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  • Polymorphic classes in templates

    - by soxarered
    Let's say we have a class hierarchy where we have a generic Animal class, which has several classes directly inherit from it (such as Dog, Cat, Horse, etc..). When using templates on this inheritance hierarchy, is it legal to just use SomeTemplateClass<Animal> and then shove in Dogs and Cats and Horses into this templated object? For example, assume we have a templated Stack class, where we want to host all sorts of animals. Can I simply state Stack<Animal> s; Dog d; s.push(d); Cat c; s.push(c);

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  • Inheriting from multiple classes in Java (and possibly not using interface)

    - by sheidaei
    So, let's say we have classes A, B and C and I want to inherit from all those classes and have another class called D, it can be done using implements and interfaces in Java. But let's say we don't want to use this simple solution, would you be able to inherit class D from classes A, B and C in any other way in Java? (This question might be related to design patterns, it has been brought up after challenging my colleague at lunch discussing design patterns) I don't think there is any other way to have multiple inheritance in Java other than using multiple interfaces.

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  • Property hiding and reflection (C#)

    - by tehMick
    Declaring a property in a derived class that matches the name of a property in the base class "hides" it (unless it overrides it with the override keyword). Both the base and derived class properties will be returned by Type.GetProperties() if their types don't match. However, if their types do match, shockingly only the derived class's property is returned. For instance: class A { protected double p; public int P { get { return (int)p; } set { p = value; } } } class B : A { public new int P { get { return (int)p; } set { p = value; } } } class C : B { public new float P { get { return (float)p; } set { p = value; } } } Calling typeof(C).GetProperties() will only return B.P and C.P. Is it possible to call GetProperties() in a way that returns all three? There is almost certainly a way to do it by traversing the inheritance hierarchy, but is there a cleaner solution?

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  • Subtyping and assignment in Java

    - by Danrex
    Arghh I just know people are going to hate me for asking this... I was just playing around with inheritance and I noticed you can instantiate a subclass object in one of two ways when you write code. So then I wondered if there is any functional difference between these two methods. So in the code below, does this produce the exact same result...a MountainBike object, or is there some difference I should know about? Bicycle is the superclass for this example. If I do Bicycle bike or MountainBike bike I am effectively making a MountainBike due to new MountainBike()? So basically the difference is just semantics at this point? Bicycle bike = new MountainBike(); MountainBike bike = new MountainBike();

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  • Using custom DataContractResolver in WCF, to transport inheritance trees involving generics

    - by Benson
    I've got a WCF service, in which there are operations which accept a non-generic base class as parameter. [DataContract] class Foo { ... } This base class is in turn inherited, by such generics classes as [DataContract] class Bar : Foo { ... } To get this to work, I'd previously have to register KnownTypes for the Foo class, and have these include all possible variations of Bar (such as Bar, Bar and even Bar). With the DataContractResolver in .NET 4, however, I should be able to build a resolver which properly stores (and restores) the classes. My questions: Are DataContractResolvers typically only used on the service side, and not by the client? If so, how would that be useful in this scenario? Am I wrong to write a DataContractResolver which serializes the fully qualified type name of a generic type, such as Bar1[List1[string, mscorlib], mscorlib] ? Couldn't the same DataContractResolver on the client side restore these types?

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  • How to expose service contract interfaces with multiple inheritance in WCF service on single endpoin

