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  • How to delay static initialization within a property

    - by Mystagogue
    I've made a class that is a cross between a singleton (fifth version) and a (dependency injectable) factory. Call this a "Mono-Factory?" It works, and looks like this: public static class Context { public static BaseLogger LogObject = null; public static BaseLogger Log { get { return LogFactory.instance; } } class LogFactory { static LogFactory() { } internal static readonly BaseLogger instance = LogObject ?? new BaseLogger(null, null, null); } } //USAGE EXAMPLE: //Optional initialization, done once when the application launches... Context.LogObject = new ConLogger(); //Example invocation used throughout the rest of code... Context.Log.Write("hello", LogSeverity.Information); The idea is for the mono-factory could be expanded to handle more than one item (e.g. more than a logger). But I would have liked to have made the mono-factory look like this: public static class Context { private static BaseLogger LogObject = null; public static BaseLogger Log { get { return LogFactory.instance; } set { LogObject = value; } } class LogFactory { static LogFactory() { } internal static readonly BaseLogger instance = LogObject ?? new BaseLogger(null, null, null); } } The above does not work, because the moment the Log property is touched (by a setter invocation) it causes the code path related to the getter to be executed...which means the internal LogFactory "instance" data is always set to the BaseLogger (setting the "LogObject" is always too late!). So is there a decoration or other trick I can use that would cause the "get" path of the Log property to be lazy while the set path is being invoked?

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  • NHibernate mapping one table on two classes with where selection

    - by Rene Schulte
    We would like to map a single table on two classes with NHibernate. The mapping has to be dynamically depending on the value of a column. Here's a simple example to make it a bit clearer: We have a table called Person with the columns id, Name and Sex. The data from this table should be mapped either on the class Male or on the class Female depending on the value of the column Sex. In Pseudocode: create instance of Male with data from table Person where Person.Sex = 'm'; create instance of Female with data from table Person where Person.Sex = 'f'; The benefit is we have strongly typed domain models and can later avoid switch statements. Is this possible with NHibernate or do we have to map the Person table into a flat Person class first? Then afterwards we would have to use a custom factory method that takes a flat Person instance and returns a Female or Male instance. Would be good if NHibernate (or another library) can handle this.

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  • Referring to the type of an inner class in Scala

    - by saucisson
    The following code tries to mimic Polymorphic Embedding of DSLs: rather than giving the behavior in Inner, it is encoded in the useInner method of its enclosing class. I added the enclosing method so that user has only to keep a reference to Inner instances, but can always get their enclosing instance. By doing this, all Inner instances from a specific Outer instance are bound to only one behavior (but it is wanted here). abstract class Outer { sealed class Inner { def enclosing = Outer.this } def useInner(x:Inner) : Boolean } def toBoolean(x:Outer#Inner) : Boolean = x.enclosing.useInner(x) It does not compile and scala 2.8 complains about: type mismatch; found: sandbox.Outer#Inner required: _81.Inner where val _81:sandbox.Outer From Programming Scala: Nested classes and A Tour of Scala: Inner Classes, it seems to me that the problem is that useInnerexpects as argument an Inner instance from a specific Outer instance. What is the true explanation and how to solve this problem ?

