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  • Fluent NHibernate: Example of a one-to-many relationship on an abstract class of a table-per-subclas

    - by BigTommy79
    Hi All, I've been trying for ages to find an example (because I can't get it to work myself) of the correct mapping for a one-to-many relationship on an abstract class of a table-per-subclass implementation, in fluent nHibernate. An example below: I'm looking to map the list of Fines on the Debt abstract base class to the Fine class. if anyone knows of any tutorial or example they've come across before please let me know. Thanks, Tim public abstract class Entity { public int Id { get; set; } } public abstract class Debt : Entity { public decimal Balance { get; set; } public IList<Fine> Fines { get; set; } public Debt() { Fines = new List<Fine>(); } } public class CarLoan : Debt { } public class CreditCard : Debt { } public class LoanApplication : Entity { public IList<Debt> ExistingDebts { get; set; } public LoanApplication() { ExistingDebts = new List<Debt>(); } } public class Fine { public Int64 Cash { get; set; } }

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  • Ultra-grand super acts_as_tree rails query

    - by Bloudermilk
    Right now I'm dealing with an issue regarding an intense acts_as_tree MySQL query via rails. The model I am querying is Foo. A Foo can belong to any one City, State or Country. My goal is to query Foos based on their location. My locations table is set up like so: I have a table in my database called locations I use a combination of acts_as_tree and polymorphic associations to store each individual location as either a City, State or Country. (This means that my table consists of the rows id, name, parent_id, type) Let's say for instance, I want to query Foos in the state "California". Beside Foos that directly belong to "California", I should get all Foos that belong every City in "California" like Foos in "Los Angeles" and "San Francisco". Not only that, but I should get any Foos that belong to the Country that "California" is in, "United States". I've tried a few things with associations to no avail. I feel like I'm missing some super-helpful Rails-fu here. Any advice?

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  • What about parallelism across network using multiple PCs?

    - by MainMa
    Parallel computing is used more and more, and new framework features and shortcuts make it easier to use (for example Parallel extensions which are directly available in .NET 4). Now what about the parallelism across network? I mean, an abstraction of everything related to communications, creation of processes on remote machines, etc. Something like, in C#: NetworkParallel.ForEach(myEnumerable, () => { // Computing and/or access to web ressource or local network database here }); I understand that it is very different from the multi-core parallelism. The two most obvious differences would probably be: The fact that such parallel task will be limited to computing, without being able for example to use files stored locally (but why not a database?), or even to use local variables, because it would be rather two distinct applications than two threads of the same application, The very specific implementation, requiring not just a separate thread (which is quite easy), but spanning a process on different machines, then communicating with them over local network. Despite those differences, such parallelism is quite possible, even without speaking about distributed architecture. Do you think it will be implemented in a few years? Do you agree that it enables developers to easily develop extremely powerfull stuff with much less pain? Example: Think about a business application which extracts data from the database, transforms it, and displays statistics. Let's say this application takes ten seconds to load data, twenty seconds to transform data and ten seconds to build charts on a single machine in a company, using all the CPU, whereas ten other machines are used at 5% of CPU most of the time. In a such case, every action may be done in parallel, resulting in probably six to ten seconds for overall process instead of forty.

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  • Refreshing a MKMapView when the user location is updated or using default values

