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• C# array of objects - conditional validation

  - by fishdump

  Sorry about the vague title! I have an class with a number of member variables (system, zone, site, ...) public sealed class Cello { public String Company; public String Zone; public String System; public String Site; public String Facility; public String Process; //... } I have an array of objects of this class. private Cello[] m_cellos = null; // ... I need to know whether the array contains objects with the same site but different systems, zones or companies since such a situation would be illegal. I have various other checks to make but they are all along similar lines. The Array class has a number of functions that look promising but I am not very up on defining 'key selector' functions and things like that. Any suggestions or pointers would be greatly appreciated. --- Alistair.

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• Wordpress is_front_page if statement

  - by Anders Kitson

  I have the following code below. I am trying to get rid of the box articles div when I am on the home page the code works when the html is outside of the else portion of the IF statement, as soon as I put it inside the page goes blank, I can't seem to figure out where I have broken the code. Any help would be great. <?php if(is_front_page()) { if(function_exists('wp_content_slider')) { wp_content_slider(); } } else{ ?> <div class="box articles"> <div class="block" id="articles"> <h2><?php the_title(); ?></h2> <div class="article"> <div class="entry"> <?php the_content(); ?> </div> <?php edit_post_link('Modifca Contenuto.', '<p>', '</p>'); ?> </div> </div> </div> <?php endwhile; endif; ?> <? } ?>

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• CherryPy always returning HTTP 200 [closed]

  - by DarkArctic

  I'm having a bit of a problem when browsing to a non-existent resource. I get a response code of 200 instead of 404. I'm using the MethodDispatcher and I have a class that overloads the __getattr__ method to instantiate a resource if a child exists or to return AttributeError if one doesn't. My class is always returning the AttributeError correctly, but the data I actually get is always from the last good resource. Here's a simplified (except for __getattr__) version of my class: class BaseResource(object): exposed = True def __init__(self, name): self.children = [] # Pretend this has child resources def __getattr__(self, name): if name in self._children: uuid, application, obj_type, server = self._children[name] try: resource = getattr(app[application], obj_type) except AttributeError as e: raise cherrypy.HTTPError(500, e) return resource(uuid) else: raise AttributeError('Child with name \'{}\' could not be found.'.format(name)) def GET(self): cherrypy.log.error('*** {} not found, raising AttributeError'.format(name)) return 'GET request for {}'.format(self._name) So fetching I get the following when I browse to the following resources: http://localhost:8000/users - This resource exists, so it returns it correctly. http://localhost:8000/users/fake - This returns the "users" resource giving an HTTP 200. http://localhost:8000/users/fake/reallyfake - This returns the "users" resource again. So my question is, where can I start looking to find out why my code isn't returning a 404 for a non-existent resource. I'm sure I've done something wrong, but I'm not sure what. Whatever I did wrong I've undone and I'm now getting a 404 returned correctly. I'm sorry I can't give any detail on what the issue was, but I'm honestly not sure what I did.

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• How to setPage() a JEditorPane with a localfile which is outside of the .jar file?

  - by Jaguar

  My program has the following path in the .jar file src/test/Program.class and my program is as follow... Program.java package test; import java.io.File; import java.io.IOException; import javax.swing.JEditorPane; import javax.swing.JFrame; public class Program { JEditorPane editorPane; public Program() { File file = new File("temp.htm"); try { file.createNewFile(); editorPane = new JEditorPane(); editorPane.setPage(Program.class.getResource("temp.htm")); } catch (IOException e) { e.printStackTrace(); } } public JEditorPane getEditorPane(){ return editorPane; } public static void main(String[] args) { JFrame frame = new JFrame(); frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE); frame.setSize(400, 400); frame.setVisible(true); Program p = new Program(); frame.getContentPane().add(p.getEditorPane()); } } The problem is that I have compiled the program in a .jar file. The file.createNewFile(); creates the temp.htm file outside the .jar file So when editorPane.setPage(Program.class.getResource("temp.htm")); is called the file is not found as it searches for file inside the test package. How to setPage() the temp.htm file whiich is outside the .jar file but in the same folder as the .jar file? As the temp.htm is a localfile and I want a relative path instead of an absolute path. Thanks.