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  • ASMLib

    - by wcoekaer
    Oracle ASMlib on Linux has been a topic of discussion a number of times since it was released way back when in 2004. There is a lot of confusion around it and certainly a lot of misinformation out there for no good reason. Let me try to give a bit of history around Oracle ASMLib. Oracle ASMLib was introduced at the time Oracle released Oracle Database 10g R1. 10gR1 introduced a very cool important new features called Oracle ASM (Automatic Storage Management). A very simplistic description would be that this is a very sophisticated volume manager for Oracle data. Give your devices directly to the ASM instance and we manage the storage for you, clustered, highly available, redundant, performance, etc, etc... We recommend using Oracle ASM for all database deployments, single instance or clustered (RAC). The ASM instance manages the storage and every Oracle server process opens and operates on the storage devices like it would open and operate on regular datafiles or raw devices. So by default since 10gR1 up to today, we do not interact differently with ASM managed block devices than we did before with a datafile being mapped to a raw device. All of this is without ASMLib, so ignore that one for now. Standard Oracle on any platform that we support (Linux, Windows, Solaris, AIX, ...) does it the exact same way. You start an ASM instance, it handles storage management, all the database instances use and open that storage and read/write from/to it. There are no extra pieces of software needed, including on Linux. ASM is fully functional and selfcontained without any other components. In order for the admin to provide a raw device to ASM or to the database, it has to have persistent device naming. If you booted up a server where a raw disk was named /dev/sdf and you give it to ASM (or even just creating a tablespace without asm on that device with datafile '/dev/sdf') and next time you boot up and that device is now /dev/sdg, you end up with an error. Just like you can't just change datafile names, you can't change device filenames without telling the database, or ASM. persistent device naming on Linux, especially back in those days ways to say it bluntly, a nightmare. In fact there were a number of issues (dating back to 2004) : Linux async IO wasn't pretty persistent device naming including permissions (had to be owned by oracle and the dba group) was very, very difficult to manage system resource usage in terms of open file descriptors So given the above, we tried to find a way to make this easier on the admins, in many ways, similar to why we started working on OCFS a few years earlier - how can we make life easier for the admins on Linux. A feature of Oracle ASM is the ability for third parties to write an extension using what's called ASMLib. It is possible for any third party OS or storage vendor to write a library using a specific Oracle defined interface that gets used by the ASM instance and by the database instance when available. This interface offered 2 components : Define an IO interface - allow any IO to the devices to go through ASMLib Define device discovery - implement an external way of discovering, labeling devices to provide to ASM and the Oracle database instance This is similar to a library that a number of companies have implemented over many years called libODM (Oracle Disk Manager). ODM was specified many years before we introduced ASM and allowed third party vendors to implement their own IO routines so that the database would use this library if installed and make use of the library open/read/write/close,.. routines instead of the standard OS interfaces. PolyServe back in the day used this to optimize their storage solution, Veritas used (and I believe still uses) this for their filesystem. It basically allowed, in particular, filesystem vendors to write libraries that could optimize access to their storage or filesystem.. so ASMLib was not something new, it was basically based on the same model. You have libodm for just database access, you have libasm for asm/database access. Since this library interface existed, we decided to do a reference implementation on Linux. We wrote an ASMLib for Linux that could be used on any Linux platform and other vendors could see how this worked and potentially implement their own solution. As I mentioned earlier, ASMLib and ODMLib are libraries for third party extensions. ASMLib for Linux, since it was a reference implementation implemented both interfaces, the storage discovery part and the IO part. There are 2 components : Oracle ASMLib - the userspace library with config tools (a shared object and some scripts) oracleasm.ko - a kernel module that implements the asm device for /dev/oracleasm/* The userspace library is a binary-only module since it links with and contains Oracle header files but is generic, we only have one asm library for the various Linux platforms. This library is opened by Oracle ASM and by Oracle database processes and this library interacts with the OS through the asm device (/dev/asm). It can install on Oracle Linux, on SuSE SLES, on Red Hat RHEL,.. The library itself doesn't actually care much about the OS version, the kernel module and device cares. The support tools are simple scripts that allow the admin to label devices and scan for disks and devices. This way you can say create an ASM disk label foo on, currently /dev/sdf... So if /dev/sdf disappears and next time is /dev/sdg, we just scan for the label foo and we discover it as /dev/sdg and life goes on without any worry. Also, when the database needs access to the device, we don't have to worry about