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  • FluentNHibernate error -- "Invalid object name"

    - by goober
    I'm attempting to do the most simple of mappings with FluentNHibernate & Sql2005. Basically, I have a database table called "sv_Categories". I'd like to add a category, setting the ID automatically, and adding the userid and title supplied. Database table layout: CategoryID -- int -- not-null, primary key, auto-incrementing UserID -- uniqueidentifier -- not null Title -- varchar(50) -- not null Simple. My SessionFactory code (which works, as far as I can tell): _SessionFactory = Fluently.Configure().Database( MsSqlConfiguration.MsSql2005 .ConnectionString(c => c.FromConnectionStringWithKey("SVTest"))) .Mappings(x => x.FluentMappings.AddFromAssemblyOf<CategoryMap>()) .BuildSessionFactory(); My ClassMap code: public class CategoryMap : ClassMap<Category> { public CategoryMap() { Id(x => x.ID).Column("CategoryID").Unique(); Map(x => x.Title).Column("Title").Not.Nullable(); Map(x => x.UserID).Column("UserID").Not.Nullable(); } } My Class code: public class Category { public virtual int ID { get; private set; } public virtual string Title { get; set; } public virtual Guid UserID { get; set; } public Category() { // do nothing } } And the page where I save the object: public void Add(Category catToAdd) { using (ISession session = SessionProvider.GetSession()) { using (ITransaction Transaction = session.BeginTransaction()) { session.Save(catToAdd); Transaction.Commit(); } } } I receive the error Invalid object name 'Category'. Description: An unhandled exception occurred during the execution of the current web request. Please review the stack trace for more information about the error and where it originated in the code. Exception Details: System.Data.SqlClient.SqlException: Invalid object name 'Category'. I think it might be that I haven't told the CategoryMap class to use the "sv_Categories" table, but I'm not sure how to do that. Any help would be appreciated. Thanks!

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  • SWIG: From Plain C++ to working Wrapper

    - by duckworthd
    Hi everyone. I've been trying to create a SWIG wrapper for this tiny little C++ class for the better part of 3 hours with no success, so I was hoping one of you out there could lend me a small hand. I have the following class: #include <stdio.h> class Example { public: Example(); ~Example(); int test(); }; #include "example.h" Along with the implementation: Example::Example() { printf("Example constructor called\n"); } Example::~Example() { printf("Example destructor called\n"); } int Example::test() { printf("Holy shit, I work!\n"); return 42; } I've read through the introduction page ( www.swig.org/Doc1.3/Java.html ) a few times without gaining a whole lot of insight into the situation. My steps were Create an example.i file Compile original alongside example_wrap.cxx (no linking) link resulting object files together Create a little java test file (see below) javac all .java files there and run Well steps 4 and 5 have created a host of problems for me, starting with the basic ( library 'example' not found due to not being in java's path ) to the weird ( library not found even unless LD_LIBRARY_PATH is set to something, even if it's nothing at all). I've included my little testing code below public class test2 { static { String libpath = System.getProperty("java.library.path"); String currentDir = System.getProperty("user.dir"); System.setProperty("java.library.path", currentDir + ":" + libpath); System.out.println(System.getProperty("java.library.path")); System.loadLibrary("example"); } public static void main(String[] args){ System.out.println("It loads!"); } } Well, if anyone has navigated these murky waters of wrapping, I could not be happier than if you could light the way, particularly if you could provide the example.i and bash commands to go along with it.

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  • Spring Controller's URL request mapping not working as expected