    - by koichirose
    I'm trying to refresh my map view and load new data from the server when the device acquires the user location. Here's what I'm doing: - (void)viewDidLoad { CGRect bounds = self.view.bounds; mapView = [[MKMapView alloc] initWithFrame:bounds]; mapView.showsUserLocation=YES; mapView.delegate=self; [self.view insertSubview:mapView atIndex:0]; [self refreshMap]; } - (void)mapView:(MKMapView *)theMapView didUpdateUserLocation:(MKUserLocation *)userLocation { //this is to avoid frequent updates, I just need one position and don't need to continuously track the user's location if (userLocation.location.horizontalAccuracy > self.myUserLocation.location.horizontalAccuracy) { self.myUserLocation = userLocation; CLLocationCoordinate2D centerCoord = { userLocation.location.coordinate.latitude, userLocation.location.coordinate.longitude }; [theMapView setCenterCoordinate:centerCoord zoomLevel:10 animated:YES]; [self refreshMap]; } } - (void)refreshMap { [[UIApplication sharedApplication] setNetworkActivityIndicatorVisible:YES]; [self.mapView removeAnnotations:self.mapView.annotations]; //default position NSString *lat = @"45.464161"; NSString *lon = @"9.190336"; if (self.myUserLocation != nil) { lat = [[NSNumber numberWithDouble:myUserLocation.coordinate.latitude] stringValue]; lon = [[NSNumber numberWithDouble:myUserLocation.coordinate.longitude] stringValue]; } NSString *url = [[NSString alloc] initWithFormat:@"http://myserver/geo_search.json?lat=%@&lon=%@", lat, lon]; NSURLRequest *theRequest=[NSURLRequest requestWithURL:[NSURL URLWithString:url] cachePolicy:NSURLRequestUseProtocolCachePolicy timeoutInterval:60.0]; [[NSURLConnection alloc] initWithRequest:theRequest delegate:self]; [url release]; [[UIApplication sharedApplication] setNetworkActivityIndicatorVisible:NO]; } I also have a - (void)connection:(NSURLConnection *)connection didReceiveData:(NSData *)data, to create and add the annotations. Here's what happens: sometimes I get the location after a while, so I already loaded data close to the default location. Then I get the location and it should remove the old annotations and add the new ones, instead I keep seeing the old annotations and the new ones are added anyway (let's say I receive 10 annotations each time, so it means that I have 20 on my map when I should have 10). What am I doing wrong?

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  • Is encrypting session id (or other authenticate value) in cookie useful at all?

    - by Ji
    In web development, when session state is enabled, a session id is stored in cookie(in cookieless mode, query string will be used instead). In asp.net, the session id is encrypted automatically. There are plenty of topics on the internet regarding how you should encrypt your cookie, including session id. I can understand why you want to encrypt private info such as DOB, but any private info should not be stored in cookie at first place. So for other cookie values such as session id, what is the purpose encryption? Does it add security at all? no matter how you secure it, it will be sent back to server for decryption. Be be more specific, For authentication purpose, turn off session, i don't want to deal with session time out any more store some sort of id value in the cookie, on the server side, check if the id value exists and matches, if it is, authenticate user. let the cookie value expire when browser session is ended, this way. vs Asp.net form authentication mechanism (it relies on session or session id, i think) does latter one offer better security?

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  • Weird behavior of matching array keys after json_decode()

    - by arnorhs
    I've got some very weird behavior in my PHP code. I don't know if this is actually a good SO question, since it almost looks like a bug in PHP. I had this problem in a project of mine and isolated the problem: // json object that will be converted into an array $json = '{"5":"88"}'; $jsonvar = (array) json_decode($json); // notice: Casting to an array // Displaying the array: var_dump($jsonvar); // Testing if the key is there var_dump(isset($jsonvar["5"])); var_dump(isset($jsonvar[5])); That code outputs the following: array(1) { ["5"]=> string(2) "88" } bool(false) bool(false) The big problem: Both of those tests should produce bool(true) - if you create the same array using regular php arrays, this is what you'll see: // Let's create a similar PHP array in a regular manner: $phparr = array("5" => "88"); // Displaying the array: var_dump($phparr); // Testing if the key is there var_dump(isset($phparr["5"])); var_dump(isset($phparr[5])); The output of that: array(1) { [5]=> string(2) "88" } bool(true) bool(true) So this doesn't really make sense. I've tested this on two different installations of PHP/apache. You can copy-paste the code to a php file yourself to test it. It must have something to do with the casting from an object to an array.

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  • How to accommodate for the different screen resolution of iPhone 4?

