nil context:NULL]; [UIView setAnimationDuration:0.5]; [UIView setAnimationTransition:UIViewAnimationTransitionFlipFromRight forView:window cache:NO]; [horoscopesViewController.view removeFromSuperview]; [self.window addSubview:[viewController view]]; [UIView commitAnimations]; [horoscopesViewController release]; horoscopesViewController = nil; } - (void)applicationDidFinishLaunching:(UIApplication *)application { // Override point for customization after app launch [window addSubview:viewController.view]; [window makeKeyAndVisible]; } - (void)dealloc { [viewController release]; [window release]; [super dealloc]; } @end Lovescopes4ViewController.h #import <UIKit/UIKit.h> #import "HoroscopesViewController.h" @interface Lovescopes4ViewController : UIViewController { HoroscopesViewController *hvc; } -(IBAction)loadAries; @property (nonatomic, retain) HoroscopesViewController *hvc; @end Lovescope4ViewController.m #import "Lovescopes4ViewController.h" #import "Lovescopes4AppDelegate.h" @implementation Lovescopes4ViewController @synthesize hvc; -(IBAction)loadAries { NSString *selected =@"Aries"; [hvc loadZodiac:selected]; Lovescopes4AppDelegate *mainDelegate = (Lovescopes4AppDelegate *) [[UIApplication sharedApplication] delegate]; [mainDelegate loadHoroscope]; } HoroscopesViewController.h #import <UIKit/UIKit.h> @interface HoroscopesViewController : UIViewController { IBOutlet UILabel *zodiacLabel; } -(void)loadZodiac:(id)zodiacSign; -(IBAction)back; @property (nonatomic, retain) IBOutlet UILabel *zodiacLabel; @end HoroscopesViewController.m #import "HoroscopesViewController.h" #import "Lovescopes4AppDelegate.h" @implementation HoroscopesViewController @synthesize zodiacLabel; /* // The designated initializer. Override if you create the controller programmatically and want to perform customization that is not appropriate for viewDidLoad. - (id)initWithNibName:(NSString *)nibNameOrNil bundle:(NSBundle *)nibBundleOrNil { if (self = [super initWithNibName:nibNameOrNil bundle:nibBundleOrNil]) { // Custom initialization } return self; } */ /* // Implement viewDidLoad to do additional setup after loading the view, typically from a nib. - (void)viewDidLoad { [super viewDidLoad]; } */ /* // Override to allow orientations other than the default portrait orientation. - (BOOL)shouldAutorotateToInterfaceOrientation:(UIInterfaceOrientation)interfaceOrientation { // Return YES for supported orientations return (interfaceOrientation == UIInterfaceOrientationPortrait); } */ -(void)loadZodiac:(id)zodiacSign { zodiacLabel.text = [NSString stringWithFormat: @"%@", zodiacSign]; } -(IBAction)back { Lovescopes4AppDelegate *mainDelegate = (Lovescopes4AppDelegate *) [[UIApplication sharedApplication] delegate]; [mainDelegate loadMainPage]; }

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  • A methology that allows for a single Java code base covering many different versions?

    - by Thorbjørn Ravn Andersen
    I work in a small shop where we have a LOT of legacy Cobol code and where a methology has been adopted to allow us to minimize forking and branching as much as possible. For a given release we have three levels: CORE - bottom layer, this code is common to all releases GROUP - optional code common to several customers. CUSTOMER - optional code specific for a single customer. When a program is needed, it is first searched for in CUSTOMER, then in GROUP and finally in CORE. A given application for us invokes many programs which all are looked for in this sequence (think exe files and PATH under Windows). We also have Java programs interacting with this legacy code, and as the core-group-customer lookup mehchanism does not lend it self easily to Java it has tended to grow in a CVS branch for each customer, requiring much too much maintainance. The Java part and the backend part tend to be developed in parallel. I have been assigned to figure out a way to make the two worlds meet. Essentially we want a Java enviornment which allows us to have a single code base with sources for each release, where we easily can select a group and a customer and work with the application as it goes for that customer, and then easily switch to another codeset and THAT customer. I was thinking of perhaps a scenario with an Eclipse project for each core, customer, and group and then use Project Sets to select those we need for a given scenario. The problem I cannot get my head about, is how we would create robust code in the CORE projects which will work regardless of which group and customer is selected. A Factory class which knows which sub class of a passed Class object to invoke instead of each and every new? Others must have had similar code base management problems. Anybody with experiences to share? EDIT: The conclusion to this problem above has been that CVS needs to be replaced with a source code management system better suited for dealing with many branches concurrently and the migration of source from one component to the other while keeping history. Inspired by the recent migration by slf4j and logback we are currently looking at git as it handles branches very well. We've considered subversion and mercurial too but git appears to be better for single location, multibranched projects. I've asked about Perforce in another question, but my personal inclination is towards open source solutions for something as crucial as this. EDIT: After some more pondering, we've found that our actual pain point is that we use branches in CVS, and that branches in CVS are the easiest to work with if you branch ALL files! The revised conclusion is that we can do this with CVS alone, by switching to a forest of java projects, each corresponding to one of the levels above, and use the Eclipse build paths to tie them together so each CUSTOMER version pulls in the appropriate GROUP and CORE project. We still want to switch to a better versioning system but this is so important a decision so we want to delay it as much as possible. EDIT: I now have a proof-of-concept implementation of the CORE-GROUP-CUSTOMER concept using Google Guice 2.0 - the @ImplementedBy tag is just what we need. I wonder what everybody else does? Using if's all over the place? EDIT: Now I also need this functionality for web applications. Guice was until the JSR-330 is in place. Anybody with versioning experience? EDIT: JSR-330/299 is now in place with the JEE6 reference implementation Weld based on JBoss Seam and I have reimplemented the proof-of-concept with Weld and can see that if we use @Alternative along with ... in beans.xml we can get the behaviour we desire. I.e. provide a new implementation for a given functionality in CORE without changing a bit in the CORE jars. Initial reading up on the Servlet 3.0 specification indicates that it may support the same functionality for web application resources (not code). We will now do initial testing on the real application.

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  • Technology to communicate with someone with expressive aphasia?

    - by rascher
    A family member had a stroke a few years back and now has expressive aphasia. She understands what is said to her, is cognitive of what is going on, but cannot express herself. She is able to respond to yes/no questions (do you want to go shopping? are you looking for your earrings?) She is not, however, able to read (English is not her native language and she hasn't read Hindi for decades.) I am the technologist in the family, and I intend to come up with something to help us communicate. The idea is to have some sort of picture book where she can point to what she wants. My first question: does some sort of assistive technology for people with expressive aphasia already exist? These can be hardware or software devices? If not, then such a software doesn't seem difficult to write. My initial thought is to have an interface with pictures - maybe separated by category (food, shopping) - where she can point to an individual picture to indicate what she needs. We could easily add more items with such a software, and we could have an interface where she (or we) could "flip pages". Which suggests that the best solution would use a touch screen rather than a mouse. It would be really difficult to train her to aim a mouse or find keys on a keyboard. We're thinking of maybe getting a tablet and writing some basic software. But tablets computers are expensive and fragile - I'm not sure if it would be able to stand spills or being knocked about in a nursing home. So my next question: what kind of tablet-like devices are out there which I can program on? I don't know anything about hardware, but if there is something then we could special-order it. What would be safe and durable for such a project? We could do something on an iPod or cell phone, but I feel like that interface would be too small. Finally, does anyone here have experience with this kind of assistive technology? Things I might not anticipate when designing such a system? edit I've added a (pretty hefty!) bounty. I'd kinda like to open this question up to any suggestions, comments, and experiences that people might have. This is a pretty real and important project, so while we will (are working on) a solution, any insights would be particularly helpful. Right now the plan is to mount a screen in her room. We'll either teach her to use a trackball or use a touch-screen panel, after seeing what she is able to use with a simple prototype. Then software akin to an old "hypercard" deck: ---------------------------------------------------------------- | -------------- -------------- | | | Clothes | | Food | ... | | -------------- -------------- | | | | Pic of item 1 Pic of item 2 Pic of item 3 | | | | | | | | | | Pic of item 4 Pic of item 5 Pic of item 6 | | | | | | | | | | <-Back Next-> | ---------------------------------------------------------------- commentcommentcomment!

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  • How do I make a custom delegate protocol for a UIView subclass?

    - by timothy5216
    I'm making some tabs and I want to have my own delegate for them but when I try to send an action to the delegate nothing happens. I also tried following this tutorial: link text But it doesn't work for me :( Here is my code: TiMTabBar.h @protocol TiMTabBarDelegate; @interface TiMTabBar : UIView { id<TiMTabBarDelegate> __delegate; ... int selectedItem; ... } //- (id)init; - (id)initWithDelegate:(id)aDelegate; - (void)setSelectedIndex:(int)item; .. @property (nonatomic) int selectedItem; @property(assign) id <TiMTabBarDelegate> __delegate; .. ... @end @protocol TiMTabBarDelegate<NSObject> //@optional - (void)tabBar:(TiMTabBar *)_tabBar didSelectIndex:(int)index; @end TiMTabBar.m: #import "TiMTabBar.h" ... @interface NSObject (TiMTabBarDelegate) - (void)tabBar:(TiMTabBar *)_tabBar didSelectIndex:(int)index; @end @implementation TiMTabBar @synthesize selectedItem; @synthesize __delegate; ... /* - (id)init { ... return self; } */ - (id)initWithDelegate:(id)aDelegate; { //[super init]; __delegate = aDelegate; return self; } - (void)awakeFromNib { //[self init]; //[self initWithDelegate:self]; ... } - (void)setSelectedIndex:(int)item { selectedItem = item; if (self.__delegate != NULL && [self.__delegate respondsToSelector:@selector(tabBar:didSelectIndex:)]) { [__delegate tabBar:self didSelectIndex:selectedItem]; } ... if (item == 0) { ... } else if (item == 1) { ... } else if (item == 2) { ... } else if (item == 3) { ... } else if (item == 4) { ... } else { ... } } /* - (void)tabBar:(TiMTabBar *)_tabBar didSelectIndex:(int)index; { //[delegate tabBar:self didSelectIndex:index]; //if (self.delegate != NULL && [self.delegate respondsToSelector:@selector(tabBar:didSelectIndex:)]) { //[delegate tabBar:self didSelectIndex:selectedItem]; //} NSLog(@"tabBarDelegate: %d",index); } */ @end The delegate only works works inside itself and not in any other files like: @interface XXXController : UIViewController <TiMTabBarDelegate> { ... ... IBOutlet TiMTabBar *tabBar; ... } ... @end XXXController.m: #import "XXXController.h" #import <QuartzCore/QuartzCore.h> @implementation XXXController - (void)viewDidLoad { [super viewDidLoad]; [self becomeFirstResponder]; ... tabBar = [[TiMTabBar alloc] initWithDelegate:self]; //tabBar.__delegate = self; ... } #pragma mark TiMTabBar Stuff - (void)tabBar:(TiMTabBar *)_tabBar didSelectIndex:(int)index; { NSLog(@"Controller/tabBarDelegate: %d",index); } @end None of this seems to work in XXXController. Anyone know how to make this work?

