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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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  • Where should global Application Settings be stored on Windows 7?

    - by Kerido
    Hi everybody, I'm working hard on making my product work seamlessly on Windows 7. The problem is that there is a small set of global (not user-specific) application settings that all users should be able to change. On previous versions I used HKLM\Software\__Company__\__Product__ for that purpose. This allowed Power Users and Administrators to modify the Registry Key and everything worked correctly. Now that Windows Vista and Windows 7 have this UAC feature, by default, even an Administrator cannot access the Key for writing without elevation. A stupid solution would, of course, mean adding requireAdministrator option into the application manifest. But this is really unprofessional since the product itself is extremely far from administration-related tasks. So I need to stay with asInvoker. Another solution could mean programmatic elevation during moments when write access to the Registry Key is required. Let alone the fact that I don't know how to implement that, it's pretty awkward also. It interferes with normal user experience so much that I would hardly consider it an option. What I know should be relatively easy to accomplish is adding write access to the specified Registry Key during installation. I created a separate question for that. This also very similar to accessing a shared file for storing the settings. My feeling is that there must be a way to accomplish what I need, in a way that is secure, straightforward and compatible with all OS'es. Any ideas?

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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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  • odd behavior with C# ftp client class

    - by geoff
    I found an ftp client class in c# over a year ago and have been using it in a process that uploads files on a nightly basis. A few days ago we started having a problem where it would time out. I'm not well versed in this so I'm not sure why it's doing this. When the program starts uploading a file it checks to see if it's logged in and if not, it calls the login method. In that method is this block of code. if (this.resultCode != 230) { this.sendCommand("PASS " + password); if (!(this.resultCode == 230 || this.resultCode == 202)) { this.cleanup(); throw new FtpException(this.result.Substring(4)); } } On the line that says this.sendCommand("PASS"... it goes into this code. private void sendCommand(String command) { if (this.verboseDebugging) Debug.WriteLine(command, "FtpClient"); Byte[] cmdBytes = Encoding.ASCII.GetBytes((command + "\r\n").ToCharArray()); clientSocket.Send(cmdBytes, cmdBytes.Length, 0); this.readResponse(); } If I let the program run, it times out. However if I step through it into the sendCommand method it executes fine. Does anyone know why it would work fine when I step through it? Nothing on our end has changed and I've been told nothing on the client's end has changed so I'm stumped. Thanks.

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  • Disabling browser print options (headers, footers, margins) from page?

    - by Anthony
    I have seen this question asked in a couple of different ways on SO and several other websites, but most of them are either too specific or out-of-date. I'm hoping someone can provide a definitive answer here without pandering to speculation. Is there a way, either with CSS or javascript, to change the default printer settings when someone prints within their browser? And of course by "prints from their browser" I mean some form of HTML, not PDF or some other plug-in reliant mime-type. Please note: If some browsers offer this and others don't (or if you only know how to do it for some browsers) I welcome browser-specific solutions. Similarly, if you know of a mainstream browser that has specific restrictions against EVER doing this, that is also helpful, but some fairly up-to-date documentation would be appreciated. (simply saying "that goes against XYZ's security policy" isn't very convincing when XYZ has made significant changes in said policy in the last three years). Finally, when I say "change default print settings" I don't mean forever, just for my page, and I am referring specifically to print margins, headers, and footers. I am very aware that CSS offers the option of changing the page orientation as well as the page margins. One of the many struggles is with Firefox. If I set the page margins to 1 inch, it ADDS this to the half inch it already puts into place. I very much want to reduce the usage of PDFs on my client's site, but the infringement on presentation (as well as the lack of reliability) are their main concern.

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  • Releasing Autopool crashes on iOS 4.0 (and only on 4.0)

    - by samsam
    Hi there. I'm wondering what could cause this. I have several methods in my code that i call using performSelectorInBackground. Within each of these methods i have an Autoreleasepool that is being alloced/initialized at the beginning and released at the end of the method. this perfectly works on iOS 3.1.3 / 3.2 / 4.2 / 4.2.1 but it fataly crashes on iOS 4.0 with a EXC_BAD_ACCESS Exception that happens after calling [myPool release]. After I noticed this strange behaviour I was thinking about rewriting portions of my code and to make my app "less parallel" in case that the client os is 4.0. After I did that, the next point where the app crashed was within the ReachabilityCallback-Method from Apples Reachability "Framework". well, now I'm not quite sure what to do. The things i do within my threaded methods is pretty simple xml parsing (no cocoa calls or stuff that would affect the UI). After each method finishes it posts a notification which the coordinating-thread listens to and once all the parallelized methods have finished, the coordinating thread calls viewcontrollers etc... I have absolutely no clue what could cause this weird behaviour. Especially because Apples Code fails as well. any help is greatly appreciated! thanks, sam

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  • How is an AppDelegate instanciated?

