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• Resetting Objects vs. Constructing New Objects

  - by byronh

  Is it considered better practice and/or more efficient to create a 'reset' function for a particular object that clears/defaults all the necessary member variables to allow for further operations, or to simply construct a new object from outside? I've seen both methods employed a lot, but I can't decide which one is better. Of course, for classes that represent database connections, you'd have to use a reset method rather than constructing a new one resulting in needless connecting/disconnecting, but I'm talking more in terms of abstraction classes. Can anyone give me some real-world examples of when to use each method? In my particular case I'm thinking mostly in terms of ORM or the Model in MVC. For example, if I would want to retrieve a bunch of database objects for display and modify them in one operation.

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• Implementing 1 to n mapping for ORM c++

  - by karan

  I am writing a project where I need to implement a stripped down version of an ORM solution in C++. I am struck in implementing 1-n relationships for the same. For instance, if the following are the classes: class A { ... } class B { ... std::list<A> _a_list; ... } I have provided load/save methods for loading/saving to the db. Now, if I take the case of B and the following workflow: 1 entry from _a_list is removed 1 entry from _a_list is modified 1 entry is added to _a_list Now, I need to update the db using something like "b.save()". So, what would be the best way to save the changes, i.e, identify the additions, deletions and updates to _a_list.

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• Fast parsing of PHP in C#

  - by Jessica Shea

  Hello there, I've got a requirement for parsing PHP files in C#. We essentially require some of the devs in another country to upload PHP files and once uploaded we need to check the php files and get a list of all the methods and classes/functions etc. I thought of using a regex but I can't workout if a function belongs to a class etc, so I was wondering if theres already something 'out there' that will parse out PHP files and spit out its functions (I'm trying to avoid writing a full blow AST implementation). Does anyone have any idea? I looked at Coco/R but I couldn't find a PHP grammar file. I'm using .NET 2.0 and C#.

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• Show facebook status stream of a dedicated person on a website

  - by Pascal

  Hi all, I've been stomping at this all day :( I want to display a status feed of both twitter and facebook on my website. For twitter, this is not a problem, as my account is public, I can easily get the feed. Facebook however, is a whole different story! I can't seem to find an easy way to just get my last status updates and display it on my website. The code I currently have, needs authentication of the visitor, and I don't want that! This is my current code: $facebook = new Facebook($api_key, $secret); $stream = $facebook->api_client->fql_query("SELECT message,source,time FROM status WHERE uid = $user_id LIMIT 6"); I've seen several possible solutions, including the RSS feed, but as Facebook keeps changing the way their site works, none of the previous methods I've seen (including those from as late as januari) currently work! Is there anybody who can provide me with a currently working solution to this (simple?) problem?

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• How to inject dependencies into a CustomUserNamePasswordValidator in WCF?

  - by Dannerbo

  I'm using a UserNamePasswordValidator in WCF along with Unity for my dependency injection, but since WCF creates the instance of the UserNamePasswordValidator, I cannot inject my container into the class. So how would one go about this? The simplest solution I can think of is to create a static proxy/wrapper class around a static instance of a UnityContainer, which exposes all the same methods... This way, any class can access the container, and I don't need to inject it everywhere. So I could just do UnityContainerWrapper.Resolve() anywhere in code. So basically this solution solves 2 problems for me, I can use it in classes that I'm not creating an instance of, and I can use it anywhere without having to inject the container into a bunch of classes. The only downside I can think of is that I'm now potentially exposing my container to a bunch of classes that wouldn't of had access to the container before. Not really sure if this is even a problem though?

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• Is there a faster TList implementation ?

  - by dmauric.mp

  My application makes heavy use of TList, so I was wondering if there are any alternative implementations that are faster or optimized for particular use case. I know of RtlVCLOptimize.pas 2.77, which has optimized implementations of several TList methods. But I'd like to know if there is anything else out there. I also don't require it to be a TList descendant, I just need the TList functionality regardless of how it's implemented. It's entirely possible, given the rather basic functionality TList provides, that there is not much room for improvement, but would still like to verify that, hence this question.