    - by Vaibhav Gawali
    I have only simple data types in method signature of service (such as int, string). My service class implements single ServiceContract interface say IMathService, and this interface in turn inherits from some other base interface say IAdderService. I want to expose the MathService using interface contract IAdderService as a service on a single endpoint. However some of the clinet's which know about IMathService should be able to access the extra services provided by IMathService on that single endpoint i.e. by just typecasting IAdderService to IMathService. //Interfaces and classes at server side [ServiceContract] public interface IAdderService { [OperationContract] int Add(int num1, int num2); } [ServiceContract] public interface IMathService : IAdderService { [OperationContract] int Substract(int num1, int num2); } public class MathService : IMathService { #region IMathService Members public int Substract(int num1, int num2) { return num1 - num2; } #endregion #region IAdderService Members public int Add(int num1, int num2) { return num1 + num2; } #endregion } //Run WCF service as a singleton instace MathService mathService = new MathService(); ServiceHost host = new ServiceHost(mathService); host.Open(); Server side Configuration: <configuration> <system.serviceModel> <services> <service name="IAdderService" behaviorConfiguration="AdderServiceServiceBehavior"> <endpoint address="net.pipe://localhost/AdderService" binding="netNamedPipeBinding" bindingConfiguration="Binding1" contract="TestApp.IAdderService" /> <endpoint address="mex" binding="mexNamedPipeBinding" contract="IMetadataExchange" /> <host> <baseAddresses> <add baseAddress="net.pipe://localhost/AdderService"/> </baseAddresses> </host> </service> </services> <bindings> <netNamedPipeBinding> <binding name="Binding1" > <security mode = "None"> </security> </binding > </netNamedPipeBinding> </bindings> <behaviors> <serviceBehaviors> <behavior name="AdderServiceServiceBehavior"> <serviceMetadata /> <serviceDebug includeExceptionDetailInFaults="True" /> </behavior> </serviceBehaviors> </behaviors> </system.serviceModel> </configuration> Client Side imeplementation: IAdderService adderService = new ChannelFactory<IAdderService>("AdderService").CreateChannel(); int result = adderService.Add(10, 11); IMathService mathService = adderService as IMathService; result = mathService.Substract(100, 9); Client side configuration: <configuration> <system.serviceModel> <client> <endpoint name="AdderService" address="net.pipe://localhost/AdderService" binding="netNamedPipeBinding" bindingConfiguration="Binding1" contract="TestApp.IAdderService" /> </client> <bindings> <netNamedPipeBinding> <binding name="Binding1" maxBufferSize="65536" maxConnections="10"> <security mode = "None"> </security> </binding > </netNamedPipeBinding> </bindings> </system.serviceModel> </configuration> Using above code and configuration I am not able to typecast IAdderService instnace to IMathService, it fails and I get null instance of IMathService at client side. My observation is if server exposes IMathService to client then client can safely typecast to IAdderService and vice versa is also possible. However if server exposes IAdderService then the typecast fails. Is there any solution to this? or am I doing it in a wrong way.

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  • Inheritance with POCO entities in Entity Framework 4

    - by Juvaly
    Hi All, I have a Consumer class and a BillableConsumer : Consumer class. When trying to do any operation on my "Consumers" set, I get the error message "Object mapping could not be found for Type with identity Models.BillableConsumer. From the CSDL: <EntityType Name="BillableConsumer" BaseType="Models.Consumer"> <Property Type="String" Name="CardExpiratoin" Nullable="false" /> <Property Type="String" Name="CardNumber" Nullable="false" /> <Property Type="String" Name="City" Nullable="false" /> <Property Type="String" Name="Country" Nullable="false" /> <Property Type="String" Name="CVV" Nullable="false" /> <Property Type="String" Name="NameOnCard" Nullable="false" /> <Property Type="String" Name="PostalCode" Nullable="false" /> <Property Type="String" Name="State" /> <Property Type="String" Name="StreetAddress" Nullable="false" /> </EntityType> From the C-S: <EntitySetMapping Name="Consumers"> <EntityTypeMapping TypeName="IsTypeOf(Models.Consumer)"> <MappingFragment StoreEntitySet="consumer"> <ScalarProperty Name="LoginID" ColumnName="LoginID" /> <ScalarProperty Name="FirstName" ColumnName="FirstName" /> <ScalarProperty Name="LastName" ColumnName="LastName" /> </MappingFragment> </EntityTypeMapping> <EntityTypeMapping TypeName="IsTypeOf(Models.BillableConsumer)"> <MappingFragment StoreEntitySet="billinginformation"> <ScalarProperty Name="CardExpiratoin" ColumnName="CardExpiratoin" /> <ScalarProperty Name="CardNumber" ColumnName="CardNumber" /> <ScalarProperty Name="City" ColumnName="City" /> <ScalarProperty Name="Country" ColumnName="Country" /> <ScalarProperty Name="CVV" ColumnName="CVV" /> <ScalarProperty Name="LoginID" ColumnName="LoginID" /> <ScalarProperty Name="NameOnCard" ColumnName="NameOnCard" /> <ScalarProperty Name="PostalCode" ColumnName="PostalCode" /> <ScalarProperty Name="State" ColumnName="State" /> <ScalarProperty Name="StreetAddress" ColumnName="StreetAddress" /> </MappingFragment> </EntityTypeMapping> </EntitySetMapping> Is this because I did not specifically add the BillableConsumer entity to the object set? How do I do that in a POCO scenario? Thanks! UPDATE: I decided to test whether or not POCOs generated with the T4 template would solve the problem and they did. The most annoying part is that when I restored my original classes from SVN to try and figure out how they are different - they worked as well!! Not adding this as an answer because someone else might have an actual explanation...