    - by mystify
    This is a programming question! Read on before you vote to close! According to Apple, iPhone 4 has a new screen resolution: 3.5-inch (diagonal) widescreen Multi-Touch display 960-by-640-pixel resolution at 326 ppi This little detail affects our apps in a heavy way. Most of the demo apps on the net have one thing in common: They position views in the believe that the screen has a fixed size of 320 x 480 pixels. So what most -if not all- developers do is: They designed everything in such a way, that a touchable area is -for example- 50 x 50 pixels big. Just enough to tap it. Things have been positioned relative to the upper left, to reach a specific position on screen - let's say the center, or somewhere at the bottom. Edit: It seems Apple has integrated an switch that allows to tell if an app is highRes or not. Nice. When we develop high-resolution apps, probably they won't work on older devices. And if they did, they would suffer a lot from 4-times the size of any image, having to scale them down in memory. This is community wiki. Just add anything that you think is relevant to this huge problem (constant screen res was one of the main reasons why I didn't go for Android!!).

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  • Asp.Net 2 integrated sites How to Logout second site programatically.

    - by NBrowne
    Hi , I am working with an asp.net 2.0 site (call it site 1) which has an iframe in it which loads up another site (site2) which is also an asp.net site which is developed by our team. When you log onto site 1 then behind the scenes site 2 is also logged in so that when you click the iframe tab then this displays site 2 with the user logged in (to prevent the user from having to log in twice). The problem i have is that when a user logs out of site 1 then we call some cleanup methods to perform FormsAuthentication.SignOut and clean session variables etc but at the moment no cleanup is called when the user on site 2. So the issue is that if the user opens up Site 2 from within a browser then website 2 opens with the user still logged in which is undesired. Can anyone give me some guidance as to the best approach for this?? One possible approach i though of was just that on click of logout button i could do a call to a custom page on Site 2 which would do the logout. Code below HttpWebRequest request; request = ((HttpWebRequest)(WebRequest.Create("www.mywebsite.com/Site2Logout.aspx"))); request.Method = "POST"; HttpCookie cookie = HttpContext.Current.Request.Cookies[FormsAuthentication.FormsCookieName]; Cookie authenticationCookie = new Cookie( FormsAuthentication.FormsCookieName, cookie.Value, cookie.Path, HttpContext.Current.Request.Url.Authority); request .CookieContainer = new CookieContainer(); request .CookieContainer.Add(authenticationCookie); response.GetResponse(); Problem i am having with this code is that when i run it and debug on Site 2 and check to see if the user is Authenticated they are not which i dont understand because if i open browser and browse to Site 2 i am Still authenticated. Any ideas , different direction to take etc ??? Please let me know if you need any more info or if i something i have said dosent make sense. Thanks

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  • design pattern for related inputs

    - by curiousMo
    My question is a design question : let's say i have a data entry web page with 4 drop down lists, each depending on the previous one, and a bunch of text boxes. ddlCountry (DropDownList) ddlState (DropDownList) ddlCity (DropDownList) ddlBoro (DropDownList) txtAddress (TxtBox) txtZipcode(TxtBox) and an object that represents a datarow with a value for each: countrySeqid stateSeqid citySeqid boroSeqid address zipCode naturally the country, state, city and boro values will be values of primary keys of some lookup tables. when the user chooses to edits that record, i would load it from database and load it into the page. the issue that I have is how to streamline loading the DropDownLists. i have some code that would grab the object,look thru its values and move them to their corresponding input controls in one shot. but in this case i will have to load the ddlCountry with possible values, then assign values, then do the same thing for the rest of the ddls. I guess i am looking for an elegant solution. i am using asp.net, but i think it is irrelevant to the question. i am looking more into a design pattern.

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  • There is a Default instance of form in VB.Net but not in C#, WHY?

