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  • Ruby on Rails user login form in main layout

    - by Jimmy
    Hey guys I have a simple ror application for some demo stuff. I am running into a problem with trying to move my login form from the users controller and just have it displayed in the main navigation so that a user can easily log in from anywhere. The problem is the form doesn't generate the correct action for the html form. Ruby code: <% form_for(url_for(:action => 'login'), :method => 'post') do |f| %> <li><%= f.text_field("username") %></li> <li><%= f.password_field("password") %></li> <li><%= submit_tag("Login")%></li> <% end %> The problem is depending on the controller I am currently in this generates HTML actions like <form action="/home" method="post">...</form> when it should be generating HTML like so <form action="/login" method="post">...</form> I know I could simply do an HTML form here but I want to keep things as easy to maintain as possible. Any help?

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  • this is my first time asking here, I wanted to create a linked list while sorting it thanks

    - by user2738718
    package practise; public class Node { // node contains data and next public int data; public Node next; //constructor public Node (int data, Node next){ this.data = data; this.next = next; } //list insert method public void insert(Node list, int s){ //case 1 if only one element in the list if(list.next == null && list.data > s) { Node T = new Node(s,list); } else if(list.next == null && list.data < s) { Node T = new Node(s,null); list.next = T; } //case 2 if more than 1 element in the list // 3 elements present I set prev to null and curr to list then performed while loop if(list.next.next != null) { Node curr = list; Node prev = null; while(curr != null) { prev = curr; curr = curr.next; if(curr.data > s && prev.data < s){ Node T = new Node(s,curr); prev.next = T; } } // case 3 at the end checks for the data if(prev.data < s){ Node T = new Node(s,null); prev.next = T; } } } } // this is a hw problem, i created the insert method so i can check and place it in the correct order so my list is sorted This is how far I got, please correct me if I am wrong, I keep inserting node in the main method, Node root = new Node(); and root.insert() to add.

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  • FluentNHibernate: Not.Nullable() doesn't affect output schema

    - by alex
    Hello I'm using fluent nhibernate v. 1.0.0.595. There is a class: public class Weight { public virtual int Id { get; set; } public virtual double Value { get; set; } } I want to map it on the following table: create table [Weight] ( WeightId INT IDENTITY NOT NULL, Weight DOUBLE not null, primary key (WeightId) ) Here is the map: public class WeightMap : ClassMap<Weight> { public WeightMap() { Table("[Weight]"); Id(x => x.Id, "WeightId"); Map(x => x.Value, "Weight").Not.Nullable(); } } The problem is that this mapping produces table with nullable Weight column: Weight DOUBLE null Not-nullable column is generated only with default convention for column name (i.e. Map(x = x.Value).Not.Nullable() instead of Map(x = x.Value, "Weight").Not.Nullable()), but in this case there will be Value column instead of Weight: create table [Weight] ( WeightId INT IDENTITY NOT NULL, Value DOUBLE not null, primary key (WeightId) ) I found similiar problem here: http://code.google.com/p/fluent-nhibernate/issues/detail?id=121, but seems like mentioned workaround with SetAttributeOnColumnElement("not-null", "true") is outdated. Does anybody encountered with this problem? Is there a way to specify named column as not-nullable?

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  • Problem with inner classes of the same name in Visual C++

    - by starblue
    I have a problem with Visual C++, where apparently inner classes with the same name but in different outer classes are confused. The problem occurs for two layers, where each layer has a listener interface as an inner class. B is a listener of A, and has its own listener in a third layer above it (not shown). The structure of the code looks like this: A.h class A { class Listener { Listener(); virtual ~Listener() = 0; } [...] } B.h class B : public A::Listener { class Listener { Listener(); virtual ~Listener() = 0; } [...] } B.cpp B::Listener::Listener() {} B::Listener::~Listener() {} I get the error B.cpp(49) : error C2509: '{ctor}' : member function not declared in 'B' The C++ compiler for Renesas sh2a has no problem with this, but then it is more liberal than Visual C++ in some other respects, too. If I rename the listener interfaces to have different names the problem goes away, but I'd like to avoid that (the real class names instead of A or B are rather long). Is what I'm doing correct C++, or is the complaint by Visual C++ justified? Is there a way to work around this problem without renaming the listener interfaces?