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  • Avoid web.config inheritance in child web application using inheritInChildApplications

    - by Blankman
    I am trying to add <location inheritInChildApplications="false"> to my parent web application's web.config but it doesn't seem to be working. My parent's web.config has: <configuration> <configSections> </configSections> // 10 or so custom config sections like log4net, hibernate, <connectionStrings> </connectionStrings> <appSettings> </appSettings> <system.diagnostics> </system.diagnostics> <system.web> <webParts> </webParts> <membership> </membership> <compilation> </compilation> </system.web> <location ..> <system.web> </system.web> </location> <system.webServer> </system.webServer> My child web application is setup as an application in IIS, and is inheriting from the parent's web.config which is causing problems. Where exactly should I place the <location inheritInChildApplications="false"> so it ignores all the various web.config settings?

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  • WPF: disable inheritance of properties

    - by Maximilian Csuk
    Hi! I would like to use a TabControl as the main navigation in the application I am working on. So I would like to make the font in the headers of the TabItems bigger and also give it another background-color. However, I do not want this to be inherited. For example, if I use this code: <TabControl FontSize="18pt"> <TabItem Header="Tab 1"> <Button>Button 1</Button> </TabItem> </TabControl> The font in the button is also 18pt big. I know that this is normal dependency property behaviour because the property is inherited, but that's not what I want in this case. I would like to change the TabItems without changing anything in the children. Isn't that possible? Because re-setting all children to default values is a PITA. Thanks for your time.

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  • MVC2 DataAnnotations validation with inheritance

    - by bhiku
    Hi, I have a .NET 2.0 class the properties of which are marked virtual.I need to use the class as a model in a MVC2 application. So, I have created a .NET 3.5 class inheriting from the .NET 2.0 class and added the DataAnnotations attributes to the overriden properties in the new class. A snippet of what I have done is below // .NET 2.0 class public class Customer { private string _firstName = ""; public virtual string FirstName { get { return _firstName; } set { _firstName = value; } } } // .NET 3.5 class public class MVCCustomer : Customer { [Required(ErrorMessage="Firstname is required")] public override string FirstName { get { return base.FirstName; } set { base.FirstName = value; } } } I have used the class as the model for a MVC2 view using the HtmlFor helpers. Serverside validation works correctly but the client side validation does not. Specifically the validation error is not displayed on the page. What am I missing, or is it only possible to do this using buddy classes. Thanks.

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  • JS: variable inheritance in anonymous functions - scope

    - by tkSimon
    hey guys, someone from doctype sent me here. long story short: var o="before"; x = function() //this needs to be an anonymous function { alert(o); //the variable "o" is from the parent scope }; o="after"; //this chages "o" in the anonymous function x(); //this results in in alert("after"); //which is not the way i want/need it in reality my code is somewhat more complex. my script iterates through many html objects and adds an event listener each element. i do this by declaring an anonymous function for each element and call another function with an ID as argument. that ID is represented by the "o"-variable in this example. after some thinking i understand why it is the way it is, but is there a way to get js to evaluate o as i declare the anonymous function without dealing with the id attribute and fetching my ID from there? my full source code is here: http://pastebin.com/GMieerdw the anonymous function is on line 303

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  • How to approach ninject container/kernel in inheritance situation