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• Member function overloading/template specialization issue

  - by Ferruccio

  I've been trying to call the overloaded table::scan_index(std::string, ...) member function without success. For the sake of clarity, I have stripped out all non-relevant code. I have a class called table which has an overloaded/templated member function named scan_index() in order to handle strings as a special case. class table : boost::noncopyable { public: template <typename T> void scan_index(T val, std::function<bool (uint recno, T val)> callback) { // code } void scan_index(std::string val, std::function<bool (uint recno, std::string val)> callback) { // code } }; Then there is a hitlist class which has a number of templated member functions which call table::scan_index(T, ...) class hitlist { public: template <typename T> void eq(uint fieldno, T value) { table* index_table = db.get_index_table(fieldno); // code index_table->scan_index<T>(value, [&](uint recno, T n)->bool { // code }); } }; And, finally, the code which kicks it all off: hitlist hl; // code hl.eq<std::string>(*fieldno, p1.to_string()); The problem is that instead of calling table::scan_index(std::string, ...), it calls the templated version. I have tried using both overloading (as shown above) and a specialized function template (below), but nothing seems to work. After staring at this code for a few hours, I feel like I'm missing something obvious. Any ideas? template <> void scan_index<std::string>(std::string val, std::function<bool (uint recno, std::string val)> callback) { // code }

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• Visual C++ 2010, rvalue reference bug?

  - by Sergey Shandar

  Is it a bug in Visual C++ 2010 or right behaviour? template<class T> T f(T const &r) { return r; } template<class T> T f(T &&r) { static_assert(false, "no way"); return r; } int main() { int y = 4; f(y); } I thought, the function f(T &&) should never be called but it's called with T = int &. The output: main.cpp(10): error C2338: no way main.cpp(17) : see reference to function template instantiation 'T f<int&>(T)' being compiled with [ T=int & ] Update 1 Do you know any C++x0 compiler as a reference? I've tried comeau online test-drive but could not compile r-value reference. Update 2 Workaround (using SFINAE): #include <boost/utility/enable_if.hpp> #include <boost/type_traits/is_reference.hpp> template<class T> T f(T &r) { return r; } template<class T> typename ::boost::disable_if< ::boost::is_reference<T>, T>::type f(T &&r) { static_assert(false, "no way"); return r; } int main() { int y = 4; f(y); // f(5); // generates "no way" error, as expected. }

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• PHP Multiple navigation highlights

  - by Blackbird

  I'm using this piece of code below to highlight the "active" menu item on my global navigation. <?php $path = $_SERVER['PHP_SELF']; $page = basename($path); $page = basename($path, '.php'); ?> <ul id="nav"> <li class="home"><a href="index.php">Home</a></li> <li <?php if ($page == 'search') { ?>class="active"<?php } ?>><a href="#">Search</a></li> <li <?php if ($page == 'help') { ?>class="active"<?php } ?>><a href="help.php">Help</a></li> </ul> All works great but, on a couple of pages, I have a second sub menu (sidebar menu) within a global page. I basically need to add a OR type statement into the php somehow, but I haven't a clue a how. Example of what i mean: <li <?php if ($page == 'help') OR ($page == 'help-overview') OR ($page == 'help-cat-1') { ?>class="active"<?php } ?>><a href="#">Search</a></li> Thanks!

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• Using groovy ws with enum types?

  - by Jared

  I'm trying to use groovy ws to call a webservice. One of the properties of the generated class is it's self a class with an enum type. Although the debug messages show that the com.test.FinalActionType is created at runtime when the WSDL is read I can't create an instance of it using code like proxy.create("com.test.FinalActionType") When I try and assign a string to my class uin place of an instance of FinalActionType groovy is not able to do the conversion. How can I get an instance of this class to use in a webservice call? I've pasted the important part of the WSDL below. <xsd:simpleType name="FinalActionType"> <xsd:restriction base="xsd:string"> <xsd:enumeration value="stop"/> <xsd:enumeration value="quit"/> <xsd:enumeration value="continue"/> <xsd:whiteSpace value="collapse"/> </xsd:restriction> </xsd:simpleType>

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• How do I alias the scala setter method 'myvar_$(myval)' to something more pleasing when in java?

  - by feydr

  I've been converting some code from java to scala lately trying to tech myself the language. Suppose we have this scala class: class Person() { var name:String = "joebob" } Now I want to access it from java so I can't use dot-notation like I would if I was in scala. So I can get my var's contents by issuing: person = Person.new(); System.out.println(person.name()); and set it via: person = Person.new(); person.name_$eq("sallysue"); System.out.println(person.name()); This holds true cause our Person Class looks like this in javap: Compiled from "Person.scala" public class Person extends java.lang.Object implements scala.ScalaObject{ public Person(); public void name_$eq(java.lang.String); public java.lang.String name(); public int $tag() throws java.rmi.RemoteException; } Yes, I could write my own getters/setters but I hate filling classes up with that and it doesn't make a ton of sense considering I already have them -- I just want to alias the _$eq method better. (This actually gets worse when you are dealing with stuff like antlr because then you have to escape it and it ends up looking like person.name_\$eq("newname"); Note: I'd much rather have to put up with this rather than fill my classes with more setter methods. So what would you do in this situation?

