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• insertNewObjectForEntityForName: inManagedObjectContext: returning NSNumber bug?

  - by beinstein

  I'm relatively well versed in CoreData and have been using it for several years with little or no difficulty. All of a sudden I'm now dumbfounded by an error. For the life of me, I can't figure out why insertNewObjectForEntityForName:inManagedObjectContext: is all of a sudden returning some sort of strange instance of NSNumber. GDB says the returned object is of the correct custom subclass of NSManagedObject, but when I go to print a description of the NSManagedObject itself, I get the following error: *** -[NSCFNumber objectID]: unrecognized selector sent to instance 0x3f26f50 What's even stranger, is that I'm able to set some relationships and attributes using setValue:forKey: and all is good. But when I try to set once specific relationship, I get this error: *** -[NSCFNumber entity]: unrecognized selector sent to instance 0x3f26f50 Has anyone ever encountered anything like this before? I've tried clean all targets, restarting everything, even changing the model to the relationship in question is a to-one instead of a to-many. Nothing makes any difference.

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• spring - @ContextConfiguration fail to load config file in src/test/resources

  - by robinmag

  Hi, I've tried to load the spring config file in src/test/resources classpath with the following abstract class: @RunWith(SpringJUnit4ClassRunner.class) @ContextConfiguration(locations={"classpath:/applicationContext.xml"}) public class BaseIntegrationTests { } I have the applicationContext.xml file in src/test/resources but spring cant load it. Thank you.

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• Django: Inherit Permssions from abstract models?

  - by lazerscience

  Is it possible to inherit permissions from an abstract model in Django? I can not really find anything about that. For me this doesn't work! class PublishBase(models.Model): class Meta: abstract = True get_latest_by = 'created' permissions = (('change_foreign_items', "Can change other user's items"),) EDIT: Not working means it fails silently. Permission is not created, as it wouldn't exist on the models inheriting from this class.

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• Advantage of using a static member function instead of an equivalent non-static member function?

  - by jonathanasdf

  I was wondering whether there's any advantages to using a static member function when there is a non-static equivalent. Will it result in faster execution (because of not having to care about all of the member variables), or maybe less use of memory (because of not being included in all instances)? Basically, the function I'm looking at is an utility function to rotate an integer array representing pixel colours an arbitrary number of degrees around an arbitrary centre point. It is placed in my abstract Bullet base class, since only the bullets will be using it and I didn't want the overhead of calling it in some utility class. It's a bit too long and used in every single derived bullet class, making it probably not a good idea to inline. How would you suggest I define this function? As a static member function of Bullet, of a non-static member function of Bullet, or maybe not as a member of Bullet but defined outside of the class in Bullet.h? What are the advantages and disadvantages of each?

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• NHibernate Unique Constraint on Name and Parent Object fails because NH inserts Null

  - by James

  Hi, I have an object as follows Public Class Bin Public Property Id As Integer Public Property Name As String Public Property Store As Store End Class Public Class Store Public Property Id As Integer Public Property Bins As IEnumerable(Of Bin) End Class I have a unique constraint in the database on Bin.Name and BinStoreID to ensure unique names within stores. However, when NHibernate persists the store, it first inserts the Bin records with a null StoreID before performing an update later to set the correct StoreID. This violates the Unique Key If I persist two stores with a Bin of the same name because The Name columns are the same and the StoreID is null for both. Is there something I can add to the mapping to ensure that the correct StoreID is included in the INSERT rather than performing an update later? We are using HiLo identity generation so we are not relying on DB generated identity columns Thanks James

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• How do I flag only one of the formsets in django admin?

  - by azuer88

  I have these (simplified) models: class Question(models.Model): question = models.CharField(max_length=60) class Choices(models.Model): question = models.ForeignKey(Question) text = models.CharField(max_length=60) is_correct = models.BooleanField(default=False) I've made Choices as an inline of Question (in admin). Is there a way to make sure that only one Choice will have is_correct = True? Ideally, is_correct will be displayed as a radio button when it is displayed in the admin formset (TabularInline). my admin.py has: from django.contrib import admin class OptionInline(admin.TabularInline): model = Option extra = 5 max_num = 5 class QuestionAdmin(admin.ModelAdmin): inlines = [OptionInline, ] admin.site.register(QType) admin.site.register(Question, QuestionAdmin)

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• Objective C, Linking Error with extern variable..