    - by Bas
    I have the following situation: class RuleEngine {} abstract class RuleImplementation {} class RootRule : RuleImplementation {} class Rule1 : RuleImplementation {} class Rule2 : RuleImplementation {} The RuleEngine is injected by Ninject and has a kernel at it's disposal, the role of the RuleEngine is to fire off the root rule, which on it's turn will load all the other rules also using Ninject, but using a different Module and creating a new Kernel. Now my question is, some of the rules require some dependencies which I want to inject using Ninject. What would be the best way to create the kernel for these rules and also still do proper unit testing with it? (the kernel shouldn't become a real pain in my tests) I've been thinking of the following possibilitys: The kernel that I use in the RuleEngine class could be tossed around to RuleImplementation and thus be available for every rule. But tossing around Kernels isn't really something I wish to do. When creating the rules, I could give the kernel (which creates the rules) as a constructor argument for each rule. I could create a method inside the RuleImplementation which creates a kernel and makes it possible for the rules to retrieve the kernel using a get() in the abstract class Whats the convention of passing around/creating kernels? Just create new kernels, or reuse them?

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  • How do I stop inheritance in xaml?

    - by cfouche
    Hi Let's say I have some Control that has been disabled. It contains a bunch of elements, but I want one of those child elements to remain enabled. Something like this: <ContentControl IsEnabled="False"> <Border> <Button Content="Button" IsEnabled="True"/> </Border> </ContentControl> So in this example, the Button's IsEnabled="True" setting gets overridden by its parent. Is there a way of stopping this from happening? This seems like a strange thing to be doing, but I have a situation where, when a Control is disabled and a user mouses down on it, I still want an event to be triggered. I read in WPF Unleashed that wrapping something in a Frame control, "..isolates the content from the rest of the UI [and] properties that would normally be inherited down the element tree stop when they reach the Frame", but wrapping the Button in the example above in a Frame doesn't work. Am I on the wrong track here?

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  • C# inheritance XmlSerializer

    - by ikurtz
    greetngs, i have two classes: [Serializable] public class FireGridUnit { public GridUnit FireGridLocation { get; set; } } [Serializable] public class FireResult: FireGridUnit { public bool Hit { get; set; } public bool ShipDestroyed { get; set; } public Ship.ValidShips DestroyedShipType {get; set;} public bool Win { get; set; } } as you see FireResult inherits FireGrdUnit. in my code when i try to use them i get a runtime error: Unable to cast object of type 'NietzscheBattleships.FireGridUnit' to type 'NietzscheBattleships.FireResult'. is this because if i am serializing the class has to be independant ie not be inherited? many thanks.

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  • web.config inheritance problem