    - by Atharva
    I have created a mapping in web.xml something like this: <servlet> <servlet-name>dispatcher</servlet-name> <servlet-class>org.springframework.web.servlet.DispatcherServlet</servlet-class> <load-on-startup>1</load-on-startup> </servlet> <servlet-mapping> <servlet-name>dispatcher</servlet-name> <url-pattern>/about/*</url-pattern> </servlet-mapping> In my controller I have something like this: import org.springframework.stereotype.Controller; @Controller public class MyController{ @RequestMapping(value="/about/us", method=RequestMethod.GET) public ModelAndView myMethod1(ModelMap model){ //some code return new ModelAndView("aboutus1.jsp",model); } @RequestMapping(value="/about", method=RequestMethod.GET) public ModelAndView myMethod2(ModelMap model){ //some code return new ModelAndView("aboutus2.jsp",model); } } And my dispatcher-servlet.xml has view resolver like: <mvc:annotation-driven/> <bean id="viewResolver" class="org.springframework.web.servlet.view.InternalResourceViewResolver" p:viewClass="org.springframework.web.servlet.view.JstlView" p:prefix="/WEB-INF/jsp/" p:suffix=".jsp"/> To my surprise: request .../about/us is not reaching to myMethod1 in the controller. The browser shows 404 error. I put a logger inside the method but it isn't printing anything, meaning, its not being executed. .../about works fine! What can be the done to make .../about/us request work? Any suggestions?

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  • jQuery draggable removing without changing position of other elements

    - by Yurish
    Hi! I am building a page layout configuration system on jQuery. So everyone, who is using my website can make it personal by moving elements on webpage. But, I have a problem. Every element on my page is a draggable div with option to be removed from page if necessary. When user wants to remove an element, he clicks on inner div and the following function is called: <script language="javascript"> $(function() { $('.close').click(function(){ $(this).parent().hide(); }); }); </script> <div class="main"><div class="close"></div></div> When user wants to add an element on page, he clicks on link and followinf function is called: function addNewWidget(page_name, size){ var page = $('#'+page_name); var closeDiv = $(document.createElement("div")).attr("class", "close").html('X'); closeDiv.click(function(){ $(this).parent().hide(); }); var div = $(document.createElement("div")) div.attr("class", "drag"); div.appendTo(page); closeDiv.appendTo(div); div.draggable({ containment: "#page", scroll: false, grid: [200, 200] }); div.css("top:0; left:0"); div.addClass(size); div.addClass('widget'); } Everything works fine, but when element is removed, other elements, which were on page are moving up. It is because of element positioning in the code. These divs in the code are before div, which was removed, and their absolute top is changed by -heghtOfRemovedElement Is there any way to prevent other elements from moving up?

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  • Drupal - Search box not working - custom theme template

    - by vr3690
    Hello, I am using a customised version of search-theme-from.tpl When I use the search box, I do get transferred to the search page. But the search does not actually take place. The search box on the search results page does work though. This is my search-them-form.tpl.php file (demo : <input type="text" name="search_theme_form_keys" id="edit-search-theme-form-keys" value="Search" title="Enter the terms you wish to search for" class="logininput" height="24px" onblur="restoreSearch(this)" onfocus="clearInput(this)" /> <input type="submit" name="op" id="edit-submit" value="" class="form-submit" style="display: none;" /> <input type="hidden" name="form_token" id="edit-search-theme-form-form-token" value="<?php print drupal_get_token('search_theme_form'); ?>" /> <input type="hidden" name="form_id" id="edit-search-theme-form" value="search_theme_form" /> There is also a javascript file involved. I guess it's use is pretty clear from the code: function trim(str) { return str.replace(/^\s+|\s+$/g, ''); } function clearInput(e) { e.value=""; // clear default text when clicked e.className="longininput_onfocus"; //change class } function restoreSearch(e) { if (trim(e.value) == '') { { e.value="Search"; // reset default text onBlur e.className="logininput"; //reset class } } } What can be the problem and how can I fix it?

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  • Ruby on Rails: How to create associated models on the fly ?