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  • What is "elegant" code?

    - by Breton
    I see a lot of lip service and talk about the most "elegant" way to do this or that. I think if you spend enough time programming you begin to obtain a sort of intuitive feel for what it is we call "elegance". But I'm curious. Even if we can look at a bit of code, and say instinctively "That's elegant", or "That's messy", I wonder if any of us really understands what that means. Is there a precise definition for this "elegance" we keep referring to? If there is, what is it? Now, what I mean by a precise definition, is a series of statements which can be used to derive questions about a peice of code, or a program as a whole, and determine objectively, or as objectively as possible, whether that code is "elegant" or not. May I assert, that perhaps no such definition exists, and it's all just personal preference. In this case, I ask you a slightly different question: Is there a better word for "elegance", or a better set of attributes to use for judging code quality that is perhaps more objective than merely appealing to individual intuition and taste? Perhaps code quality is a matter of taste, and the answer to both of my questions is "no". But I can't help but feel that we could be doing better than just expressing wishy washy feelings about our code quality. For example, user interface design is something that to a broad range of people looks for all the world like a field of study that oughtta be 100% subjective matter of taste. But this is shockingly and brutally not the case, and there are in fact many objective measures that can be applied to a user interface to determine its quality. A series of tests could be written to give a definitive and repeatable score to user interface quality. (See GOMS, for instance). Now, okay. is Elegance simply "code quality" or is it something more? Is it something that can be measured? Or is it a matter of taste? Does our profession have room for taste? Maybe I'm asking the wrong questions altogether. Help me out here. Bonus Round If there is such a thing as elegance in code, and that concept is useful, do you think that justifies classifying the field of programming as an "Art" capital A, or merely a "craft". Or is it just an engineering field populated by a bunch of wishful thinking humans? Consider this question in the light of your thoughts about the elegance question. Please note that there is a distinction between code which is considered "art" in itself, and code that was written merely in the service of creating an artful program. When I ask this question, I ask if the code itself justifies calling programming an art. Bounty Note I liked the answers to this question so much, I think I'd like to make a photographic essay book from it. Released as a free PDF, and published on some kind of on demand printing service of course, such as "zazz" or "tiggle" or "printley" or something . I'd like some more answers, please!

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  • WCF via SSL connectivity problems

    - by Brett Widmeier
    Hello, I am hosting a WCF service from inside a Windows service using WAS. When I set the service to listen on 127.0.0.1, I have connectivity from my local machine as well as from my network. However, when I set it to listen on my outbound interface port 443, I can no longer even see the wsdl by connecting with a browser. Strangely, I can connect to the service by using telnet. The cert I am using was generated for my interface by a CA, and I have successfully used this exact cert with this service before. When checking the application log, I see that the service starts without error and is listening on the correct interface. From this information, it seems to me that the config file is in a valid state, but somehow misconfigured for what I want. I have, however, previously deployed this same setup on other sites using this config file. In case it is helpful, below is my config file. Any thoughts? <!--<system.diagnostics> <sources> <source name="System.ServiceModel" switchValue="Warning, ActivityTracing" propagateActivity="true"> <listeners> <add type="System.Diagnostics.DefaultTraceListener" name="Default"> <filter type="" /> </add> <add name="ServiceModelTraceListener"> <filter type="" /> </add> </listeners> </source> </sources> <sharedListeners> <add initializeData="app_tracelog.svclog" type="System.Diagnostics.XmlWriterTraceListener, System, Version=2.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089" name="ServiceModelTraceListener" traceOutputOptions="Timestamp"> <filter type="" /> </add> </sharedListeners> </system.diagnostics>--> <appSettings/> <connectionStrings/> <system.serviceModel> <!--<diagnostics> <messageLogging logEntireMessage="true" logMalformedMessages="true" logMessagesAtServiceLevel="true" logMessagesAtTransportLevel="true" maxMessagesToLog ="1000" maxSizeOfMessageToLog="524288"/> </diagnostics>--> <bindings> <basicHttpBinding> <binding name="basicHttps"> <security mode="Transport"> <transport clientCredentialType="None"/> <message /> </security> </binding> </basicHttpBinding> </bindings> <services> <service behaviorConfiguration="ServiceBehavior" name="<fully qualified name of service>"> <endpoint address="" binding="basicHttpBinding" name="OrdersSoap" contract="<fully qualified name of contract>" bindingNamespace="http://emr.orders.com/WebServices" bindingConfiguration="basicHttps" /> <endpoint binding="mexHttpsBinding" address="mex" contract="IMetadataExchange" /> <host> <baseAddresses> <add baseAddress="https://<external IP>/<name of service>>/" /> </baseAddresses> </host> </service> </services> <behaviors> <serviceBehaviors> <behavior name="ServiceBehavior"> <serviceMetadata httpsGetEnabled="False"/> <serviceDebug includeExceptionDetailInFaults="True" /> <dataContractSerializer maxItemsInObjectGraph="2147483646"/> </behavior> </serviceBehaviors> </behaviors> </system.serviceModel>

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  • iPhone dev - viewDidUnload subviews

    - by Mk12
    I'm having a hard time undestand a couple of the methods in UIViewController, but first I'll say what I think they are meant for (ignoring interface builder because I'm not using it): -init: initialize non view-related stuff that won't need to be released in low memory situations (i.e. not objects or objects that can't be recreated easily). -loadView: create the view set the [self view] property. -viewDidLoad: Create all the other view elements -viewDidUnload: Release objects created in -viewDidLoad. didReceiveMemoryWarning: Low-memory situation, release unnecessary things such as cached data, if this view doesn't have a superview then the [super didReceiveMemoryWarning] will go on to release (unload) the view and call -viewDidUnload. -dealloc: release everything -viewWillAppear:, -viewDidAppear:, -viewWillDisappear:, -viewDidDisappear: self-explanatory, not necessary unless you want to respond (do something) to those events. I'm not sure about a couple of things. First, the Apple docs say that when -viewDidUnload is called, the view has already been released and set to nil. Will -loadView get called again to recreate the view later on? There's a few things I created in -viewDidLoad that I didn't make a ivar/property for because there is no need and it will be retained by the view (because they are subviews of it). So when the view is released, it will release those too, right? When the view is released, will it release all its subviews? Because all the objects I created in -viewDidLoad are subviews of [self view]. So if they already get released why release them again in -viewDidUnload? I can understand data that is necessary when the view is visible being loaded and unloaded in these methods, but like I asked, why release the subviews if they already get released? EDIT: After reading other questions, I think I might have got it (my 2nd question). In the situation where I just use a local variable, alloc it, make it a subview and release, it will have a retain count of 1 (from adding it as a subview), so when the view is released it is too. Now for the view elements with ivars pointing to them, I wasn't using properties because no outside class would need to access them. But now I think that that's wrong, because in this situation: // MyViewController.h @interface MyViewController : UIViewController { UILabel *myLabel; } // MyViewController.m . . . - (void)viewDidLoad { myLabel = [[UILabel alloc] initWithFrame:CGRectMake(0, 0, 40, 10)]; [myLabel setText:@"Foobar"]; [[self view] addSubview:myLabel]; } - (void)viewDidUnload [ // equivalent of [self setMyLabel:nil]; without properties [myLabel release]; myLabel = nil; } In that situation, the label will be sent the -release message after it was deallocated because the ivar didn't retain it (because it wasn't a property). But with a property the retain count would be two: the view retaining it and the property. So then in -viewDidUnload it will get deallocated. So its best to just always use properties for these things, am I right? Or not? EDIT: I read somewhere that -viewDidLoad and -viewDidUnload are only for use with Interface Builder, that if you are doing everything programmatically you shouldn't use them. Is that right? Why?

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  • Having problem loading data from AppDelegate using UITableView into a flip view, loads first view bu

    - by Ms. Ryann
    AppDelegate: @implementation Ripe_ProduceGuideAppDelegate -(void)applicationDidFinishLaunching:(UIApplication *)application { Greens *apricot = [[Greens alloc] init]; apricot.produceName = @"Apricot"; apricot.produceSight = @"Deep orange or yellow orange in appearance, may have red tinge, no marks or bruises. "; apricot.produceTouch = @"Firm to touch and give to gentle pressure, plump."; apricot.produceSmell = @"Should be Fragrant"; apricot.produceHtoP = @"raw, salads, baked, sauces, glazes, desserts, poached, stuffing."; apricot.produceStore = @"Not ripe: place in brown paper bag, at room temperature and out of direct sunlight, close bag for 2 - 3 days. Last for a week. Warning: Only refrigerate ripe apricots."; apricot.produceBest = @"Spring & Summer"; apricot.producePic = [UIImage imageNamed:@"apricot.jpg"]; Greens *artichoke = [[Greens alloc] init]; artichoke.produceName = @"Artichoke"; artichoke.produceSight = @"Slightly glossy dark green color and sheen, tight petals that are not be too open, no marks, no brown petals or dried out look. Stem should not be dark brown or black."; artichoke.produceTouch = @"No soft spots"; artichoke.produceSmell = @" Should not smell"; artichoke.produceHtoP = @"steam, boil, grill, saute, soups"; artichoke.produceStore = @"Stand up in vase of cold water, keeps for 2 -3 days. Or, place in refrigerator loose without plastic bag. May be frozen, if cooked but not raw."; artichoke.produceBest = @"Spring"; artichoke.producePic = [UIImage imageNamed:@"artichoke.jpg"]; self.produce = [[NSMutableArray alloc] initWithObjects:apricot, artichoke, nil]; [apricot release]; [artichoke release]; FirstView: @implementation ProduceView -(id)initWithIndexPath: (NSIndexPath *)indexPath { if (self == [super init] ){ index = indexPath; } return self; } -(void)viewDidLoad { Ripe_ProduceGuideAppDelegate *delegate = (Ripe_ProduceGuideAppDelegate *) [[UIApplication sharedApplication] delegate]; Greens *thisProduce = [delegate.produce objectAtIndex:index.row]; self.title = thisProduce.produceName; sightView.text = thisProduce.produceSight; touchView.text = thisProduce.produceTouch; smellView.text = thisProduce.produceSmell; picView.image = thisProduce.producePic; } FlipView: @implementation FlipsideViewController @synthesize flipDelegate; -(id)initWithIndexPath: (NSIndexPath *)indexPath { if ( self == [super init]) { index = indexPath; } return self; } -(void)viewDidLoad { Ripe_ProduceGuideAppDelegate *delegate = (Ripe_ProduceGuideAppDelegate *) [[UIApplication sharedApplication] delegate]; Greens*thisProduce = [delegate.produce objectAtIndex:index.row]; self.title = thisProduce.produceName; bestView.text = thisProduce.produceBest; htopView.text = thisProduce.produceHtoP; storeView.text = thisProduce.produceStore; picView.image = thisProduce.producePic; } *the app works, the flip view for Artichoke shows the information for Apricot. Been working on it for two days. I have been working with iPhone apps for two months now and would very much appreciate any assistance with this problem. Thank you very much.