file permissions or anything it will be taken care of. So it's a convenience thing. The kernel module oracleasm.ko is a Linux kernel module/device driver. It implements a device /dev/oracleasm/* and any and all IO goes through ASMLib - /dev/oracleasm. This kernel module is obviously a very specific Oracle related device driver but it was released under the GPL v2 so anyone could easily build it for their Linux distribution kernels. Advantages for using ASMLib : A good async IO interface for the database, the entire IO interface is based on an optimal ASYNC model for performance A single file descriptor per Oracle process, not one per device or datafile per process reducing # of open filehandles overhead Device scanning and labeling built-in so you do not have to worry about messing with udev or devlabel, permissions or the likes which can be very complex and error prone. Just like with OCFS and OCFS2, each kernel version (major or minor) has to get a new version of the device drivers. We started out building the oracleasm kernel module rpms for many distributions, SLES (in fact in the early days still even for this thing called United Linux) and RHEL. The driver didn't make sense to get pushed into upstream Linux because it's unique and specific to the Oracle database. As it takes a huge effort in terms of build infrastructure and QA and release management to build kernel modules for every architecture, every linux distribution and every major and minor version we worked with the vendors to get them to add this tiny kernel module to their infrastructure. (60k source code file). The folks at SuSE understood this was good for them and their customers and us and added it to SLES. So every build coming from SuSE for SLES contains the oracleasm.ko module. We weren't as successful with other vendors so for quite some time we continued to build it for RHEL and of course as we introduced Oracle Linux end of 2006 also for Oracle Linux. With Oracle Linux it became easy for us because we just added the code to our build system and as we churned out Oracle Linux kernels whether it was for a public release or for customers that needed a one off fix where they also used asmlib, we didn't have to do any extra work it was just all nicely integrated. With the introduction of Oracle Linux's Unbreakable Enterprise Kernel and our interest in being able to exploit ASMLib more, we started working on a very exciting project called Data Integrity. Oracle (Martin Petersen in particular) worked for many years with the T10 standards committee and storage vendors and implemented Linux kernel support for DIF/DIX, data protection in the Linux kernel, note to those that wonder, yes it's all in mainline Linux and under the GPL. This basically gave us all the features in the Linux kernel to checksum a data block, send it to the storage adapter, which can then validate that block and checksum in firmware before it sends it over the wire to the storage array, which can then do another checksum and to the actual DISK which does a final validation before writing the block to the physical media. So what was missing was the ability for a userspace application (read: Oracle RDBMS) to write a block which then has a checksum and validation all the way down to the disk. application to disk. Because we have ASMLib we had an entry into the Linux kernel and Martin added support in ASMLib (kernel driver + userspace) for this functionality. Now, this is all based on relatively current Linux kernels, the oracleasm kernel module depends on the main kernel to have support for it so we can make use of it. Thanks to UEK and us having the ability to ship a more modern, current version of the Linux kernel we were able to introduce this feature into ASMLib for Linux from Oracle. This combined with the fact that we build the asm kernel module when we build every single UEK kernel allowed us to continue improving ASMLib and provide it to our customers. So today, we (Oracle) provide Oracle ASMLib for Oracle Linux and in particular on the Unbreakable Enterprise Kernel. We did the build/testing/delivery of ASMLib for RHEL until RHEL5 but since RHEL6 decided that it was too much effort for us to also maintain all the build and test environments for RHEL and we did not have the ability to use the latest kernel features to introduce the Data Integrity features and we didn't want to end up with multiple versions of asmlib as maintained by us. SuSE SLES still builds and comes with the oracleasm module and they do all the work and RHAT it certainly welcome to do the same. They don't have to rebuild the userspace library, it's really about the kernel module. And finally to re-iterate a few important things : Oracle ASM does not in any way require ASMLib to function completely. ASMlib is a small set of extensions, in particular to make device management easier but there are no extra features exposed through Oracle ASM with ASMLib enabled or disabled. Often customers confuse ASMLib with ASM. again, ASM exists on every Oracle supported OS and on every supported Linux OS, SLES, RHEL, OL withoutASMLib Oracle ASMLib userspace is available for OTN and the kernel module is shipped along with OL/UEK for every build and by SuSE for SLES for every of their builds ASMLib kernel module was built by us for RHEL4 and RHEL5 but we do not build it for RHEL6, nor for the OL6 RHCK kernel. Only for UEK ASMLib for Linux is/was a reference implementation for any third party vendor to be able to offer, if they want to, their own version for their own OS or storage ASMLib as provided by Oracle for Linux continues to be enhanced and evolve and for the kernel module we use UEK as the base OS kernel hope this helps.

