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  • Problems in php coding

    - by anwar
    Hi there everyone im new to PHP and Joomla and I have developed a component in Joomla but my code is giving me errors. I have tried to solve the problem but I’am unable to solve it. So can anyone suggest me what is the problem with my code? Thanks in advance. Here are my two files: 1st view.html.php defined('_JEXEC') or die('=;)'); jimport('joomla.application.component.view'); class namnamViewlistrestaurant extends JView { function display($tpl = null) { $item = 'item'; RestUser::RestrictDirectAccess(); //-- Custom css JHTML::stylesheet( 'style.css', 'components/com_namnam/assets/css/' ); $cuisine=Lookups::getLookup('cuisine'); $lists['cuisine'] = JHTML::_('select.genericlist', $cuisine, 'idcuisine[]', 'class="inputbox" size="7"', 'value', 'text', $item->idcuisine); $category=Lookups::getLookup('restcategory'); $lists['category'] = JHTML::_('select.genericlist', $category, 'idcategory[]', 'class="inputbox" multiple="multiple" size="7"', 'value', 'text', $item->idcategory); $items = & $this->get('Data'); $pagination =& $this->get('Pagination'); $lists = & $this->get('List'); $this->assignRef('items', $items); $this->assignRef('pagination', $pagination); $this->assignRef('lists', $lists); parent::display($tpl); }//function }//class And 2nd is listrestaurant.php defined('_JEXEC') or die('=;)'); jimport('joomla.application.component.model'); class namnamModellistrestaurant extends JModel { var $_data; var $_total = null; var $_pagination = null; function __construct() { parent::__construct(); global $mainframe, $option; $limit = $mainframe->getUserStateFromRequest( 'global.list.limit', 'limit', $mainframe->getCfg('list_limit'), 'int' ); $limitstart = $mainframe->getUserStateFromRequest( $option.'.limitstart', 'limitstart', 0, 'int' ); $limitstart = ($limit != 0 ? (floor($limitstart / $limit) * $limit) : 0); $this->setState('limit', $limit); $this->setState('limitstart', $limitstart); } function _buildQuery() { $where = array(); $where[]=" idowner=".RestUser::getUserID()." "; if ($this->search) { $where[] = 'LOWER(name) LIKE \''. $this->search. '\''; } $where =( count($where) ) ? ' WHERE ' . implode( ' AND ', $where ) : ''; $orderby = ''; #_ECR_MAT_FILTER_MODEL1_ if (($this->filter_order) && ($this->filter_order_Dir)) { $orderby = ' ORDER BY '. $this->filter_order .' '. $this->filter_order_Dir; } $this->_query = ' SELECT *' . ' FROM #__namnam_restaurants ' . $where . $orderby ; return $this->_query; } function getData() { if (empty($this->_data)) { $query = $this->_buildQuery(); $this->_data = $this->_getList($query, $this->getState('limitstart'), $this->getState('limit')); } return $this->_data; } function getList() { // table ordering $lists['order_Dir'] = $this->filter_order_Dir; $lists['order'] = $this->filter_order; // search filter $lists['search']= $this->search; return $lists; } function getTotal() { // Load the content if it doesn't already exist if (empty($this->_total)) { $query = $this->_buildQuery(); $this->_total = $this->_getListCount($query); } return $this->_total; } function getPagination() { // Load the content if it doesn't already exist if (empty($this->_pagination)) { jimport('joomla.html.pagination'); $this->_pagination = new JPagination($this->getTotal(), $this->getState('limitstart'), $this->getState('limit') ); } return $this->_pagination; } }//class And the errors are: Notice: Trying to get property of non-object in C:\wamp\www\namnam.com\components\com_namnam\views\listrestaurant\view.html.php on line 26 Notice: Trying to get property of non-object in C:\wamp\www\namnam.com\components\com_namnam\views\listrestaurant\view.html.php on line 29 Notice: Undefined property: namnamModellistrestaurant::$search in C:\wamp\www\namnam.com\components\com_namnam\models\listrestaurant.php on line 38 Notice: Undefined property: namnamModellistrestaurant::$filter_order in C:\wamp\www\namnam.com\components\com_namnam\models\listrestaurant.php on line 48 Notice: Undefined property: namnamModellistrestaurant::$search in C:\wamp\www\namnam.com\components\com_namnam\models\listrestaurant.php on line 38 Notice: Undefined property: namnamModellistrestaurant::$filter_order in C:\wamp\www\namnam.com\components\com_namnam\models\listrestaurant.php on line 48 Notice: Undefined property: namnamModellistrestaurant::$filter_order_Dir in C:\wamp\www\namnam.com\components\com_namnam\models\listrestaurant.php on line 76 Notice: Undefined property: namnamModellistrestaurant::$filter_order in C:\wamp\www\namnam.com\components\com_namnam\models\listrestaurant.php on line 77 Notice: Undefined property: namnamModellistrestaurant::$search in C:\wamp\www\namnam.com\components\com_namnam\models\listrestaurant.php on line 80