    - by Misha Moroshko
    I have the following models: class Product < ActiveRecord::Base belongs_to :brand belongs_to :model accepts_nested_attributes_for :brand, :model ... end class Brand < ActiveRecord::Base has_many :products has_many :models ... end class Model < ActiveRecord::Base has_many :products belongs_to :brand accepts_nested_attributes_for :brand ... end I have a problem to create a new product. Here is the relevant code in the controller: class ProductsController < ApplicationController ... def create @product = Product.new(params[:product]) if @product.save ... # Here is the error end ... end When user adds a new brand and a new model, params[:product] contains the following: "brand_attributes"=>{"name"=>"my_new_brand"} "model_attributes"=>{"model_no"=>"my_new_model"} and I got the following error: Mysql2::Error: Column 'brand_id' cannot be null: INSERT INTO `models` ... because model has a foreign key brand_id which is not set. I can't set it because the brand (like the model) is created on the fly when the product is created. I don't want to create the brand before the product, because then I the product has errors, I will need to delete the created brand. Then I tried to change params[:product] like this: "brand_attributes"=>{"name"=>"my_new_brand", "model_attributes"=>{"model_no"=>"my_new_model"}} but I end up with this: unknown attribute: model_attributes What would be the proper way to handle this ?

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  • Who deletes the copied instance in + operator ? (c++)

    - by Dima
    Hello, I searched how to implement + operator properly all over the internet and all the results i found do the following steps : const MyClass MyClass::operator+(const MyClass &other) const { MyClass result = *this; // Make a copy of myself. Same as MyClass result(*this); result += other; // Use += to add other to the copy. return result; // All done! } I have few questions about this "process" : Isn't that stupid to implement + operator this way, it calls the assignment operator(which copies the class) in the first line and then the copy constructor in the return (which also copies the class , due to the fact that the return is by value, so it destroys the first copy and creates a new one.. which is frankly not really smart ... ) When i write a=b+c, the b+c part creates a new copy of the class, then the 'a=' part copies the copy to himself. who deletes the copy that b+c created ? Is there a better way to implement + operator without coping the class twice, and also without any memory issues ? thanks in advance

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  • Hibernate Search + Spring

    - by Zane
    I'm trying to integrate Hibernate Search with Spring, but I can't seem to index anything. I was able to get Hibernate Search to work without Spring, but I'm having a problem integrating it with Spring. Any help would be much appreciated. Below is my springmvc-servlet.xml: <bean id="transactionManager" class="org.springframework.orm.jpa.JpaTransactionManager"> <property name="entityManagerFactory" ref="entityManagerFactory" /> </bean> <bean id="entityManagerFactory" class="org.springframework.orm.jpa.LocalEntityManagerFactoryBean"> <property name="persistenceUnitName" value="enewsclipsPersistenceUnit" /> </bean> And here is my DAO class: @Repository public class SearchDaoImpl implements SearchDao { JpaTemplate jpaTemplate; @Autowired public SearchDaoImpl(EntityManagerFactory entityManagerFactory) { this.jpaTemplate = new JpaTemplate(entityManagerFactory); } @SuppressWarnings("unchecked") public void updateSearchIndex() { /* Implement the callback method */ jpaTemplate.execute(new JpaCallback() { public Object doInJpa(EntityManager em) throws PersistenceException { List<Article> articles = em.createQuery("select a from Article a").getResultList(); FullTextEntityManager ftEm = Search.getFullTextEntityManager(em); ftEm.getTransaction().begin(); for(Article article : articles) { System.out.println("Indexing Item " + article.getTitle()); ftEm.index(article); } ftEm.getTransaction().commit(); return null; } }); } } I think that it may have to do with the transactions but I'm not exactly sure. If you could just point me in the right direction, that would be helpful too! Thank you.

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  • Is is possible to do an end-run around generics covariance in C# < 4 in this hypothetical situation?

    - by John Feminella
    Suppose I have a small inheritance hierarchy of Animals: public interface IAnimal { string Speak(); } public class Animal : IAnimal { public Animal() {} public string Speak() { return "[Animal] Growl!"; } } public class Ape : IAnimal { public string Speak() { return "[Ape] Rawrrrrrrr!"; } } public class Bat : IAnimal { public string Speak() { return "[Bat] Screeeeeee!"; } } Next, here's an interface offering a way to turn strings into IAnimals. public interface ITransmogrifier<T> where T : IAnimal { T Transmogrify(string s); } And finally, here's one strategy for doing that: public class Transmogrifier<T> : ITransmogrifier<T> where T : IAnimal, new() { public T Transmogrify(string s) { T t = default(T); if (typeof(T).Name == s) t = new T(); return t; } } Now, the question. Is it possible to replace the sections marked [1], [2], and [3] such that this program will compile and run correctly? If you can't do it without touching parts other than [1], [2], and [3], can you still get an IAnimal out of each instance of a Transmogrifier in a collection containing arbitrary implementations of an IAnimal? Can you even form such a collection to begin with? static void Main(string[] args) { var t = new Transmogrifier<Ape>(); Ape a = t.Transmogrify("Ape"); Console.WriteLine(a.Speak()); // Works! // But can we make an arbitrary collection of such animals? var list = new List<Transmogrifier< [1] >>() { // [2] }; // And how about we call Transmogrify() on each one? foreach (/* [3] */ transmogrifier in list) { IAnimal ia = transmogrifier.Transmogrify("Bat"); } } }

