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• Programatically adding,changing and removing controls bound to model objects (MVVM)

  - by Ittai

  I have the following scenario and I'm trying to decide how it can and should be implemented in silverlight and c# via MVVM. Scenario: I have the following objects in my scenario: MyModel, MyModelControl, MyView and MyViewModel. MyModelcontrol is a custom UserControl of mine and the rest I think are pretty much self explanatory. MyViewModel is a Subscriber of a message which hands it a Collection<MyModel> newCol and let's mark curCol as the current Collection<MyModel> that MyViewModel holds. I then want to programatically add MyModelControl controls for each MyModel instance which belongs to newCol and not to curCol. I also want to bind the MyModelControl instance to the corresponding MyModel instance. In a similar manner I want to remove the controls which don't belong now to the collection and I want to update a property for those which belong to both. I do not want to remove all controls which belong to curCol and then add all controls for newCol as the creation of MyModelControl is "expensive". I'd appreciate help with how this should be implemented in SL as I'm new to it and to the MVVM pattern. Comments regarding the design would also be welcomed. B.T.W This will run on Windows Phone 7 so I think there are some limitations on versions, if this is an issue please comment and I'll verify which versions exactly I can use on the phone.

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• Spring security or BCrypt algorithm which one is good for accounts like project?

  - by Ranjith Kumar Nethaji

  I am using spring security for hashing my password.And is it safe ,because am using spring security for first time. my code here <security:http auto-config="true"> <security:intercept-url pattern="/welcome*" access="ROLE_USER" /> <security:form-login login-page="/login" default-target-url="/welcome" authentication-failure-url="/loginfailed" /> <security:logout logout-success-url="/logout" /> </security:http> authentication-failure-url="/loginfailed" /> <security:logout logout-success-url="/logout" /> </security:http> <authentication-manager> <authentication-provider> <password-encoder hash="sha" /> <user-service> <user name="k" password="7c4a8d09ca3762af61e59520943dc26494f8941b" authorities="ROLE_USER" /> </user-service> </authentication-provider> </authentication-manager> .And I havnt used bcrypt algorithm.what is your feedback for both?any recommendation?

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• Importing a C DLL's functions into a C++ program

  - by bobobobo

  I have a 3rd party library that's written in C. It exports all of its functions to a DLL. I have the .h file, and I'm trying to load the DLL from my C++ program. The first thing I tried was surrounding the parts where I #include the 3rd party lib in #ifdef __cplusplus extern "C" { #endif and, at the end #ifdef __cplusplus } // extern "C" #endif But the problem there was, all of the DLL file function linkage looked like this in their header files: a_function = (void *)GetProcAddress(dll, "a_function"); While really a_function had type int (*a_function) (int *). Apparently MSVC++ compiler doesn't like this, while MSVC compiler does not seem to mind. So I went through (brutal torture) and fixed them all to the pattern typedef int (*_a_function) (int *); _a_function a_function ; Then, to link it to the DLL code, in main(): a_function = (_a_function)GetProcAddress(dll, "a_function"); This SEEMS to make the compiler MUCH, MUCH happier, but it STILL complains with this final set of 143 errors, each saying for each of the DLL link attempts: error LNK2005: _a_function already defined in main.obj main.obj Multiple symbol definition errors.. sounds like a job for extern! SO I went and made ALL the function pointer declarations as follows: function_pointers.h typedef int (*_a_function) (int *); extern _a_function a_function ; And in a cpp file: function_pointers.cpp #include "function_pointers.h" _a_function a_function ; ALL fine and dandy.. except for linker errors now of the form: error LNK2001: unresolved external symbol _a_function main.obj Main.cpp includes "function_pointers.h", so it should know where to find each of the functions.. I am bamboozled. Does any one have any pointers to get me functional? (Pardon the pun..)

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• Does the Eclipse editor have an equivalent of emacs's "align-regex"?