  - by LCYSoft

  I have a very simple java code like this. I don't have any idea how to do this in Objective C. Especially, the static part which calls the getLocalAddress() method and assign it into the static string variable. I know how to set a static variable and a static method in Objective but I dont know how to implement that static { } part in java. Thanks in advance... public class Address { public static String localIpAddress; static { localIpAddress = getLocalIpAddress(); } public Address() { } static String getLocalIpAddress() { //do something to get local ip address } } I added this in my .h file #import <Foundation/Foundation.h> extern NSString *localIpAddress; @class WifiAddrss; @interface Address : NSObject { } @end And my .m file looks like #import "Address.h" #import "WifiAddress.h" @implementation Address +(void)initialize{ if(self == [Address class]){ localIpAddress = [self getLocalIpAddress]; } } +(NSString *)getLocalIpAddress{ return address here } -(id)init{ self = [super init]; if (self == nil){ NSLog(@"init error"); } return self; } @end And Now I am getting a linking error and it complains about "extern NSString *localIpAddress" part. If I change the extern to static, it works fine. But what I wanted to do is that I want make the scope of "localIpAddress" variable as grobal. Since if I put "static" in front of a variable in Objective-C then the variable is only visible in the class. But this time, I want to make that as a grobal variable. So my question is how to make "localIpAddress" variable as a grobal variable which is initialized once when the first time Address class is created.. Thanks in advance...

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• Interfaces with structs, by reference using Generics

  - by Fraga

  I can't pass by reference an interface with a struct in it, what am I doing wrong? Here is the example code: class Processor<T> where T : new() { public Processor() { Data = new T(); } public T Data; } class PeriodsProcessor : Processor<Periods> { public PeriodsProcessor() { DataBase DB = new DataBase(); Console.WriteLine(Data.Value); DB.ModifyData<Period>(Data); Console.WriteLine(Data.Value); Console.ReadLine(); } } public class Period { public string Name; } public interface IDataTable<T> { string Value { get; set; } T Filter { get; set; } } [Serializable] public struct Periods : IDataTable<Period> { public string Value { get; set; } public Period Filter { get; set; } } public class DataBase { public void ModifyData<T>(IDataTable<T> data) where T : new() { data.Value = "CHANGE"; } } class Program { static void Main(string[] args) { PeriodsProcessor PeriodsProcessor = new PeriodsProcessor(); } }

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• list of polymorphic objects

  - by LivingThing

  I have a particular scenario below. The code below should print 'say()' function of B and C class and print 'B says..' and 'C says...' but it doesn't .Any ideas.. I am learning polymorphism so also have commented few questions related to it on the lines of code below. class A { public: // A() {} virtual void say() { std::cout << "Said IT ! " << std::endl; } virtual ~A(); //why virtual destructor ? }; void methodCall() // does it matters if the inherited class from A is in this method { class B : public A{ public: // virtual ~B(); //significance of virtual destructor in 'child' class virtual void say () // does the overrided method also has to be have the keyword 'virtual' { cout << "B Sayssss.... " << endl; } }; class C : public A{ public: //virtual ~C(); virtual void say () { cout << "C Says " << endl; } }; list<A> listOfAs; list<A>::iterator it; # 1st scenario B bObj; C cObj; A *aB = &bObj; A *aC = &cObj; # 2nd scenario // A aA; // B *Ba = &aA; // C *Ca = &aA; // I am declaring the objects as in 1st scenario but how about 2nd scenario, is this suppose to work too? listOfAs.insert(it,*aB); listOfAs.insert(it,*aC); for (it=listOfAs.begin(); it!=listOfAs.end(); it++) { cout << *it.say() << endl; } } int main() { methodCall(); retrun 0; }