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  • Random number generation in MVC applications

    - by SlimShaggy
    What is the correct way of generating random numbers in an ASP.NET MVC application if I need exactly one number per request? According to MSDN, in order to get randomness of sufficient quality, it is necessary to generate multiple numbers using a single System.Random object, created once. Since a new instance of a controller class is created for each request in MVC, I cannot use a private field initialized in the controller's constructor for the Random object. So in what part of the MVC app should I create and store the Random object? Currently I store it in a static field of the controller class and lazily initialize it in the action method that uses it: public class HomeController : Controller { ... private static Random random; ... public ActionResult Download() { ... if (random == null) random = new Random(); ... } } Since the "random" field can be accessed by multiple instances of the controller class, is it possible for its value to become corrupted if two instances attempt to initialize it simultaneously? And one more question: I know that the lifetime of statics is the lifetime of the application, but in case of an MVC app what is it? Is it from IIS startup till IIS shutdown?

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  • Are TestContext.Properties usable ?

    - by DBJDBJ
    Using Visual Studio generate Test Unit class. Then comment in, the class initialization method. Inside it add your property, using the testContext argument. Upon test app startup this method is indeed called by the testing infrastructure. //Use ClassInitialize to run code before running the first test in the class [ClassInitialize()] public static void MyClassInitialize(TestContext testContext) { /* * Any user defined testContext.Properties * added here will be erased after this method exits */ testContext.Properties.Add("key", 1 ) ; // place the break point here } After leaving MyClassInitialize, any properties added by user are lost. Only the 10 "official" ones are left. Actually TestContext gets overwritten, with the inital offical one, each time before each test method is called. It it not overwritten only if user has test initialization method, the changes made over there are passed to the test. //Use TestInitialize to run code before running each test [TestInitialize()]public void MyTestInitialize(){ this.TestContext.Properties.Add("this is preserved",1) ; } This effectively means TestContext.Properties is "mostly" read only, for users. Which is not clearly documented in MSDN. It seems to me this is very messy design+implementation. Why having TestContext.Properties as an collection, at all ? Users can do many other solutions to have class wide initialization. Please discuss. --DBJ

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  • Query distinct list of choices for Django form with App Engine Datastore

    - by Brian
    I've been trying to figure this out for hours across a couple of days, and can not get it to work. I've been everywhere. I'll continue trying to figure it out, but was hoping for a quicker solution. I'm using App Engine datastore + Django. Using a query in a view and custom forms, I was able to get a list to the form but then I was not able to post. I have been trying to figure out how to dynamically add the choices as part of the Django form... I've tried various ways with no success. Help! Below are the two models. I'd like to get a distinct list of address_id to show in the location field in InfoForm. This fields could (and maybe should) be named the same, but I thought it'd be easier if they were named different. class Info(db.Model): user = db.UserProperty() location = db.StringProperty() info = db.StringProperty() created = db.DateTimeProperty(auto_now_add=True) modified = db.DateTimeProperty(auto_now=True) class Locations(db.Model): user = db.UserProperty() address_id = db.StringProperty() address = db.StringProperty() class InfoForm(djangoforms.ModelForm): info = forms.ChoiceField(choices=INFO_CHOICES) location = forms.ChoiceField() class Meta: model = Info exclude = ['user','created','modified']