    - by pwny
    I have an iOS application for which I want to create a ViewController programmatically. I started an empty XCode project and modified the main method so it looks like this int main(int argc, char *argv[]) { NSAutoreleasePool *pool = [[NSAutoreleasePool alloc] init]; int retVal = UIApplicationMain(argc, argv, nil, @"MyAppDelegate_iPad"); [pool release]; return retVal; } The app is a Universal Application, MyAppDelegate_iPad is a subclass of MyAppDelegate, which is a subclass of NSObject <UIApplicationDelegate>. My problem is that the applicationDidFinishLoading method I've overridden in MyAppDelegate_iPad is never called (break point on the first line never hits). The method looks like this -(void) applicationDidFinishLaunching:(UIApplication *)application { window = [[UIWindow alloc] initWithFrame:[[UIScreen mainScreen] bounds]]; if(!window) { [self release]; return; } window.backgroundColor = [UIColor whiteColor]; rootController = [[MyViewController alloc] init]; [window addSubview:rootController.view]; [window makeKeyAndVisible]; [window layoutSubviews]; } I removed the line to link to a nib file from my plist file (I used to get the default "My Universal app on iPad" white screen) and now all that is displayed is a black screen. applicationDidFinishLoading is still not being called. Am I doing something wrong? How should I properly create my AppDelegate instance?

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  • waveInProc / Windows audio question...

    - by BTR
    I'm using the Windows API to get audio input. I've followed all the steps on MSDN and managed to record audio to a WAV file. No problem. I'm using multiple buffers and all that. I'd like to do more with the buffers than simply write to a file, so now I've got a callback set up. It works great and I'm getting the data, but I'm not sure what to do with it once I have it. Here's my callback... everything here works: // Media API callback void CALLBACK AudioRecorder::waveInProc(HWAVEIN hWaveIn, UINT uMsg, DWORD dwInstance, DWORD dwParam1, DWORD dwParam2) { // Data received if (uMsg == WIM_DATA) { // Get wav header LPWAVEHDR mBuffer = (WAVEHDR *)dwParam1; // Now what? for (unsigned i = 0; i != mBuffer->dwBytesRecorded; ++i) { // I can see the char, how do get them into my file and audio buffers? cout << mBuffer->lpData[i] << "\n"; } // Re-use buffer mResultHnd = waveInAddBuffer(hWaveIn, mBuffer, sizeof(mInputBuffer[0])); // mInputBuffer is a const WAVEHDR * } } // waveInOpen cannot use an instance method as its callback, // so we create a static method which calls the instance version void CALLBACK AudioRecorder::staticWaveInProc(HWAVEIN hWaveIn, UINT uMsg, DWORD_PTR dwInstance, DWORD_PTR dwParam1, DWORD_PTR dwParam2) { // Call instance version of method reinterpret_cast<AudioRecorder *>(dwParam1)->waveInProc(hWaveIn, uMsg, dwInstance, dwParam1, dwParam2); } Like I said, it works great, but I'm trying to do the following: Convert the data to short and copy into an array Convert the data to float and copy into an array Copy the data to a larger char array which I'll write into a WAV Relay the data to an arbitrary output device I've worked with FMOD a lot and I'm familiar with interleaving and all that. But FMOD dishes everything out as floats. In this case, I'm going the other way. I guess I'm basically just looking for resources on how to go from LPSTR to short, float, and unsigned char. Thanks much in advance!

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  • Dynamic Variable Names in Included Module in Ruby?