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  • Can I get an example please?

    - by Doug
    $starcraft = array( "drone" => array( "cost" => "6_0-", "gas" => "192", "minerals" => "33", "attack" => "123", ) "zealot" => array( "cost" => "5_0-", "gas" => "112", "minerals" => "21", "attack" => "321", ) ) I'm playing with oop and I want to display the information in this array using a class, but I don't know how to construct the class to display it. This is what I have so far, and I don't know where to go from here. Am I supposed to use setters and getters? class gamesInfo($game) { $unitname; $cost; $gas; $minerals; $attack; }

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  • How to generate a compiler error based on an attribute being missing in C#?

    - by RodH257
    I create a number of add-ins for the Revit Structure API. Each tool has to habe a class which implements the interface IExternalCommand. In the latest version of Revit, for your tool to work you need to have two attributes on the class that implements that interface: [Regeneration(RegenerationOption.Manual)] [Transaction(TransactionMode.Automatic)] The values in brackets can change, but there must be something there. Often I am finding myself forgetting to put the attributes on, then when it comes to runtime it crashes. Is there any way in Visual Studio 2010 to add a compiler warning or error saying that if your class implements that interface it must have those 2 attributes? I have resharper if that helps. Can anyone point me into the right direction?

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  • Rail plugin acts_as_taggable_on :through

    - by Craig
    I have two models: class Employee < ActiveRecord::Base has_many :projects end class Project < ActiveRecord::Base acts_as_taggable_on :skills, :roles end I would like to find Employees using the tags associated with their projects. The geokit-rails plugin supports a similar concept, using its ':through' relationship. Ideally, I would be able to: specify which tags (i.e. skills, roles) would be included in the conditions order the employees by the total number of projects with matching tags be able to access the matching-tag count for each employee for the purposes of building a tag cloud Any thoughts would be appreciated.

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  • hackage package dependencies and future-proof libraries

    - by yairchu
    In the dependencies section of a cabal file: Build-Depends: base >= 3 && < 5, transformers >= 0.2.0 Should I be doing something like Build-Depends: base >= 3 && < 5, transformers >= 0.2.0 && < 0.3.0 (putting upper limits on versions of packages I depend on) or not? I'll use a real example: my "List" package on Hackage (List monad transformer and class) If I don't put the limit - my package could break by a change in "transformers" If I do put the limit - a user that uses "transformers" but is using a newer version of it will not be able to use lift and liftIO with ListT because it's only an instance of these classes of transformers-0.2.x I guess that applications should always put upper limits so that they never break, so this question is only about libraries: Shall I use the upper version limit on dependencies or not?

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  • Prim's MST algorithm implementation with Java