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• IE8 problems with .animate() of opacity property - descendant remains opaque throughout

  - by Fabian

  Basically I have something like this: <ul> <li> <a> <div class="trigger-layer"></div> <div class="title-layer">Text here</div> <div class="hover-layer"></div> </a> </li> </ul> I use jQuery to animate the <ul> as follow: $ul = xxx (where I assign the selector to var $ul) $ul.animate({opacity: 0}, 1000, function() {$ul.css("display", "none")}); However in IE8, as the <ul> fades off, the <div class="title-layer">Text here</div> remains clear and opaque. Finally the animation ends, the display: none; property is applied onto the <ul> and the text disappears aburptly.

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• axis-java2wsdl task classpath setting problem

  - by qkrsppopcmpt

  Hey Guys, here is my build.xml <?xml version="1.0" standalone="yes"?> <path id='axis2.classpath'> <fileset dir='D:\Tools\axis2-1.5.1-bin\axis2-1.5.1\lib'> <include name='**/*.jar' /> </fileset> </path> <path id='compiled.class.path'> <fileset dir='./bin/pkg'> <include name='*.class' /> </fileset> </path> <taskdef resource="axis-tasks.properties" classpathref="axis2.classpath" /> <target name="run" > <axis-java2wsdl output="out/TestService.wsdl" location="http://localhost:8080/axis2/service/TestService" namespace="service" classname="TestService"> <classpath refid="compiled.class.path"/> <mapping namespace="TestService" package="pkg"/> </axis-java2wsdl> </target> here is my file structure: prj-bin-pkg-TestService.class/////////// prj-src-pkg-TestService.java/////////// prj-build.xml I get java.lang.ClassNotFoundException: TestService. Can anybody tell me how to fix it? Thanks so much. !!!!!!!!!!!!!

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• Validating Checkbox and Radio Button in C#

  - by Solution

  Hi, I am using c# for coding! Below is my html for checkbox and radion button <input type="radio" style="float: left;" name="documents" id="Checkbox9" value="yes" runat="server" /> <label style="width: 35px!important;" class="checkbox"> <%=GetResourceString("c_HSGStudent")%> </label> <input type="radio" style="float: left;" name="documents" id="Checkbox10" value="no" runat="server" /> <label style="width: 25px!important;" class="checkbox"> <%=GetResourceString("c_HSGParent")%> </label> <input type="radio" style="float: left;" cheked name="documents" id="Radio1" value="yes" runat="server" /> <label style="width: 35px!important;" class="checkbox"> <%=GetResourceString("c_HSGStudent")%> </label> <input type="radio" style="float: left;" name="documents" id="Radio2" value="no" runat="server" /> <label style="width: 25px!important;" class="checkbox"> <%=GetResourceString("c_HSGParent")%> </label> You can see I have two checkboxes and two radio buttons, My problem is that on my submit button click I want to check whether user have checked at-least one checkbox or radio button. It will be good if we can have .NET solution like (customvalidator). Please suggest! Thanks

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• Entity and N-Tier architecture in C#

  - by acadia

  Hello, I have three tables as shown below Emp ---- empID int empName deptID empDetails ----------- empDetailsID int empID int empDocuments -------------- docID empID docName docType I am creating a entity class so that I can use n-tier architecture to do database transactions etc in C#. I started creating class for the same as shown below using System; using System.Collections.Generic; using System.Linq; using System.Text; namespace employee { class emp { private int empID; private string empName; private int deptID; public int EmpID { get; set; } public string EmpName { get; set; } public int deptID { get; set; } } } My question is as empDetails and empDocuments are related to emp by empID. How do I have those in my emp class. I would appreciate if you can direct me to an example. Thanks

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• Why do I get null objects in a many-to-many bag?