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• Question about the Cloneable interface and the exception that should be thrown

  - by Nazgulled

  Hi, The Java documentation says: A class implements the Cloneable interface to indicate to the Object.clone() method that it is legal for that method to make a field-for-field copy of instances of that class. Invoking Object's clone method on an instance that does not implement the Cloneable interface results in the exception CloneNotSupportedException being thrown. By convention, classes that implement this interface should override Object.clone (which is protected) with a public method. See Object.clone() for details on overriding this method. Note that this interface does not contain the clone method. Therefore, it is not possible to clone an object merely by virtue of the fact that it implements this interface. Even if the clone method is invoked reflectively, there is no guarantee that it will succeed. And I have this UserProfile class: public class UserProfile implements Cloneable { private String name; private int ssn; private String address; public UserProfile(String name, int ssn, String address) { this.name = name; this.ssn = ssn; this.address = address; } public UserProfile(UserProfile user) { this.name = user.getName(); this.ssn = user.getSSN(); this.address = user.getAddress(); } // get methods here... @Override public UserProfile clone() { return new UserProfile(this); } } And for testing porpuses, I do this in main(): UserProfile up1 = new UserProfile("User", 123, "Street"); UserProfile up2 = up1.clone(); So far, no problems compiling/running. Now, per my understanding of the documentation, removing implements Cloneable from the UserProfile class should throw an exception in up1.clone() call, but it doesn't. I've read around here that the Cloneable interface is broken but I don't really know what that means. Am I missing something?

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• What to pass to UserType, BlobType.setPreparedStatement session parameter

  - by dlots

  http://blog.xebia.com/2009/11/09/understanding-and-writing-hibernate-user-types/ I am attempting to defined a customer serialization UserType that mimics, the XStreamUserType referenced and provided here: http://code.google.com/p/aphillips/source/browse/commons-hibernate-usertype/trunk/src/main/java/com/qrmedia/commons/persistence/hibernate/usertype/XStreamableUserType.java My serializer outputs a bytearray that should presumably written to a Blob. I was going to do: public class CustomSerUserType extends DirtyCheckableUserType { protected SerA ser=F.g(SerA.class); public Class<Object> returnedClass() { return Object.class; } public int[] sqlTypes() { return new int[] {Types.BLOB}; } public Object nullSafeGet(ResultSet resultSet,String[] names,Object owner) throws HibernateException,SQLException { if() } public void nullSafeSet(PreparedStatement preparedStatement,Object value,int index) throws HibernateException,SQLException { BlobType.nullSafeSet(preparedStatement,ser.ser(value),index); } } Unfortunetly, the BlobType.nullSafeSet method requires the session. So how does one define a UserType that gets access to a servlet requests session? EDIT: There is a discussion of the issue here and it doesn't appear there is a solution: Best way to implement a Hibernate UserType after deprecations?

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• Problem using FluentNHibernate, SQLite and Enums

  - by weenet

  I have a Sharp Architecture based app using Fluent NHibernate with Automapping. I have the following Enum: public enum Topics { AdditionSubtraction = 1, MultiplicationDivision = 2, DecimalsFractions = 3 } and the following Class: public class Strategy : BaseEntity { public virtual string Name { get; set; } public virtual Topics Topic { get; set; } public virtual IList Items { get; set; } } If I create an instance of the class thusly: Strategy s = new Strategy { Name = "Test", Topic = Topics.AdditionSubtraction }; it Saves correctly (thanks to this mapping convention: public class EnumConvention : IPropertyConvention, IPropertyConventionAcceptance { public void Apply(FluentNHibernate.Conventions.Instances.IPropertyInstance instance) { instance.CustomType(instance.Property.PropertyType); } public void Accept(FluentNHibernate.Conventions.AcceptanceCriteria.IAcceptanceCriteria criteria) { criteria.Expect(x = x.Property.PropertyType.IsEnum); } } However, upon retrieval, I get an error regarding an attempt to convert Int64 to Topics. This works fine in SQL Server. Any ideas for a workaround? Thanks.