    - by user1290164
    I'm trying to write a program that'll find the MST of a given undirected weighted graph with Kruskal's and Prim's algorithms. I've successfully implemented Kruskal's algorithm in the program, but I'm having trouble with Prim's. To be more precise, I can't figure out how to actually build the Prim function so that it'll iterate through all the vertices in the graph. I'm getting some IndexOutOfBoundsException errors during program execution. I'm not sure how much information is needed for others to get the idea of what I have done so far, but hopefully there won't be too much useless information. This is what I have so far: I have a Graph, Edge and a Vertex class. Vertex class mostly just an information storage that contains the name (number) of the vertex. Edge class can create a new Edge that has gets parameters (Vertex start, Vertex end, int edgeWeight). The class has methods to return the usual info like start vertex, end vertex and the weight. Graph class reads data from a text file and adds new Edges to an ArrayList. The text file also tells us how many vertecis the graph has, and that gets stored too. In the Graph class, I have a Prim() -method that's supposed to calculate the MST: public ArrayList<Edge> Prim(Graph G) { ArrayList<Edge> edges = G.graph; // Copies the ArrayList with all edges in it. ArrayList<Edge> MST = new ArrayList<Edge>(); Random rnd = new Random(); Vertex startingVertex = edges.get(rnd.nextInt(G.returnVertexCount())).returnStartingVertex(); // This is just to randomize the starting vertex. // This is supposed to be the main loop to find the MST, but this is probably horribly wrong.. while (MST.size() < returnVertexCount()) { Edge e = findClosestNeighbour(startingVertex); MST.add(e); visited.add(e.returnStartingVertex()); visited.add(e.returnEndingVertex()); edges.remove(e); } return MST; } The method findClosesNeighbour() looks like this: public Edge findClosestNeighbour(Vertex v) { ArrayList<Edge> neighbours = new ArrayList<Edge>(); ArrayList<Edge> edges = graph; for (int i = 0; i < edges.size() -1; ++i) { if (edges.get(i).endPoint() == s.returnVertexID() && !visited(edges.get(i).returnEndingVertex())) { neighbours.add(edges.get(i)); } } return neighbours.get(0); // This is the minimum weight edge in the list. } ArrayList<Vertex> visited and ArrayList<Edges> graph get constructed when creating a new graph. Visited() -method is simply a boolean check to see if ArrayList visited contains the Vertex we're thinking about moving to. I tested the findClosestNeighbour() independantly and it seemed to be working but if someone finds something wrong with it then that feedback is welcome also. Mainly though as I mentioned my problem is with actually building the main loop in the Prim() -method, and if there's any additional info needed I'm happy to provide it. Thank you. Edit: To clarify what my train of thought with the Prim() method is. What I want to do is first randomize the starting point in the graph. After that, I will find the closest neighbor to that starting point. Then we'll add the edge connecting those two points to the MST, and also add the vertices to the visited list for checking later, so that we won't form any loops in the graph. Here's the error that gets thrown: Exception in thread "main" java.lang.IndexOutOfBoundsException: Index: 0, Size: 0 at java.util.ArrayList.rangeCheck(Unknown Source) at java.util.ArrayList.get(Unknown Source) at Graph.findClosestNeighbour(graph.java:203) at Graph.Prim(graph.java:179) at MST.main(MST.java:49) Line 203: return neighbour.get(0); in findClosestNeighbour() Line 179: Edge e = findClosestNeighbour(startingVertex); in Prim()

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  • Java Polymorphism - Selecting correct method based on subtype

    - by Marty Pitt
    Hi Given the following Class and Service layer signatures: public class PersonActionRequest { PersonVO person // ... other fields } public class MyServiceLayerClass { public void requestAction(PersonActionRequest request) { PersonVO abstractPerson = request.getPerson(); // call appropriate executeAction method based on subclass of PersonVO } private void executeAction(PersonVO person) {} private void executeAction(EmployeeVO employee) {} private void executeAction(ManagerVO manager) {} private void executeAction(UnicornWranglerVO unicornWrangler) {} } As discussed here, java will select the best method based on type info at compile time. (Ie., it will always select executeAction(PersonVO person) ). What's the most appropriate way to select the correct method? The internet tells me that using instanceof gets me slapped. However, I don't see the appropraite way to select the method without explictly casting abstractPerson to one of the other concrete types. Thanks Marty

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  • Cannot install Ruby on CentOS

    - by James
    Hey folks, I just cannot install Ruby on my CentOS (which is also hosting a cPanel). sudo yum install ruby ruby-devel ruby-irb ruby-rdoc ruby-ri audit_log_user_command(): Connection refused Loaded plugins: fastestmirror Loading mirror speeds from cached hostfile base: mirror.sov.uk.goscomb.net updates: mirror.sov.uk.goscomb.net addons: mirror.sov.uk.goscomb.net extras: mirror.sov.uk.goscomb.net base | 1.1 kB 00:00 updates | 951 B 00:00 addons | 951 B 00:00 extras | 1.1 kB 00:00 Excluding Packages in global exclude list Finished Setting up Install Process Parsing package install arguments No package ruby available. No package ruby-devel available. No package ruby-irb available. No package ruby-rdoc available. No package ruby-ri available. Nothing to do What can be the problem? Thanks

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  • How do I tell eclipse to auto-generate or retain stubs when it starts and does a clean build?