    - by viatropos
    I'm hoping to implement something like all of the great plugins out there for ruby, so that you can do this: acts_as_commentable has_attached_file :avatar But I have one constraint: That helper method can only include a module; it can't define any variables or methods. Here's what the structure looks like, and I'm wondering if you know the missing piece in the puzzle: # 1 - The workhorse, encapsuling all dynamic variables module My::Module def self.included(base) base.extend ClassMethods base.class_eval do include InstanceMethods end end module InstanceMethods self.instance_eval %Q? def #{options[:my_method]} "world!" end ? end module ClassMethods end end # 2 - all this does is define that helper method module HelperModule def self.included(base) base.extend(ClassMethods) end module ClassMethods def dynamic_method(options = {}) include My::Module(options) end end end # 3 - send it to active_record ActiveRecord::Base.send(:include, HelperModule) # 4 - what it looks like class TestClass < ActiveRecord::Base dynamic_method :my_method => "hello" end puts TestClass.new.hello #=> "world!" That %Q? I'm not totally sure how to use, but I'm basically just wanting to somehow be able to pass the options hash from that helper method into the workhorse module. Is that possible? That way, the workhorse module could define all sorts of functionality, but I could name the variables whatever I wanted at runtime.

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  • Java constructor using generic types

    - by Beer Me
    I'm having a hard time wrapping my head around Java generic types. Here's a simple piece of code that in my mind should work, but I'm obviously doing something wrong. Eclipse reports this error in BreweryList.java: The method breweryMethod() is undefined for the type <T> The idea is to fill a Vector with instances of objects that are a subclass of the Brewery class, so the invocation would be something like: BreweryList breweryList = new BreweryList(BrewerySubClass.class, list); BreweryList.java package com.beerme.test; import java.util.Vector; public class BreweryList<T extends Brewery> extends Vector<T> { public BreweryList(Class<T> c, Object[] j) { super(); for (int i = 0; i < j.length; i++) { T item = c.newInstance(); // breweryMethod() is an instance method // of Brewery, of which <T> is a subclass (right?) c.breweryMethod(); // "The method breweryMethod() is undefined // for the type <T>" } } } Brewery.java package com.beerme.test; public class Brewery { public Brewery() { super(); } protected void breweryMethod() { } } BrewerySubClass.java package com.beerme.test; public class BrewerySubClass extends Brewery { public BrewerySubClass() { super(); } public void brewerySubClassMethod() { } } I'm sure this is a complete-generics-noob question, but I'm stuck. Thanks for any tips!

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  • Global name not defined error in Django/Python trying to set foreignkey

    - by Mark
    Summary: I define a method createPage within a file called PageTree.py that takes a Source model object and a string. The method tries to generate a Page model object. It tries to set the Page model object's foreignkey to refer to the Source model object which was passed in. This throws a NameError exception! I'm trying to represent a website which is structured like a tree. I define the Django models Page and Source, Page representing a node on the tree and Source representing the contents of the page. (You can probably skip over these, this is a basic tree implementation using doubly linked nodes). class Page(models.Model): name = models.CharField(max_length=50) parent = models.ForeignKey("self", related_name="children", null=True); firstChild = models.ForeignKey("self", related_name="origin", null=True); nextSibling = models.ForeignKey("self", related_name="prevSibling", null=True); previousSibling = models.ForeignKey("self", related_name="nxtSibling", null=True); source = models.ForeignKey("Source"); class Source(models.Model): #A source that is non dynamic will be refered to as a static source #Dynamic sources contain locations that are names of functions #Static sources contain locations that are places on disk name = models.CharField(primary_key=True, max_length=50) isDynamic = models.BooleanField() location = models.CharField(max_length=100); I've coded a python program called PageTree.py which allows me to request nodes from the database and manipulate the structure of the tree. Here is the trouble making method: def createPage(pageSource, pageName): page = Page() page.source = pageSource page.name = pageName page.save() return page I'm running this program in a shell through manage.py in Windows 7 manage.py shell from mysite.PageManager.models import Page, Source from mysite.PageManager.PageTree import * ... create someSource = Source(), populate the fields, and save it ... createPage(someSource, "test") ... NameError: global name 'source' is not defined When I type in the function definition for createPage into the shell by hand, the call works without error. This is driving me bonkers and help is appreciated.

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  • PHP Access property of a class from within a class instantiated in the original class.