  - by rjray

  I've been using Eclipse pretty regularly for several years now, but I admit to not having explored all the esoterica it has to offer, particularly in the areas of what formatting features the editors offer. The main thing I miss from (X)emacs is the "align-regex" command, which let me take several lines into a region and then format them so that some common pattern in all lines was aligned. The simplest example of this is a series of variable assignments: var str = new String('aString'); var index = 0; var longCamelCaseObjectName = new LongNameObject(); After doing align-regex on "=", that would become: var str = new String('aString'); var index = 0; var longCamelCaseObjectName = new LongNameObject(); Now, you may have your own thoughts on stylistic (ab)use of white space and alignment, etc., but that's just an example (I'm actually trying to align a different kind of mess entirely). Can anyone tell me off-hand if there's an easy key-combo-shortcut for this in Eclipse? Or even a moderately-tricky one?

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• What's the *right* way to handle a POST in FP?

  - by Malvolio

  I'm just getting started with FP and I'm using Scala, which may not be the best way, since I can always fall back to an imperative style if the going gets tough. I'd just rather not. I've got a very specific question that points to a broader lacuna in my understanding of FP. When a web application is processing a GET request, the user wants information that already exists on the web-site. The application only has to process and format the data in some way. The FB way is clear. When a web application is processing a POST request, the user wants change the information held on the site. True, the information is not typically held in application variables, it's in a database or a flat-file, but still, I get the feeling I'm not grokking FP properly. Is there a pattern for handling updates to static data in an FP language? My vague picture of this is that the application is handed the request and the then-current site state. The application does its thing and returns the new site-state. If the current site-state hasn't changed since the application started, the new state becomes the current state and the reply is sent back to the browser (this is my dim image of Clojure's style); if the current state has been changed (by another thread, well, something else happens ...

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• Progressive enhancement of anchor tags to avoid onclick="return false;"

  - by Chris Beck

  Unobtrusive JS suggests that we don't have any onclick attributes in our HTML templates. <a href="/controller/foo/1">View Foo 1</a> A most basic progressive enhancement is to convert an that anchor tag to use XHR to retrieve a DOM fragment. So, I write JS to add an event listener for a."click" then make an XHR to a.href. Alas, the browser still wants to navigate to "/controller/foo". So, I write JS to dynamically inject a.onclick = "return false;". Still unobtrusive (I guess), but now I'm paying the the cost of an extra event handler. To avoid the cost of 2 event listeners, I could shove my function call into the onclick attribute <a href="/controller/foo/1" onclick="myXHRFcn(); return false;"> But that's grodo for all sorts of reasons. To make it more interesting, I might have 100 anchor tags that I want to enhance. A better pattern is a single listener on a parent node that relies on event bubbling. That's cool, but how do I short circuit the browser from navigating to the URL without this on every anchor node? onclick="return false;" Manipulating the href is not an option. It must stay intact so the context menu options to copy or open in new page work as expected.

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• How to write curiously recurring templates with more than 2 layers of inheritance?

  - by Kyle

  All the material I've read on Curiously Recurring Template Pattern seems to one layer of inheritance, ie Base and Derived : Base<Derived>. What if I want to take it one step further? #include <iostream> using std::cout; template<typename LowestDerivedClass> class A { public: LowestDerivedClass& get() { return *static_cast<LowestDerivedClass*>(this); } void print() { cout << "A\n"; } }; template<typename LowestDerivedClass> class B : public A<LowestDerivedClass> { public: void print() { cout << "B\n"; } }; class C : public B<C> { public: void print() { cout << "C\n"; } }; int main() { C c; c.get().print(); // B b; // Intentionally bad syntax, // b.get().print(); // to demonstrate what I'm trying to accomplish return 0; } How can I rewrite this code to compile without errors (and output "C\nB\n")?

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• Extra NotifyIcon shown in system tray