    - by Erick Robertson
    I'm working on a Java application that uses JavaSpace. We're developing this in Eclipse. There are a couple instances where we are inserting code into the JavaSpace to do some more advanced space notification logic. Doing this requires that we generate stubs for the classes used within the JavaSpace. We use an external script to generate these stubs. The problem is that whenever Eclipse restarts, it does a clean build of the whole application. When it does this, it deletes all the stubs and we have to regenerate them. I would like to find a way to either tell Eclipse not to remove the _stub.class and _skel.class files within the bin folder where the .class files are placed. Either that, or somehow teach Eclipse to generate the stub files whenever it does a rebuild (and I suppose whenever the source files from which the stubs are generated changes). How can I do one of these, so that we don't have to manually build the stubs every time we start up Eclipse?

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  • How to call a Thor task multiple times?

    - by deepak
    Thor like Rake (and Make) has task management. If I call a task multiple times, it will effectively call the task only once. How can I call a task multiple times? I tried modifying the @_invocations hash, but that did not work: require 'csv' require './config/environment' class MisReport < Thor desc "all", "generate mysql and postgres mis" def all generate("pg_mis_report", "pg") generate("mysql_mis_report", "mysql") end desc "generate", "generate mis report" def generate(file_name = "mis_report_#{Time.now.to_s(:number)}", connection = "postgres") if connection == "pg" puts "== postgres database" ActiveRecord::Base.establish_connection :development_mysql else puts "== mysql database" ActiveRecord::Base.establish_connection :development end # generate MIS puts puts "mis file is at: #{file_path}" end end

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  • Silverlight: Binding to static value

    - by queen3
    I need TextBlock.Text to be retrieved from translation manager, something like <TextBlock Text="{Binding TranslateManager.Translate('word')}" /> I don't want to set DataSource for all text blocks. The only way I found how to do this is to bind to "static" class and use converter: <TextBlock Text="{Binding Value, Source={StaticResource Translation}, Converter={StaticResource Translation}, ConverterParameter=NewProject}" /> And these helper class public class TranslationManager : IValueConverter { public static string Translate(string word) { return translate(word); } // this is dummy for fake static binding public string Value { get; set; } public object Convert(object value, Type targetType, object parameter, CultureInfo culture) { var name = parameter as string; return TranslationManager.Translate(name, name); } } But, is there a better - shorter - way?

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  • Zend_XmlRpc :Failed to parse response error

    - by davykiash
    Am trying to get a simple hello world XMLRPC server setup to work.However I get this Failed to parse response error error when I run the test URL http://localhost/client/index/ on my browser In my Rpc Controller that handles all my XMLRPC calls class RpcController extends Zend_Controller_Action { public function init() { $this->_helper->layout->disableLayout(); $this->_helper->viewRenderer->setNoRender(); } public function xmlrpcAction() { $server = new Zend_XmlRpc_Server(); $server->setClass('Service_Rpctest','test'); $server->handle(); } } In my client Controller that calls the XMLRPC Server class ClientController extends Zend_Controller_Action { public function indexAction() { $clientrpc = new Zend_XmlRpc_Client('http://localhost/rpc/xmlrpc/'); //Render Output to the view $this->view->rpcvalue = $clientrpc->call('test.sayHello'); } } In my Service_Rpctest function <?php class Service_Rpctest { /** * Return the Hello String * * @return string */ public function sayHello() { $value = 'Hello'; return $value; } } What am I missing?

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  • Trouble Extending Network with Apple Airport Extreme (PC won't connect with Ethernet)

    - by 0x783czar
    So I have an Apple Airport Extreme base station that I use to create a wifi network at my house. But on a separate story from this station i have a PC (running Windows 7) that does not have a wireless card. Luckily, I have another Airport Extreme Base Station, so I figured I'd have my second station "extend" the existing network. I asked Apple if this was possible, which it was, and walked through the setup wizard to extend the network. Then I ran an ethernet cable from the Station to my PC. However the PC refuses to connect to the Internet. It says it can access the network, "Unidentified Network (Limited Connectivity)", but that's it. It tells me that my computer does not have an IP address. I tried running the cable to another computer (my Apple MacBook Pro) and got a similar error. Any thoughts?