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  • JPA IndirectSet changes not reflected in Spring frontend

    - by Jon
    I'm having an issue with Spring JPA and IndirectSets. I have two entities, Parent and Child, defined below. I have a Spring form in which I'm trying to create a new Child and link it to an existing Parent, then have everything reflected in the database and in the web interface. What's happening is that it gets put into the database, but the UI doesn't seem to agree. The two entities that are linked to each other in a OneToMany relationship like so: @Entity @Table(name = "parent", catalog = "myschema", uniqueConstraints = @UniqueConstraint(columnNames = "ChildLinkID")) public class Parent { private Integer id; private String childLinkID; private Set<Child> children = new HashSet<Child>(0); @Id @GeneratedValue(strategy = IDENTITY) @Column(name = "id", unique = true, nullable = false) public Integer getId() { return this.id; } public void setId(Integer id) { this.id = id; } @Column(name = "ChildLinkID", unique = true, nullable = false, length = 6) public String getChildLinkID() { return this.childLinkID; } public void setChildLinkID(String childLinkID) { this.childLinkID = childLinkID; } @OneToMany(cascade = CascadeType.ALL, fetch = FetchType.LAZY, mappedBy = "parent") public Set<Child> getChildren() { return this.children; } public void setChildren(Set<Child> children) { this.children = children; } } @Entity @Table(name = "child", catalog = "myschema") public class Child extends private Integer id; private Parent parent; @Id @GeneratedValue(strategy = IDENTITY) @Column(name = "id", unique = true, nullable = false) public Integer getId() { return this.id; } public void setId(Integer id) { this.id = id; } @ManyToOne(fetch = FetchType.LAZY) @JoinColumn(name = "ChildLinkID", referencedColumnName = "ChildLinkID", nullable = false) public Parent getParent() { return this.parent; } public void setParent(Parent parent) { this.parent = parent; } } And of course, assorted simple properties on each of them. Now, the problem is that when I edit those simple properties from my Spring interface, everything works beautifully. I can persist new entities of these types and they'll appear when using the JPATemplate to do a find on, say, all Parents (getJpaTemplate().find("select p from Parent p")) or on individual entities by ID or another property. The problem I'm running into is that now, I'm trying to create a new Child linked to an existing Parent through a link from the Parent's page. Here's the important bits of the Controller (note that I've placed the JPA foo in the controller here to make it clearer; the actual JpaDaoSupport is actually in another class, appropriately tiered): protected Object formBackingObject(HttpServletRequest request) throws Exception { String parentArg = request.getParameter("parent"); int parentId = Integer.parseInt(parentArg); Parent parent = getJpaTemplate().find(Parent.class, parentId); Child child = new Child(); child.setParent(parent); NewChildCommand command = new NewChildCommand(); command.setChild(child); return command; } protected ModelAndView onSubmit(Object cmd) throws Exception { NewChildCommand command = (NewChildCommand)cmd; Child child = command.getChild(); child.getParent().getChildren().add(child); getJpaTemplate().merge(child); return new ModelAndView(new RedirectView(getSuccessView())); } Like I said, I can run through the form and fill in the new values for the Child -- the Parent's details aren't even displayed. When it gets back to the controller, it goes through and saves it to the underlying database, but the interface never reflects it. Once I restart the app, it's all there and populated appropriately. What can I do to clear this up? I've tried to call extra merges, tried refreshes (which gave a transaction exception), everything short of just writing my own database access code. I've made sure that every class has an appropriate equals() and hashCode(), have full JPA debugging on to see that it's making appropriate SQL calls (it doesn't seem to make any new calls to the Child table) and stepped through in the debugger (it's all in IndirectSets, as expected, and between saving and displaying the Parent the object takes on a new memory address). What's my next step?

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  • [NSCustomView isOpaque]: message sent to deallocated instance 0x123456

    - by JxXx
    Hi all I receive that message in debugger console since I added the following arguments for debugging my application with XCode. NSZombieEnabled: YES NSZombieLevel: 16 I was looking for zombie objects... Before doing so, the application failed before I could know where what and why was happening.... Now I´m pretty sure that 'something' outside code is trying to access an object previously released and I can't know where or why it happens neither where it was released... My application is based on this proof of concept (very interesting and colorful) of QuartzCore Framework: http://www.cimgf.com/2008/03/03/core-animation-tutorial-wizard-dialog-with-transitions/ Based on it, I added a few more nsviews to my project and a title and an index to each one, also I added some buttons, text and images depending on what 'dialog' (ACLinkedView object) it was... The transition from an ACLinkedView object to another is going through a validation that depends on the view where you are ... As you see I used this proof of concept as the foundation of my application and it grew and grew into an application that makes use of configuration files, web services (using gSOAP and C ...) I hope you can give me some clues to where is my error ... I´ve been the hole week debugging unsuccessfully, as I said before, I think that that message comes from a point outside my code. I'd say that the problem s related with bad memory allocation or automatisms (nearly completely unknowns for me) during loading the nib components... I will try to explain all this with parts of mycode. This is my ACLinkedView definition: #import <Cocoa/Cocoa.h> @interface ACLinkedView : NSView { // The Window (to close it if needed) IBOutlet NSWindow *mainWindow; // Linked Views IBOutlet ACLinkedView *previousView; IBOutlet ACLinkedView *nextView; // Buttons IBOutlet NSButton *previousButton; IBOutlet NSButton *nextButton; IBOutlet NSButton *helpButton; //It has to be a Button!! IBOutlet NSImageView *bannerImg; NSString *sName; int iPosition; } - (void) SetName: (NSString*) Name; - (void) SetPosition: (int) Position; - (NSString*) GetName; - (int) GetPosition; - (void) windowWillClose:(NSNotification*)aNotification; @property (retain) NSWindow *mainWindow; @property (retain) ACLinkedView *previousView, *nextView; @property (retain) NSButton *previousButton, *nextButton, *helpButton; @property (retain) NSImageView *bannerImg; @property (retain) NSString *sName; @end The ACLinkedView's AwakeFromNib is this: #import <Cocoa/Cocoa.h> @interface ACLinkedView : NSView { // The Window (to close it if needed) IBOutlet NSWindow *mainWindow; // Linked Views IBOutlet ACLinkedView *previousView; IBOutlet ACLinkedView *nextView; // Buttons IBOutlet NSButton *previousButton; IBOutlet NSButton *nextButton; IBOutlet NSButton *helpButton; //It has to be a Button!! IBOutlet NSImageView *bannerImg; NSString *sName; int iPosition; } - (void) SetName: (NSString*) Name; - (void) SetPosition: (int) Position; - (NSString*) GetName; - (int) GetPosition; - (void) windowWillClose:(NSNotification*)aNotification; @property (retain) NSWindow *mainWindow; @property (retain) ACLinkedView *previousView, *nextView; @property (retain) NSButton *previousButton, *nextButton, *helpButton; @property (retain) NSImageView *bannerImg; @property (retain) NSString *sName; @end (As you can see the initialization of each ACLinkedView object depends on it's position wich is seted up into the Interface Builder by linking actions, buttons and CustomViews... Does I explain enough? Do you think that I should put more of my code here, i.e. AppDelegate definition or it´s awakeFromNib method? Can you help me in any way? Thanks in advance. Juan

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  • Rendering a Long Document on iPad

    - by benjismith
    I'm implementing a document viewer with highlighting/annotation capabilities for a custom document format on iPad. The documents are kind of long (100 to 200 pages, if printed on paper) and I've had a hard time finding the right approach. Here are the requirments: 1) Basic rich-text styling: control of left/right margins. Control of font name, size, foreground/background color, and line spacing. Bold, italics, underline, etc. 2) Selection and highlighting of arbitrary text regions (not limited to paragraph boundaries, like in Safari/UIWebView). 3) Customization of the Cut/Copy/Paste popup (what is that thing called anyhow? UIActionBar?) This is one of the essential requirements of the app. My first implementation was based on UIWebView. I just rendered the document as HTML with CSS for text styling. But I couldn't get the kind of text selection behavior I wanted (across paragraph boundaries) and the UIActionBar can't be customized from within UIWebView. So I started working on a javascript approach, faking the device text-selection behavior using JQuery to trap touch events and dynamically modifying the DOM to change the background color of selected regions of text. I built a fake UIActionBar control as a hidden DIV, positioning it and unhiding it whenever there was an active selection region. Not too shabby. The main problem is that it's SLOOOOOOOW. Scrolling through the document is nice and quick, but dynamically changing the DOM is not very snappy. Plus, I couldn't figure out how to recreate the magnifier loupe, so my fake text-selection GUI doesn't look quite the same as the native implementation. Also, I haven't yet implemented the communication bridge between the javascript layer and the objective-c layer (where the rest of the app lives), but it was shaping up to be a huge hassle. So I've been looking at CoreText, but there are precious few examples on the web. I spent a little time with this simple little demo: http://github.com/jonasschnelli/I7CoreTextExample/ It shows how to use CoreText to draw an NSAttributedText string into a UIView. But it has its own problems: It doesn't implement text-selection behavior, and it doesn't present a UIActionBar, so I don't have any idea how to make that happen. And, more importantly, it tries to draw the entire document all at once, with significant performance degradations for long documents. My documents can have thousands of paragraphs, and less than 1% of the document is ever on screen at a time. On the plus side, these documents already contain precise formatting information. I know the exact page-position of every line of text, so I don't need a layout engine. Does anyone know how to implement this sort of view using CoreText? I understand that a full-fledged implementation is overkill for a question like this, but I'm looking for a good CoreText example with a few basic requirements: 1) Precise layout & formatting control (using the formatting metrics and text styles I've already calculated). 2) Arbitrary selection of text. 3) Customization of the UIActionBar. 4) Efficient recycling of resources for off-screen objects. I'd be happy to implement my own recycling when text elements scroll off-screen, but wouldn't that require re-implementing UIScrollView? I'm brand-new to iPhone development, and still getting used to Objective-C, but I've been working in other languages (Java, C#, flex/actionscript, etc) for more than ten years, so I feel confident in my ability to get the work done, if only I had a better feel for the iPhone SDK and the common coding patterns for stuff like this. Is it just me, or does the SDK documentation really suck? Anyhow, thanks for your help!