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  • Hibernate Transient Extends problem

    - by mrvreddy
    @MappedSuperclass public abstract class BaseAbstract implements Serializable{ private static final long serialVersionUID = 1L; protected String test = //some random value; public String getTest() { return test; } public void setTest(String test){ this.test = test; } } @Entity public class Artist extends BaseAbstract { private static final long serialVersionUID = 1L; private Integer id; @override @Transient public String getTest() { return test; } ..... } My question is... when i am trying to do any operation on the artist, along with id and name, test is also getting saved which should not be the case... if i add the same transient on the baseabstract class getTest() method, i see test column NOT getting created(ideally what it should happen) but if i try to override the method with adding annotaion in the sub class it creates the test column... I dont know why this is happening since when hibernate is creating the artist object and checks for annotations, it should see the transient annotation present on the getTest() of artist method...and should not create a column in the database... Let me know if you need any clarification.... Any response on this is greatly appreciated.... Thank you

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  • How to process events chain.

    - by theblackcascade
    I need to process this chain using one LoadXML method and one urlLoader object: ResourceLoader.Instance.LoadXML("Config.xml"); ResourceLoader.Instance.LoadXML("GraphicsSet.xml"); Loader starts loading after first frameFunc iteration (why?) I want it to start immediatly.(optional) And it starts loading only "GraphicsSet.xml" Loader class LoadXml method: public function LoadXML(URL:String):XML { urlLoader.addEventListener(Event.COMPLETE,XmlLoadCompleteListener); urlLoader.load(new URLRequest(URL)); return xml; } private function XmlLoadCompleteListener(e:Event):void { var xml:XML = new XML(e.target.data); trace(xml); trace(xml.name()); if(xml.name() == "Config") XMLParser.Instance.GameSetup(xml); else if(xml.name() == "GraphicsSet") XMLParser.Instance.GraphicsPoolSetup(xml); } Here is main: public function Main() { Mouse.hide(); this.addChild(Game.Instance); this.addEventListener(Event.ENTER_FRAME,Game.Instance.Loop); } And on adding a Game.Instance to the rendering queue in game constuctor i start initialize method: public function Game():void { trace("Constructor"); if(_instance) throw new Error("Use Instance Field"); Initialize(); } its code is: private function Initialize():void { trace("initialization"); ResourceLoader.Instance.LoadXML("Config.xml"); ResourceLoader.Instance.LoadXML("GraphicsSet.xml"); } Thanks.

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  • How to add a gwt widget to a gwt Composite already visible at runtime using MVP?

    - by mary4pfc
    Hi! I'm building an application whose menus depend on user roles. Once user is logged in and, therefore, her roles are known, I want to create the Hyperlinks related to the user and add them to the menu. I'm using MVP. Here's my code for the presenter: public class AdminMenuAreaPresenter extends WidgetPresenter<AdminMenuAreaPresenter.Display> { public interface Display extends WidgetDisplay{ public void addLink(String link); } private DispatchAsync dispatcher; private SessionManager sessionManager; @Inject public AdminMenuAreaPresenter(AdminMenuAreaPresenter.Display display, EventBus bus, DispatchAsync dispatcher, SessionManager sessionManager){ super(display, bus); this.dispatcher = dispatcher; this.sessionManager = sessionManager; this.bind(); } @Override protected void onBind() { super.onBind(); registerHandler(eventBus.addHandler(LoginEvent.TYPE, new LoginEventHandler() { @Override public void onLogin(LoginEvent event) { display.addLink("register user"); } })); } @Override protected void onUnbind() { // TODO Auto-generated method stub } @Override protected void onRevealDisplay() { // TODO Auto-generated method stub } } And here's the View: public class AdminMenuAreaView extends Composite implements AdminMenuAreaPresenter.Display{ private VerticalPanel vPanel; private Hyperlink registerUserLink; public AdminMenuAreaView(){ vPanel = new VerticalPanel(); initWidget(vPanel); } @Override public Widget asWidget() { return this; } public void addLink(String s){ registerUserLink = new Hyperlink(s, "this is new target"); this.vPanel.add(registerUserLink); registerUserLink.setVisible(true); } public HasClickHandlers getRegisterUserLink(){ return registerUserLink; } What am I doing wrong? Flow program goes throgh the addLink() method, but nothing is added to the view either dom document. Thank you.