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  • Sharing a connection string

    - by coure06
    hi, I am developing a class library (C#) that i will use it for my different projects (later). My class library dll will use the connection string /data context of the project which will reference my new dll. How can i do it? Lets say i have a class Library Project named "CLP", and a website project "WP". I can add reference to CLP.dll file but how i will pass a connection string/data context object to that dll? as CLP.dll will access db based on the connection string of the "WP". Not sure my problem is clear or not!

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  • How do I migrate a ManyToOne to a ManyToMany relationship in Hibernate?

    - by spderosso
    I have a instance field of a class X that is mapped using Hibernate as a Many to One relationship. E.g: public class X{ ... @ManyToOne(optional=false) private Y iField; ... } That is correctly working with a particular schema. I know want to change this instance field iField to a List and a Many to Many relationship. public class X{ ... @ManyToMany(optional=false) private List<Y> iField; ... } What steps should I follow? Do I have to change the schema? in which way? In case you need more info let me know. Thanks!

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  • php 5.3.2 not throwing exceptions

    - by tipu
    I'm attempting to throw an exception using php 5.3.2 and it is giving me the following error: Parse error: syntax error, unexpected T_THROW I am attempting to throw an exception the following way: throw new Exception('Property ' . $name . ' doesn\'t exist in class Index', ''); Edit: I also tried throw new Exception('Property ' . $name . ' doesn\'t exist in class Index'); it didn't change the error I was getting. The complete method: public function __get($name) { if(property_exists($this, $name) throw new Exception('Property ' . $name . ' doesn\'t exist in class Index'); return $this->$name; }

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  • How do I convert CamelCase into human-readable names in Java?

    - by Frederik
    I'd like to write a method that converts CamelCase into a human-readable name. Here's the test case: public void testSplitCamelCase() { assertEquals("lowercase", splitCamelCase("lowercase")); assertEquals("Class", splitCamelCase("Class")); assertEquals("My Class", splitCamelCase("MyClass")); assertEquals("HTML", splitCamelCase("HTML")); assertEquals("PDF Loader", splitCamelCase("PDFLoader")); assertEquals("A String", splitCamelCase("AString")); assertEquals("Simple XML Parser", splitCamelCase("SimpleXMLParser")); assertEquals("GL 11 Version", splitCamelCase("GL11Version")); }

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  • How to show percentage of 'memory used' in a win32 process?

    - by pj4533
    I know that memory usage is a very complex issue on Windows. I am trying to write a UI control for a large application that shows a 'percentage of memory used' number, in order to give the user an indication that it may be time to clear up some memory, or more likely restart the application. One implementation used ullAvailVirtual from MEMORYSTATUSEX as a base, then used HeapWalk() to walk the process heap looking for additional free memory. The HeapWalk() step was needed because we noticed that after a while of running the memory allocated and freed by the heap was never returned and reported by the ullAvailVirtual number. After hours of intensive working, the ullAvailVirtual number no longer would accurately report the amount of memory available. However, this method proved not ideal, due to occasional odd errors that HeapWalk() would return, even when the process heap was not corrupted. Further, since this is a UI control, the heap walking code was executing every 5-10 seconds. I tried contacting Microsoft about why HeapWalk() was failing, escalated a case via MSDN, but never got an answer other than "you probably shouldn't do that". So, as a second implementation, I used PagefileUsage from PROCESS_MEMORY_COUNTERS as a base. Then I used VirtualQueryEx to walk the virtual address space adding up all regions that weren't MEM_FREE and returned a value for GetMappedFileNameA(). My thinking was that the PageFileUsage was essentially 'private bytes' so if I added to that value the total size of the DLLs my process was using, it would be a good approximation of the amount of memory my process was using. This second method seems to (sorta) work, at least it doesn't cause crashes like the heap walker method. However, when both methods are enabled, the values are not the same. So one of the methods is wrong. So, StackOverflow world...how would you implement this? which method is more promising, or do you have a third, better method? should I go back to the original method, and further debug the odd errors? should I stay away from walking the heap every 5-10 seconds? Keep in mind the whole point is to indicate to the user that it is getting 'dangerous', and they should either free up memory or restart the application. Perhaps a 'percentage used' isn't the best solution to this problem? What is? Another idea I had was a color based system (red, yellow, green, which I could base on more factors than just a single number)

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  • strange problem with WriteBeginTag