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  • Php template caching design

    - by Thomas
    Hello to all, I want to include caching in my app design. Caching templates for starters. The design I have used so far is very modular. I have created an ORM implementation for all my tables and each table is represented by the corresponding class. All the requests are handled by one controller which routes them to the appropriate webmethod functions. I am using a template class for handling UI parts. What I have in mind for caching includes the implementation of a separate Cache class for handling caching with the flexibility to either store in files, apc or memcache. Right now I am testing with file caching. Some thoughts Should I include the logic of checking for cached versions in the Template class or in the webmethods which handle the incoming requests and which eventually call the Template class. In the first case, things are pretty simple as I will not have to change anything more than pass the template class an extra argument (whether to load from cache or not). In the second case however, I am thinking of checking for a cached version immediately in the webmethod and if found return it. This will save all the processing done until the logic reaches the template (first case senario). Both senarios however, rely on an accurate mechanism of invalidating caches, which brings as to Invalidating caches As I see it (and you can add your input freely) a template cached file, becomes invalidate if: a. the expiration set, is reached. b. the template file itself is updated (ie by the developer when adding a new line) c. the webmethod that handles the request changes (ie the developer adds/deletes something in the code) d. content coming from the db and ending in the template file is modified I am thinking of storing a json encoded array inside the cached file. The first value will be the expiration timestamp of the cache. The second value will be the modification time of the php file with the code handling the request (to cope with option c above) The third will be the content itself The validation process I am considering, according to the above senarios, is: a. If the expiration of the cached file (stored in the array) is reached, delete the cache file b. if the cached file's mod time is smaller than the template's skeleton file mod time, delete the cached file c. if the mod time of the php file is greated than the one stored in the cache, delete the cached file. d. This is tricky. In the ORM implementation I ahve added event handlers (which fire when adding, updating, deleting objects). I could delete the cache file every time an object thatprovides content to the template, is modified. The problem is how to keep track which cached files correpond to each schema object. Take this example, a user has his shortprofile page and a full profile page (2 templates) These templates can be cached. Now, every time the user modifies his profile, the event handler would need to know which templates or cached files correspond to the User, so that these files can be deleted. I could store them in the db but I am looking for a beter approach

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  • Trouble with setting entry point for GWT service

    - by Xorty
    Hello. I've followed serveral tutorials and read official docs at code.google.com, but still didn't manage to resolve this thing. I am creating simple service that'll check if user can be logged. CLIENT SIDE: public interface LoginService extends RemoteService { /** * Checks, if user has valid login. * @param user User's login. * @return True if such a login is in the database. */ boolean isValidUser(User user); } And here is Async interface: public interface LoginServiceAsync { /** * Checks, if user has valid login. * @param user User's login. * @param callback the callback to return True if such a login is in the database. */ void isValidUser(User user, AsyncCallback<Boolean> callback); } SERVER SIDE: public class LoginServiceImpl extends RemoteServiceServlet implements LoginService { /** * serial version UID */ private static final long serialVersionUID = 1044980345057997696L; /**{@inheritDoc} */ @Override public boolean isValidUser(User user) { boolean success = true; //TODO change } } Now I have entry point class MailClient.java. I append here widget like: CustomWidgets.getLoginWidget(this); // access rootPanel and append widget Now I need to make actual call to my service, and here is problem: LoginServiceAsync loginService = (LoginServiceAsync) GWT.create(LoginService.class); User user = new User(boxName.getText(), boxPassword.getText()); AsyncCallback<Boolean> callback = new AsyncCallback<Boolean>() { @Override public void onFailure(Throwable caught) { Window.alert(caught.getMessage()); //TODO change } @Override public void onSuccess(Boolean result) { Window.alert("success"); //TODO change } }; ((ServiceDefTarget) loginService).setServiceEntryPoint(GWT.getModuleBaseURL()+"login"); // dunno what should be here So to recap, I don't know how to set service's entry point. Here's my MailClient.gwt.xml file: <module> <inherits name="com.google.gwt.user.User"/> <inherits name="com.google.gwt.user.theme.standard.Standard"/> <entry-point class="com.xorty.mailclient.client.MailClient"/> <servlet path="/login" class="com.xorty.mailclient.server.servlets.LoginServiceImpl" /> <inherits name="com.xorty.mailclient.MailClient"/> <inherits name="com.xorty.mailclient.MailClient"/> <inherits name="com.xorty.mailclient.MailClient"/> <inherits name="com.xorty.mailclient.MailClient"/> <inherits name="com.xorty.mailclient.MailClient"/> </module> My web.xml file: <?xml version="1.0" encoding="UTF-8"?> <web-app version="2.4" xmlns="http://java.sun.com/xml/ns/j2ee" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://java.sun.com/xml/ns/j2ee http://java.sun.com/xml/ns/j2ee/web-app_2_4.xsd"> <!-- Default page to serve --> <welcome-file-list> <welcome-file>MailClient.html</welcome-file> </welcome-file-list> <servlet> <servlet-name>LoginService</servlet-name> <servlet-class>com.xorty.mailclient.server.servlets.LoginServiceImpl</servlet-class> </servlet> <servlet-mapping> <servlet-name>LoginService</servlet-name> <url-pattern>/com.xorty.mailclient.MailClient/login</url-pattern> </servlet-mapping> </web-app> And here is screenshot of project structure:

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  • Help with refactoring PHP code

    - by Richard Knop
    I had some troubles implementing Lawler's algorithm but thanks to SO and a bounty of 200 reputation I finally managed to write a working implementation: http://stackoverflow.com/questions/2466928/lawlers-algorithm-implementation-assistance I feel like I'm using too many variables and loops there though so I am trying to refactor the code. It should be simpler and shorter yet remain readable. Does it make sense to make a class for this? Any advice or even help with refactoring this piece of code is welcomed: <?php /* * @name Lawler's algorithm PHP implementation * @desc This algorithm calculates an optimal schedule of jobs to be * processed on a single machine (in reversed order) while taking * into consideration any precedence constraints. * @author Richard Knop * */ $jobs = array(1 => array('processingTime' => 2, 'dueDate' => 3), 2 => array('processingTime' => 3, 'dueDate' => 15), 3 => array('processingTime' => 4, 'dueDate' => 9), 4 => array('processingTime' => 3, 'dueDate' => 16), 5 => array('processingTime' => 5, 'dueDate' => 12), 6 => array('processingTime' => 7, 'dueDate' => 20), 7 => array('processingTime' => 5, 'dueDate' => 27), 8 => array('processingTime' => 6, 'dueDate' => 40), 9 => array('processingTime' => 3, 'dueDate' => 10)); // precedence constrainst, i.e job 2 must be completed before job 5 etc $successors = array(2=>5, 7=>9); $n = count($jobs); $optimalSchedule = array(); for ($i = $n; $i >= 1; $i--) { // jobs not required to precede any other job $arr = array(); foreach ($jobs as $k => $v) { if (false === array_key_exists($k, $successors)) { $arr[] = $k; } } // calculate total processing time $totalProcessingTime = 0; foreach ($jobs as $k => $v) { if (true === array_key_exists($k, $arr)) { $totalProcessingTime += $v['processingTime']; } } // find the job that will go to the end of the optimal schedule array $min = null; $x = 0; $lastKey = null; foreach($arr as $k) { $x = $totalProcessingTime - $jobs[$k]['dueDate']; if (null === $min || $x < $min) { $min = $x; $lastKey = $k; } } // add the job to the optimal schedule array $optimalSchedule[$lastKey] = $jobs[$lastKey]; // remove job from the jobs array unset($jobs[$lastKey]); // remove precedence constraint from the successors array if needed if (true === in_array($lastKey, $successors)) { foreach ($successors as $k => $v) { if ($lastKey === $v) { unset($successors[$k]); } } } } // reverse the optimal schedule array and preserve keys $optimalSchedule = array_reverse($optimalSchedule, true); // add tardiness to the array $i = 0; foreach ($optimalSchedule as $k => $v) { $optimalSchedule[$k]['tardiness'] = 0; $j = 0; foreach ($optimalSchedule as $k2 => $v2) { if ($j <= $i) { $optimalSchedule[$k]['tardiness'] += $v2['processingTime']; } $j++; } $i++; } echo '<pre>'; print_r($optimalSchedule); echo '</pre>';

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  • Explicit method tables in C# instead of OO - good? bad?