    - by abszero
    Hello everyone, I am having an issue when I try and prevent inhertiance from a parent web.config down to a child specifically related to the node. My parent web.config contains about a dozen appSettings values while my child web.config contains none. Now, I originally began wrapping around only my system.net, web, etc nodes however when I ran my child application I recieved the following error: The configuration section 'appSettings' cannot be read because it is missing a section declaration I really wasn't sure what this meant and a google search didn't yield me any decent results so I attempted to move the location node to also encompass the field in my parent web.config but to no avail. My child web.config is pretty vanilla so I am not sure what the problem is. Any help you can provide would be greatly appreciated! Thanks. The child config is completely vanilla except for the addition of an Xml Namespace and a 'clear' in the config sections as follows: <configuration xmlns="http://schemas.microsoft.com/.NetConfiguration/v2.0"> <configSections> <clear /> <sectionGroup name="system.web.extensions" type="System.Web.Configuration.SystemWebExtensionsSectionGroup, System.Web.Extensions, Version=3.5.0.0, Culture=neutral, PublicKeyToken=31BF3856AD364E35"> <sectionGroup name="scripting" type="System.Web.Configuration.ScriptingSectionGroup, System.Web.Extensions, Version=3.5.0.0, Culture=neutral, PublicKeyToken=31BF3856AD364E35"> <section name="scriptResourceHandler" type="System.Web.Configuration.ScriptingScriptResourceHandlerSection, System.Web.Extensions, Version=3.5.0.0, Culture=neutral, PublicKeyToken=31BF3856AD364E35" requirePermission="false" allowDefinition="MachineToApplication"/> <sectionGroup name="webServices" type="System.Web.Configuration.ScriptingWebServicesSectionGroup, System.Web.Extensions, Version=3.5.0.0, Culture=neutral, PublicKeyToken=31BF3856AD364E35"> <section name="jsonSerialization" type="System.Web.Configuration.ScriptingJsonSerializationSection, System.Web.Extensions, Version=3.5.0.0, Culture=neutral, PublicKeyToken=31BF3856AD364E35" requirePermission="false" allowDefinition="Everywhere" /> <section name="profileService" type="System.Web.Configuration.ScriptingProfileServiceSection, System.Web.Extensions, Version=3.5.0.0, Culture=neutral, PublicKeyToken=31BF3856AD364E35" requirePermission="false" allowDefinition="MachineToApplication" /> <section name="authenticationService" type="System.Web.Configuration.ScriptingAuthenticationServiceSection, System.Web.Extensions, Version=3.5.0.0, Culture=neutral, PublicKeyToken=31BF3856AD364E35" requirePermission="false" allowDefinition="MachineToApplication" /> <section name="roleService" type="System.Web.Configuration.ScriptingRoleServiceSection, System.Web.Extensions, Version=3.5.0.0, Culture=neutral, PublicKeyToken=31BF3856AD364E35" requirePermission="false" allowDefinition="MachineToApplication" /> </sectionGroup> </sectionGroup> </sectionGroup> </configSections> The error in question is thrown at The parent web.config is far from vanilla as it is part of an Umbraco install. Here is the corrosponding section from the parent config <configuration xmlns="http://schemas.microsoft.com/.NetConfiguration/v2.0"> <configSections> <section name="urlrewritingnet" restartOnExternalChanges="true" requirePermission="false" type="UrlRewritingNet.Configuration.UrlRewriteSection, UrlRewritingNet.UrlRewriter" /> <!-- ASPNETAJAX --> <sectionGroup name="system.web.extensions" type="System.Web.Configuration.SystemWebExtensionsSectionGroup, System.Web.Extensions, Version=1.0.61025.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35"> <sectionGroup name="scripting" type="System.Web.Configuration.ScriptingSectionGroup, System.Web.Extensions, Version=1.0.61025.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35"> <section name="scriptResourceHandler" type="System.Web.Configuration.ScriptingScriptResourceHandlerSection, System.Web.Extensions, Version=1.0.61025.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35" requirePermission="false" allowDefinition="MachineToApplication" /> <sectionGroup name="webServices" type="System.Web.Configuration.ScriptingWebServicesSectionGroup, System.Web.Extensions, Version=1.0.61025.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35"> <section name="jsonSerialization" type="System.Web.Configuration.ScriptingJsonSerializationSection, System.Web.Extensions, Version=1.0.61025.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35" requirePermission="false" allowDefinition="Everywhere" /> <section name="profileService" type="System.Web.Configuration.ScriptingProfileServiceSection, System.Web.Extensions, Version=1.0.61025.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35" requirePermission="false" allowDefinition="MachineToApplication" /> <section name="authenticationService" type="System.Web.Configuration.ScriptingAuthenticationServiceSection, System.Web.Extensions, Version=1.0.61025.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35" requirePermission="false" allowDefinition="MachineToApplication" /> </sectionGroup> </sectionGroup> </sectionGroup> <sectionGroup name="applicationSettings" type="System.Configuration.ApplicationSettingsGroup, System, Version=2.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089"> <section name="umbraco.presentation.Properties.Settings" type="System.Configuration.ClientSettingsSection, System, Version=2.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089" requirePermission="false" /> </sectionGroup> </configSections> The next line after the ConfigSections is: <location path="." inheritInChildApplications="false"> AppSettings, CnxStrings, System.Web, Net, WebServer settings </location>

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  • Selective Inheritance Python

    - by user1682595
    I am making a python program which is using classes, I want one class to only selectively inherit from another e.g: class X(object): def __init__(self): self.hello = 'hello' class Y(object): def __init__(self): self.moo = 'moo' class Z(): def __init__(self, mode): if mode == 'Y': # Class will now Inherit from Y elif mode == 'X': # Class will now Inherit for X How can I do this without making another class?