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  • Multiple leaf methods problem in composite pattern

    - by Ondrej Slinták
    At work, we are developing an PHP application that would be later re-programmed into Java. With some basic knowledge of Java, we are trying to design everything to be easily re-written, without any headaches. Interesting problem came out when we tried to implement composite pattern with huge number of methods in leafs. What are we trying to achieve (not using interfaces, it's just an example): class Composite { ... } class LeafOne { public function Foo( ); public function Moo( ); } class LeafTwo { public function Bar( ); public function Baz( ); } $c = new Composite( Array( new LeafOne( ), new LeafTwo( ) ) ); // will call method Foo in all classes in composite that contain this method $c->Foo( ); It seems like pretty much classic Composite pattern, but problem is that we will have quite many leaf classes and each of them might have ~5 methods (of which few might be different than others). One of our solutions, which seems to be the best one so far and might actually work, is using __call magic method to call methods in leafs. Unfortunately, we don't know if there is an equivalent of it in Java. So the actual question is: Is there a better solution for this, using code that would be eventually easily re-coded into Java? Or do you recommend any other solution? Perhaps there's some different, better pattern I could use here. In case there's something unclear, just ask and I'll edit this post.

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  • java , eclipse jar problem

    - by Raxvan
    Hello , i'm kind of new to java. I use eclipse and i imported some jar files with some classes by going to properties - Add External Jars; The problem is that when i try to use a class from the jar i get the following exception: Exception in thread "main" java.lang.NoClassDefFoundError: nextapp/echo2/app/event/ActionListener at java.lang.ClassLoader.defineClass1(Native Method) at java.lang.ClassLoader.defineClass(Unknown Source) at java.security.SecureClassLoader.defineClass(Unknown Source) at java.net.URLClassLoader.defineClass(Unknown Source) at java.net.URLClassLoader.access$000(Unknown Source) at java.net.URLClassLoader$1.run(Unknown Source) at java.security.AccessController.doPrivileged(Native Method) at java.net.URLClassLoader.findClass(Unknown Source) at java.lang.ClassLoader.loadClass(Unknown Source) at sun.misc.Launcher$AppClassLoader.loadClass(Unknown Source) at java.lang.ClassLoader.loadClass(Unknown Source) at java.lang.ClassLoader.loadClassInternal(Unknown Source) at Program.main(Program.java:12) Caused by: java.lang.ClassNotFoundException: nextapp.echo2.app.event.ActionListener at java.net.URLClassLoader$1.run(Unknown Source) at java.security.AccessController.doPrivileged(Native Method) at java.net.URLClassLoader.findClass(Unknown Source) at java.lang.ClassLoader.loadClass(Unknown Source) at sun.misc.Launcher$AppClassLoader.loadClass(Unknown Source) at java.lang.ClassLoader.loadClass(Unknown Source) at java.lang.ClassLoader.loadClassInternal(Unknown Source) ... 13 more The class is supposed to create a window, i guess that the jar has to import somehow other stuff or something like that, How can i fix this? PS. Sorry for the bad code , i don't know tags here. thansk, Raxvan

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  • google maps api keys to be set webserver-wide, (as env var? inside apache?)