    - by FunctorSalad
    Hi! I hope the title doesn't sound too subjective; I absolutely do not mean to start a debate on OO in general. I'd merely like to discuss the basic pros and cons for different ways of solving the following sort of problem. Let's take this minimal example: you want to express an abstract datatype T with functions that may take T as input, output, or both: f1 : Takes a T, returns an int f2 : Takes a string, returns a T f3 : Takes a T and a double, returns another T I'd like to avoid downcasting and any other dynamic typing. I'd also like to avoid mutation whenever possible. 1: Abstract-class-based attempt abstract class T { abstract int f1(); // We can't have abstract constructors, so the best we can do, as I see it, is: abstract void f2(string s); // The convention would be that you'd replace calls to the original f2 by invocation of the nullary constructor of the implementing type, followed by invocation of f2. f2 would need to have side-effects to be of any use. // f3 is a problem too: abstract T f3(double d); // This doesn't express that the return value is of the *same* type as the object whose method is invoked; it just expresses that the return value is *some* T. } 2: Parametric polymorphism and an auxilliary class (all implementing classes of TImpl will be singleton classes): abstract class TImpl<T> { abstract int f1(T t); abstract T f2(string s); abstract T f3(T t, double d); } We no longer express that some concrete type actually implements our original spec -- an implementation is simply a type Foo for which we happen to have an instance of TImpl. This doesn't seem to be a problem: If you want a function that works on arbitrary implementations, you just do something like: // Say we want to return a Bar given an arbitrary implementation of our abstract type Bar bar<T>(TImpl<T> ti, T t); At this point, one might as well skip inheritance and singletons altogether and use a 3 First-class function table class /* or struct, even */ TDictT<T> { readonly Func<T,int> f1; readonly Func<string,T> f2; readonly Func<T,double,T> f3; TDict( ... ) { this.f1 = f1; this.f2 = f2; this.f3 = f3; } } Bar bar<T>(TDict<T> td; T t); Though I don't see much practical difference between #2 and #3. Example Implementation class MyT { /* raw data structure goes here; this class needn't have any methods */ } // It doesn't matter where we put the following; could be a static method of MyT, or some static class collecting dictionaries static readonly TDict<MyT> MyTDict = new TDict<MyT>( (t) => /* body of f1 goes here */ , // f2 (s) => /* body of f2 goes here */, // f3 (t,d) => /* body of f3 goes here */ ); Thoughts? #3 is unidiomatic, but it seems rather safe and clean. One question is whether there are any performance concerns with it. I don't usually need dynamic dispatch, and I'd prefer if these function bodies get statically inlined in places where the concrete implementing type is known statically. Is #2 better in that regard?

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  • My xcode mapview wont work when combined with webview

    - by user1715702
    I have a small problem with my mapview. When combining the mapview code with the code for webview, the app does not zoom in on my position correctly (just gives me a world overview where i´m supposed to be somewhere in California - wish I was). And it doesn´t show the pin that I have placed on a specific location. These things works perfectly fine, as long as the code does not contain anything concerning webview. Below you´ll find the code. If someone can help me to solve this, I would be som thankful! ViewController.h #import <UIKit/UIKit.h> #import <MapKit/MapKit.h> #define METERS_PER_MILE 1609.344 @interface ViewController : UIViewController <MKMapViewDelegate>{ BOOL _doneInitialZoom; IBOutlet UIWebView *webView; } @property (weak, nonatomic) IBOutlet MKMapView *_mapView; @property (nonatomic, retain) UIWebView *webView; @end ViewController.m #import "ViewController.h" #import "NewClass.h" @interface ViewController () @end @implementation ViewController @synthesize _mapView; @synthesize webView; - (void)viewDidLoad { [super viewDidLoad]; [_mapView setMapType:MKMapTypeStandard]; [_mapView setZoomEnabled:YES]; [_mapView setScrollEnabled:YES]; MKCoordinateRegion region = { {0.0,0.0} , {0.0,0.0} }; region.center.latitude = 61.097557; region.center.longitude = 12.126545; region.span.latitudeDelta = 0.01f; region.span.longitudeDelta = 0.01f; [_mapView setRegion:region animated:YES]; newClass *ann = [[newClass alloc] init]; ann.title = @"Hjem"; ann.subtitle = @"Her bor jeg"; ann.coordinate = region.center; [_mapView addAnnotation:ann]; NSString *urlAddress = @"http://google.no"; //Create a URL object. NSURL *url = [NSURL URLWithString:urlAddress]; //URL Requst Object NSURLRequest *requestObj = [NSURLRequest requestWithURL:url]; //Load the request in the UIWebView. [webView loadRequest:requestObj]; } - (void)viewDidUnload { [self setWebView:nil]; [self set_mapView:nil]; [super viewDidUnload]; // Release any retained subviews of the main view. } - (BOOL)shouldAutorotateToInterfaceOrientation:(UIInterfaceOrientation)interfaceOrientation { return (interfaceOrientation != UIInterfaceOrientationPortraitUpsideDown); } - (void)viewWillAppear:(BOOL)animated { // 1 CLLocationCoordinate2D zoomLocation; zoomLocation.latitude = 61.097557; zoomLocation.longitude = 12.126545; // 2 MKCoordinateRegion viewRegion = MKCoordinateRegionMakeWithDistance(zoomLocation, 0.5*METERS_PER_MILE, 0.5*METERS_PER_MILE); // 3 MKCoordinateRegion adjustedRegion = [_mapView regionThatFits:viewRegion]; // 4 [_mapView setRegion:adjustedRegion animated:YES]; } @end NewClass.h #import <UIKit/UIKit.h> #import <MapKit/MKAnnotation.h> @interface newClass : NSObject{ CLLocationCoordinate2D coordinate; NSString *title; NSString *subtitle; } @property (nonatomic, assign) CLLocationCoordinate2D coordinate; @property (nonatomic, copy) NSString *title; @property (nonatomic, copy) NSString *subtitle; @end NewClass.m #import "NewClass.h" @implementation newClass @synthesize coordinate, title, subtitle; @end

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  • Receiving Multicast Messages on a Multihomed Windows PC

    - by Basti
    I'm developing a diagnostic tool on a PC with several Network Interfaces based on multicast/udp. The user can select a NIC, the application creates sockets, binds them to this NIC and adds them to the specific multicast group. The sending of multicast messages works fine. However receiving of messages only succeeds if I bind the sockets to a specific NIC of my PC. It almost looks like as there is a 'default' NIC for receiving multicast messages in Windows which is always the first NIC returned by the GetAdapterInfo function. I monitored the network with Wireshark and discovered that the "IGMP Join Group" message isn't sent from the NIC I bound the socket at, but by this 'default' NIC. If I disable this NIC (or remove the network cable), the next NIC of the list returned by GetAdapterInfo is used for receiving multicast messages. I was successful to change this 'default' NIC by adding an additional entry to the routing table of my PC, but I don't think this is a good solution of the problem. The problem also occurs with the code appended below. The join group messages isn't sent via 192.168.52 but via a different NIC. // socket_tst.cpp : Defines the entry point for the console application. // #include tchar.h #include winsock2.h #include ws2ipdef.h #include IpHlpApi.h #include IpTypes.h #include stdio.h int _tmain(int argc, _TCHAR* argv[]) { WSADATA m_wsaData; SOCKET m_socket; sockaddr_in m_sockAdr; UINT16 m_port = 319; u_long m_interfaceAdr = inet_addr("192.168.1.52"); u_long m_multicastAdr = inet_addr("224.0.0.107"); int returnValue = WSAStartup(MAKEWORD(2,2), &m_wsaData); if (returnValue != S_OK) { return returnValue; } // Create sockets if (INVALID_SOCKET == (m_socket = socket(AF_INET, SOCK_DGRAM, IPPROTO_UDP)) ) { return WSAGetLastError(); } int doreuseaddress = TRUE; if (setsockopt(m_socket,SOL_SOCKET,SO_REUSEADDR,(char*) &doreuseaddress,sizeof(doreuseaddress)) == SOCKET_ERROR) { return WSAGetLastError(); } // Configure socket addresses memset(&m_sockAdr,0,sizeof(m_sockAdr)); m_sockAdr.sin_family = AF_INET; m_sockAdr.sin_port = htons(m_port); m_sockAdr.sin_addr.s_addr = m_interfaceAdr; //bind sockets if ( bind( m_socket, (SOCKADDR*) &m_sockAdr, sizeof(m_sockAdr) ) == SOCKET_ERROR ) { return WSAGetLastError(); } // join multicast struct ip_mreq_source imr; memset(&imr,0,sizeof(imr)); imr.imr_multiaddr.s_addr = m_multicastAdr; // address of multicastgroup imr.imr_sourceaddr.s_addr = 0; // sourceaddress (not used) imr.imr_interface.s_addr = m_interfaceAdr; // interface address /* first join multicast group, then registerer selected interface as * multicast sending interface */ if( setsockopt( m_socket ,IPPROTO_IP ,IP_ADD_MEMBERSHIP ,(char*) &imr , sizeof(imr)) == SOCKET_ERROR) { return SOCKET_ERROR; } else { if( setsockopt(m_socket ,IPPROTO_IP ,IP_MULTICAST_IF ,(CHAR*)&imr.imr_interface.s_addr ,sizeof(&imr.imr_interface.s_addr)) == SOCKET_ERROR ) { return SOCKET_ERROR; } } printf("receiving msgs...\n"); while(1) { // get inputbuffer from socket int sock_return = SOCKET_ERROR; sockaddr_in socketAddress; char buffer[1500]; int addressLength = sizeof(socketAddress); sock_return = recvfrom(m_socket, (char*) &buffer, 1500, 0, (SOCKADDR*)&socketAddress, &addressLength ); if( sock_return == SOCKET_ERROR) { int wsa_error = WSAGetLastError(); return wsa_error; } else { printf("got message!\n"); } } return 0; } Thanks four your help!

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  • Learning to implement DIC in MVC

    - by Tom
    I am learning to apply DIC to MVC project. So, I have sketched this DDD-ish DIC-ready-ish layout to my best understanding. I have read many blogs articles wikis for the last few days. However, I am not confident about implementing it correctly. Could you please demonstrate to me how to put them into DIC the proper way? I prefer Ninject or Windsor after all the readings, but anyDIC will do as long as I can get the correct idea how to do it. Web controller... public class AccountBriefingController { //create private IAccountServices accountServices { get; set; } public AccountBriefingController(IAccountServices accsrv) accountServices = accsrv; } //do work public ActionResult AccountBriefing(string userid, int days) { //get days of transaction records for this user BriefingViewModel model = AccountServices.GetBriefing(userid, days); return View(model); } } View model ... public class BriefingViewModel { //from user repository public string UserId { get; set; } public string AccountNumber {get; set;} public string FirstName { get; set; } public string LastName { get; set; } //from account repository public string Credits { get; set; } public List<string> Transactions { get; set; } } Service layer ... public interface IAccountServices { BriefingViewModel GetBriefing(); } public class AccountServices { //create private IUserRepository userRepo {get; set;} private IAccountRepository accRepo {get; set;} public AccountServices(UserRepository ur, AccountRepository ar) { userRepo = ur; accRepo = ar; } //do work public BriefingViewModel GetBriefing(string userid, int days) { var model = new BriefingViewModel(); //<---is that okay to new a model here?? var user = userRepo.GetUser(userid); if(user != null) { model.UserId = userid; model.AccountNumber = user.AccountNumber; model.FirstName = user.FirstName; model.LastName = user.LastName; //account records model.Credits = accRepo.GetUserCredits(userid); model.Transactions = accRepo.GetUserTransactions(userid, days); } return model; } } Domain layer and data models... public interface IUserRepository { UserDataModel GetUser(userid); } public interface IAccountRepository { List<string> GetUserTransactions(userid, days); int GetUserCredits(userid); } // Entity Framework DBContext goes under here Please point out if my implementation is wrong, e.g.I can feel in AccountServices-GetBriefing - new BriefingViewModel() seems wrong to me, but I don't know how to fit the stud into DIC? Thank you very much for your help!