    - by Iain
    I'm not certain how to explain this with the correct terms so maybe an example is the best method... $master = new MasterClass(); $master->doStuff(); class MasterClass { var $a; var $b; var $c; var $eventProccer; function MasterClass() { $this->a = 1; $this->eventProccer = new EventProcess(); } function printCurrent() { echo '<br>'.$this->a.'<br>'; } function doStuff() { $this->printCurrent(); $this->eventProccer->DoSomething(); $this->printCurrent(); } } class EventProcess { function EventProcess() {} function DoSomething() { // trying to access and change the parent class' a,b,c properties } } My problem is i'm not certain how to access the properties of the MasterClass from within the EventProcess-DoSomething() method? I would need to access, perform operations on and update the properties. The a,b,c properties will be quite large arrays and the DoSomething() method would be called many times during the execuction of the script. Any help or pointers would be much appreciated :)

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  • FormStartPosition.CenterParent does not work

    - by kol
    In the following code, only the second method works for me (.NET 4.0). FormStartPosition.CenterParent does not center the child form over its parent. Why? Source: this SO question using System; using System.Drawing; using System.Windows.Forms; class Program { private static Form f1; public static void Main() { f1 = new Form() { Width = 640, Height = 480 }; f1.MouseClick += f1_MouseClick; Application.Run(f1); } static void f1_MouseClick(object sender, MouseEventArgs e) { Form f2 = new Form() { Width = 400, Height = 300 }; switch (e.Button) { case MouseButtons.Left: { // 1st method f2.StartPosition = FormStartPosition.CenterParent; break; } case MouseButtons.Right: { // 2nd method f2.StartPosition = FormStartPosition.Manual; f2.Location = new Point( f1.Location.X + (f1.Width - f2.Width) / 2, f1.Location.Y + (f1.Height - f2.Height) / 2 ); break; } } f2.Show(f1); } }

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  • C++, generic programming and virtual functions. How do I get what I want?

    - by carleeto
    This is what I would like to do using templates: struct op1 { virtual void Method1() = 0; } ... struct opN { virtual void MethodN() = 0; } struct test : op1, op2, op3, op4 { virtual void Method1(){/*do work1*/}; virtual void Method2(){/*do work2*/}; virtual void Method3(){/*do work3*/}; virtual void Method4(){/*do work4*/}; } I would like to have a class that simply derives from a template class that provides these method declarations while at the same time making them virtual. This is what I've managed to come up with: #include <iostream> template< size_t N > struct ops : ops< N - 1 > { protected: virtual void DoStuff(){ std::cout<<N<<std::endl; }; public: template< size_t i > void Method() { if( i < N ) ops<i>::DoStuff(); } //leaving out compile time asserts for brevity } struct test : ops<6> { }; int main( int argc, char ** argv ) { test obj; obj.Method<3>(); //prints 3 return 0; } However, as you've probably guessed, I am unable to override any of the 6 methods I have inherited. I'm obviously missing something here. What is my error? No, this isn't homework. This is curiosity.

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  • How to animate a path like it's being drawn, dot by dot? (Raphael.js)

    - by Anton
    How to animate a vector path like it's being drawn by hand? In other words, slowly show the path pixel by pixel. I'm using Raphaël.js, but if your answer is not library specific—like maybe there's some general programming pattern for doing that kind of thing (I'm fairly new to vector animation)—it's welcome! Update I know it's easy to do with straight paths, as easy as an example on that page:: path("M114 253").animate({path: "M114 253 L 234 253"}); But try to change code on that page, say, this way:: path("M114 26").animate({path: "M114 26 C 24 23 234 253 234 253"}); And you'll see what I mean. Path is certainly animated from it initial state (point "M114 26") to the end state (curve "C 24 23 234 253 234 253" starting on point "M114 26"), but not in a way specified in question, not like it's being drawn. (Sorry for not making clear from the start that I don't mean animating straight lines.) I don't see how animateAlong can do that either. It can animate an object along a path, and how can I make this path to gradually show itself while object is being animated along it?

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  • Which is the correct design pattern for my PHP application?

    - by user1487141
    I've been struggling to find good way to implement my system which essentially matches the season and episode number of a show from a string, you can see the current working code here: https://github.com/huddy/tvfilename I'm currently rewriting this library and want a nicer way to implement how the the match happens, currently essentially the way it works is: There's a folder with classes in it (called handlers), every handler is a class that implements an interface to ensure a method called match(); exists, this match method uses the regex stored in a property of that handler class (of which there are many) to try and match a season and episode. The class loads all of these handlers by instantiating each one into a array stored in a property, when I want to try and match some strings the method iterates over these objects calling match(); and the first one that returns true is then returned in a result set with the season and episode it matched. I don't really like this way of doing it, it's kind of hacky to me, and I'm hoping a design pattern can help, my ultimate goal is to do this using best practices and I wondered which one I should use? The other problems that exist are: More than one handler could match a string, so they have to be in an order to prevent the more greedy ones matching first, not sure if this is solvable as some of the regex patterns have to be greedy, but possibly a score system, something that shows a percentage of how likely the match is correct, i'd have no idea how to actually implement this though. I'm not if instantiating all those handlers is a good way of doing it, speed is important, but using best practices and sticking to design patterns to create good, extensible and maintainable code is my ultimate priority. It's worth noting the handler classes sometimes do other things than just regex matching, they sometimes prep the string to be matched by removing common words etc. Cheers for any help Billy