    - by Shekhar_Pro
    I'm just curious to know that there is The (Name) property, which represents the name of the Form class.This property is used within the namespace to uniquely identify the class that the Form is an instance of and, in the case of Visual Basic, is used to access the default instance of the form. Now where this Default Instance come from, why can't C# have a equivalent method to this. Also for example to show a form in C# we do something like this: //Only method Form1 frm = new Form1(); frm.Show(); But in VB.Net we have both ways to do it: //'First common method (used slash because editor wouldn't format it properly) Form1.Show(); //'Second method Dim frm as New Form1(); frm.Show(); My question comes from this first method. What is this Form1, is it an instance of Form1 or the Form1 class itself. Now as i mentioned above the Form name is the Default instance in VB.Net. But we also know that Form1 is a class defined in Designer so how can the names be same for both the Instance and class name. If Form1 is Class then there is no (Static\Shared) method named Show(). So where does this method come from. And finally why C# can't have an equivalent of this. If there some mistake in my question Please let me know *I've checked this on stackoverflow, but couldn't find an answer to this.If you do find then please give a link to it.*

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  • C Programming. How to deep copy a struct?

    - by user69514
    I have the following two structs where "child struct" has a "rusage struct" as an element. Then I create two structs of type "child" let's call them childA and childB How do I copy just the rusage struct from childA to childB? typedef struct{ int numb; char *name; pid_t pid; long userT; long systemT; struct rusage usage; }child; typedef struct{ struct timeval ru_utime; /* user time used */ struct timeval ru_stime; /* system time used */ long ru_maxrss; /* maximum resident set size */ long ru_ixrss; /* integral shared memory size */ long ru_idrss; /* integral unshared data size */ long ru_isrss; /* integral unshared stack size */ long ru_minflt; /* page reclaims */ long ru_majflt; /* page faults */ long ru_nswap; /* swaps */ long ru_inblock; /* block input operations */ long ru_oublock; /* block output operations */ long ru_msgsnd; /* messages sent */ long ru_msgrcv; /* messages received */ long ru_nsignals; /* signals received */ long ru_nvcsw; /* voluntary context switches */ long ru_nivcsw; /* involuntary context switches */ }rusage; I did the following, but I guess it copies the memory location, because if I changed the value of usage in childA, it also changes in childB. memcpy(&childA,&childB, sizeof(rusage)); I know that gives childB all the values from childA. I have already taken care of the others fields in childB, I just need to be able to copy the rusage struct called usage that resides in the "child" struct.

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  • How should I handle header files in a bundle?

    - by ldiqual
    I want to develop a program that relies on plugins (here: loadable bundles) to work. Multiple plugins are asked to use the same AFNetworking ressource to make network requests. However, I don't know where to put AFNetworking and CustomPluginProtocol headers. Here is how my program structure looks like for now: MyApp.xcodeproj - AFNetworking - Header.h - Plugins - Plugin1.xcodeproj - PrincipalClass.m - Plugin2.xcodeproj - PrincipalClass.m - Classes - CustomPluginProtocol.h - MainClass.m Of course, every principalClass from PluginN complies to the CustomPluginProtocol. Do the headers have to be copied in each bundle ? Can I just include the main program AFNetworking headers from my plugins ? If so (and that's what I do for now), I don't have any completion. How can I get it ? Edit Ok, so maybe I wasn't clear in my question. I want my plugins to use sources from the main application, let's say CommonClass.m and CommonClass.h. Do the plugins need CommonClass.h in their bundle, and if not, how do I enable completion when I'm in the plugin scope ?

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  • Source folders for a maven project in eclipse

    - by 4NDR01D3
    Hello all, I have a that uses maven... and I want to put it in my working environment with eclipse(Galileo)... the project is in a svn server, and I can create check out the project and everything looks OK. I even can run the unit test and everything is working there. However, now that everything is there I wanted to work in the code, and oh surprise there are no packages in my project... I mean all the source code is in the src folder and browsing through it i can see all my files, ut if I open the files from there, the files are opened as text files with no coloring, but worst no help at all about errors in compilation. I don't know what im I doing wrong now, because I had the same project in other machine and it was working well. So here is what I did, please let me know if you notice if I did something wrong, miss any steps or anything that can help me: In the SVN Repository (Using subclipse 1.6.10) I added my SVN Repository Browsed to the folder where I have the pom file Right Click Check out as a Maven project...(Using m2eclipse 0.10.020100209) Used the default options and finish. The projects were created with no problem. I said projects because this maven project has modules, and each module became a project in eclipse. Back in the java perspective, Right click in the project, Run as maven test(Using JWebUnitTest, because I am testing a servlet) BUILD SUCCESS!! But as I said there is not packages so I can't really develop in this environment. Any help?? Thanks!