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  • CoreData, transient atribute and EXC_BAD_ACCESS.

    - by Lukasz
    I'm trying to build simple file browser and i'm stuck. I defined classes, build window, add controllers, views.. Everything works but only ONE time. Selecting again Folder in NSTableView or trying to get data from Folder.files causing silent EXC_BAD_ACCESS (code=13, address0x0) from main. Info about files i keep outside of CoreData, in simple class, I don't want to save them: #import <Foundation/Foundation.h> @interface TPDrawersFileInfo : NSObject @property (nonatomic, retain) NSString * filename; @property (nonatomic, retain) NSString * extension; @property (nonatomic, retain) NSDate * creation; @property (nonatomic, retain) NSDate * modified; @property (nonatomic, retain) NSNumber * isFile; @property (nonatomic, retain) NSNumber * size; @property (nonatomic, retain) NSNumber * label; +(TPDrawersFileInfo *) initWithURL: (NSURL *) url; @end @implementation TPDrawersFileInfo +(TPDrawersFileInfo *) initWithURL: (NSURL *) url { TPDrawersFileInfo * new = [[TPDrawersFileInfo alloc] init]; if (new!=nil) { NSFileManager * fileManager = [NSFileManager defaultManager]; NSError * error; NSDictionary * infoDict = [fileManager attributesOfItemAtPath: [url path] error:&error]; id labelValue = nil; [url getResourceValue:&labelValue forKey:NSURLLabelNumberKey error:&error]; new.label = labelValue; new.size = [infoDict objectForKey: @"NSFileSize"]; new.modified = [infoDict objectForKey: @"NSFileModificationDate"]; new.creation = [infoDict objectForKey: @"NSFileCreationDate"]; new.isFile = [NSNumber numberWithBool:[[infoDict objectForKey:@"NSFileType"] isEqualToString:@"NSFileTypeRegular"]]; new.extension = [url pathExtension]; new.filename = [[url lastPathComponent] stringByDeletingPathExtension]; } return new; } Next I have class Folder, which is NSManagesObject subclass // Managed Object class to keep info about folder content @interface Folder : NSManagedObject { NSArray * _files; } @property (nonatomic, retain) NSArray * files; // Array with TPDrawersFileInfo objects @property (nonatomic, retain) NSString * url; // url of folder -(void) reload; //if url changed, load file info again. @end @implementation Folder @synthesize files = _files; @dynamic url; -(void)awakeFromInsert { [self addObserver:self forKeyPath:@"url" options:NSKeyValueObservingOptionNew context:@"url"]; } -(void)awakeFromFetch { [self addObserver:self forKeyPath:@"url" options:NSKeyValueObservingOptionNew context:@"url"]; } -(void)prepareForDeletion { [self removeObserver:self forKeyPath:@"url"]; } -(void) observeValueForKeyPath:(NSString *)keyPath ofObject:(id)object change:(NSDictionary *)change context:(void *)context { if (context == @"url") { [self reload]; } } -(void) reload { NSMutableArray * result = [NSMutableArray array]; NSError * error = nil; NSFileManager * fileManager = [NSFileManager defaultManager]; NSString * percented = [self.url stringByAddingPercentEscapesUsingEncoding:NSUTF8StringEncoding]; NSArray * listDir = [fileManager contentsOfDirectoryAtURL: [NSURL URLWithString: percented] includingPropertiesForKeys: [NSArray arrayWithObject: NSURLCreationDateKey ] options:NSDirectoryEnumerationSkipsHiddenFiles error:&error]; if (error!=nil) {NSLog(@"Error <%@> reading <%@> content", error, self.url);} for (id fileURL in listDir) { TPDrawersFileInfo * fi = [TPDrawersFileInfo initWithURL:fileURL]; [result addObject: fi]; } _files = [NSArray arrayWithArray:result]; } @end In app delegate i defined @interface TPAppDelegate : NSObject <NSApplicationDelegate> { IBOutlet NSArrayController * foldersController; Folder * currentFolder; } - (IBAction)chooseDirectory:(id)sender; // choose folder and - (Folder * ) getFolderObjectForPath: path { //gives Folder object if already exist or nil if not ..... } - (IBAction)chooseDirectory:(id)sender { //Opens panel, asking for url NSOpenPanel * panel = [NSOpenPanel openPanel]; [panel setCanChooseDirectories:YES]; [panel setCanChooseFiles:NO]; [panel setMessage:@"Choose folder to show:"]; NSURL * currentDirectory; if ([panel runModal] == NSOKButton) { currentDirectory = [[panel URLs] objectAtIndex:0]; } Folder * folderObject = [self getFolderObjectForPath:[currentDirectory path]]; if (folderObject) { //if exist: currentFolder = folderObject; } else { // create new one Folder * newFolder = [NSEntityDescription insertNewObjectForEntityForName:@"Folder" inManagedObjectContext:self.managedObjectContext]; [newFolder setValue:[currentDirectory path] forKey:@"url"]; [foldersController addObject:newFolder]; currentFolder = newFolder; } [foldersController setSelectedObjects:[NSArray arrayWithObject:currentFolder]]; } Please help ;)

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  • Problem with incomplete type while trying to detect existence of a member function

    - by abir
    I was trying to detect existence of a member function for a class where the function tries to use an incomplete type. The typedef is struct foo; typedef std::allocator<foo> foo_alloc; The detection code is struct has_alloc { template<typename U,U x> struct dummy; template<typename U> static char check(dummy<void* (U::*)(std::size_t),&U::allocate>*); template<typename U> static char (&check(...))[2]; const static bool value = (sizeof(check<foo_alloc>(0)) == 1); }; So far I was using incomplete type foo with std::allocator without any error on VS2008. However when I replaced it with nearly an identical implementation as template<typename T> struct allocator { T* allocate(std::size_t n) { return (T*)operator new (sizeof(T)*n); } }; it gives an error saying that as T is incomplete type it has problem instantiating allocator<foo> because allocate uses sizeof. GCC 4.5 with std::allocator also gives the error, so it seems during detection process the class need to be completely instantiated, even when I am not using that function at all. What I was looking for is void* allocate(std::size_t) which is different from T* allocate(std::size_t). My questions are (I have three questions, but as they are correlated , so I thought it is better not to create three separate questions). Why MS std::allocator doesn't check for incomplete type foo while instantiating? Are they following any trick which can be implemented ? Why the compiler need to instantiate allocator<T> to check the existence of the function when sizeof is not used as sfinae mechanism to remove/add allocate in the overload resolutions set? It should be noted that, if I remove the generic implementation of allocate leaving the declaration only, and specialized it for foo afterwards such as struct foo{}; template< struct allocator { foo* allocate(std::size_t n) { return (foo*)operator new (sizeof(foo)*n); } }; after struct has_alloc it compiles in GCC 4.5 while gives error in VS2008 as allocator<T> is already instantiated and explicit specialization for allocator<foo> already defined. Is it legal to use nested types for an std::allocator of incomplete type such as typedef foo_alloc::pointer foo_pointer; ? Though it is practically working for me, I suspect the nested types such as pointer may depend on completeness of type it takes. It will be good to know if there is any possible way to typedef such types as foo_pointer where the type pointer depends on completeness of foo. NOTE : As the code is not copy paste from editor, it may have some syntax error. Will correct it if I find any. Also the codes (such as allocator) are not complete implementation, I simplified and typed only the portion which I think useful for this particular problem.

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  • Remotely Schedule and Stream Recorded TV in Windows 7 Media Center