  - by Kettch19

  I'm having an issue with an app where my NotifyIcon displays an extra icon. The steps to reproduce it are easy, but the problem is that the extra icon shows up after any of the actual codebehind we've added fires. Put simply, clicking a button triggers execution of method FooBar() which runs all the way through fine but its primary duty is to fire a backgroundworker to log into another of our apps. It only appears if this particular button is clicked. Strangely enough, we have a WndProc method override and if I step through until the extra NotifyIcon appears, it always appears during this method so something else beyond the codebehind must be triggering the behavior. Our WndProc method is currently (although I don't think it's caused by the WndProc): Protected Overrides Sub WndProc(ByRef m As System.Windows.Forms.Message) 'Check for WM_COPYDATA message from other app or drag/drop action and handle message If m.Msg = NativeMethods.WM_COPYDATA Then ' get the standard message structure from lparam Dim CD As NativeMethods.COPYDATASTRUCT = m.GetLParam(GetType(NativeMethods.COPYDATASTRUCT)) 'setup byte array Dim B(CD.cbData) As Byte 'copy data from memory into array Runtime.InteropServices.Marshal.Copy(New IntPtr(CD.lpData), B, 0, CD.cbData) 'Get message as string and process ProcessWMCopyData(System.Text.Encoding.Default.GetString(B)) 'empty array Erase B 'set message result to 'true', meaning message handled m.Result = New IntPtr(1) End If 'pass on result and all messages not handled by this app MyBase.WndProc(m) End Sub The only place in the code where the NotifyIcon in question is manipulated at all is in the following event handler (again, don't think this is the culprit, but just for more info): Private Sub TrayIcon_MouseDoubleClick(ByVal sender As System.Object, ByVal e As System.Windows.Forms.MouseEventArgs) Handles TrayIcon.MouseDoubleClick If Me.Visible Then Me.Hide() Else PositionBottomRight() Me.Show() End If End Sub The backgroundworker's DoWork is as follows (just a class call to log in to our other app, but again just for info): Private Sub LoginBackgroundWorker_DoWork(ByVal sender As Object, ByVal e As System.ComponentModel.DoWorkEventArgs) Handles LoginBackgroundWorker.DoWork Settings.IsLoggedIn = _wdService.LogOn(Settings.UserName, Settings.Password) End Sub Does anyone else have ideas on what might be causing this or how to possibly further debug this? I've been banging my head on this without seeing a pattern so another set of eyes would be extremely appreciated. :) I've posted this on MSDN winforms forums as well and have had no luck there so far either.

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• shell script segment to avoid overwriting files

  - by johndashen

  I have a perl script (or any executable) E which will take a file foo.xml and write a file foo.txt. I use a Beowulf cluster to run E for a large number of XML files, but I'd like to write a simple job server script in shell (bash) which doesn't overwrite existing txt files. I'm currently doing something like #!/bin/sh PATTERN="[A-Z]*0[1-2][a-j]"; # this matches foo in all cases todo=`ls *.xml | grep $PATTERN`; isdone=`ls *.foo | grep $PATTERN`; whatsleft=todo - isdone; # what's the unix magic? #and then call the job server; jobserve E "$whatsleft"; and then I don't know how to get the difference between $todo and $isdone. I'd prefer using sort/uniq to something like a for loop with grep inside, but I'm not sure how to do it (pipes? temporary files?) As a bonus question, is there a way to do lookahead search in bash grep?

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• Expandable columns in a datagrid

  - by Jobe

  Im working on a WPF-applications to present and correct large amounts of data. Im about to implement a datagrid containing data from 3 different sources that are populated from external services. To start with I will only populate the grid with data from one source, the master source. However, sometimes an automated validator will trigger a validation warning or error on one cell and the requirement states that the user should be able to view data from the additional 2 sources in columns next to the selected one. Something like this: Standard view: | col1 src1 | col2 src1 | col3 src1 | | | | | | |faulty | | | | | | User want to show data from source 2 and 3 next to the column "col2 src1" like this: | col1 src1 | col2 src1 | col2 src2 | col2 src3 | col3 src1 | | | | | | | | |corrected | | | | | | | | | | and then be able to correct the faulty formatted cell with data from the other 2 soruces, and then collapse the columns again. I am trying to use the mvvm pattern on this one so I have populated the DataGrid with a ListCollectionView so far. The list contains items with properties like this: MyRowItem {string col1, string col2, string col3} I will then have 2 additional collections with items of type like above but from 2 other sources. I have no idea how to implement this functionality and could use some help on the logics. What approach should I head for?