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• Rails 3 equivalent of complex SQL query

  - by Bryan

  Given the following models: class Recipe < ActiveRecord::Base has_many :recipe_ingredients has_many :ingredients, :through => :recipe_ingredients end class RecipeIngredient < ActiveRecord::Base belongs_to :recipe belongs_to :ingredient end class Ingredient < ActiveRecord::Base end How can I perform the following SQL query using Arel in Rails 3? SELECT * FROM recipes WHERE NOT EXISTS ( SELECT * FROM ingredients WHERE name IN ('chocolate', 'cream') AND NOT EXISTS ( SELECT * FROM recipe_ingredients WHERE recipe_ingredients.recipe_id = recipes.id AND recipe_ingredients.ingredient_id = ingredients.id))

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• Is it possible to replace groovy method for existing object?

  - by Jean Barmash

  The following code tried to replace an existing method in a Groovy class: class A { void abc() { println "original" } } x= new A() x.abc() A.metaClass.abc={-> println "new" } x.abc() A.metaClass.methods.findAll{it.name=="abc"}.each { println "Method $it"} new A().abc() And it results in the following output: original original Method org.codehaus.groovy.runtime.metaclass.ClosureMetaMethod@103074e[name: abc params: [] returns: class java.lang.Object owner: class A] Method public void A.abc() new Does this mean that when modify the metaclass by setting it to closure, it doesn't really replace it but just adds another method it can call, thus resulting in metaclass having two methods? Is it possible to truly replace the method so the second line of output prints "new"? When trying to figure it out, I found that DelegatingMetaClass might help - is that the most Groovy way to do this?

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• While loop: Output something different on every second result

  - by Wade D Ouellet

  Hi, I am running a plugin called Category Posts Widget for WordPress: http://wordpress.org/extend/plugins/category-posts/ It uses a while loop to display the names of all posts in a certain category. I want to get it so that there is a different class attached to the li tag on every second output. Here is the block of code for the plugin: // Post list echo "<ul>\n"; while ( $cat_posts->have_posts() ) { $cat_posts->the_post(); ?> <li class="cat-post-item"> <a class="post-title" href="<?php the_permalink(); ?>" rel="bookmark" title="Permanent link to <?php the_title_attribute(); ?>"><?php the_title(); ?></a> <?php if ( function_exists('the_post_thumbnail') && current_theme_supports("post-thumbnails") && $instance["thumb"] && has_post_thumbnail() ) : ?> <a href="<?php the_permalink(); ?>" title="<?php the_title_attribute(); ?>"> <?php the_post_thumbnail( 'cat_post_thumb_size'.$this->id ); ?> </a> <?php endif; ?> <?php if ( $instance['date'] ) : ?> <p class="post-date"><?php the_time("j M Y"); ?></p> <?php endif; ?> <?php if ( $instance['excerpt'] ) : ?> <?php the_excerpt(); ?> <?php endif; ?> <?php if ( $instance['comment_num'] ) : ?> <p class="comment-num">(<?php comments_number(); ?>)</p> <?php endif; ?> </li> <?php } echo "</ul>\n"; I am just trying to get it so on each second one in the output list, the li has a different class, so cat-post-item-alt for example. Thanks, Wade

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• ASP.NET how to implement IServiceLayer