    - by DigitalGeekery
    Have you ever been away from home and suddenly realized you forgot to record your favorite program? Now Windows 7 Media Center, users can schedule recordings remotely from their phones or mobile devices with Remote Potato. How it Works Remote Potato installs server software on the host computer running Windows 7 Media Center. Once the software is installed, we’ll need to do some port forwarding on the router and setup an optional dynamic DNS address. When setup is completed, we will access the application through a web based interface. Silverlight is required for Streaming recorded TV, but scheduling recordings can be done through an HTML interface. Installing Remote Potato Download and install Remote Potato on the Media Center PC. (See download link below) If you plan to stream any Recorded TV, you’ll also want to install the streaming pack located on the same page. It isn’t required to stream all shows, only shows that require the AC3 audio codec. Click Yes to allow Remote Potato to add rules to the Windows Firewall for remote access. You’ll likely need to accept a few UAC prompts. When notified that the rules were added, click OK. Remote Potato will then prompt you to allow administrator privileges to reserve a URL for it’s web server. Click Yes. Remote Potato server will start. Click on the configuration button at the right to to reveal the settings tabs.   One the General tab, you’ll have the option to run Remote Potato on startup and minimized in the System Tray. If you’re running Media Center on a dedicated HTPC, you’ll probably want to enable both startup options. Forwarding Ports on Your Router You’ll need to forward a couple ports on your router. By default, these will be ports 9080 and 9081. In this example we’re using a Linksys WRT54GL router, however, the steps for port forwarding will vary from router to router. On the Linksys configuration page, click on the Applications & Gaming Tab, and then the Port Range Forward tab. Under Application, type in a name of your choosing. In both the Start and End boxes, type the port number 9080. Enter the local IP address of your Media Center computer in the IP address column. Click the check box under Enable. Repeat the process on the next line, but this time use port 9081. When finished, click the Save Settings button. Note: It’s highly recommended that you configure the home computer running Media Center & Remote Potato with a static IP address.   Find your IP Address You’ll need to find the IP address assigned to your router from your ISP. There are many ways to do this but a quick and easy way is to visit a site like checkip.dyndns.org (link available below) The current external IP address of your router will be displayed in the browser.   Dynamic DNS This is an optional step, but  it’s highly recommended. Many routers, such as the Linksys WRT54GL we are using, support Dynamic DNS (DDNS). What Dynamic DNS allows you to do is affiliate your home router’s external IP address to a domain name. Every time your home router is assigned a a new IP address by your ISP, the domain name is updated to point to your new IP address. Remote Potato’s user interface is accessed over the Internet is by connecting to your router’s IP address followed by a colon and the port number. (Ex: XXX.XXX.XXX.XXX:9080) Instead of constantly having to look up and remember an IP address, you can use DDNS along with a 3rd party provider like DynDNS.com, to sign up for a free domain name and configure it to be updated each time your router is assigned a new IP address. Go to the DynDNS.com website (See link at the end of the article) and sign up for a free Domain name. You’ll need to register and confirm by email.   Once you’ve signed in and selected your domain name click Activate Services. You’ll get a confirmation message that your domain name has been activated.    On the Linksys WRT54GL click on the Setup tab an then DDNS. Select DynDNS.org, or TZO.com if you prefer to use their service, from the drop down list.   With DynDNS, you’ll need to fill in your username and password you signed up with at the DynDNS website and the hostname you chose. Note: You can connect over your local network with the IP Address of the computer running Remote Potato followed by a colon and the port number. Ex: 192.168.1.2:9080 Logging in Remote Potato and Recording a Show Once you connect, you’ll see the start page. To view the TV listings, click on TV Guide. You’ll then see your guide listings. There are a few ways to navigate the listings. At the top left, you can click on any of the preset time buttons to jump to  the listings at that time of the day.  Click on the arrows to the right and left of the day and date at the top center to proceed to the previous or next day. Or, jump to a specific day with the date and date buttons at the top right.   To setup a recording, click on a program.   You can choose to record the individual show or the entire series by clicking on Record Show or Record Series.   Remote Potato on Mobile Devices Perhaps the coolest feature of Remote Potato is the ability to schedule recording from your phone or mobile device. Note: For any devices or computers without Silverlight, you will be prompted to view the HTML page. Select Browse Listings. Select your program to record. In the Program Details, select Record Show to record the single episode or Record Series to record all instances of the series. You will then see a red dot on the program listing to indicate that the show is scheduled for recording.   Streaming Recorded TV Click on Recorded TV from the home screen to access your previously recorded TV programs. Click on the selection you wish to stream. Click on Play. If you receive this error message, you’ll need to install the streaming pack for Remote Potato. This is found on the same download page as installation files. (See link below) The Begin from slider allows you to start playback from the start (by default) or a different time of the program by moving the slider. The Quality (bitrate) setting  allows you to choose the quality of the playback. We found the video quality on the Normal setting to be pretty lousy, and Low was just pointless. High was the best overall viewing experience as it provided smooth quality video playback. We experienced significant stuttering during playback using the Ultra High setting.   Click Start when you are ready to begin. When playback begins you’ll see a slider at the top right.   Move the slider left or right to increase or decrease the size of the video. There’s also a button to switch to full screen.   Media Center users who travel frequently or are always on the go will likely find Remote Potato to be a blessing. Since being released earlier this year, updates for Remote Potato have come fast and furious. The latest beta release includes support for streaming music and photos. If you like those nice network TV logos, check out our article on adding TV channel logos to Windows Media Center. Downloads and Links Download Remote Potato and Streaming Pack Find your IP address Sign Up for a Domain Name at DynDNS.com Similar Articles Productive Geek Tips Schedule Updates for Windows Media CenterUsing Netflix Watchnow in Windows Vista Media Center (Gmedia)Add a Sleep Timer to Windows 7 Media CenterStartup Customizations for Media Center in Windows 7Enable Media Streaming in Windows Home Server to Windows Media Player TouchFreeze Alternative in AutoHotkey The Icy Undertow Desktop Windows Home Server – Backup to LAN The Clear & Clean Desktop Use This Bookmarklet to Easily Get Albums Use AutoHotkey to Assign a Hotkey to a Specific Window Latest Software Reviews Tinyhacker Random Tips DVDFab 6 Revo Uninstaller Pro Registry Mechanic 9 for Windows PC Tools Internet Security Suite 2010 FoxClocks adds World Times in your Statusbar (Firefox) Have Fun Editing Photo Editing with Citrify Outlook Connector Upgrade Error Gadfly is a cool Twitter/Silverlight app Enable DreamScene in Windows 7 Microsoft’s “How Do I ?” Videos

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  • Implementing a generic repository for WCF data services

    - by cibrax
    The repository implementation I am going to discuss here is not exactly what someone would call repository in terms of DDD, but it is an abstraction layer that becomes handy at the moment of unit testing the code around this repository. In other words, you can easily create a mock to replace the real repository implementation. The WCF Data Services update for .NET 3.5 introduced a nice feature to support two way data bindings, which is very helpful for developing WPF or Silverlight based application but also for implementing the repository I am going to talk about. As part of this feature, the WCF Data Services Client library introduced a new collection DataServiceCollection<T> that implements INotifyPropertyChanged to notify the data context (DataServiceContext) about any change in the association links. This means that it is not longer necessary to manually set or remove the links in the data context when an item is added or removed from a collection. Before having this new collection, you basically used the following code to add a new item to a collection. Order order = new Order {   Name = "Foo" }; OrderItem item = new OrderItem {   Name = "bar",   UnitPrice = 10,   Qty = 1 }; var context = new OrderContext(); context.AddToOrders(order); context.AddToOrderItems(item); context.SetLink(item, "Order", order); context.SaveChanges(); Now, thanks to this new collection, everything is much simpler and similar to what you have in other ORMs like Entity Framework or L2S. Order order = new Order {   Name = "Foo" }; OrderItem item = new OrderItem {   Name = "bar",   UnitPrice = 10,   Qty = 1 }; order.Items.Add(item); var context = new OrderContext(); context.AddToOrders(order); context.SaveChanges(); In order to use this new feature, you first need to enable V2 in the data service, and then use some specific arguments in the datasvcutil tool (You can find more information about this new feature and how to use it in this post). DataSvcUtil /uri:"http://localhost:3655/MyDataService.svc/" /out:Reference.cs /dataservicecollection /version:2.0 Once you use those two arguments, the generated proxy classes will use DataServiceCollection<T> rather than a simple ObjectCollection<T>, which was the default collection in V1. There are some aspects that you need to know to use this feature correctly. 1. All the entities retrieved directly from the data context with a query track the changes and report those to the data context automatically. 2. A entity created with “new” does not track any change in the properties or associations. In order to enable change tracking in this entity, you need to do the following trick. public Order CreateOrder() {   var collection = new DataServiceCollection<Order>(this.context);   var order = new Order();   collection.Add(order);   return order; } You basically need to create a collection, and add the entity to that collection with the “Add” method to enable change tracking on that entity. 3. If you need to attach an existing entity (For example, if you created the entity with the “new” operator rather than retrieving it from the data context with a query) to a data context for tracking changes, you can use the “Load” method in the DataServiceCollection. var order = new Order {   Id = 1 }; var collection = new DataServiceCollection<Order>(this.context); collection.Load(order); In this case, the order with Id = 1 must exist on the data source exposed by the Data service. Otherwise, you will get an error because the entity did not exist. These cool extensions methods discussed by Stuart Leeks in this post to replace all the magic strings in the “Expand” operation with Expression Trees represent another feature I am going to use to implement this generic repository. Thanks to these extension methods, you could replace the following query with magic strings by a piece of code that only uses expressions. Magic strings, var customers = dataContext.Customers .Expand("Orders")         .Expand("Orders/Items") Expressions, var customers = dataContext.Customers .Expand(c => c.Orders.SubExpand(o => o.Items)) That query basically returns all the customers with their orders and order items. Ok, now that we have the automatic change tracking support and the expression support for explicitly loading entity associations, we are ready to create the repository. The interface for this repository looks like this,public interface IRepository { T Create<T>() where T : new(); void Update<T>(T entity); void Delete<T>(T entity); IQueryable<T> RetrieveAll<T>(params Expression<Func<T, object>>[] eagerProperties); IQueryable<T> Retrieve<T>(Expression<Func<T, bool>> predicate, params Expression<Func<T, object>>[] eagerProperties); void Attach<T>(T entity); void SaveChanges(); } The Retrieve and RetrieveAll methods are used to execute queries against the data service context. While both methods receive an array of expressions to load associations explicitly, only the Retrieve method receives a predicate representing the “where” clause. The following code represents the final implementation of this repository.public class DataServiceRepository: IRepository { ResourceRepositoryContext context; public DataServiceRepository() : this (new DataServiceContext()) { } public DataServiceRepository(DataServiceContext context) { this.context = context; } private static string ResolveEntitySet(Type type) { var entitySetAttribute = (EntitySetAttribute)type.GetCustomAttributes(typeof(EntitySetAttribute), true).FirstOrDefault(); if (entitySetAttribute != null) return entitySetAttribute.EntitySet; return null; } public T Create<T>() where T : new() { var collection = new DataServiceCollection<T>(this.context); var entity = new T(); collection.Add(entity); return entity; } public void Update<T>(T entity) { this.context.UpdateObject(entity); } public void Delete<T>(T entity) { this.context.DeleteObject(entity); } public void Attach<T>(T entity) { var collection = new DataServiceCollection<T>(this.context); collection.Load(entity); } public IQueryable<T> Retrieve<T>(Expression<Func<T, bool>> predicate, params Expression<Func<T, object>>[] eagerProperties) { var entitySet = ResolveEntitySet(typeof(T)); var query = context.CreateQuery<T>(entitySet); foreach (var e in eagerProperties) { query = query.Expand(e); } return query.Where(predicate); } public IQueryable<T> RetrieveAll<T>(params Expression<Func<T, object>>[] eagerProperties) { var entitySet = ResolveEntitySet(typeof(T)); var query = context.CreateQuery<T>(entitySet); foreach (var e in eagerProperties) { query = query.Expand(e); } return query; } public void SaveChanges() { this.context.SaveChanges(SaveChangesOptions.Batch); } } For instance, you can use the following code to retrieve customers with First name equal to “John”, and all their orders in a single call. repository.Retrieve<Customer>(    c => c.FirstName == “John”, //Where    c => c.Orders.SubExpand(o => o.Items)); In case, you want to have some pre-defined queries that you are going to use across several places, you can put them in an specific class. public static class CustomerQueries {   public static Expression<Func<Customer, bool>> LastNameEqualsTo(string lastName)   {     return c => c.LastName == lastName;   } } And then, use it with the repository. repository.Retrieve<Customer>(    CustomerQueries.LastNameEqualsTo("foo"),    c => c.Orders.SubExpand(o => o.Items));