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  • Why is my code stopping and not returning an exception?

    - by BeckyLou
    I have some code that starts a couple of threads to let them execute, then uses a while loop to check for the current time passing a set timeout period, or for the correct number of results to have been processed (by checking an int on the class object) (with a Thread.Sleep() to wait between loops) Once the while loop is set to exit, it calls Abort() on the threads and should return data to the function that calls the method. When debugging and stepping through the code, I find there can be exceptions in the code running on the separate threads, and in some cases I handle these appropriately, and at other times I don't want to do anything specific. What I have been seeing is that my code goes into the while loop and the thread sleeps, then nothing is returned from my function, either data or an exception. Code execution just stops completely. Any ideas what could be happening? Code sample: System.Threading.Thread sendThread = new System.Threading.Thread(new System.Threading.ThreadStart(Send)); sendThread.Start(); System.Threading.Thread receiveThread = new System.Threading.Thread(new System.Threading.ThreadStart(Receive)); receiveThread.Start(); // timeout Int32 maxSecondsToProcess = this.searchTotalCount * timeout; DateTime timeoutTime = DateTime.Now.AddSeconds(maxSecondsToProcess); Log("Submit() Timeout time: " + timeoutTime.ToString("yyyyMMdd HHmmss")); // while we're still waiting to receive results & haven't hit the timeout, // keep the threads going while (resultInfos.Count < this.searchTotalCount && DateTime.Now < timeoutTime) { Log("Submit() Waiting..."); System.Threading.Thread.Sleep(10 * 1000); // 1 minute } Log("Submit() Aborting threads"); // <== this log doesn't show up sendThread.Abort(); receiveThread.Abort(); return new List<ResultInfo>(this.resultInfos.Values);

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  • Check a list of packages to install with apt-get

    - by Joel
    I am writing a post-install script for Ubuntu in Perl (same script as seen here). One of the steps is to install a list of packages. The problem is that if apt-get install fails in some of many different ways for any one of the packages the script dies badly. I would like to prevent that from happening. This happens because of the ways that apt-get install fails for packages that it doesn't like. For example when I try to install a nonsense word (i.e. typed in the wrong package name) $ sudo apt-get install oblihbyvl Reading package lists... Done Building dependency tree Reading state information... Done E: Unable to locate package oblihbyvl but if instead the package name has been obsoleted (installing handbrake from ppa) $ sudo apt-get install handbrake Reading package lists... Done Building dependency tree Reading state information... Done Package handbrake is not available, but is referred to by another package. This may mean that the package is missing, has been obsoleted, or is only available from another source E: Package 'handbrake' has no installation candidate $ apt-cache search handbrake handbrake-cli - versatile DVD ripper and video transcoder - command line handbrake-gtk - versatile DVD ripper and video transcoder - GTK GUI I have tried parsing the results of apt-cache and apt-get -s install to try to catch all possibilities before doing the install, but I seem to keep finding new ways to allow failures to continue to the actual install system command. My question is, is there some facility either in Perl (e.g. a module, though I would like to avoid installing modules if possible as this is supposed to be the first thing run after a new install of Ubuntu) or apt-* or dpkg that would let me be sure that the packages are all available to be installed before installing and if not fail gracefully in some way that lets the user decide what to do?

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  • Mercurial Subrepos, how to control which changeset I want to use for a subrepo?