    - by ~knb
    I have a web site with many virtual hosts and each registered with several domain names (ending in .org, .de), site1.mysite.de, site2.mysite.org Then I have different templating systems based on several programming languages (perl and php) in use on the web server. The Google Maps Api requires a unique Google Maps api key for each vhost. I want to have something like a web-server wide variable $goomapkey that I can call from inside my code. In PHP code, Now I have a kludgy case-analysis solution like $domain = substr($_SERVER['SERVER_NAME'], -3); if (".de" == $domain){ //if ("xxxxxx" eq substr($ENV{SERVER_NAME}, 0, 5)){ // $gookey = "ABQIAAA..."; //} else { //site1.de $gookey = "ABQIAAAA1Js..."; //} } elseif ("dev" == substr($_SERVER['SERVER_NAME'], 0, 3)){ //dev.mysite.org $gookey = "ABQIAAAA1JsSb..."; } else { //www.mysite.org $gookey = "ABQIAAAA1JsS..."; //TODO: Add more keys for each virtual host, for my.machinename.de, IP-address based URL, ... } ... inside my php-based CMS. A non-ideal solution, because it is, php-only, and I still have to set it at several html templates inside the CMS, and there are too many cases. I want the google maps api key to be set by the apache web server who examines the request *early in the request loop before any php page template code is constructed and evaluated. is an environment variable a good solution? which technology should be used to set the $goomapkey variable? I'd prefer mod_perl2 Apache request handler, but the documentation is confusing (many API changes in the past ). Which Apache module could I use? Is there a built-in Apache module that does the same thing?

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  • Can a custom MFC window/dialog be a class template instantiation?

    - by John
    There's a bunch of special macros that MFC uses when creating dialogs, and in my quick tests I'm getting weird errors trying to compile a template dialog class. Is this likely to be a big pain to achieve? Here's what I tried: MyDlg.h template <class W> class CMyDlg : public CDialog { typedef CDialog super; DECLARE_DYNAMIC(CMyDlg <W>) public: CMyDlg (CWnd* pParent); // standard constructor virtual ~CMyDlg (); // Dialog Data enum { IDD = IDD_MYDLG }; protected: virtual void DoDataExchange(CDataExchange* pDX); // DDX/DDV support DECLARE_MESSAGE_MAP() private: W *m_pWidget; //W will always be a CDialog }; IMPLEMENT_DYNAMIC(CMyDlg<W>, super) <------------------- template <class W> CMyDlg<W>::CMyDlg(CWnd* pParent) : super(CMyDlg::IDD, pParent) { m_pWidget = new W(this); } I get a whole bunch of errors but main one appears to be: error C2955: 'CMyDlg' : use of class template requires template argument list I tried using some specialised template versions of macros but it doesn't help much, other errors change but this one remains. Note my code is all in one file, since C++ templates don't like .h/.cpp like normal. I'm assuming someone must have done this in the past, possibly creating custom versions of macros, but I can't find it by searching, since 'template' has other meanings.

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  • Why doesn't my UIViewController class keep track of an NSArray instance variable.

    - by TaoStoner
    Hey, I am new to Objective-C 2.0 and Xcode, so forgive me if I am missing something elementary here. Anyways, I am trying to make my own UIViewController class called GameView to display a new view. To work the game I need to keep track of an NSArray that I want to load from a plist file. I have made a method 'loadGame' which I want to load the correct NSArray into an instance variable. However it appears that after the method executes the instance variable loses track of the array. Its easier if I just show you the code.... @interface GameView : UIViewController { IBOutlet UIView *view IBOutlet UILabel *label; NSArray *currentGame; } -(IBOutlet)next; -(void)loadDefault; ... @implementation GameView - (IBOutlet)next{ int numElements = [currentGame count]; int r = rand() % numElements; NSString *myString = [currentGame objectAtIndex:(NSUInteger)r]; [label setText: myString]; } - (void)loadDefault { NSDictionary *games; NSString *path = [[NSBundle mainBundle] bundlePath]; NSString *finalPath = [path stringByAppendingPathComponent:@"Games.plist"]; games = [NSDictionary dictionaryWithContentsOfFile:finalPath]; currentGame = [games objectForKey:@"Default"]; } when loadDefault gets called, everything runs perfectly, but when I try to use the currentGame NSArray later in the method call to next, currentGame appears to be nil. I am also aware of the memory management issues with this code. Any help would be appreciated with this problem.