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  • How to implement Xml Serialization with inherited classes in C#

    - by liorafar
    I have two classes : base class name Component and inheritd class named DBComponent [Serializable] public class Component { private string name = string.Empty; private string description = string.Empty; } [Serializable] public class DBComponent : Component { private List<string> spFiles = new List<string>(); // Storage Procedure Files [XmlArrayItem("SPFile", typeof(string))] [XmlArray("SPFiles")] public List<string> SPFiles { get { return spFiles; } set { spFiles = value; } } public DBComponent(string name, string description) : base(name, description) { } } [Serializable] public class ComponentsCollection { private static ComponentsCollection instance = null; private List<Component> components = new List<Component>(); public List<Component> Components { get { return components; } set { components = value; } } public static ComponentsCollection GetInstance() { if (ccuInstance == null) { lock (lockObject) { if (instance == null) PopulateComponents(); } } return instance; } private static void PopulateComponents() { instance = new CCUniverse(); XmlSerializer xs = new XmlSerializer(instance.GetType()); instance = xs.Deserialize(XmlReader.Create("Components.xml")) as ComponentsCollection; } } } I want read\write from a Xml file. I know that I need to implement the Serialization for DBComponent class otherwise it will not read it.But i cannot find any simple article for that. all the articles that I found were too complex for this simple scenario. The Xml file looks like this: <?xml version="1.0" encoding="utf-8" ?> <ComponentsCollection> <Components> <DBComponent Name="Tenant Historical Database" Description="Tenant Historical Database"> <SPFiles> <SPFile>Setup\TenantHistoricalSP.sql</SPFile> </SPFiles> </DBComponent> <Component Name="Agent" Description="Desktop Agent" /> </Components> </ComponentsCollection> Can someone please give me a simple example of how to read this kind of xml file and what should be implemented ? Thanks Lior

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  • C# reflection instantiation

    - by NickLarsen
    I am currently trying to create a generic instance factory for which takes an interface as the generic parameter (enforced in the constructor) and then lets you get instantiated objects which implement that interface from all types in all loaded assemblies. The current implementation is as follows:     public class InstantiationFactory     {         protected Type Type { get; set; }         public InstantiationFactory()         {             this.Type = typeof(T);             if (!this.Type.IsInterface)             {                 // is there a more descriptive exception to throw?                 throw new ArgumentException(/* Crafty message */);             }         }         public IEnumerable GetLoadedTypes()         {             // this line of code found in other stack overflow questions             var types = AppDomain.CurrentDomain.GetAssemblies()                 .SelectMany(a = a.GetTypes())                 .Where(/* lambda to identify instantiable types which implement this interface */);             return types;         }         public IEnumerable GetImplementations(IEnumerable types)         {             var implementations = types.Where(/* lambda to identify instantiable types which implement this interface */                 .Select(x = CreateInstance(x));             return implementations;         }         public IEnumerable GetLoadedImplementations()         {             var loadedTypes = GetLoadedTypes();             var implementations = GetImplementations(loadedTypes);             return implementations;         }         private T CreateInstance(Type type)         {             T instance = default(T);             var constructor = type.GetConstructor(Type.EmptyTypes);             if (/* valid to instantiate test */)             {                 object constructed = constructor.Invoke(null);                 instance = (T)constructed;             }             return instance;         }     } It seems useful to me to have my CreateInstance(Type) function implemented as an extension method so I can reuse it later and simplify the code of my factory, but I can't figure out how to return a strongly typed value from that extension method. I realize I could just return an object:     public static class TypeExtensions     {         public object CreateInstance(this Type type)         {             var constructor = type.GetConstructor(Type.EmptyTypes);             return /* valid to instantiate test */ ? constructor.Invoke(null) : null;         }     } Is it possible to have an extension method create a signature per instance of the type it extends? My perfect code would be this, which avoids having to cast the result of the call to CreateInstance():     Type type = typeof(MyParameterlessConstructorImplementingType);     MyParameterlessConstructorImplementingType usable = type.CreateInstance();

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  • Django: Save data from form in DB

    - by Anry
    I have a model: class Cost(models.Model): project = models.ForeignKey(Project) cost = models.FloatField() date = models.DateField() For the model I created a class form: class CostForm(ModelForm): class Meta: model = Cost fields = ['date', 'cost'] view.py: def cost(request, offset): if request.method == 'POST': #HOW save data in DB? return HttpResponseRedirect('/') else: form = CostForm() In the template file determined: <form action="/cost/{{ project }}/" method="post" accept-charset="utf-8"> <label for="date">Date:</label><input type="text" name="date" value={{ current_date }} id="date" /> <label for="cost">Cost:</label><input type="text" name="cost" value="0" id="cost" /> <p><input type="submit" value="Add"></p> </form> How save data from form in DB? P.S. offset = project name Model: class Project(models.Model): title = models.CharField(max_length=150) url = models.URLField() manager = models.ForeignKey(User) timestamp = models.DateTimeField() I tried to write: def cost(request, offset): if request.method == 'POST': form = CostForm(request.POST) if form.is_valid(): instance = form.save(commit=False) instance.project = Project.objects.filter(title=offset) instance.date = request.date instance.cost = request.cost instance.save() return HttpResponseRedirect('/') else: form = CostForm() But it does not work :(

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  • Java dynamic proxy questions.