    - by Lasse V. Karlsen
    I am reading up on subrepos, and have been running some tests locally, seems to work OK so far, but I have one question. How do I specify/control which changeset I want to use for a particular subrepo? For instance, let's say I have the following two projects: class library application o fourth commit o second commit, added a feature | | o third commit o initial commit | | o second commit |/ o initial commit Now, I want the class library as a subrepo of my application, but due to the immaturity of the longest branch (the one ending up as fourth commit), I want to temporarily use the "second commit" tip. How do I go about configuring that, assuming it is even possible? Here's a batch file that sets up the above two repos + adds the library as a subrepo. If you run the batch file, it will output: [C:\Temp] :test ... v4 As you can see from that last line there, it verifies the contents of the file in the class library, which is "v4" from the fourth commit. I'd like it to be "v2", and persist as "v2" until I'm ready to pull down a newer version from the class library repository. Can anyone tell me if it is possible to do what I want, and if so, what I need to do in order to lock my subrepo to the right changeset? Batch-file: @echo off if exist app rd /s /q app if exist lib rd /s /q lib if exist app-clone rd /s /q app-clone rem == app == hg init app cd app echo program>main.txt hg add main.txt hg commit -m "initial commit" echo program+feature1>main.txt hg commit -m "second commit, added a feature" cd .. rem == lib == hg init lib cd lib echo v1>lib.txt hg add lib.txt hg commit -m "initial commit" echo v2>lib.txt hg commit -m "second commit" hg update 0 echo v3>lib.txt hg commit -m "third commit" echo v4>lib.txt hg commit -m "fourth commit" cd .. rem == subrepos == cd app hg clone ..\lib lib echo lib = ..\lib >.hgsub hg add .hgsub hg commit -m "added subrepo" cd .. rem == clone == hg clone app app-clone type app-clone\lib\lib.txt

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  • When is Googling it wrong?

    - by Drahcir
    I've been going through Stack Overflow for quite a bit now and noticed certain people (usually experienced programmers) frown upon Googling (researching) certain problems. Since I myself tend to use Google quite a bit to solve certain programming related issues I found certain comments rather demoralising. Now some of you may have come here trigger happy to delete this post but I needed some clarification. I usually Google things that usually syntax related that I would have never figured out on my own. For example I once wondered how to access the properties of a class that I didn't have a direct relationship to. So after a bit of research I discovered reflection and got what I wanted. Now in another scenario is learning a new language, in my case Silverlight were it differs in certain aspects of .NET compared to say ASP.NET. A few weeks ago I had no idea how to load another Silverlight page (usercontrol) and had to Google my way to the solution which I found wasn't as simple as I had imagined. In scenario three is were I myself frown up, that is just stealing a huge chunk of code to avoid doing the work yourself, for example paging a HTML table using JavaScript, where one just copies and pastes the JavasSript code without as much as trying to understand how it works. I do admit I have done this once or twice before for trivial tasks that had very little time limit and weren't all that important but most of the time still have to throw away what I found because it took too much time to adapt it and get what I wanted out of it. In the last scenario, I sometimes have a piece of code that I would be really unhappy about, as in I find it sloppy or too overcomplicated and try to look on the Internet to see other ways to tackle the same problem, let's say filtering through a table. With the knowledge I acquire I learned new coding practices that help me work more efficiently like "Do not repeat yourself" and such. Now in your opinion when do you find it wrong to use Google (or any other researching tool) to find a solution to your problem?

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  • Ruby on Rails login using legacy user database

    - by ricsmania
    Hello, I have a Rails application that connects to a legacy database (Oracle) and displays some information from a particular user. Right now the user is passed as a URL parameter, but this has obvious security issues because users should only be able to see their own data. To solve that, I want to implement a user login, and I did some research and came across 2 components for that, restful_authentication and authlogic. The problem is that I need to use an existing user/password database instead of creating a new one, which is the common way to use those components. The password is encrypted by a custom Oracle package, but let's assume it is stored as plain text to make things simpler. I only need very basic functionality, which is login a user and keep them logged in forever until logout. No changes to the database will be made by this application, so there's no need for sign up, e-mail activation, reset password, etc. Can someone point me in the right direction on how to do that? Is any of those 2 components a good solution? If not, what would be recommended? Thanks!