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  • Implementing client callback functionality in WCF

    - by PoweredByOrange
    The project I'm working on is a client-server application with all services written in WCF and the client in WPF. There are cases where the server needs to push information to the client. I initially though about using WCF Duplex Services, but after doing some research online, I figured a lot of people are avoiding it for many reasons. The next thing I thought about was having the client create a host connection, so that the server could use that to make a service call to the client. The problem however, is that the application is deployed over the internet, so that approach requires configuring the firewall to allow incoming traffic and since most of the users are regular users, that might also require configuring the router to allow port forwarding, which again is a hassle for the user. My third option is that in the client, spawns a background thread which makes a call to the GetNotifications() method on server. This method on the server side then, blocks until an actual notification is created, then the thread is notified (using an AutoResetEvent object maybe?) and the information gets sent to the client. The idea is something like this: Client private void InitializeListener() { Task.Factory.StartNew(() => { while (true) { var notification = server.GetNotifications(); // Display the notification. } }, CancellationToken.None, TaskCreationOptions.LongRunning, TaskScheduler.Default); } Server public NotificationObject GetNotifications() { while (true) { notificationEvent.WaitOne(); return someNotificationObject; } } private void NotificationCreated() { // Inform the client of this event. notificationEvent.Set(); } In this case, NotificationCreated() is a callback method called when the server needs to send information to the client. What do you think about this approach? Is this scalable at all?

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  • C++ socket protocol design issue (ring inclusion)

    - by Martin Lauridsen
    So I have these two classes, mpqs_client and client_protocol. The mpqs_client class handles a Boost socket connection to a server (sending and receiving messages with some specific format. Upon receiving a message, it calls a static method, parse_message(..), in the class client_protocol, and this method should analyse the message received and perform some corresponding action. Given some specific input, the parse_message method needs to send some data back to the server. As mentioned, this happens through the class mpqs_client. So I could, from mpqs_client, pass "this" to parse_message(..) in client_protocol. However, this leads to a two-way association relationship between the two classes. Something which I reckon is not desireable. Also, to implement this, I would need to include the other in each one, and this gives me a terrible pain. I am thinking this is more of a design issue. What is the best solution here? Code is posted below. Class mpqs_client: #include "mpqs_client.h" mpqs_client::mpqs_client(boost::asio::io_service& io_service, tcp::resolver::iterator endpoint_iterator) : io_service_(io_service), socket_(io_service) { ... } ... void mpqs_client::write(const network_message& msg) { io_service_.post(boost::bind(&mpqs_client::do_write, this, msg)); } Class client_protocol: #include "../network_message.hpp" #include "../protocol_consts.h" class client_protocol { public: static void parse_message(network_message& msg, mpqs_sieve **instance_, mpqs_client &client_) { ... switch (type) { case MPQS_DATA: ... break; case POLYNOMIAL_DATA: ... break; default: break; } }

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  • Recommendations for IPC between parent and child processes in .NET?

    - by Jeremy
    My .NET program needs to run an algorithm that makes heavy use of 3rd party libraries (32-bit), most of which are unmanaged code. I want to drive the CPU as hard as I can, so the code runs several threads in parallel to divide up the work. I find that running all these threads simultaneously results in temporary memory spikes, causing the process' virtual memory size to approach the 2 GB limit. This memory is released back pretty quickly, but occasionally if enough threads enter the wrong sections of code at once, the process crosses the "red line" and either the unmanaged code or the .NET code encounters an out of memory error. I can throttle back the number of threads but then my CPU usage is not as high as I would like. I am thinking of creating worker processes rather than worker threads to help avoid the out of memory errors, since doing so would give each thread of execution its own 2 GB of virtual address space (my box has lots of RAM). I am wondering what are the best/easiest methods to communicate the input and output between the processes in .NET? The file system is an obvious choice. I am used to shared memory, named pipes, and such from my UNIX background. Is there a Windows or .NET specific mechanism I should use?

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  • MS Exam 70-536 - How to throw and handle exception from thread?