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• Pick up relevant information from a string using regular expression C#3.0

  - by Newbie

  Hi, I have a situation. I have been given some file name which can be like <filename>YYYYMMDD<fileextension> some valid file names that will satisfy the above pattern are as under xxx20100326.xls, xxx2v20100326.csv, x_20100326.xls, xy2z_abc_20100326_xyz.csv, abc.xyz.20100326.doc, ab2.v.20100326.doc, abc.v.20100326_xyz.xls In what ever be the above defined case, I need to pick up the dates only. So for all the cases, the output will be 20100326. I am trying to achieve the same but no luck. Here is what I have done so far string testdata = "x2v20100326.csv"; string strYYYY = @"\d{4}"; string strMM = @"(1[0-2]|0[1-9])"; string strDD = @"(3[0-1]|[1-2][0-9]|0[1-9])"; string regExPattern = @"\A" + strYYYY + strMM + strDD + @"\Z"; Regex regex = new Regex(regExPattern); Match match = regex.Match(testdata); if (match.Success) { string result = match.Groups[0].Value; } I am using c#3.0 and dotnet framework 3.5 Please help. It is very urgent Thanks in advance.

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• Mono Develop 2.4.1 + linq error.

  - by Nev_Rahd

  I just started to learn Mono Develop Installed Mono Develop 2.4.1 and trial version of Mono Touch. my Code: using System; using System.Xml.Linq; using System.Collections.Generic; namespace RSSReader { public static class RSSRepository { public static IList<FeedItem> GetFeeds(string url) { XDocument rssFeed = XDocument.Load(url); Console.Write(rssFeed.ToString()); var feeds = new List<FeedItem>(); try { var query = from item in rssFeed.Descendants("item") select new FeedItem { Title = item.Element("title").Value, Published = DateTime.Parse(item.Element("pubDate").Value), Url = item.Element("link").Value }; feeds = query.ToList(); } catch (Exception ex){ Console.WriteLine(ex.Message); } return feeds; } } } This is throwing an error: An implementation of 'select' query expression pattern could not be found. Are you missing 'System.linq' using directive or 'System.Core.dll' assembly reference? I got both references to System.Xml.Linq and System.Core What am i missing ?

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• Is it OK to set state within Event Raising methods?

  - by Greg

  I ran across this pattern in the code of a library I'm using. It sets state within the event raising method, but only if the event is not null. protected virtual void OnMyEvent(EventArgs e) { if(MyEvent != null) { State = "Executing"; // Only sets state if MyEvent != null. MyEvent(this,e); } } Which means that the state is not set when overriding the method: protected override void OnMyEvent(EventArgs e) { base.OnMyEvent(e); Debug.Assert( State == "Executing" ); // This fails } but is only set when handling the event: foo.MyEvent += (o, args) => Debug.Assert(State == "Executing"); // This passes Setting state within the if(MyEvent != null) seems like bad form, but I've checked the Event Design Guidelines and it doesn't mention this. Do you think this code is incorrect? If so, why? (Reference to design guidelines would be helpful). Edit for Context: It's a Control, I'm trying to create subclass of it, and the state that it's setting is calling EnsureChildControls() conditionally based upon there being an event handler. I can call EnsureChildControls() myself, but I consider that something of a hack.

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• Creating mock Objects in PHP unit

  - by Mike

  Hi, I've searched but can't quite find what I'm looking for and the manual isn't much help in this respect. I'm fairly new to unit testing, so not sure if I'm on the right track at all. Anyway, onto the question. I have a class: <?php class testClass { public function doSomething($array_of_stuff) { return AnotherClass::returnRandomElement($array_of_stuff); } } ?> Now, clearly I want the AnotherClass::returnRandomElement($array_of_stuff); to return the same thing every time. My question is, in my unit test, how do I mockup this object? I've tried adding the AnotherClass to the top of the test file, but when I want to test AnotherClass I get the "Cannot redeclare class" error. I think I understand factory classes, but I'm not sure how I would apply that in this instance. Would I need to write an entirely seperate AnotherClass class which contained test data and then use the Factory class to load that instead of the real AnotherClass? Or is using the Factory pattern just a red herring. I tried this: $RedirectUtils_stub = $this->getMockForAbstractClass('RedirectUtils'); $o1 = new stdClass(); $o1->id = 2; $o1->test_id = 2; $o1->weight = 60; $o1->data = "http://www.google.com/?ffdfd=fdfdfdfd?route=1"; $RedirectUtils_stub->expects($this->any()) ->method('chooseRandomRoot') ->will($this->returnValue($o1)); $RedirectUtils_stub->expects($this->any()) ->method('decodeQueryString') ->will($this->returnValue(array())); in the setUp() function, but these stubs are ignored and I can't work out whether it's something I'm doing wrong, or the way I'm accessing the AnotherClass methods. Help! This is driving me nuts.