  - by rockinthesixstring

  I'm trying to follow the tutorial found here to implement a service layer in my MVC application. What I can't figure out is how to wire it all up. here's what I have so far. IUserRepository.vb Namespace Data Public Interface IUserRepository Sub AddUser(ByVal openid As String) Sub UpdateUser(ByVal id As Integer, ByVal about As String, ByVal birthdate As DateTime, ByVal openid As String, ByVal regionid As Integer, ByVal username As String, ByVal website As String) Sub UpdateUserReputation(ByVal id As Integer, ByVal AmountOfReputation As Integer) Sub DeleteUser(ByVal id As Integer) Function GetAllUsers() As IList(Of User) Function GetUserByID(ByVal id As Integer) As User Function GetUserByOpenID(ByVal openid As String) As User End Interface End Namespace UserRepository.vb Namespace Data Public Class UserRepository : Implements IUserRepository Private dc As DataDataContext Public Sub New() dc = New DataDataContext End Sub #Region "IUserRepository Members" Public Sub AddUser(ByVal openid As String) Implements IUserRepository.AddUser Dim user = New User user.LastSeen = DateTime.Now user.MemberSince = DateTime.Now user.OpenID = openid user.Reputation = 0 user.UserName = String.Empty dc.Users.InsertOnSubmit(user) dc.SubmitChanges() End Sub Public Sub UpdateUser(ByVal id As Integer, ByVal about As String, ByVal birthdate As Date, ByVal openid As String, ByVal regionid As Integer, ByVal username As String, ByVal website As String) Implements IUserRepository.UpdateUser Dim user = (From u In dc.Users Where u.ID = id Select u).Single user.About = about user.BirthDate = birthdate user.LastSeen = DateTime.Now user.OpenID = openid user.RegionID = regionid user.UserName = username user.WebSite = website dc.SubmitChanges() End Sub Public Sub UpdateUserReputation(ByVal id As Integer, ByVal AmountOfReputation As Integer) Implements IUserRepository.UpdateUserReputation Dim user = (From u In dc.Users Where u.ID = id Select u).FirstOrDefault ''# Simply take the current reputation from the select statement ''# and add the proper "AmountOfReputation" user.Reputation = user.Reputation + AmountOfReputation dc.SubmitChanges() End Sub Public Sub DeleteUser(ByVal id As Integer) Implements IUserRepository.DeleteUser Dim user = (From u In dc.Users Where u.ID = id Select u).FirstOrDefault dc.Users.DeleteOnSubmit(user) dc.SubmitChanges() End Sub Public Function GetAllUsers() As System.Collections.Generic.IList(Of User) Implements IUserRepository.GetAllUsers Dim users = From u In dc.Users Select u Return users.ToList End Function Public Function GetUserByID(ByVal id As Integer) As User Implements IUserRepository.GetUserByID Dim user = (From u In dc.Users Where u.ID = id Select u).FirstOrDefault Return user End Function Public Function GetUserByOpenID(ByVal openid As String) As User Implements IUserRepository.GetUserByOpenID Dim user = (From u In dc.Users Where u.OpenID = openid Select u).FirstOrDefault Return user End Function #End Region End Class End Namespace IUserService.vb Namespace Data Interface IUserService End Interface End Namespace UserService.vb Namespace Data Public Class UserService : Implements IUserService Private _ValidationDictionary As IValidationDictionary Private _repository As IUserRepository Public Sub New(ByVal validationDictionary As IValidationDictionary, ByVal repository As IUserRepository) _ValidationDictionary = validationDictionary _repository = repository End Sub Protected Function ValidateUser(ByVal UserToValidate As User) As Boolean Dim isValid As Boolean = True If UserToValidate.OpenID.Trim().Length = 0 Then _ValidationDictionary.AddError("OpenID", "OpenID is Required") isValid = False End If If UserToValidate.MemberSince = Nothing Then _ValidationDictionary.AddError("MemberSince", "MemberSince is Required") isValid = False End If If UserToValidate.LastSeen = Nothing Then _ValidationDictionary.AddError("LastSeen", "LastSeen is Required") isValid = False End If If UserToValidate.Reputation = Nothing Then _ValidationDictionary.AddError("Reputation", "Reputation is Required") isValid = False End If Return isValid End Function End Class End Namespace I have also wired up the IValidationDictionary.vb and the ModelStateWrapper.vb as described in the article above. What I'm having a problem with is actually implementing it in my controller. My controller looks something like this. Public Class UsersController : Inherits BaseController Private UserService As Data.IUserService Public Sub New() UserService = New Data.UserService(New Data.ModelStateWrapper(Me.ModelState), New Data.UserRepository) End Sub Public Sub New(ByVal service As Data.IUserService) UserService = service End Sub .... End Class however on the line that says Public Sub New(ByVal service As Data.IUserService) I'm getting an error 'service' cannot expose type 'Data.IUserService' outside the project through class 'UsersController' So my question is TWO PARTS How can I properly implement a Service Layer in my application using the concepts from that article? Should there be any content within my IUserService.vb?