    - by Tony
    1.Does dynamic proxy instance subclass the target class? The java doc says the proxy instance implements "a list of interfaces", says nothing about subclassing, but through debugging, I saw that the proxy instance did inherit the target class properites.What does the "a list of interfaces " mean? Can I exclude those interfaces implemented by target class ? 2.Can I invoke target class specific methods on a proxy instance? 3. I think dynamic proxy is an interface methods invocation proxy but rather than a target class proxy, is that right (I am deeply infected by hibernate proxy object concept)?

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  • Using clases in PHP to store function

    - by Artur
    Hello! I need some advise on my PHP code organisation. I need classes where I can store different functions, and I need access to those classes in different parts of my project. Making an object of this classes each time is too sadly, so I've found a two ways have to solve it. First is to use static methods, like class car { public static $wheels_count = 4; public static function change_wheels_count($new_count) { car::$wheels_count = $new_count; } } Second is to use singleton pattern: class Example { // Hold an instance of the class private static $instance; // The singleton method public static function singleton() { if (!isset(self::$instance)) { $c = __CLASS__; self::$instance = new $c; } return self::$instance; } } But author of the article about singletons said, that if I have too much singletons in my code I should reconstruct it. But I need a lot of such classes. Can anybody explain prons and cons of each way? Which is mostly used? Are there more beautiful ways?

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  • Calling 32 bit unmanaged dlls from C# randomly failing

    - by Bert
    Hi, I'm having an issue when calling 32 bit delphi dll's from c# web site. The code generally runs fine, but occasionally I get an error Unable to load DLL '': The specified module could not be found. (Exception from HRESULT: 0x8007007E). This issue persists until I recycle the app pool for the site, and then it works fine again. On the same server, there is also a web service that is calling the same set of dlls. This web service doesn't seem to have the same issue that the web site has. Both applications are using .net framework 3.5, separate app pools on IIS. Here is the code I'm using to wrap the dlls: public sealed class Mapper { static Mapper instance = null; [DllImport("kernel32.dll")] private static extern bool SetDllDirectory(string lpPathName); private Mapper() { SetDllDirectory(ConfigManager.Path); } public static Mapper Instance { get { if (instance == null) { instance = new Mapper(); } return instance; } } public int Foo(string bar, ref double val) { return Loader.Foo(bar, ref val); } } public static class Loader { [DllImport("some.dll", CallingConvention = CallingConvention.StdCall, CharSet = CharSet.Unicode, EntryPoint = "foo")] public static extern int Foo(string bar, ref double val); } Then I call it like this: double val = 0.0; Mapper.Instance.Foo("bar", ref val); Any ideas as to why it would "randomly" Unable to load DLL '': The specified module could not be found. (Exception from HRESULT: 0x8007007E). The other problem is that I haven't been able to replicate the issue in the development environment. I thought that due to 2 applications calling the same dlls, that there could be some locks occurring. To replicate this, I created an app that spawned multiple threads and repeatedly called the 32bit dlls, and then used the web site to call these same dlls. I still couldn't replicate the issue. Some possible fixes that I can think of: Wrap the 32 bit dlls in web service (because the webservice doesn't seem to suffer from the same problem). But this may be worthless if it turns out that the web service also fails. Set up state server for the session state and periodically recycle the app pool for the site.This isn't fixing the problem, only avoiding it. Wrap the dll's in exe, and call that exe. Then I shouldn't get the same issue. But this also seems like a hacky solution. Implement the mapper class differently ? But how else should I be doing the call? The other draw back is that other applications are using this mapper, so I'd need to change there code too. Thanks

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  • Why this Either-monad code does not type check?