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  • Capturing wildcards in java generics

    - by Rollerball
    From this orcale java tutorial: The WildcardError example produces a capture error when compiled: import java.util.List; public class WildcardError { void foo(List<?> i) { i.set(0, i.get(0)); } } After this error demonstration, they fix the problem by using a helper method: public class WildcardFixed { void foo(List<?> i) { fooHelper(i); } // Helper method created so that the wildcard can be captured // through type inference. private <T> void fooHelper(List<T> l) { l.set(0, l.get(0)); } } First, they say that the list input parameter (i) is seen as an Object: In this example, the compiler processes the i input parameter as being of type Object. Why then i.get(0) does not return an Object? if it was already passed in as such? Furthermore what is the point of using a <?> when then you have to use an helper method using <T>. Would not be better using directly which can be inferred?

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  • Which is the event listener after doSave() in Symfony?

    - by fesja
    Hi, I've been looking at this event-listeners page http://www.doctrine-project.org/documentation/manual/1_1/pl/event-listeners and I'm not sure which is the listener I have to use to make a change after the doSave() method in the BaseModelForm.class.php. // PlaceForm.class.php protected function doSave ( $con = null ) { ... parent::doSave($con); .... // Only for new forms, insert place into the tree if($this->object->level == null){ $parent = Place::getPlace($this->getValue('parent'), Language::getLang()); ... $node = $this->object->getNode(); $method = ($node->isValidNode() ? 'move' : 'insert') . 'AsFirstChildOf'; $node->$method($parent); //calls $this->object->save internally } return; } What I want to do is to make a custom slug with the ancestors' name of that new place. So if I inserting "San Francisco", the slug would be "usa-california-san-francisco" public function postXXXXXX($event) { ... $event->getInvoker()->slug = $slug; } The problem is that I'm inserting a new object with no reference to its parent. After it's saved, I insert it to the tree. So I can't change the slug until then. I think a Transaction listener could work, but I'm use there is a better way I'm not seeing right now. thanks!

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  • What the heck is the "Structure and Interpretation of Computer Programs" cover drawing about?

    - by Paul Reiners
    What the heck is the Structure and Interpretation of Computer Programs cover drawing about? I mean I know what "eval", "apply", and '?' all mean, but I'm having a hard time deciphering the rest of the picture. Who the heck is the maiden? Does she work for the wizard? Why the heck is she pointing at the table? Is she pointing at that little bowl-type thing? Or the books? Or the table in general? Is she trying to tell the wizard that he should apply some sort of Lisp wizardry to the table or the items on it? Or is she just telling him something prosaic, such as his food is getting cold? What the heck is the one leg on that table that looks like...a leg...with a foot at the end (as legs tend to have)? How does the table balance on one leg? (Or is that another leg in the shadows?) [Note: I'm waiting for a lengthy build to finish in case you were wondering.]

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  • Which pattern to use for logging? Dependency Injection or Service Locator?

    - by andlju
    Consider this scenario. I have some business logic that now and then will be required to write to a log. interface ILogger { void Log(string stuff); } interface IDependency { string GetInfo(); } class MyBusinessObject { private IDependency _dependency; public MyBusinessObject(IDependency dependency) { _dependency = dependency; } public string DoSomething(string input) { // Process input var info = _dependency.GetInfo(); var intermediateResult = PerformInterestingStuff(input, info); if (intermediateResult== "SomethingWeNeedToLog") { // How do I get to the ILogger-interface? } var result = PerformSomethingElse(intermediateResult); return result; } } How would you get the ILogger interface? I see two main possibilities; Pass it using Dependency Injection on the constructor. Get it via a singleton Service Locator. Which method would you prefer, and why? Or is there an even better pattern? Update: Note that I don't need to log ALL method calls. I only want to log a few (rare) events that may or may not occur within my method.