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  • Webservice complex types and class inheritance

    - by pygorex1
    Using the following Webservice definition using aClientArgs as a complex type: [System.Web.Script.Services.ScriptService] public class Controller : System.Web.Services.WebService { [WebMethod] public void save_client(aClientArgs client) { // Save client data } } Then defining aClientArgs as a sub-class: public class aArgs { public string id = null; public string name = null; } public class aClientArgs : aArgs { public string address = null; public string website = null; } Returns the following WSDL fragment for the save_client args: <save_client xmlns="http://tempuri.org/"> <client> <address>string</address> <website>string</website> </client> </save_client> When I'm expecting the following: <save_client xmlns="http://tempuri.org/"> <client> <id>string</id> <name>string</name> <address>string</address> <website>string</website> </client> </save_client> So it appears that the .NET WebService is not treating inherited properties as arguments/variables for purposes of a web service. How do I get .NET to also use the properties of the base class?

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  • Annotate over Multi-table Inheritance in Django

    - by user341584
    I have a base LoggedEvent model and a number of subclass models like follows: class LoggedEvent(models.Model): user = models.ForeignKey(User, blank=True, null=True) timestamp = models.DateTimeField(auto_now_add=True) class AuthEvent(LoggedEvent): good = models.BooleanField() username = models.CharField(max_length=12) class LDAPSearchEvent(LoggedEvent): type = models.CharField(max_length=12) query = models.CharField(max_length=24) class PRISearchEvent(LoggedEvent): type = models.CharField(max_length=12) query = models.CharField(max_length=24) Users generate these events as they do the related actions. I am attempting to generate a usage-report of how many of each event-type each user has caused in the last month. I am struggling with Django's ORM and while I am close I am running into a problem. Here is the query code: ef usage(request): # Calculate date range today = datetime.date.today() month_start = datetime.date(year=today.year, month=today.month - 1, day=1) month_end = datetime.date(year=today.year, month=today.month, day=1) - datetime.timedelta(days=1) # Search for how many LDAP events were generated per user, last month baseusage = User.objects.filter(loggedevent__timestamp__gte=month_start, loggedevent__timestamp__lte=month_end) ldapusage = baseusage.exclude(loggedevent__ldapsearchevent__id__lt=1).annotate(count=Count('loggedevent__pk')) authusage = baseusage.exclude(loggedevent__authevent__id__lt=1).annotate(count=Count('loggedevent__pk')) return render_to_response('usage.html', { 'ldapusage' : ldapusage, 'authusage' : authusage, }, context_instance=RequestContext(request)) Both ldapusage and authusage are both a list of users, each user annotated with a .count attribute which is supposed to represent how many particular events that user generated. However in both lists, the .count attributes are the same value. Infact the annotated 'count' is equal to how many events that user generated, regardless of type. So it would seem that my specific authusage = baseusage.exclude(loggedevent__authevent__id__lt=1) isn't excluding by subclass. I have tried id_lt=1, id_isnull=True, and others. Halp.

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  • edmx - The operation could not be completed - After adding Inheritance

    - by vdh_ant
    Hey guys I have an edmx model which I have draged 2 tables onto - One called 'File' and the other 'ApplicaitonFile'. These two tables have a 1 to 1 relationship in the database. If I stop here everything works fine. But in my model, I want 'ApplicaitonFile' to inherit from 'File'. So I delete the 1 to 1 relationship then configure 'ApplicaitonFile' from 'File' and then remove the FileId from 'ApplicaitonFile' which was the primary key. (Note I am following the instructions from here). If I leave the model open at this point everything is fine, but as soon as I close it, if I try and reopen it again I get the following error "The operation could not be completed". I have been searching for a solution and found this - http://stackoverflow.com/questions/944050/entity-model-does-not-load but as far as I can tell I don't have a duplicate InheritanceConnectors (although I don't know exactly what I'm looking for but I can't see anything out of the ordinary - like 2 connectors with the same name) and the relationship I originally have is a 1 to 1 not a 1 to 0..1 Any ideas???

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  • Is currying just a way to avoid inheritance?

    - by Alex Mcp
    So my understanding of currying (based on SO questions) is that it lets you partially set parameters of a function and return a "truncated" function as a result. If you have a big hairy function takes 10 parameters and looks like function (location, type, gender, jumpShot%, SSN, vegetarian, salary) { //weird stuff } and you want a "subset" function that will let you deal with presets for all but the jumpShot%, shouldn't you just break out a class that inherits from the original function? I suppose what I'm looking for is a use case for this pattern. Thanks!