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• Caching vector addition over changing collections

  - by DRMacIver

  I have the following setup: I have a largish number of uuids (currently about 10k but expected to grow unboundedly - they're user IDs) and a function f : id - sparse vector with 32-bit integer values (no need to worry about precision). The function is reasonably expensive (not outrageously so, but probably on the order of a few 100ms for a given id). The dimension of the sparse vectors should be assumed to be infinite, as new dimensions can appear over time, but in practice is unlikely to ever exceed about 20k (and individual results of f are unlikely to have more than a few hundred non-zero values). I want to support the following operations efficiently: add a new ID to the collection invalidate an existing ID retrieve sum f(id) in O(changes since last retrieval) i.e. I want to cache the sum of the vectors in a way that's reasonable to do incrementally. One option would be to support a remove ID operation and treat invalidation as a remove followed by an add. The problem with this is that it requires us to keep track of all the old values of f, which is expensive in space. I potentially need to use many instances of this sort of cached structure, so I would like to avoid that. The likely usage pattern is that new IDs are added at a fairly continuous rate and are frequently invalidated at first. Ids which have been invalidated recently are much more likely to be invalidated again than ones which have remained valid for a long time, but in principle an old Id can still be invalidated. Ideally I don't want to do this in memory (or at least I want a way that lets me save the result to disk efficiently), so an idea which lets me piggyback off an existing DB implementation of some sort would be especially appreciated.

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• Zend_Router requirements mismatch

  - by elbicho

  Hello you all: I have two routes that match a url with the same apparent pattern, the difference lies in the $actionRoute, this should only be matched if the variable :action on it equals 'myaction'. If I go to /en/mypage/whatever/myaction it goes as expected through $actionRoute. If I go to /en/mypage/whatever/blahblah it gets rejected by $actionRoute and matched by $genRoute. If I go to /en/mypage/whatever it should be matched by $genRoute but it gets matched by $actionRoute instead throwing and exception because the action noactionAction() does not exist. Don't know what I'm doing wrong, I'd appreciate your help. $genRoute = new Zend_Controller_Router_Route( ':lang/mypage/:var1/:var2', array( 'lang' => '', 'module' => 'mymodule', 'controller' => 'index', 'action' => 'index', 'var1' => 'noone', 'var2' => 'no' ), array( 'var1' => '[a-z\-]+?', 'lang' => '(es|en|fr|de){1}' ) ); $actionRoute = new Zend_Controller_Router_Route( ':lang/mypage/:var1/:action', array( 'lang' => '', 'module' => 'mymodule', 'controller' => 'index', 'action' => 'noaction', 'var1' => 'noone', ), array( 'action' => '(myaction)+?', 'var' => '[a-z\-]+?', 'lang' => '(es|en|fr|de){1}', ) ); $router->addRoute('genroute',$genRoute); $router->addRoute('actionroute',$actionRoute);

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• Managing a log stream in C++ in a cout-like notation

  - by Andry

  Hello! I have a class in c++ in order to write log files for an application of mine. I have already built the class and it works, it is something like this: class Logger { std::string _filename; public: void print(std::string tobeprinted); } Well, it is intuitive that, in order to print a line in the log file, for an object of Logger, it is simply necessary to do the following: Logger mylogger("myfile.log"); mylogger.print(std::string("This is a log line")); Well. Using a method approach is not the same as using a much better pattern like << is. I would like to do the following: Logger mylogger("myfile.log"); mylogger << "This is a log line"; That's all. I suppose I must overload the << operator... But overloading using this signature (the classic one): ostream& operator<<(ostream& output, const MyObj& o); But I do not have a ostream... So, should I do as follows? Logger& operator<<(Logger& output, const std::string& o); Is this the right way? Thanks

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• Zend Framework: How to display multiple actions, each requiring different authorizations levels, on