    - by Max Gontar
    Hello! In MS Exam 70-536 .Net Foundation, Chapter 7 "Threading" in Lesson 1 Creating Threads there is a text: Be aware that because the WorkWithParameter method takes an object, Thread.Start could be called with any object instead of the string it expects. Being careful in choosing your starting method for a thread to deal with unknown types is crucial to good threading code. Instead of blindly casting the method parameter into our string, it is a better practice to test the type of the object, as shown in the following example: ' VB Dim info As String = o as String If info Is Nothing Then Throw InvalidProgramException("Parameter for thread must be a string") End If // C# string info = o as string; if (info == null) { throw InvalidProgramException("Parameter for thread must be a string"); } So, I've tried this but exception is not handled properly (no console exception entry, program is terminated), what is wrong with my code (below)? class Program { static void Main(string[] args) { Thread thread = new Thread(SomeWork); try { thread.Start(null); thread.Join(); } catch (InvalidProgramException ex) { Console.WriteLine(ex.Message); } finally { Console.ReadKey(); } } private static void SomeWork(Object o) { String value = (String)o; if (value == null) { throw new InvalidProgramException("Parameter for "+ "thread must be a string"); } } } Thanks for your time!

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  • How to structure this Symfony web project?

    - by James William
    I am new to Symfony and am not sure how to best structure my web project. The solution must accommodate 3 use cases: Public access to www.mydomain.com for general use Member only access to member.mydomain.com Administrator access to admin.mydomain.com All three virtual hosts point to the Symfony /web directory Questions: Is this 3 separate applications in my Symfony project (e.g. "frontend", "backend" and "admin" or "public", "member", "admin")? Is this a good approach if there is to be some duplicate code (e.g. generating a member list would be common across all 3 applications, but presented differently)? How would I route to the various applications based on the subdomain when a user accesses *.mydomain.com? Where in Symfony should this routing logic be placed? Or, is this one application with modules for each of the above use cases? EDIT: I do not have access to httpd.conf in apache to specify a default page for virtual hosts. I can only specify a directory for each subdomain using the hostin provider's cPanel.

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  • In Emacs, how can I use imenu more sensibly with C#?

    - by Cheeso
    I've used emacs for a long time, but I haven't been keeping up with a bunch of features. One of these is speedbar, which I just briefly investigated now. Another is imenu. Both of these were mentioned in in-emacs-how-can-i-jump-between-functions-in-the-current-file? Using imenu, I can jump to particular methods in the module I'm working in. But there is a parse hierarchy that I have to negotiate before I get the option to choose (with autocomplete) the method name. It goes like this. I type M-x imenu and then I get to choose Using or Types. The Using choice allows me to jump to any of the using statements at the top level of the C# file (something like imports statements in a Java module, for those of you who don't know C#). Not super helpful. I choose Types. Then I have to choose a namespace and a class, even though there is just one of each in the source module. At that point I can choose between variables, types, and methods. If I choose methods I finally get the list of methods to choose from. The hierarchy I traverse looks like this; Using Types Namespace Class Types Variables Methods method names Only after I get to the 5th level do I get to select the thing I really want to jump to: a particular method. Imenu seems intelligent about the source module, but kind of hard to use. Am I doing it wrong?

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  • How do I break down an NSTimeInterval into year, months, days, hours, minutes and seconds on iPhone?

    - by willc2
    I have a time interval that spans years and I want all the time components from year down to seconds. My first thought is to integer divide the time interval by seconds in a year, subtract that from a running total of seconds, divide that by seconds in a month, subtract that from the running total and so on. That just seems convoluted and I've read that whenever you are doing something that looks convoluted, there is probably a built-in method. Is there? I integrated Alex's 2nd method into my code. It's in a method called by a UIDatePicker in my interface. NSDate *now = [NSDate date]; NSDate *then = self.datePicker.date; NSTimeInterval howLong = [now timeIntervalSinceDate:then]; NSDate *date = [NSDate dateWithTimeIntervalSince1970:howLong]; NSString *dateStr = [date description]; const char *dateStrPtr = [dateStr UTF8String]; int year, month, day, hour, minute, sec; sscanf(dateStrPtr, "%d-%d-%d %d:%d:%d", &year, &month, &day, &hour, &minute, &sec); year -= 1970; NSLog(@"%d years\n%d months\n%d days\n%d hours\n%d minutes\n%d seconds", year, month, day, hour, minute, sec); When I set the date picker to a date 1 year and 1 day in the past, I get: 1 years 1 months 1 days 16 hours 0 minutes 20 seconds which is 1 month and 16 hours off. If I set the date picker to 1 day in the past, I am off by the same amount. Update: I have an app that calculates your age in years, given your birthday (set from a UIDatePicker), yet it was often off. This proves there was an inaccuracy, but I can't figure out where it comes from, can you?