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  • @webservice inheritance java

    - by javamonkey79
    I am trying to build a java ee webservice that has a common base class, but the child classes are the actual @webservice classes (and expose the parent class methods as @webmethod's) Like this: public abstract class Parent { @WebMethod public void doSomething(){//...does stuff} } @WebService public class Child extends Parent {} I've tried (and have failed): - annotating the parent class as a webservice as well - making sure all parent methods are annotated with @WebMethod Is this possible, if so, how?

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  • ValueError with multi-table inheritance in Django Admin

    - by jorde
    I created two new classes which inherit model Entry: class Entry(models.Model): LANGUAGE_CHOICES = settings.LANGUAGES language = models.CharField(max_length=2, verbose_name=_('Comment language'), choices=LANGUAGE_CHOICES) user = models.ForeignKey(User) country = models.ForeignKey(Country, null=True, blank=True) created = models.DateTimeField(auto_now=True) class Comment(Entry): comment = models.CharField(max_length=2000, blank=True, verbose_name=_('Comment in English')) class Discount(Entry): discount = models.CharField(max_length=2000, blank=True, verbose_name=_('Comment in English')) coupon = models.CharField(max_length=2000, blank=True, verbose_name=_('Coupon code if needed')) After adding these new models to admin via admin.site.register I'm getting ValueError when trying to create a comment or a discount via admin. Adding entries works fine. Error msg: ValueError at /admin/reviews/discount/add/ Cannot assign "''": "Discount.discount" must be a "Discount" instance. Request Method: GET Request URL: http://127.0.0.1:8000/admin/reviews/discount/add/ Exception Type: ValueError Exception Value: Cannot assign "''": "Discount.discount" must be a "Discount" instance. Exception Location: /Library/Python/2.6/site-packages/django/db/models/fields/related.py in set, line 211 Python Executable: /usr/bin/python Python Version: 2.6.1

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  • PowerShell Cmdlet Parameters and Inheritance

    - by Adam Driscoll
    I have an interface: public interface X {} I have a class: public class Y : X {} I have one cmdlet: [Cmdlet("Get", "Y")] public class GetYCmdlet : PSCmdlet { protected override void ProcessRecord() { WriteObject(new Y()); } } I have another cmdlet: [Cmdlet("Set", "X")] public class SetYCmdlet : PSCmdlet { [Parameter] public X SomeObj {get;set;} } When I do this: $y = Get-Y Set-X -SomeObj $y I get this: Could not convert "Y" to "X". Method not supported. Any ideas?

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  • Expression Tree with Property Inheritance causes an argument exception

    - by Adam Driscoll
    Following this post: link text I'm trying to create an expression tree that references the property of a property. My code looks like this: public interface IFoo { void X {get;set;} } public interface IBar : IFoo { void Y {get;set;} } public interface IFooBarContainer { IBar Bar {get;set;} } public class Filterer { //Where T = "IFooBarContainer" public IQueryable<T> Filter<T>(IEnumerable<T> collection) { var argument = Expression.Parameter(typeof (T), "item"); //... //where propertyName = "IBar.X"; PropertyOfProperty(argument, propertyName); } private static MemberExpression PropertyOfProperty(Expression expr, string propertyName) { return propertyName.Split('.').Aggregate<string, MemberExpression>(null, (current, property) => Expression.Property(current ?? expr, property)); } } I receive the exception: System.ArgumentException: Instance property 'X' is not defined for type 'IBar' ReSharper turned the code in the link above into the condensed statement in my example. Both forms of the method returned the same error. If I reference IBar.Y the method does not fail.

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  • metaclass multiple inheritance inconsistency

    - by Matt Anderson
    Why is this: class MyType(type): def __init__(cls, name, bases, attrs): print 'created', cls class MyMixin: __metaclass__ = MyType class MyList(list, MyMixin): pass okay, and works as expected: created <class '__main__.MyMixin'> created <class '__main__.MyList'> But this: class MyType(type): def __init__(cls, name, bases, attrs): print 'created', cls class MyMixin: __metaclass__ = MyType class MyObject(object, MyMixin): pass Is not okay, and blows up thusly?: created <class '__main__.MyMixin'> Traceback (most recent call last): File "/tmp/junk.py", line 11, in <module> class MyObject(object, MyMixin): pass TypeError: Error when calling the metaclass bases Cannot create a consistent method resolution order (MRO) for bases object, MyMixin

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