    - by pf_miles
    instance Monad (Either a) where return = Left fail = Right Left x >>= f = f x Right x >>= _ = Right x this code frag in 'baby.hs' caused the horrible compilation error: Prelude> :l baby [1 of 1] Compiling Main ( baby.hs, interpreted ) baby.hs:2:18: Couldn't match expected type `a1' against inferred type `a' `a1' is a rigid type variable bound by the type signature for `return' at <no location info> `a' is a rigid type variable bound by the instance declaration at baby.hs:1:23 In the expression: Left In the definition of `return': return = Left In the instance declaration for `Monad (Either a)' baby.hs:3:16: Couldn't match expected type `[Char]' against inferred type `a1' `a1' is a rigid type variable bound by the type signature for `fail' at <no location info> Expected type: String Inferred type: a1 In the expression: Right In the definition of `fail': fail = Right baby.hs:4:26: Couldn't match expected type `a1' against inferred type `a' `a1' is a rigid type variable bound by the type signature for `>>=' at <no location info> `a' is a rigid type variable bound by the instance declaration at baby.hs:1:23 In the first argument of `f', namely `x' In the expression: f x In the definition of `>>=': Left x >>= f = f x baby.hs:5:31: Couldn't match expected type `b' against inferred type `a' `b' is a rigid type variable bound by the type signature for `>>=' at <no location info> `a' is a rigid type variable bound by the instance declaration at baby.hs:1:23 In the first argument of `Right', namely `x' In the expression: Right x In the definition of `>>=': Right x >>= _ = Right x Failed, modules loaded: none. why this happen? and how could I make this code compile ? thanks for any help~

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  • Cocoa & Cocoa Touch. How do I create an NSData object from a plain ole pointer?

    - by dugla
    I have malloc'd a whole mess of data in an NSOperation instance. I have a pointer: data = malloc(humungous_amounts_of_god_knows_what); uint8_t* data; How do I package this up as an NSData instance and return it to the main thread? I am assuming that after conversion to an NSData instance I can simply call: free(data); Yes? Also, back on the main thread how do I retrieve the pointer? Thanks, Doug

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  • Discover generic types

    - by vittore
    Thanks @dtb for help, he advised really need piece of code for generic service locator static class Locator { private static class LocatorEntry<T> where T : ... { public static IDataManager<T> instance; } public static void Register<T>(IDataManager<T> instance) where T : ... { LocatorEntry<T>.instance = instance; } public static IDataManager<T> GetInstance<T>() where T : ... { return LocatorEntry<T>.instance; } } However in my previous version I used reflection on assembly to discover a hundred of DataManager's I want to write an method discover like the following void Discover() { var pManager = new ProtocolSQLDataManager(); Register(pManager); var rManager = new ResultSQLDataManager(); Register(rManager); var gType = typeof(ISQLDataAccessManager<>); foreach (Type type in Assembly.GetExecutingAssembly().GetTypes()) { if (type.IsSubclassOf(gType) && !type.IsAbstract)) { var manager = Activator.CreateInstance(type); // put something here in order to make next line of code works Register<T>(manager); } } } How to cast type to appropriate type in order to make Register working( and call appropriate Register ?

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  • Edit the opposite side of a many to many relationship with django generic form

    - by Ed
    I have two models: class Actor(models.Model): name = models.CharField(max_length=30, unique = True) event = models.ManyToManyField(Event, blank=True, null=True) class Event(models.Model): name = models.CharField(max_length=30, unique = True) long_description = models.TextField(blank=True, null=True) In a previous question: http://stackoverflow.com/questions/2503243/django-form-linking-2-models-by-many-to-many-field, I created an EventForm with a save function: class EventForm(forms.ModelForm): class Meta: model = Event def save(self, commit=True): instance = forms.ModelForm.save(self) instance.actors_set.clear() for actor in self.cleaned_data['actors']: instance.actors_set.add(actors) return instance This allowed me to add m2m links from the other side of the defined m2m connection. Now I want to edit the entry. I've been using a generic function: def generic_edit(request, modelname, object_id): modelname = modelname.lower() form_class = form_dict[modelname] return update_object(request, form_class = form_class, object_id = object_id, template_name = 'createdit.html' ) but this pulls in all the info except the many-to-many selections saved to this object. I think I need to do something similar to this: http://stackoverflow.com/questions/1700202/editing-both-sides-of-m2m-in-admin-page, but I haven't figured it out. How do I use the generic update_object to edit the other side of many-to-many link?

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  • Problem in Closing Exe

    - by chandruswami
    In C#, I am using form1 as homescreen,.. while running exe from Debug folder, form1.exe appears in Process tab in task manager,... The problem is: Through form1 at runtime, i may create more instances of form1 while trying to close particular instance, the instances closed,.. but still exe appears in task manager. what i found: If i close the instances in the order what we created,.. all exe closes correctly,.. but if close the 4th instance and then 3rd instance,.. exe remains in task manager. (instead of 3rd and then 4th instance) I also used Application.Exit() but still the Exe remains in taskmanager,......