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  • Refactoring Tabs

    - by Nimbuz
    HTML: <ul> <li><a href="#tab1">tab1</a></li> <li><a href="#tab2">tab2</a></li> </ul> <div id="tab1" class="tab-content">content 1</div> <div id="tab2" class="tab-content">content 2</div> jQuery $('#mode li:first').addClass('active'); $('#mode li.active').append('<span class="arrow">&nbsp;</span>'); $('#mode li a').click(function () { $('#mode li').removeClass('active') $('.arrow').remove(); $(this).parent().addClass('active').append('<span class="arrow">&nbsp;</span>'); var a = $(this).attr('href'); $('.tab-content').hide(); $(a).show(); return false; }); .. works, but looking ugly. Can it be simplified/reduced further? Many thanks!

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  • Call event from original thread ??

    - by user311883
    Hi all, Here is my problem, I have a class which have a object who throw an event and in this event I throw a custom event from my class. But unfortunately the original object throw the event from another thread and so my event is also throw on another thread. This cause a exception when my custom event try to access from controls. Here is a code sample to better understand : class MyClass { // Original object private OriginalObject myObject; // My event public delegate void StatsUpdatedDelegate(object sender, StatsArgs args); public event StatsUpdatedDelegate StatsUpdated; public MyClass() { // Original object event myObject.AnEvent += new EventHandler(myObject_AnEvent); } // This event is called on another thread private void myObject_AnEvent(object sender, EventArgs e) { // Throw my custom event here StatsArgs args = new StatsArgs(..........); StatsUpdated(this, args); } } So when on my windows form I call try to update a control from the event StatsUpdated I get a cross thread exception cause it has been called on another thread. What I want to do is throw my custom event on the original class thread, so control can be used within it. Anyone can help me ?

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  • which is better: a lying copy constructor or a non-standard one?

    - by PaulH
    I have a C++ class that contains a non-copyable handle. The class, however, must have a copy constructor. So, I've implemented one that transfers ownership of the handle to the new object (as below) class Foo { public: Foo() : h_( INVALID_HANDLE_VALUE ) { }; // transfer the handle to the new instance Foo( const Foo& other ) : h_( other.Detach() ) { }; ~Foo() { if( INVALID_HANDLE_VALUE != h_ ) CloseHandle( h_ ); }; // other interesting functions... private: /// disallow assignment const Foo& operator=( const Foo& ); HANDLE Detach() const { HANDLE h = h_; h_ = INVALID_HANDLE_VALUE; return h; }; /// a non-copyable handle mutable HANDLE h_; }; // class Foo My problem is that the standard copy constructor takes a const-reference and I'm modifying that reference. So, I'd like to know which is better (and why): a non-standard copy constructor: Foo( Foo& other ); a copy-constructor that 'lies': Foo( const Foo& other ); Thanks, PaulH

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  • Static member function pointer to hold non static member function

    - by user1425406
    This has defeated me. I want to have a static class variable which is a pointer to a (non-static) member function. I've tried all sorts of ways, but with no luck (including using typedefs, which just seemed to give me a different set of errors). In the code below I have the static class function pointer funcptr, and I can call it successfully from outside the class, but not from within the member function CallFuncptr - which is what I want to do. Any suggestions? #include <stdio.h> class A { public: static int (A::*funcptr)(); int Four() { return 4;}; int CallFuncptr() { return (this->*funcptr)(); } // doesn't link - undefined reference to `A::funcptr' }; int (A::*funcptr)() = &A::Four; int main() { A fred; printf("four? %d\n", (fred.*funcptr)()); // This works printf("four? %d\n", fred.CallFuncptr()); // But this is the way I want to call it }

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  • How does a java compiler resolve a non-imported name

    - by gexicide
    Consider I use a type X in my java compilation unit from package foo.bar and X is not defined in the compilation unit itself nor is it directly imported. How does a java compiler resolve X now efficiently? There are a few possibilities where X could reside: X might be imported via a star import a.b.* X might reside in the same package as the compilation unit X might be a language type, i.e. reside in java.lang The problem I see is especially (2.). Since X might be a package-private type, it is not even required that X resides in a compilation unit that is named X.java. Thus, the compiler must look into all entries of the class path and search for any classes in a package foo.bar, it then must read every class that is in package foo.bar to check whether X is included. That sounds very expensive. Especially when I compile only a single file, the compiler has to read dozens of class files only to find a type X. If I use a lot of star imports, this procedure has to be repeated for a lot of types (although class files won't be read twice, of course). So is it advisable to import also types from the same package to speed up the compilation process? Or is there a faster method for resolving an unimported type X which I was not able to find?