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• Several numpy arrays with SWIG

  - by Petter

  I am using SWIG to pass numpy arrays from Python to C++ code: %include "numpy.i" %init %{ import_array(); %} %apply (float* INPLACE_ARRAY1, int DIM1) {(float* data, int n)}; class Class { public: void test(float* data, int n) { //... } }; and in Python: c = Class() a = zeros(5) c.test(a) This works, but how can I pass multiple numpy arrays to the same function?

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• Strange php behaviour on a gd function

  - by mck89

  Hi, i met a very strange PHP behaviour, i don't understand why it behaves like this. I'm using the imagesetbrush function in this way: class foo { function setbrush($image) { //$this->_resource contains the main image resource imagesetbrush($this->_resource, $image); } } ... $res=imagecreatefrompng("image.png"); $class->setbrush($res); in this way it works, but if i change the code like this: class foo { function setbrush($image) { $res=imagecreatefrompng($image); imagesetbrush($this->_resource, $res); } } ... $class->setbrush("image.png"); it doesn't work anymore. Do you see some error? It doesn't show me any message it simply doesn't execute the function.

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• Python - Get Instance Variables

  - by Chris Bunch

  Is there a built-in method in Python to get an array of all a class' instance variables? For example, if I have this code: class hi: def __init__(self): self.ii = "foo" self.kk = "bar" Is there a way for me to do this: >>> mystery_method(hi) ["ii", "kk"] Thanks guys! Edit: I originally had asked for class variables erroneously. Thanks to all who brought this to my attention!

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• Fluent NHibernate mapping List<Point> as value to single column

  - by Paja

  I have this class: public class MyEntity { public virtual int Id { get; set; } public virtual List<Point> Vectors { get; set; } } How can I map the Vectors in Fluent NHibernate to a single column (as value)? I was thinking of this: public class Vectors : ISerializable { public List<Point> Vectors { get; set; } /* Here goes ISerializable implementation */ } public class MyEntity { public virtual int Id { get; set; } public virtual Vectors Vectors { get; set; } } Is it possible to map the Vectors like this, hoping that Fluent NHibernate will initialize Vectors class as standard ISerializable? Or how else could I map List<Point> to a single column? I guess I will have to write the serialization/deserialization routines myself, which is not a problem, I just need to tell FNH to use those routines. I guess I should use IUserType or ICompositeUserType, but I have no idea how to implement them, and how to tell FNH to cooperate.

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• Why does sorl.thumbnail ImageField fail in the admin?

  - by Mark0978

  I have code that looks like this: from sorl.thumbnail import ImageField class Gallery(models.Model): pass class GalleryImage(models.Model): image = ImageField(upload_to='galleries') In the admin: class GalleryImageInline(admin.TabularInline): model = GalleryImage class GalleryAdmin(admin.ModelAdmin): inlines = (GalleryImageInline,) If I use the sorl.thumbnail as above, it is impossible to add images in the admin. I get the validation error Enter a list of values. If I replace the sorl.thumbnail.ImageField with a plain django ImageField, everything works. If I want sorl.thumbnail to clean up the cache thumbnails, I need to use it in the model, but if I use it in the model, I can't seem to add any images to need thumbnails. Anyone else found and fixed this problem yet?