    - by user276640
    i use such code, but it renders with error <li class="dd0"><div id="dt1"<a href="http://localhost:1675/Category/29-books.aspx">Books</a></div></li> there is no > in opening tag div. what the problem? writer.WriteBeginTag("li"); //writer.WriteAttribute("class", this.CssClass); writer.WriteAttribute("class", "dd0"); if (!String.IsNullOrEmpty(this.LiLeftMargin)) { writer.WriteAttribute("style", string.Format("margin-left: {0}px", this.LiLeftMargin)); } writer.Write(HtmlTextWriter.TagRightChar); writer.WriteBeginTag("div"); writer.WriteAttribute("id", "dt1"); this.HyperLink.RenderControl(writer); writer.WriteEndTag("div"); writer.WriteEndTag("li");

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  • Where should Nhibernate IPostInsertEventListener go in the 3 tier architecture

    - by Quintin Par
    I have a IPostInsertEventListener implementation like public class NHibernateEventListener : IPostInsertEventListener, IPostUpdateEventListener which catches some entity inserts and does an additional insert to another table for ETL. Essentially it requires references to the Nhibernate, Domain entity and Repository<> Now where do I go about adding this class? If I add it to ApplicationServices I’ll end up referencing Nhibernate at that layer. If I add this to the Data layer, I’ll have to reference Domain (circular). How do I go implementing this class with S#arp principles? Any thoughts?

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  • C# Initialize Subclass based on Parent object

    - by ctrlShiftBryan
    So basically I have this public class Ticket{ public TicketNumber {get; set;} ..a bunch more properties... } I want to add some properties using a subclass like this using subsumption instead of composition. public class TicketViewModel(Ticket ticket){ //set each property from value of Ticket passed in this.TicketNumber = ticket.TicketNumber; ...a bunch more lines of code.. //additional VM properties public SelectList TicketTypes {get; private set;} } How do I instantiate the properties without having to write all the lines like this this.TicketNumber = ticket.TicketNumber; Is there some kind of shortcut? Something like in the subclass constructor? this = ticket; Obviously this doesn't work but is their some way so I don't have to modify my subclass if addng/removing a property to the parent class? Or something?

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  • Weird behavior of std::vector

    - by Nima
    I have a class like this: class OBJ{...}; class A { public: vector<OBJ> v; A(int SZ){v.clear(); v.reserve(SZ);} }; A *a = new A(123); OBJ something; a->v.push_back(something); This is a simplified version of my code. The problem is in debug mode it works perfect. But in release mode it crashes at "push_back" line. (with all optimization flags OFF) I debugged it in release mode and the problem is in the constructor of A. the size of the vector is something really big with dummy values and when I clear it, it doesn't change... Do you know why? Thanks,

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  • Naming a typedef for a boost::shared_ptr<const Foo>

    - by Blair Zajac
    Silly question, but say you have class Foo: class Foo { public: typedef boost::shared_ptr<Foo> RcPtr; void non_const_method() {} void const_method() const {} }; Having a const Foo::RcPtr doesn't prevent non-const methods from being invoked on the class, the following will compile: #include <boost/shared_ptr.hpp> int main() { const Foo::RcPtr const_foo_ptr(new Foo); const_foo_ptr->non_const_method(); const_foo_ptr->const_method(); return 0; } But naming a typedef ConstRcPtr implies, to me, that the typedef would be typedef const boost::shared_ptr<Foo> ConstRcPtr; which is not what I'm interested in. An odder name, but maybe more accurate, is RcPtrConst: typedef boost::shared_ptr<const Foo> RcPtrConst; However, Googling for RcPtrConst gets zero hits, so people don't use this as a typedef name :) Does anyone have any other suggestions?

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  • augment the factory pattern in java

    - by TP
    I am trying to use a factory pattern to create a QuestionTypeFactory where the instantiated classes will be like MultipleChoice, TrueFalseQuestion etc. The factory code looks something like this class QuestionFactory { public enum QuestionType { TrueFalse, MultipleChoice, Essay } public static Question createQuestion(QuestionType quesType) { switch (quesType) { case TrueFalse: return new TrueFalseQuestion(); case MultipleChoice: return new MultipleChoiceQuestion(); case Essay: return new EssayQuestion(); } throw new IllegalArgumentException("Not recognized."); } } This works ok for now. If I want to add another question type I will need to modify the factory class and I do not want to do that. How can I set it up so that each question class registers itself with the Factory so that when I add a new question type, I do not have to change the code for the factory? I am a bit new to java and am not sure how to do this.

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