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• link with static library vs individual object files

  - by dododo

  For a reason i want to unpack a static lib (libx.a) into individual object files (a.o b.o c.o), and specify these object files (a.o b.o c.o) in the linker input list instead of libx.a, with other linker options remaining the same. However, i have noticed the above change has resulted in quite some difference in the output executable. Basically, (a.o b.o c.o) method will result in larger output size. So what's the difference between the two methods (libx.a and individual object files)? And is there a way to work around? The GNU binutil (for and ar ld) version i'm using is 2.16.1 Thanks.

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• Sad logic on types

  - by user2972231

  Code base is littered with code like this: BaseRecord record = // some BaseRecord switch(record.source()) { case FOO: return process((FooRecord)record); case BAR: return process((BarRecord)record); case QUUX: return process((QuuxRecord)record); . . // ~25 more cases . } and then private SomeClass process(BarRecord record) { } private SomeClass process(FooRecord record) { } private SomeClass process(QuuxRecord record) { } It makes me terribly sad. Then, every time a new class is derived from BaseRecord, we have to chase all over our code base updating these case statements and adding new process methods. This kind of logic is repeated everywhere, I think too many to add a method for each and override in the classes. How can I improve this?

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• Style of if: to nest or not to nest

  - by Marco

  A colleague of mine and me had a discussion about the following best-practice issue. Most functions/methods start with some parameter checking. I advocate the following style, which avoids nesting. if (parameter one is ugly) return ERROR; if (parameter two is nonsense || it is raining) return ERROR; // do the useful stuff return result; He, who comes from a more functional/logic programming background, prefers the following, because it reduces the number of exit points from the function. if (parameter one is ok) { if (parameter two is ok && the sun is shining) { // do the useful stuff return result } } return ERROR; Which one would you prefer and why?

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• Why is Javascript's Math.floor the slowest way to calculate floor in Javascript?

  - by z5h

  I'm generally not a fan of microbenchmarks. But this one has a very interesting result. http://ernestdelgado.com/archive/benchmark-on-the-floor/ It suggests that Math.floor is the SLOWEST way to calculate floor in Javascript. ~~n, n|n, n&n all being faster. This seems pretty shocking as I would expect that people implementing Javascript in today's modern browsers would be some pretty smart people. Does floor do something important that the other methods fail to do? Is there any reason to use it?

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• Java - How can I edit the size and position of a button using Swing?

  - by mino

  I have the following code but I'd like to structure several buttons of certain sizes. I'm just wondering how to do this as I've Googled it and found several different methods but none seem to work. Any advice? import javax.swing.*; public class GUI { public static void main(String[] args) { JFrame window = new JFrame(); window.setSize(500, 500); window.setTitle("My Application"); JButton button = new JButton("click me"); window.add(button); window.setVisible(true); } }

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• C# implementation of PushbackInputStream

  - by Mark Heath

  I need a C# implementation of Java's PushbackInputStream. I have made my own very basic one, but I wondered if there was a well tested and decently performing version already available somewhere. As it happens I always push back the same bytes I read so really it just needs to be able to reposition backwards, buffering up to a number of bytes I specify. (like Java's BufferedInputStream with the mark and reset methods). Update: I should add that I can't simply reposition the stream as CanSeek may be false. (e.g. when the input steam is a NetworkStream)

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• Convert VB6 Randomize to C#

  - by Thomas G. Mayfield

  I'm writing a C# frontend to a legacy database that uses VB6 Rnd() and Randomize() methods for user password encryption. The encryption function is very simplistic and really not all that secure, but it's what all current passwords are stored with. What I'd like to be able to do is authenticate legacy users from a C# application. I can write new encryption (or preferably hashing) code for VB6 so that all future users have a more secure password, and that can be duplicated in C#. But I don't want to require current users to have had their password reset before they can use the new frontend. Is there any way I can reimplement that algorithm in C# so that it produces identical results to the legacy VB6 code?