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• Nhibernat mapping aspnet_Users table

  - by Michael D. Kirkpatrick

  My User table I want to map to aspnet_Users: <class name="User" table="`User`"> <id name="ID" column="ID" type="Int32" unsaved-value="0"> <generator class="native" /> </id> <property name="UserId" column="UserId" type="Guid" not-null="true" /> <property name="FullName" column="FullName" type="String" not-null="true" /> <property name="PhoneNumber" column="PhoneNumber" type="String" not-null="false" /> </class> My aspnet_Users table: <class name="aspnet_Users" table="aspnet_Users"> <id name="ID" column="UserId" type="Guid" /> <property name="UserName" column="UserName" type="string" not-null="false" /> </class> I tried adding one-to-one, one-to-many and many-to-one mappings. The closest I can get is with this error: Object of type 'System.Guid' cannot be converted to type 'System.Int32'. How do I create a 1 way mapping from User to aspnet_User via the UserId column in User? I am only wanting to create a reference so I can extract read-only information, affect sorts, etc. I still need to leave UserId column in User set up like it is now. Maybe a virtual reference keying off of UserId? Is this even possible with Nhibernate? Unfortunately it acts like it only wants to use ID from User to map to aspnet_Users. Changing the table User to have it's primary key be UserId instead of ID is not an option at this point. Any help would be greatly appreciated. Thanks in advance.

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• nested QMap in qt

  - by goutham

  I am trying to use this code in my QT app QMap<QString,QMap> but there is a build problem it says C:/****/****/****/***/domparser.h:14: error: type/value mismatch at argument 2 in template parameter list for 'template<class Key, class T> class QMap'

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• When to use "property" builtin: auxiliary functions and generators

  - by Seth Johnson

  I recently discovered Python's property built-in, which disguises class method getters and setters as a class's property. I'm now being tempted to use it in ways that I'm pretty sure are inappropriate. Using the property keyword is clearly the right thing to do if class A has a property _x whose allowable values you want to restrict; i.e., it would replace the getX() and setX() construction one might write in C++. But where else is it appropriate to make a function a property? For example, if you have class Vertex(object): def __init__(self): self.x = 0.0 self.y = 1.0 class Polygon(object): def __init__(self, list_of_vertices): self.vertices = list_of_vertices def get_vertex_positions(self): return zip( *( (v.x,v.y) for v in self.vertices ) ) is it appropriate to add vertex_positions = property( get_vertex_positions ) ? Is it ever ok to make a generator look like a property? Imagine if a change in our code meant that we no longer stored Polygon.vertices the same way. Would it then be ok to add this to Polygon? @property def vertices(self): for v in self._new_v_thing: yield v.calculate_equivalent_vertex()

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• Java - Custom PropertyEditorSupport to display units

  - by I82Much

  All, I'm trying to make the properties of my node have Units associated with the measure. ( I am using the JScience.org implementation of JSR 275) So for instance, public class Robot extends AbstractNode { // in kg float vehicleMass; @Override public Sheet createSheet() { Sheet s = Sheet.createDefault(); Sheet.Set set = s.createPropertiesSet(); try { PropertySupport.Reflection vehicleMassField = new PropertySupport.Reflection(this, float.class, "vehicleMass"); vehicleMassField.setValue("units", SI.KILOGRAMS); vehicleMassField.setName("vehicleMass"); set.put(vehicleMassField); PropertyEditorManager.registerEditor(float.class, UnitInPlaceEditor.class); } catch (NoSuchMethodException ex) { Exceptions.printStackTrace(ex); } s.put(set); return s; } } I want my UnitInPlaceEditor to append the units to the end of the string representation of the number, and when the field is clicked (enters edit mode) for the units to disappear and just the number becomes selected for editing. I can make the units appear, but I cannot get the units to disappear when the field enters editing mode. public class UnitsInplaceEditor extends PropertyEditorSupport implements ExPropertyEditor { private PropertyEnv pe; @Override public String getAsText() { // Append the unit by retrieving the stored value } @Override public void setAsText(String s) { // strip off the unit, parse out the number } public void attachEnv(PropertyEnv pe) { this.pe = pe; } } Here's a screenshot of the display - I like it like this.. but here's the value being edited; note the unit stays there. Basically I want one value (string) to be displayed in the field when the field is NOT being edited, and a different to be displayed when user starts editing the field. Barring that, I'd like to put a constant jlabel for the units (uneditable) to the right of the text field. Anyone know how to do this?

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