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  • Getting functions of inherited functions to be called

    - by wrongusername
    Let's say I have a base class Animal from which a class Cow inherits, and a Barn class containing an Animal vector, and let's say the Animal class has a virtual function scream(), which Cow overrides. With the following code: Animal.h #ifndef _ANIMAL_H #define _ANIMAL_H #include <iostream> using namespace std; class Animal { public: Animal() {}; virtual void scream() {cout << "aaaAAAAAAAAAAGHHHHHHHHHH!!! ahhh..." << endl;} }; #endif /* _ANIMAL_H */ Cow.h #ifndef _COW_H #define _COW_H #include "Animal.h" class Cow: public Animal { public: Cow() {} void scream() {cout << "MOOooooOOOOOOOO!!!" << endl;} }; #endif /* _COW_H */ Barn.h #ifndef _BARN_H #define _BARN_H #include "Animal.h" #include <vector> class Barn { std::vector<Animal> animals; public: Barn() {} void insertAnimal(Animal animal) {animals.push_back(animal);} void tortureAnimals() { for(int a = 0; a < animals.size(); a++) animals[a].scream(); } }; #endif /* _BARN_H */ and finally main.cpp #include <stdlib.h> #include "Barn.h" #include "Cow.h" #include "Chicken.h" /* * */ int main(int argc, char** argv) { Barn barn; barn.insertAnimal(Cow()); barn.tortureAnimals(); return (EXIT_SUCCESS); } I get this output: aaaAAAAAAAAAAGHHHHHHHHHH!!! ahhh... How should I code this to get MOOooooOOOOOOOO!!! (and whatever other classes inheriting Animal wants scream() to be) instead?

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  • Transfering a set with a Wildcarded Generic to a List in Java

    - by Daniel Bingham
    I have a data type that contains a set and a method that expects List<? extends MyClass>. The data type has Set<? extends MyClass>. I need to be able to move the stuff out of the set and into the List. The order it goes into the list doesn't matter, it just needs to start keeping track of it so that it can be reordered when displayed. Suffice to say that changing the Set into a List in the data type is out of the question here. This seems pretty easy at first. Create a new method that takes a Set instead of a List, changes it into a list and then passes it on to the old method that just took a list. The problem comes in changing the set to a list. public void setData(Set<? extends MyClass> data) { List<? extends Myclass> newData = ArrayList< /* What goes here? */ >(); for(ConcordaEntityBean o : data) { newData.add(o); } setData(newData); } Obviously, I can't instantiate an ArrayList with a wildcard, it chokes. I don't know the type at that point. Is there some way to pull the type out of data and pass it to ArrayList? Can I just instantiate it with MyClass? Is there some other way to do this?

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  • EF4 + STE: Reattaching via a WCF Service? Using a new objectcontext each and every time?

    - by Martin
    Hi there, I am planning to use WCF (not ria) in conjunction with Entity Framework 4 and STE (Self tracking entitites). If i understnad this correctly my WCF should return an entity or collection of entities (using LIST for example and not IQueryable) to the client (in my case silverlight) The client then can change the entity or update it. At this point i believe it is self tracking???? This is where i sort of get a bit confused as there are a lot of reported problems with STEs not tracking.. Anyway... Then to update i just need to send back the entity to my WCF service on another method to do the update. I should be creating a new OBJECTCONTEXT everytime? In every method? If i am creaitng a new objectcontext everytime in everymethod on my WCF then don't i need to re-attach the STE to the objectcontext? So basically this alone wouldn't work?? using(var ctx = new MyContext()) { ctx.Orders.ApplyChanges(order); ctx.SaveChanges(); } Or should i be creating the object context once in the constructor of the WCF service so that 1 call and every additional call using the same wcf instance uses the same objectcontext? I could create and destroy the wcf service in each method call from the client - hence creating in effect a new objectcontext each time. I understand that it isn't a good idea to keep the objectcontext alive for very long. Any insight or information would be gratefully appreciated thanks

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  • How to run a long task in backgroung in iOS applications?