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• use/run python's 2to3 as or like a unittest

  - by Vincent

  I have used the 2to3 utility to convert code from the command line. What I would like to do is run it basically as a unittest. Even if it tests the file rather than parts(funtions, methods...) as would be normal for a unittest. It does not need to be a unittest and I don't what to automatically convert the files I just want to monitor the py3 compliance of files in a unittest like manor. I can't seem to find any documentation or examples for this. An example and/or documentation would be great. Thanks

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• Rails STI validation inheritance

  - by KARASZI István

  Dear Rails users! I have STI models in my Rails application. The ancestor model has validations with the validates_... methods which are working fine. But I have custom validations as well, and I would like to add more different custom validations in the descendants. These custom validations would depend on the class. If I write class DescendantA < Ancestor protected def validate # ... end end It simply overwrites the original validations. Is there a convention to do this in Rails?

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• How can I add a field with an array value to my Perl object?

  - by superstar

  What's the difference between these two constructors in perl? 1) sub new { my $class = shift; my $self = {}; $self->{firstName} = undef; $self->{lastName} = undef; $self->{PEERS} = []; bless ($self, $class); return $self; } 2) sub new { my $class = shift; my $self = { _firstName => shift, _lastName => shift, _ssn => shift, }; bless $self, $class; return $self; } I am using the second one so far, but I need to implement the PEERS array in the second one? How do I do it with the second constructor and how can we use get and set methods on those array variables?

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• How to set background image in Java?

  - by Dew

  I am developing a simple platform game using Java using BlueJ as the IDE. Right now I have player/enemy sprites, platforms and other items in the game drawn using polygons and simple shapes. Eventually I hope to replace them with actual images. For now I would like to know what is the simplest solution to setting an image (either URL or from local source) as the 'background' of my game window/canvas? I would appreciate it if it isn't something long or complex as my programming skills aren't very good and I want to keep my program as simple as possible. Kindly provide example codes with comments to elaborate on their function, and also if it's in its own class, how to call on relevant methods used by it on other classes. Thank you very much.

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• Question About Abstract Classes?

  - by IbrarMumtaz

  URL: Link (1) According to this wesbite .. you cannot implement Abstract classes but derive from them. This makes sense and I have read this many times. Like an interface, you cannot implement an instance of an abstract class, however you can implement methods, fields, and properties in the abstract class that can be used by the child class. But on MSDN URL: TextWriter CLass on MSDN TextWriter is an abstract class but it has two constructors defined ... and according to the MS 70-536 book, the following statement is valid: TextWriter tw = new File.CreateText("myFile.Txt") The static file class and it's CreateText method is fine by me as I have studied it on MSDN but can somebody explain this little contradiction I have found? Surely I am not the first? Why is instantaion of base abstract classes possible????

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• What are the pro and cons of having localization files vs hard coded variables in source code?

  - by corgrath

  Definitions: Files: Having the localization phrases stored in a physical file that gets read at application start-up and the phrases are stored in the memory to be accessed via util-methods. The phrases are stored in key-value format. One file per language. Variables: The localization texts are stored as hard code variables in the application's source code. The variables are complex data types and depending on the current language, the appropriate phrase is returned. Background: The application is a Java Servlet and the developers use Eclipse as their primary IDE. Some brief pro and cons: Since Eclipse is use, tracking and finding unused localizations are easier when they are saved as variables, compared to having them in a file. However the application's source code becomes bigger and bloated. What are the pro and cons of having localization text in files versus hard coded varibles in source code? What do you do and why?