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  • Stream classes ... design, pattern for creating views over streams

    - by ToxicAvenger
    A question regarding the design of stream classes - I need a pattern to create independent views over a single stream instance (in my case for reading). A view would be a consecutive part of the stream. The problem I have with the stream classes is that the state (reading or writing) is coupled with the underlying data/storage. So if I need to partition a stream into different segments (whether segments overlap or not doesn't matter), I cannot easily create views over the stream, the views would store start and end position. Because reading from a view - which would translate to reading from the underlying stream adjusted based on the start/end positions - would change the state of the underlying stream instance. So what I could do is take a read on a view instance, adjust the Position of the stream, read the chunks I need. But I cannot do that concurrently. Why is it designed in such a way, and what kind of pattern could I implement to create independet views over a single stream instance which would allow to read/write independently (and concurrently)?

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  • Help creating a ColumnName Convention using FluentNHibernate

    - by Rafael E. Belliard
    I've been trying to specify a custom naming convention for my database table columns. So far, I have been able to setup a convention for the table's name, but not the actual columns. I've seen a few guides on the internet, but they're not working using the latest Fluent NHibernate (1.0.0 RTM). public class CamelCaseSplitNamingConvention : IClassConvention, IComponentConvention { public void Apply(IClassInstance instance) { instance.Table(instance.EntityType.Name.ChangeCamelCaseToUnderscore()); } public void Apply(IComponentInstance instance) { // is this the correct call for columns? If not, which one? } } Please help.

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  • Working with hibernate/DAO problems

    - by Gandalf StormCrow
    Hello everyone here is my DAO class : public class UsersDAO extends HibernateDaoSupport { private static final Log log = LogFactory.getLog(UsersDAO.class); protected void initDao() { //do nothing } public void save(User transientInstance) { log.debug("saving Users instance"); try { getHibernateTemplate().saveOrUpdate(transientInstance); log.debug("save successful"); } catch (RuntimeException re) { log.error("save failed", re); throw re; } } public void update(User transientInstance) { log.debug("updating User instance"); try { getHibernateTemplate().update(transientInstance); log.debug("update successful"); } catch (RuntimeException re) { log.error("update failed", re); throw re; } } public void delete(User persistentInstance) { log.debug("deleting Users instance"); try { getHibernateTemplate().delete(persistentInstance); log.debug("delete successful"); } catch (RuntimeException re) { log.error("delete failed", re); throw re; } } public User findById( java.lang.Integer id) { log.debug("getting Users instance with id: " + id); try { User instance = (User) getHibernateTemplate() .get("project.hibernate.Users", id); return instance; } catch (RuntimeException re) { log.error("get failed", re); throw re; } } } Now I wrote a test class(not a junit test) to test is everything working, my user has these fields in the database : userID which is 5characters long string and unique/primary key, and fields such as address, dob etc(total 15 columns in database table). Now in my test class I intanciated User added the values like : User user = new User; user.setAddress("some address"); and so I did for all 15 fields, than at the end of assigning data to User object I called in DAO to save that to database UsersDao.save(user); and save works just perfectly. My question is how do I update/delete users using the same logic? Fox example I tried this(to delete user from table users): User user = new User; user.setUserID("1s54f"); // which is unique key for users no two keys are the same UsersDao.delete(user); I wanted to delete user with this key but its obviously different can someone explain please how to do these. thank you

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  • RSKeyMgmt -r unable to remove installtion ID

    - by Eves
    I have backed up databases on one 2005 SQL Server and have restored those databases on a second 2005 SQL Server. I am currently trying to remove the new server's OLD key instance ID using the Reporting Services Key Manager (RSKeyMgmt -r). Prior to running the removal command the list of the current instances shows the new server's OLD instance ID as well as the NEW instance ID from the first SQL Server. Executing the RSKeyMgmt -r command results in: "The command completed successfully". However, when I recheck the listing of current instance IDs I see both the OLD and NEW instance IDs. In addition, when I check the Application Event Viewer I see an error: Report Server Windows Service (MSSQLSERVER) has not been granted access to the catalog content Does anyone know why I would be getting the above application error? Or...does anyone know what I would need to do to give access to the catalog to the Report Server Window Service? The first SQL Server where the databases were backed up is an Enterprise edition SQL Server and the second SQL Server where the databases were restored is Standard edition. Could this be the cause of the problem? Is there a way to make this backup and restore migration work?