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  • 2 way SSL between SOA and OSB

    - by Johnny Shum
    If you have a need to use 2 way SSL between SOA composite and external partner links, you can follow these steps. Create the identity keystores, trust keystores, and server certificates. Setup keystores and SSL on WebLogic Setup server to use 2 way SSL Configure your SOA composite's partner link to use 2 way SSL Configure SOA engine two ways SSL In this case,  I use SOA and OSB for the test.  I started with a separate OSB and SOA domains.  I deployed two soap based proxies on OSB and two composites on SOA.  In SOA, one composite invokes a OSB proxy service, the other is invoked by the OSB.  Similarly,  in OSB,  one proxy invokes a SOA composite and the other is invoked by SOA. 1. Create the identity keystores, trust keystores and the server certificates Since this is a development environment, I use JDK's keytool to create the stores and use self signing certificate.  For production environment, you should use certificates from a trusted certificate authority like Verisign.    I created a script below to show what is needed in this step.  The only requirement is when creating the SOA identity certificate, you MUST use the alias mykey. STOREPASS=welcome1KEYPASS=welcome1# generate identity keystore for soa and osb.  Note: For SOA, you MUST use alias mykeyecho "creating stores"keytool -genkey -alias mykey -keyalg "RSA" -sigalg "SHA1withRSA" -dname "CN=soa, C=US" -keystore soa-default-keystore.jks -storepass $STOREPASS -keypass $KEYPASS keytool -genkey -alias osbkey -keyalg "RSA" -sigalg "SHA1withRSA" -dname "CN=osb, C=US" -keystore osb-default-keystore.jks -storepass $STOREPASS -keypass $KEYPASS# listing keystore contentsecho "listing stores contents"keytool -list -alias mykey -keystore soa-default-keystore.jks -storepass $STOREPASSkeytool -list -alias osbkey -keystore osb-default-keystore.jks -storepass $STOREPASS# exporting certs from storesecho "export certs from  stores"keytool -exportcert -alias mykey -keystore soa-default-keystore.jks -storepass $STOREPASS -file soacert.derkeytool -exportcert -alias osbkey -keystore osb-default-keystore.jks -storepass $STOREPASS -file osbcert.der # import certs to trust storesecho "import certs"keytool -importcert -alias osbkey -keystore soa-trust-keystore.jks -storepass $STOREPASS -file osbcert.der -keypass $KEYPASSkeytool -importcert -alias mykey -keystore osb-trust-keystore.jks -storepass $STOREPASS -file soacert.der  -keypass $KEYPASS SOA suite uses the JDK's SSL implementation for outbound traffic instead of the WebLogic's implementation.  You will need to import the partner's public cert into the trusted keystore used by SOA.  The default trusted keystore for SOA is DemoTrust.jks and it is located in $MW_HOME/wlserver_10.3/server/lib.   (This is set in the startup script -Djavax.net.ssl.trustStore).   If you use your own trusted keystore, then you will need to import it into your own trusted keystore. keytool -importcert -alias osbkey -keystore $MW_HOME/wlserver_10.3/server/lib/DemoTrust.jks -storepass DemoTrustKeyStorePassPhrase  -file osbcert.der -keypass $KEYPASS If you do not perform this step, you will encounter this exception in runtime when SOA invokes OSB service using 2 way SSL Message send failed: sun.security.validator.ValidatorException: PKIX path building failed: sun.security.provider.certpath.SunCertPathBuilderException: unable to find valid certification path to requested target  2.  Setup keystores and SSL on WebLogic First, you will need to login to the WebLogic console, navigate to the server's configuration->Keystore's tab.   Change the Keystores type to Custom Identity and Custom Trust and enter the rest of the fields. Then you navigate to the SSL tab, enter the fields in the identity section and expand the Advanced section.  Since I am using self signing cert on my VM enviornment, I disabled Hostname verification.  In real production system, this should not be the case.   I also enabled the option "Use Server Certs", so that the application uses the server cert to initiate https traffic (it is important to enable this in OSB). Last, you enable SSL listening port in the Server's configuration->General tab. 3.  Setup server to use 2 way SSL If you follow the screen shot in previous step, you can see in the Server->Configuration->SSL->Advanced section, there is an option for Two Way Client Cert Behavior,  you should set this to Client Certs Requested and Enforced. Repeat step 2 and 3 done on OSB.  After all these configurations,  you have to restart all the servers. 4.  Configure your SOA composite's partner link to use 2 way SSL You do this by modifying the composite.xml in your project, locate the partner's link reference and add the property oracle.soa.two.way.ssl.enabled.   <reference name="callosb" ui:wsdlLocation="helloword.wsdl">    <interface.wsdl interface="http://www.examples.com/wsdl/HelloService.wsdl#wsdl.interface(Hello_PortType)"/>    <binding.ws port="http://www.examples.com/wsdl/HelloService.wsdl#wsdl.endpoint(Hello_Service/Hello_Port)"                location="helloword.wsdl" soapVersion="1.1">      <property name="weblogic.wsee.wsat.transaction.flowOption"                type="xs:string" many="false">WSDLDriven</property>   <property name="oracle.soa.two.way.ssl.enabled">true</property>    </binding.ws>  </reference> In OSB, you should have checked the HTTPS required flag in the proxy's transport configuration.  After this,  rebuilt the composite jar file and ready to deploy in the EM console later. 5.  Configure SOA engine two ways SSL Oracle SOA Suite uses both Oracle WebLogic Server and Sun Secure Socket Layer (SSL) stacks for two-way SSL configurations. For the inbound web service bindings, Oracle SOA Suite uses the Oracle WebLogic Server infrastructure and, therefore, the Oracle WebLogic Server libraries for SSL.  This is already done by step 2 and 3 in the previous section. For the outbound web service bindings, Oracle SOA Suite uses JRF HttpClient and, therefore, the Sun JDK libraries for SSL.  You do this by configuring the SOA Engine in the Enterprise Manager Console, select soa-infra->SOA Administration->Common Properties Then click at the link at the bottom of the page:  "More SOA Infra Advances Infrastructure Configuration Properties" and then enter the full path of soa identity keystore in the value field of the KeyStoreLocation attribute.  Click Apply and Return then navigate to the domain->security->credential. Here, you provide the password to the keystore.  Note: the alias of the certficate must be mykey as described in step 1, so you only need to provide the password to the identity keystore.   You accomplish this by: Click Create Map In the Map Name field, enter SOA, and click OK Click Create Key Enter the following details where the password is the password for the SOA identity keystore. 6.  Test and Trouble Shooting Once the setup is complete and server restarted, you can deploy the composite in the EM console and test it.  In case of error,  you can read the server log file to determine the cause of the error.  For example, If you have not setup step 5 and test 2 way SSL, you will see this in the log when invoking OSB from BPEL: java.lang.Exception: oracle.sysman.emSDK.webservices.wsdlapi.SoapTestException: oracle.fabric.common.FabricInvocationException: Unable to access the following endpoint(s): https://localhost.localdomain:7002/default/helloword ####<Sep 22, 2012 2:07:37 PM CDT> <Error> <oracle.soa.bpel.engine.ws> <rhel55> <AdminServer> <[ACTIVE] ExecuteThread: '1' for queue: 'weblogic.kernel.Default (self-tuning)'> <<anonymous>> <BEA1-0AFDAEF20610F8FD89C5> ............ <11d1def534ea1be0:-4034173:139ef56d9f0:-8000-00000000000002ec> <1348340857956> <BEA-000000> <got FabricInvocationException sun.security.provider.certpath.SunCertPathBuilderException: unable to find valid certification path to requested target If you have not enable WebLogic SSL to use server certificate in the console and invoke SOA composite from OSB using two ways SSL, you will see this error: ####<Sep 22, 2012 2:07:37 PM CDT> <Warning> <Security> <rhel55> <AdminServer> <[ACTIVE] ExecuteThread: '6' for queue: 'weblogic.kernel.Default (self-tuning)'> <<WLS Kernel>> <> <11d1def534ea1be0:-51f5c76a:139ef5e1e1a:-8000-00000000000000e2> <1348340857776> <BEA-090485> <CERTIFICATE_UNKNOWN alert was received from localhost.localdomain - 127.0.0.1. The peer has an unspecified issue with the certificate. SSL debug tracing should be enabled on the peer to determine what the issue is.> ####<Sep 22, 2012 2:07:37 PM CDT> <Warning> <Security> <rhel55> <AdminServer> <[ACTIVE] ExecuteThread: '6' for queue: 'weblogic.kernel.Default (self-tuning)'> <<WLS Kernel>> <> <11d1def534ea1be0:-51f5c76a:139ef5e1e1a:-8000-00000000000000e4> <1348340857786> <BEA-090485> <CERTIFICATE_UNKNOWN alert was received from localhost.localdomain - 127.0.0.1. The peer has an unspecified issue with the certificate. SSL debug tracing should be enabled on the peer to determine what the issue is.> ####<Sep 22, 2012 2:27:21 PM CDT> <Warning> <Security> <rhel55> <AdminServer> <[ACTIVE] ExecuteThread: '0' for queue: 'weblogic.kernel.Default (self-tuning)'> <<anonymous>> <> <11d1def534ea1be0:-51f5c76a:139ef5e1e1a:-8000-0000000000000124> <1348342041926> <BEA-090497> <HANDSHAKE_FAILURE alert received from localhost - 127.0.0.1. Check both sides of the SSL configuration for mismatches in supported ciphers, supported protocol versions, trusted CAs, and hostname verification settings.> References http://docs.oracle.com/cd/E23943_01/admin.1111/e10226/soacompapp_secure.htm#CHDCFABB   Section 5.6.4 http://docs.oracle.com/cd/E23943_01/web.1111/e13707/ssl.htm#i1200848

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