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  • How to Prevent PostBack Event Handler from Firing

    - by user331744
    I have a custom class (ServerSideValidator.vb) that validates user input on server side (it doesn't use any of the .NET built in validators, therefore Page.Validate() is not an option for me). I am calling the Validate() method on page.IsPostback event and the class performs without any problem My issue is, when validation fails (returns false), I want to stop the postback event handler from firing, but load the page along with all the controls and user-input values in them. If I do, Response.End(), the page comes up blank. I can programmatically instruct the page to go to the previous page (original form before postback), but it loses all user-inputs. I thought of creating a global boolean variable in the page code behind file and check the value before performing any postback method, but this approach takes away from my plan to provide all functionalities inside the class itself. The page object is being referenced to ServerSideValidator. Seems like all the postback related properties/variables I come across inside Page class are 'Readonly' and I can't assign value(s) to control/prevent postback event from firing. Any idiea on how I can accomplish this? Please let me know if you need further details

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  • Efficient database access when dealing with multiple abstracted repositories

    - by Nathan Ridley
    I want to know how most people are dealing with the repository pattern when it involves hitting the same database multiple times (sometimes transactionally) and trying to do so efficiently while maintaining database agnosticism and using multiple repositories together. Let's say we have repositories for three different entities; Widget, Thing and Whatsit. Each repository is abstracted via a base interface as per normal decoupling design processes. The base interfaces would then be IWidgetRepository, IThingRepository and IWhatsitRepository. Now we have our business layer or equivalent (whatever you want to call it). In this layer we have classes that access the various repositories. Often the methods in these classes need to do batch/combined operations where multiple repositories are involved. Sometimes one method may make use of another method internally, while that method can still be called independently. What about, in this scenario, when the operation needs to be transactional? Example: class Bob { private IWidgetRepository _widgetRepo; private IThingRepository _thingRepo; private IWhatsitRepository _whatsitRepo; public Bob(IWidgetRepository widgetRepo, IThingRepository thingRepo, IWhatsitRepository whatsitRepo) { _widgetRepo = widgetRepo; _thingRepo= thingRepo; _whatsitRepo= whatsitRepo; } public void DoStuff() { _widgetRepo.StoreSomeStuff(); _thingRepo.ReadSomeStuff(); _whatsitRepo.SaveSomething(); } public void DoOtherThing() { _widgetRepo.UpdateSomething(); DoStuff(); } } How do I keep my access to that database efficient and not have a constant stream of open-close-open-close on connections and inadvertent invocation of MSDTS and whatnot? If my database is something like SQLite, standard mechanisms like creating nested transactions are going to inherently fail, yet the business layer should not have to be concerning itself with such things. How do you handle such issues? Does ADO.Net provide simple mechanisms to handle this or do most people end up wrapping their own custom bits of code around ADO.Net to solve these types of problems?

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  • ActiveRecord Validations for Models with has_many, belongs_to associations and STI

    - by keruilin
    I have four models: User Award Badge GameWeek The associations are as follows: User has many awards. Award belongs to user. Badge has many awards. Award belongs to badge. User has many game_weeks. GameWeek belongs to user. GameWeek has many awards. Award belongs to game_week. Thus, user_id, badge_id and game_week_id are foreign keys in awards table. Badge implements an STI model. Let's just say it has the following subclasses: BadgeA and BadgeB. Some rules to note: The game_week_id fk can be nil for BadgeA, but can't be nil for BadgeB. Here are my questions: For BadgeA, how do I write a validation that it can only be awarded one time? That is, the user can't have more than one -- ever. For BadgeB, how do I write a validation that it can only be awarded one time per game week?