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  • Inject filter into Zend_View

    - by chelmertz
    Hi! I wish to set some properties in MyFilter with constructor injection but it seems impossible with Zend_View::addFilter(string $filter_class_name) since it loads a new instance upon usage. MyFilter implements Zend_Filter_Interface. Can I somehow inject an instance of a filter to an instance of Zend_View?

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  • Using IOperationBehavior to supply a WCF parameter

    - by Chris Kemp
    This is my first step into the world of stackoverflow, so apologies if I cock anything up. I'm trying to create a WCF Operation which has a parameter that is not exposed to the outside world, but is instead automatically passed into the function. So the world sees this: int Add(int a, int b) But it is implemented as: int Add(object context, int a, int b) Then, the context gets supplied by the system at run-time. The example I'm working with is completely artificial, but mimics something that I'm looking into in a real-world scenario. I'm able to get close, but not quite the whole way there. First off, I created a simple method and wrote an application to confirm it works. It does. It returns a + b and writes the context as a string to my debug. Yay. [OperationContract] int Add(object context, int a, int b); I then wrote the following code: public class SupplyContextAttribute : Attribute, IOperationBehavior { public void Validate(OperationDescription operationDescription) { if (!operationDescription.Messages.Any(m => m.Body.Parts.First().Name == "context")) throw new FaultException("Parameter 'context' is missing."); } public void ApplyDispatchBehavior(OperationDescription operationDescription, DispatchOperation dispatchOperation) { dispatchOperation.Invoker = new SupplyContextInvoker(dispatchOperation.Invoker); } public void ApplyClientBehavior(OperationDescription operationDescription, ClientOperation clientOperation) { } public void AddBindingParameters(OperationDescription operationDescription, BindingParameterCollection bindingParameters) { // Remove the 'context' parameter from the inbound message operationDescription.Messages[0].Body.Parts.RemoveAt(0); } } public class SupplyContextInvoker : IOperationInvoker { readonly IOperationInvoker _invoker; public SupplyContextInvoker(IOperationInvoker invoker) { _invoker = invoker; } public object[] AllocateInputs() { return _invoker.AllocateInputs().Skip(1).ToArray(); } private object[] IntroduceContext(object[] inputs) { return new[] { "MyContext" }.Concat(inputs).ToArray(); } public object Invoke(object instance, object[] inputs, out object[] outputs) { return _invoker.Invoke(instance, IntroduceContext(inputs), out outputs); } public IAsyncResult InvokeBegin(object instance, object[] inputs, AsyncCallback callback, object state) { return _invoker.InvokeBegin(instance, IntroduceContext(inputs), callback, state); } public object InvokeEnd(object instance, out object[] outputs, IAsyncResult result) { return _invoker.InvokeEnd(instance, out outputs, result); } public bool IsSynchronous { get { return _invoker.IsSynchronous; } } } And my WCF operation now looks like this: [OperationContract, SupplyContext] int Amend(object context, int a, int b); My updated references no longer show the 'context' parameter, which is exactly what I want. The trouble is that whenver I run the code, it gets past the AllocateInputs and then throws an Index was outside the bounds of the Array. error somewhere in the WCF guts. I've tried other things, and I find that I can successfully change the type of the parameter and rename it and have my code work. But the moment I remove the parameter it falls over. Can anyone give me some idea of how to get this to work (or if it can be done at all).

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  • Python New-style Classes and the Super Function

    - by sfjedi
    This is not the result I expect to see: class A(dict): def __init__(self, *args, **kwargs): self['args'] = args self['kwargs'] = kwargs class B(A): def __init__(self, *args, **kwargs): super(B, self).__init__(args, kwargs) print 'Instance A:', A('monkey', banana=True) #Instance A: {'args': ('monkey',), 'kwargs': {'banana': True}} print 'Instance B:', B('monkey', banana=True) #Instance B: {'args': (('monkey',), {'banana': True}), 'kwargs': {}} I'm just trying to get classes A and B to have consistent values set. I'm not sure why the kwargs are being inserted into the args, but I'm to presume I am either calling init() wrong from the subclass or I'm trying to do something that you just can't do. Any tips?

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