  - by Jim Geurts

  I have a bag defined for a many-to-many list: <class name="Author" table="Authors"> <id name="Id" column="AuthorId"> <generator class="identity" /> </id> <property name="Name" /> <bag name="Books" table="Author_Book_Map" where="IsDeleted=0" fetch="join"> <key column="AuthorId" /> <many-to-many class="Book" column="BookId" where="IsDeleted=0" /> </bag> </class> If I return all author objects using something like the following, I will get what initially appeared to be duplicate Author records: Session.Query<Author>().List<Author>() The extra author objects are created when an author is mapped to Book objects that have IsDeleted = 1 and IsDeleted = 0. Rather than creating one Author object with an enumerable that contains only the books with IsDeleted = 0, it will create two author objects. The first author object has a Books enumerable that contains books with IsDeleted = 0. The second author object will contain an enumerable of null book objects. Similarly, if an object only has one book map, and that map points to a book with IsDeleted = 1, then an author object is returned with a Books collection having one null object. I'm thinking part of the problem stems from the map table objects linking to rows that satisfy the where condition on the bag object but do not meet the many-to-many where condition. This is happening with NHibernate version 3.0.0.4980. Is this a configuration issue or something else?

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• How can I bind to a helper property in Silverlight

  - by Matt

  For the sake of argument, here's a simple person class public class Person : DependencyObject, INotifyPropertyChanged { public event PropertyChangedEventHandler PropertyChanged; public static readonly DependencyProperty FirstNameProperty = DependencyProperty.Register( "FirstName", typeof ( string ), typeof ( Person ), null ); public static readonly DependencyProperty LastNameProperty = DependencyProperty.Register( "LastName", typeof( string ), typeof( Person ), null ); public string FirstName { get { return ( string ) GetValue( FirstNameProperty ); } set { SetValue( FirstNameProperty, value ); if(PropertyChanged != null) PropertyChanged(this, new PropertyChangedEventArgs( "FirstName" )); } } public string LastName { get { return ( string ) GetValue( LastNameProperty ); } set { SetValue( LastNameProperty, value ); if ( PropertyChanged != null ) PropertyChanged( this, new PropertyChangedEventArgs( "LastName" ) ); } } } I want to go about creating a readonly property like this public string FullName { get { return FirstName + " " + LastName; } } How does binding work in this scenario? I've tried adding a DependancyProperty and raised the PropertyChanged event for the fullname. Basically I just want to have a property that I can bind to that returns the fullname of a user whenever the first or last name changes. Here's the final class I'm using with the modifications. public class Person : DependencyObject, INotifyPropertyChanged { public event PropertyChangedEventHandler PropertyChanged; public static readonly DependencyProperty FirstNameProperty = DependencyProperty.Register( "FirstName", typeof ( string ), typeof ( Person ), null ); public static readonly DependencyProperty LastNameProperty = DependencyProperty.Register( "LastName", typeof( string ), typeof( Person ), null ); public static readonly DependencyProperty FullNameProperty = DependencyProperty.Register( "FullName", typeof( string ), typeof( Person ), null ); public string FirstName { get { return ( string ) GetValue( FirstNameProperty ); } set { SetValue( FirstNameProperty, value ); if ( PropertyChanged != null ) { PropertyChanged( this, new PropertyChangedEventArgs( "FirstName" ) ); PropertyChanged( this, new PropertyChangedEventArgs( "FullName" ) ); } } } public string LastName { get { return ( string ) GetValue( LastNameProperty ); } set { SetValue( LastNameProperty, value ); if ( PropertyChanged != null ) { PropertyChanged( this, new PropertyChangedEventArgs( "LastName" ) ); PropertyChanged( this, new PropertyChangedEventArgs( "FullName" ) ); } } } public string FullName { get { return GetValue( FirstNameProperty ) + " " + GetValue( LastNameProperty ); } } }

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• sending specific data into a collection partial

  - by mikeglaz

  I have a User class with a has_many :messages and a Message class which belongs_to :user. In the Message controller's show action has the corresponding view: <% if @messages.any? %> <ol class="microposts"> <%= render partial: 'shared/message', collection: @messages %> </ol> <% end %> And the shared/_message.html.erb template looks like this: <li id="<%= message.id %>"> <span class="content"><%= message.body %></span> <% user_id = message.from %> <% user = User.find(user_id) %> From: <%= user.name %> </li> I feel like the following two lines should be done in the Messages controller from what I read in tutorials on Rails: <% user_id = message.from %> <% user = User.find(user_id) %> But how would I pass each message's corresponding from value (which stores user.id) into the partial? thanks, mike

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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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• 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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• 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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• 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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• 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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• 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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