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• Running a stored procedure in a SqlDataSource on button click

  - by Gapton

  I am building a C# ASP.NET page where I want to call a stored procedure in a database. I have setup a SqlDataSource which points to the stored procedure. Parameters are obtained from the Web's control directly (TextBox) I have a button, when the user clicks it it should run the stored procedure, so I was going to add code like this : mySqlDataSource.run() or mySqlDataSource.exec() or mySqlDataSource.storedProcedure() but of course none of these methods exist. How do I initial the stored procedure? and how do I get the value returned by the stored procedure please? Thank you!

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• Different return value of an overridden class

  - by Samer Afach

  I have a simple but confusing question here. Is it legal to have a different return value type for overridden methods than the abstact ones defined in the base class?? I did that and the compiler didn't complain... could someone please explain? class MyBaseClass { int value; public: virtual int getValue() = 0; }; class MyClass : public MyBaseClass { double value; public: virtual double getValue(); // here!!! return is double, not int }; double MyClass::getValue() { return this->value; } The compiler totally accepted something similar (MSVC und MinGW)... could anyone please exaplain to what extent this is legal?

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• How should I declare default values for instance variables in Python?

  - by int3

  Should I give my class members default values like this: class Foo: num = 1 or like this? class Foo: def __init__(self): self.num = 1 In this question I discovered that in both cases, bar = Foo() bar.num += 1 is a well-defined operation. I understand that the first method will give me a class variable while the second one will not. However, if I do not require a class variable, but only need to set a default value for my instance variables, are both methods equally good? Or one of them more 'pythonic' than the other? One thing I've noticed is that in the Django tutorial, they use the second method to declare Models. Personally I think the second method is more elegant, but I'd like to know what the 'standard' way is.

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• Proper structure for many test cases in Python with unittest

  - by mellort

  I am looking into the unittest package, and I'm not sure of the proper way to structure my test cases when writing a lot of them for the same method. Say I have a fact function which calculates the factorial of a number; would this testing file be OK? import unittest class functions_tester(unittest.TestCase): def test_fact_1(self): self.assertEqual(1, fact(1)) def test_fact_2(self): self.assertEqual(2, fact(2)) def test_fact_3(self): self.assertEqual(6, fact(3)) def test_fact_4(self): self.assertEqual(24, fact(4)) def test_fact_5(self): self.assertFalse(1==fact(5)) def test_fact_6(self): self.assertRaises(RuntimeError, fact, -1) #fact(-1) if __name__ == "__main__": unittest.main() It seems sloppy to have so many test methods for one method. I'd like to just have one testing method and put a ton of basic test cases (ie 4! ==24, 3!==6, 5!==120, and so on), but unittest doesn't let you do that. What is the best way to structure a testing file in this scenario? Thanks in advance for the help.

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• URL of the website calling Restlet API

  - by Christopher McCann

  I have a Restlet API and the methods exposed on it are called by a PHP web app. This web app is accessible by several domain names and depending on the domain certain aspects of the app are changed (look and feel, content etc). Is there a way for Restlet to determine the URL of the calling web app? I have used getReference() but all I can get is the (internal) IP address of the calling web server (not the domain name). My only other alternative is to pass the URL of the web app with every request to the API but it would be cleaner if Restlet already knew. Thanks

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• Core Data and BOOL setup

  - by John Valen

  I am working on an app that uses Core Data as its backend for managing SQLite records. I have everything working with strings and numbers, but have just tried adding BOOL fields and can't seem to get things to work. In the .xcdatamodel, I have added a field to my object called isCurrentlyForSale which is not Optional, not Transient, and not Indexed. The attribute's type is set to Boolean with default value NO. When I created the class files from the data model, the boilerplate code added for this property in the .h header was: @property (nonatomic, retain) NSNumber * isCurrentlyForSale; along with the @dynamic isCurrentlyForSale; in the .m implementation file. I've always worked with booleans as simple BOOLs. I've read that I could use NSNumber's numberWithBool and boolValue methods, but this seems like an aweful lot of extra code for something so simple. Can the @property in the header be changed to a simple BOOL? If so is there anything to watch out for? Thanks -John

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