    - by John Canady
    I am developing an application which requires running a task in background. I am trying this by calling a method which will retrieve(download) data from web server through web services. this method will call some more methods which are in different view controller classes. Here when I tap on home button of device, the method is calling but no further execution of the remaining code. This is the code I have written in (void)applicationDidEnterBackground:(UIApplication )application { UIApplication app = [UIApplication sharedApplication]; UIBackgroundTaskIdentifier bgTask = 0; bgTask = [app beginBackgroundTaskWithExpirationHandler:^{ [app endBackgroundTask:bgTask]; bgTask = UIBackgroundTaskInvalid; }]; // Start the long-running task and return immediately. dispatch_async(dispatch_get_global_queue(DISPATCH_QUEUE_PRIORITY_DEFAULT, 0), ^{ // Do the work associated with the task. NSString *updatekey = [[NSUserDefaults standardUserDefaults] objectForKey:@"updatesetting"]; if([updatekey isEqualToString:@"enabled"]) { DataSettingsView *periodicUpdate = [[DataSettingsView alloc] init]; [periodicUpdate updateDataPeriodically]; //[periodicUpdate viewDidLoad]; //[periodicUpdate release]; } [app endBackgroundTask:bgTask]; bgTask = UIBackgroundTaskInvalid; }); } some one please help me in this background execution of long tasks with some example of code. Some help will appreciated and helpful to me.

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  • Populate table fields on query execution

    - by Jason
    I'm trying to build an ASP site that populates a Table based on the results of a selection in a ListBox. In order to do this, I've created a GridView table inside a div element. Currently the default behavior is to show all the items in the specified table in sortable order. However, I'd like to refine this further to allow for display of matches based on the results from the ListBox selection, but am not sure how to execute this. The ListBox fires off a OnSelectionChanged event to the method defined below and the GridView element is defined as <asp:GridView ID="dataListings" runat="server" AllowSorting="True" AutoGenerateColumns="False" DataSourceID="LinqDataSource1" OnDataBinding="ListBox1_SelectedIndexChanged"> protected void ListBox1_SelectedIndexChanged(object sender, EventArgs e) { int itemSelected = selectTopics.SelectedIndex; string[] listing = null; switch (itemSelected)//assign listing the array of course numbers { case 0: break; case 1: listing = arts; break; case 2: listing = currentEvents; break; .... More cases here default: listing = arts; break; } using (OLLIDBDataContext odb = new OLLIDBDataContext()) { var q = from c in odb.tbl_CoursesAndWorkshops where listing.Contains(c.tbl_Course_Description.tbl_CoursesAndWorkshops.course_workshop_number) select c; dataListings.DataSource = q; dataListings.DataBind(); } } However, this method never gets fired. I can see a request being made when changing the selection, but setting a breakpoint at the method declaration does nothing at all. Based on this, setup, I have three related questions What do I need to modify to get the OnSelectionChanged event handler to fire? How can I alter the GridView area to be empty on page load? How do I send the results from the dataListings.DataBind() execution to show in the GridView?

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  • Is there a design pattern that expresses objects (an their operations) in various states?

    - by darren
    Hi I have a design question about the evolution of an object (and its state) after some sequence of methods complete. I'm having trouble articulating what I mean so I may need to clean up the question based on feedback. Consider an object called Classifier. It has the following methods: void initialise() void populateTrainingSet(TrainingSet t) void pupulateTestingSet(TestingSet t) void train() void test() Result predict(Instance i) My problem is that these methods need to be called in a certain order. Futher, some methods are invalid until a previous method is called, and some methods are invalid after a method has been called. For example, it would be invalid to call predict() before test() was called, and it would be invalid to call train() after test() was called. My approach so far has been to maintain a private enum that represents the current stateof the object: private static enum STATE{ NEW, TRAINED, TESTED, READY}; But this seems a bit cloogy. Is there a design pattern for such a problem type? Maybe something related to the template method.

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