  - by Iain

  Imagine I have 4 database tables, and an interface that presents forms for the management of the data in each of these tables on a single webpage (using the accordion design pattern to show only one form at a time). Each form is displayed with a list of rows in the table, allowing the user to insert a new row or select a row to edit or delete. AJAX is then used to send the request to the server. A different set of forms must be displayed to different users, based on the application ACL. My question is: In terms of controllers, actions, views, and layouts, what is the best architecture for this interface? For example, so far I have a controller with add, edit and delete actions for each table. There is an indexAction for each, but it's an empty function. I've also extended Zend_Form for each table. To display the forms, I then in the IndexController pass the Forms to it's view, and echo each form. Javascript then takes care of populating the form and sending requests to the appropraite add/edit/delete action of the appropriate controller. This however doesn't allow for ACL to control the display or not of Forms to different users. Would it be better to have the indexAction instantiate the form, and then use something like $this-render(); to render each view within the view of the indexAction of the IndexController? Would ACL then prevent certain views from being rendered? Cheers.

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• Design patterns for Caching Images in a MVC?

  - by Onema

  Hi, I'm designing an image cache system that will be used in an MVC CMS. The main purpose of the image cacher is to modify images: scale, crop, etc and cache them in the client site. I have created an image cache Model and Mapper that interact with the Database, to keep track of the images and know what kind of actions have been applied to them (scale, crop, etc). In addition to the Model and Mapper I have created a ImageCacher Class that is used by the API to manage the Model and image creation based on arguments passed by the client site, this class creates the images and generates the links to the images for the View. A coworker argued that I need to include the functionality of this last Class inside the Model, as the bulk of the logic should go in the model. I respectfully disagree with him since I feel the model's responsibility is to deal with the information about the images cached at the database level, and the responsibility of the ImageCacher Class is to create the url/image that we will be caching (keeping the single responsibility principle). In addition to this I believe that a model should not have Presentation-related features, like creating or showing images. Does anyone have any insight on this? is there a particular design pattern that would make this division of tasks clear and and the image cacher reusable? Should I add all the logic in the Model? Thank you.

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• Manual Linq to SQL entity framework mapping

  - by kprobst

  I've been playing with the O/R designer in VS and I was wondering if someone could shed come light on this. I'm used to OR mappers that are largely manual (homegrown and e.g., NHibernate). I don't mind encoding the entity classes myself, since they don't change all that often to begin with, and I have this irrational fear of designers and auto generated code as it is. I have noticed that the generated entity classes contain a lot of boilerplate extensibility methods, e.g. On[Property]Changed() and so on where [Property] is a mapped member of the class. These are placed in the setters of the property accessors. I assume it's OK if I don't include these when I do my hand coding, correct? They would be nice if I needed some sort of interception pattern but that's certainly not the case. I guess I just need to know if any of those methods are required by the entity framework to keep track of changes to the mapping types in order for things to work when updating the database. Thanks!

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• Wouldn't it be nice to have a type variable referring to the class's instance.

  - by user93197

  I often have a pattern like this: class VectorBase<SubClass, Element> where SubClass : VectorBase<SubClass, Element>, new() where Element : Addable<Element> { Element[] data; public VectorBase(Element[] data) { this.data = data; } public SubClass add(SubClass second) { Element[] newData = new Element[data.Length]; for (int i = 0; i < newData.Length; i++) { newData[i] = data[i].add(second.data[i]); } SubClass result = new SubClass(); result.data = newData; return result; } } class VectorInt : VectorBase<VectorInt, Int32> { } class MyInt : Addable<MyInt> { int data; public MyInt(int data) { this.data = data; } public MyInt add(MyInt t) { return new MyInt(data + t.data); } } interface Addable<T> { T add(T t); } But I would rather just have: class VectorBase2<Element> where Element : Addable<Element> { Element[] data; public VectorBase(Element[] data) { this.data = data; } public SubClass add(SubClass second) { Element[] newData = new Element[data.Length]; for (int i = 0; i < newData.Length; i++) { newData[i] = data[i].add(second.data[i]); } SubClass result = new SubClass(data); return result; } } class VectorInt2 : VectorBase2<Int32> { } Why not make the subclass type available to all classes? Is this technically impossible?