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  • How to Prevent PostBack Event Handler from Firing

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

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  • C ++ virtual function

    - by user2950788
    masters of C++. I am trying to implement polymorphism in C++. I want to write a base class with a virtual function and then redefine that function in the child class. then demonstrate dynamic binding in my driver program. But I just couldn't get it to work. I know how to do it in C#, so I figured that I might have made some syntactical mistakes where I had used C#'s syntax in my C++ code, but these mistakes are not obvious to me at all. So I'd greatly appreciate it if you would correct my mistakes. class polyTest { public: polyTest(); virtual void type(); virtual ~polyTest(); }; void polyTest::type() { cout << "first gen"; } class polyChild: public polyTest { public: void type(); }; void polyChild::type() { cout << "second gen"; } int main() { polyChild * ptr1; polyChild * ptr2; ptr1 = new polyTest(); ptr2 = new polyChild(); ptr1 -> type(); ptr2 -> type(); }

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  • jQuery slideDown + CSS Floats

    - by danilo
    I'm using a HTML Table with several rows. Every second row - containing details about the preceding row - is hidden using CSS. When clicking the first row, the second row gets showed using jQuery show(). This is quite nice, but I would prefer the slideDown-Effect. The problem is, inside the details row, there are two floating DIVs, one floating on the left, and one on the right. Now if i slideDown the previously hidden row, the contained DIVs behave strange and "jump around". See this animated gif to understand what I mean: http://ich-wars-nicht.ch/tmp/lunapic_127365879362365_.gif The markup: <tr class="row-vm"> <td>...</td> ... </tr> <tr class="row-details"> <td colspan="8"> <div class="vmdetail-left"> ... </div> <div class="vmdetail-right"> ... </div> </td> </tr> The CSS: .table-vmlist tr.row-details { display: none; } div.vmdetail-left { float: left; width: 50%; } div.vmdetail-right { float: right; width: 50%; } And the jQuery code: if ($(this).next().css('display') == 'none') { // Show details //$(this).next().show(); $(this).next().slideDown(); } else { // Hide details //$(this).next().hide(); $(this).next().slideUp(); } Is there a way to fix this behavior, and to implement a nice slideDown-effect?

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  • Silverlight Image Data Binding

    - by Alexander
    I am new to Silverlight, and have an issue with binding. I have a class ItemsManager, that has inside its scope another class Item. class ItemsManager { ... class Item : INotifyPropertyChanged { ... private BitmapImage bitmapSource; public BitmapImage BitmapSource { get { return bitmapSource; } set { bitmapSource = value; if(PropertyChanged != null )PropertyChanged("BitmapSource") } } } } I do the following in code to test binding: { ItemsManager.Instance.AddItem("123"); //Items manager started downloading item visual //part (in my case bitmap image png) Binding b = new Binding("Source"); b.Source = ItemsManager.Instance.GetItem("123").BitmapSource; b.BindsDirectlyToSource = true; Image img = new Image(); img.SetBinding(Image.SourceProperty, b); img.Width = (double)100.0; img.Height = (double)100.0; LayoutRoot.Children.Add(img); } Once image is loaded, image doesn't appear. Though, if I set directly after image has been loaded its source, it displays well. I also noticed that PropertyChanged("BitmapSource") never fires, because PropertyChanged is null, like Image never binded to it. I am looking forward to hearing from you!