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  • How to Develop Dynamic Plug-In Based Functionality in C#

    - by Matthew
    Hello: I've been looking around for different methods of providing plug-in support for my application. Ideally, I will be creating a core functionality and based on different customers developing different plug-ins/addons such as importing, exporting data etc... What are the some methods available for making a C# application extensible via a plug-in architecture? Lets make up an example. If we have a program that consists of a main menu ( File, Edit, View, et al. ) along with a TreeView that displays different brands of cars grouped by manufacturer ( Ford, GM, for now). Right clicking on a car displays a context menu with the only option being 'delete car'. How could you develop the application so that plug-ins could be deployed so that you could allow one customer to see a new brand in the TreeView, let's say Honda, and also extent the car context menu so that they may now 'paint a car'? In Eclipse/RCP development this is easily handled by extension points and plug-ins. How does C# handle it? I've been looking into developing my own plug-in architecture and reading up on MEF.

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  • Client validate in MVC 2

    - by khoailang
    Hello, I'm very new in MVC 2, Let say, I have a page with 1 text box and 2 input typed submit, "back" and "next". I'm using client validation like this: "" type="text/javascript"/" " type="text/javascript"/ " type="text/javascript"/ . . . <% Html.EnableClientValidation(); % . . . . . . and validation rule used for that text box is [StringLength(100, ErrorMessage="This field should be no longer than 100")] My wish is that validation rules will be applied only when I click on Next button. And when I click on Back button, no validation error message will be displayed and form will be posted to server. Is it possible to do that? could you please tell me how? My problem now is that when I click Back, validation rules are applied and prevent me from posting back to server.

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  • Can I write a .NETCF Partial Class to extend System.Windows.Forms.UserControl?

    - by eidylon
    Okay... I'm writing a .NET CF (VBNET 2008 3.5 SP1) application, which has one master form, and it dynamically loads specific UserControls based on menu click, in a sort of framework idea. There are certain methods and properties these controls all need to work within the app. Right now I am doing this as an Interface, but this is aggravating as all get up, because some of the methods are optional, and yet I MUST implement them by the nature of interfaces. I would prefer to use inheritance, so that I can have certain code be inherited with overridability, but if I write a class which inherits System.Windows.Forms.UserControl and then inherit my control from that, it squiggles, and tells me that UserControls MUST inherit directly from System.Windows.Forms.UserControl. (Talk about a design flaw!) So next I thought, well, let me use a partial class to extend System.Windows.Forms.UserControl, but when I do that, even though it all seems to compile fine, none of my new properties/methods show up on my controls. Is there any way I can use partial classes to 'extend' System.Windows.Forms.UserControl? For example, can anyone give me a code sample of a partial class which simply adds a MyCount As Integer readonly property to the System.Windows.Forms.UserControl class? If I can just see how to get this going, I can take it from there and add the rest of my functionality. Thanks in advance! I've been searching google, but can't find anything that seems to work for UserControl extension on .NET CF. And the Interface method is driving me crazy as even a small change means updating ALL the controls whether they need to 'override' the method or not.

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  • How to duplicate all data in a table except for a single column that should be changed.

    - by twiga
    I have a question regarding a unified insert query against tables with different data structures (Oracle). Let me elaborate with an example: tb_customers ( id NUMBER(3), name VARCHAR2(40), archive_id NUMBER(3) ) tb_suppliers ( id NUMBER(3), name VARCHAR2(40), contact VARCHAR2(40), xxx, xxx, archive_id NUMBER(3) ) The only column that is present in all tables is [archive_id]. The plan is to create a new archive of the dataset by copying (duplicating) all records to a different database partition and incrementing the archive_id for those records accordingly. [archive_id] is always part of the primary key. My problem is with select statements to do the actual duplication of the data. Because the columns are variable, I am struggling to come up with a unified select statement that will copy the data and update the archive_id. One solution (that works), is to iterate over all the tables in a stored procedure and do a: CREATE TABLE temp as (SELECT * from ORIGINAL_TABLE); UPDATE temp SET archive_id=something; INSERT INTO temp (select * from temp); DROP TABLE temp; I do not like this solution very much as the DDL commands muck up all restore points. Does anyone else have any solution?

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