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• Memory allocation patterns in C++

  - by Mahatma

  I am confused about the memory allocation in C++ in terms of the memory areas such as Const data area, Stack, Heap, Freestore, Heap and Global/Static area. I would like to understand the memory allocation pattern in the following snippet. Can anyone help me to understand this. If there any thing more apart from the variable types mentioned in the example to help understand the concept better please alter the example. class FooBar { int n; //Stored in stack? public: int pubVar; //stored in stack? void foo(int param) //param stored in stack { int *pp = new int; //int is allocated on heap. n = param; static int nStat; //Stored in static area of memory int nLoc; //stored in stack? string str = "mystring"; //stored in stack? .. if(CONDITION) { static int nSIf; //stored in static area of memory int loopvar; //stored in stack .. } } } int main(int) { Foobar bar; //bar stored in stack? or a part of it? Foobar *pBar; //pBar is stored in stack pBar = new Foobar(); //the object is created in heap? What part of the object is stored on heap } EDIT: What confuses me is, if pBar = new Foobar(); stores the object on the heap, how come int nLoc; and int pubVar;, that are components of the object stored on stack? Sounds contradictory to me. Shouldn't the lifetime of pubvar and pBar be the same?

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• Refactoring. Your way to reduce code complexity of big class with big methods

  - by Andrew Florko

  I have a legacy class that is rahter complex to maintain: class OldClass { method1(arg1, arg2) { ... 200 lines of code ... } method2(arg1) { ... 200 lines of code ... } ... method20(arg1, arg2, arg3) { ... 200 lines of code ... } } methods are huge, unstructured and repetitive (developer loved copy/paste aprroach). I want to split each method into 3-5 small functions, whith one pulic method and several helpers. What will you suggest? Several ideas come to my mind: Add several private helper methods to each method and join them in #region (straight-forward refactoring) Use Command pattern (one command class per OldClass method in a separate file). Create helper static class per method with one public method & several private helper methods. OldClass methods delegate implementation to appropriate static class (very similiar to commands). ? Thank you in advance!

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• perl DateTime now() problem

  - by Sergey Sinkovskiy

  Having this script use DateTime; use DateTime::Format::Strptime; my $p = DateTime::Format::Strptime->new(pattern => '%F %T', time_zone => 'local'); my $dt1 = DateTime->now(time_zone=>'local')->set_time_zone('UTC'); my $dt2 = $p->parse_datetime('2010-10-23 14:10:02')->set_time_zone('UTC'); print Dumper($dt1->hms); print Dumper($dt2->hms); print Dumper($dt1 > $dt2); The problem is that $dt1 is off by 1 hour. Like $VAR1 = '12:09:55'; $VAR1 = '11:10:02'; $VAR1 = 1; If I remove set_time_zone('UTC') in both cases - dumped values are okay. My feel is that somewhere DST is taken into account unnecessarily, but can't find out. Update: I dumped $dt-time_zone-name and $dt-offset for both and that's what i get. $VAR1 = 'Europe/Kiev'; $VAR1 = 7200; $VAR1 = 'Europe/Kiev'; $VAR1 = 10800; How this could be possible?

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• Implementing a Version check between an Abstract class and it's implementation

  - by Michael Stum

  I have this abstract class and concrete implementation (they are in different assemblies): public abstract class MyAbstractClass { private static readonly int MyAbstractClassVersion = 1; public abstract int ImplementedVersion { get; } protected MyAbstractClass() { CheckVersion(); } private void CheckVersion() { var message = string.Format( "MyAbstractClass implements Version {0}, concrete is Version {1}", RepositoryVersion, ImplementedVersion); if (!MyAbstractClassVersion.Equals(ImplementedVersion)) throw new InvalidOperationException(message); } } public class ConcreteClass : MyAbstractClass { public ConcreteClass() : base() { // ConcreteClass is guaranteed to have // a constructor that calls the base constructor // I just simplified the example } public override int ImplementedVersion { get { return 2; } } } As you see, I call CheckVersion() from the abstract constructor, to get rid of the "virtual member call in base constructor" message, but I am not sure if that's really the way to do it. Sure, it works, but that doesn't mean it will always work, will it? Also, I wonder if I can get the name of the Concrete Type from the CheckVersion() function? I know that adding new abstract members will force an error anyway (System.TypeLoadException) and I'm not sure if I want this type of strict Versioning, but I'm just curious how it would be done properly given only the abstract class and an implementation (I know I could do it by using interfaces and/or a Factory pattern).

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