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  • Inheritence and usage of dynamic_cast

    - by Mewzer
    Hello, Suppose I have 3 classes as follows (as this is an example, it will not compile!): class Base { public: Base(){} virtual ~Base(){} virtual void DoSomething() = 0; virtual void DoSomethingElse() = 0; }; class Derived1 { public: Derived1(){} virtual ~Derived1(){} virtual void DoSomething(){ ... } virtual void DoSomethingElse(){ ... } virtual void SpecialD1DoSomething{ ... } }; class Derived2 { public: Derived2(){} virtual ~Derived2(){} virtual void DoSomething(){ ... } virtual void DoSomethingElse(){ ... } virtual void SpecialD2DoSomething{ ... } }; I want to create an instance of Derived1 or Derived2 depending on some setting that is not available until run-time. As I cannot determine the derived type until run-time, then do you think the following is bad practice?... class X { public: .... void GetConfigurationValue() { .... // Get configuration setting, I need a "Derived1" b = new Derived1(); // Now I want to call the special DoSomething for Derived1 (dynamic_cast<Derived1*>(b))->SpecialD1DoSomething(); } private: Base* b; }; I have generally read that usage of dynamic_cast is bad, but as I said, I don't know which type to create until run-time. Please help!

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  • Ruby on Rails unknown attribute form error

    - by Ulkmun
    I'm attempting to create a form which will allow me to upload a file.. I've got the following form.. <div class="field"> <%= f.label :title %><br /> <%= f.text_field :title %> </div> <div class="field"> <%= f.label :body %><br /> <%= f.text_area :body, "cols" => 100, "rows" => 40 %> </div> <div class="field"> <%= f.label :upload %><br /> <%= f.file_field :upload %> </div> <div class="actions"> <%= f.submit %> </div> I've got a controller which seems to error in this function.. # POST /posts # POST /posts.xml def create @post = Post.new(params[:post]) @post = DataFile.save(params[:upload]) ##render :text => "File has been uploaded successfully" respond_to do |format| if @post.save format.html { redirect_to(@post, :notice => 'Post was successfully created.') } format.xml { render :xml => @post, :status => :created, :location => @post } else format.html { render :action => "new" } format.xml { render :xml => @post.errors, :status => :unprocessable_entity } end end end That's the method that get's called when I create the post. The error is unknown attribute: upload app/controllers/posts_controller.rb:42:in ``new' app/controllers/posts_controller.rb:42:in ``create'

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  • move jQuery code to a function

    - by GSTAR
    I have the following jQuery code: $('.show-additional-link').click(function(){ $(this).parent().next().slideDown(); $(this).hide(); return false; }); HTML: <div class="row"> <label for="native_language">Select</label> <select name="native_language" id="native_language"> <option value="">Any</option> <option value="1">English</option> </select> <a class="show-additional-link" href="#">Select Additional Languages</a> </div> <div id="additional-languages" style="display: none;"> <a class="hide-additional-link" href="#">[hide]</a> <div class="row"> <!-- additional language checkboxes --> </div> </div> I would like to move the contents of my jQuery code (within the 'click' function) in to a separate function, as I will need to call it again on page load (after the form is submitted, so that the DIV is shown again automatically). I'm having trouble with this - can anyone help?

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  • C++ destructor problem with boost::scoped_ptr

    - by bb-generation
    I have a question about the following code: #include <iostream> #include <boost/scoped_ptr.hpp> class Interface { }; class A : public Interface { public: A() { std::cout << "A()" << std::endl; } virtual ~A() { std::cout << "~A()" << std::endl; } }; Interface* get_a() { A* a = new A; return a; } int main() { { std::cout << "1" << std::endl; boost::scoped_ptr<Interface> x(get_a()); std::cout << "2" << std::endl; } std::cout << "3" << std::endl; } It creates the following output: 1 A() 2 3 As you can see, it doesn't call the destructor of A. The only way I see to get the destructor of A being called, is to add a destructor for the Interface class like this: virtual ~Interface() { } But I really want to avoid any Implementation in my Interface class and virtual ~Interface() = 0; doesn't work (produces some linker errors complaining about a non existing implementation of ~Interface(). So my question is: What do I have to change in order to make the destructor being called, but (if possible) leave the Interface as an Interface (only abstract methods).

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