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  • em.createQuery keeps returning null

    - by Developer106
    I have this application which i use JSF 2.0 and EclipseLink, i have entities created for a database made in MySQL, Created these entities using netbeans 7.1.2, it gets created automaticly. Then i use session beans to work with these entities, the thing is the em.createQuery always returns a null, though I checked NamedQueries in the entities and they perfectly match a sample from the entities named queries:- @NamedQueries({ @NamedQuery(name = "Users.findAll", query = "SELECT u FROM Users u"), @NamedQuery(name = "Users.findByUserId", query = "SELECT u FROM Users u WHERE u.userId = :userId"), @NamedQuery(name = "Users.findByUsername", query = "SELECT u FROM Users u WHERE u.username = :username"), @NamedQuery(name = "Users.findByEmail", query = "SELECT u FROM Users u WHERE u.email = :email"), notice how i use this findByEmail query in the session bean :- public Users findByEmail(String email){ em.getTransaction().begin(); String find = "Users.findByEmail"; Query query = em.createNamedQuery(find); query.setParameter("email", email); Users user = (Users) query.getSingleResult(); but it always returns null from this em.createNamedQuery, i tried using .createQuery first but it also was no good. the stacktrace of the exception Caused by: java.lang.NullPointerException at com.readme.entities.sessionBeans.UsersFacade.findByEmail(UsersFacade.java:48) at com.readme.user.signup.SignupBean.checkAvailability(SignupBean.java:137) at com.readme.user.signup.SignupBean.save(SignupBean.java:146) at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57) at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) at java.lang.reflect.Method.invoke(Method.java:601) What Seems To Be The Problem Here ?

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  • Error : Number of Rows In Section in UITableView in iPhone SDK

    - by Meghan
    I am getting this error while I am trying to load the data into my table view. Terminating app due to uncaught exception 'NSInternalInconsistencyException', reason: 'Invalid update: invalid number of rows in section 0. The number of rows contained in an existing section after the update (73) must be equal to the number of rows contained in that section before the update (71), plus or minus the number of rows inserted or deleted from that section (3 inserted, 0 deleted). What could be wrong? Thanks EDIT : I am initializing the array on ViewWillAppear and adding new objects to the same array on Tableview's didSelectRowAtIndexPath method Here is the code On viewWillAppear : cellTextArray = [[NSMutableArray alloc] init]; [cellTextArray addObjectsFromArray:newPosts]; Here is the code which modifies the array on didSelectRowAtIndexPath : [cellTextArray addObjectsFromArray:newPosts]; NSMutableArray *insertIndexPaths = [NSMutableArray array]; for (NSUInteger item = count; item < count + newCount; item++) { [insertIndexPaths addObject:[NSIndexPath indexPathForRow:item inSection:0]]; } [self.table beginUpdates]; [self.table insertRowsAtIndexPaths:insertIndexPaths withRowAnimation:UITableViewRowAnimationFade]; [self.table endUpdates]; [self.table scrollToRowAtIndexPath:indexPath atScrollPosition:UITableViewScrollPositionNone animated:YES]; NSIndexPath *selected = [self.table indexPathForSelectedRow]; if (selected) { [self.table deselectRowAtIndexPath:selected animated:YES]; } Here newPosts is an array which has the values that are added to cellTextArray on didSelectRowAtIndexPath method and viewWillAppear method.

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  • Should try...catch go inside or outside a loop?

    - by mmyers
    I have a loop that looks something like this: for(int i = 0; i < max; i++) { String myString = ...; float myNum = Float.parseFloat(myString); myFloats[i] = myNum; } This is the main content of a method whose sole purpose is to return the array of floats. I want this method to return null if there is an error, so I put the loop inside a try...catch block, like this: try { for(int i = 0; i < max; i++) { String myString = ...; float myNum = Float.parseFloat(myString); myFloats[i] = myNum; } } catch (NumberFormatException ex) { return null; } But then I also thought of putting the try...catch block inside the loop, like this: for(int i = 0; i < max; i++) { String myString = ...; try { float myNum = Float.parseFloat(myString); } catch (NumberFormatException ex) { return null; } myFloats[i] = myNum; } So my question is: is there any reason, performance or otherwise, to prefer one over the other? EDIT: The consensus seems to be that it is cleaner to put the loop inside the try/catch, possibly inside its own method. However, there is still debate on which is faster. Can someone test this and come back with a unified answer? (EDIT: did it myself, but voted up Jeffrey and Ray's answers)

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