Search Results

Search found 17731 results on 710 pages for 'programming practices'.

Page 197/710 | < Previous Page | 193 194 195 196 197 198 199 200 201 202 203 204  | Next Page >

• C++ Singleton design pattern.

  - by Artem Barger

  Recently I've bumped into realization/implementation of Singleton design pattern for C++. It has looked in the following way (I have adopted it from real life example): // a lot of methods is omitted here class Singleton { public: static Singleton* getInstance( ); ~Singleton( ); private: Singleton( ); static Singleton* instance; }; From this declaration I can deduce that instance field is initiated on the heap, that means there is a memory allocation. That is completely unclear for me is when does exactly memory is going to be deallocated? Or there is a bug and memory leak? It seems like there is a problem in implementation. PS. And main question how to implement it in the right way?

  Read the article

• Atomic operations on several transactionless external systems

  - by simendsjo

  Say you have an application connecting 3 different external systems. You need to update something in all 3. In case of a failure, you need to roll back the operations. This is not a hard thing to implement, but say operation 3 fails, and when rolling back, the rollback for operation 1 fails! Now the first external system is in an invalid state... I'm thinking a possible solution is to shut down the application and forcing a manual fix of the external system, but then again... It might already have used this information (and perhaps that's why it failed), or we might not have sufficient access. Or it might not even be a good way to rollback the action! Are there some good ways of handling such cases? EDIT: Some application details.. It's a multi user web application. Most of the work is done with scheduled jobs (through Quartz.Net), so most operations is run in it's own thread. Some user actions should trigger jobs that update several systems though. The external systems are somewhat unstable. I Was thinking of changing the application to use the Command and Unit Of Work pattern

  Read the article

• Are there any inherent benefits or drawbacks to choosing Google Code vs. SourceForge vs. Codeplex?

  - by kdmurray

  I've got a couple of different projects that I'd like to post up as open source. I've been trying to decide which of the three big open-source project hosting sites makes the most sense, or if I should just host it myself. Are there any inherent drawbacks or benefits to these three? Is there a "best" place to host a project? Do different sites make more sense for different kinds of projects?

  Read the article

• Is "for(;;)" faster than "while (TRUE)"? If not, why do people use it?

  - by Chris Cooper

  for (;;) { //Something to be done repeatedly } I have seen this sort of thing used a lot, but I think it is rather strange... Wouldn't it be much clearer to say while (TRUE), or something along those lines? I'm guessing that (as is the reason for many-a-programmer to resort to cryptic code) this is a tiny margin faster? Why, and is it REALLY worth it? If so, why not just define it this way: #DEFINE while(TRUE) for(;;)

  Read the article

• iPhone:Programming UISlider to position at clicked location

  - by suse

  Hello , How to set the slider to clicked position and get the slider value on the clicked location on UISlider in iPhone programming. i know we can drag the slider to that position but i dont want to do it. Can you please tel me how to set the slider to clicked position? Is this possible to do?

  Read the article

• Is VERIFY(...) a good practice in C++ coding?

  - by sevaxx

  Also, how does it compare to throwing an exception when something goes wrong ?

  Read the article

• How do you determine how coarse or fine-grained a 'responsibility' should be when using the single r

  - by Mark Rogers

  In the SRP, a 'responsibility' is usually described as 'a reason to change', so that each class (or object?) should have only one reason someone should have to go in there and change it. But if you take this to the extreme fine-grain you could say that an object adding two numbers together is a responsibility and a possible reason to change. Therefore the object should contain no other logic, because it would produce another reason for change. I'm curious if there is anyone out there that has any strategies for 'scoping', the single-responsibility principle that's slightly less objective?

  Read the article

• [c#]Is there any diff between these two "if" conditional statement?

  - by Pandiya Chendur

  First if condition if(Txt1.Text != "" && Txt2.Text != "") Second if condition if((Txt1.Text && Txt2.Text) != "") Is there any diff between these two conditional statement?

  Read the article

• Where should global Application Settings be stored on Windows 7?

  - by Kerido

  Hi everybody, I'm working hard on making my product work seamlessly on Windows 7. The problem is that there is a small set of global (not user-specific) application settings that all users should be able to change. On previous versions I used HKLM\Software\__Company__\__Product__ for that purpose. This allowed Power Users and Administrators to modify the Registry Key and everything worked correctly. Now that Windows Vista and Windows 7 have this UAC feature, by default, even an Administrator cannot access the Key for writing without elevation. A stupid solution would, of course, mean adding requireAdministrator option into the application manifest. But this is really unprofessional since the product itself is extremely far from administration-related tasks. So I need to stay with asInvoker. Another solution could mean programmatic elevation during moments when write access to the Registry Key is required. Let alone the fact that I don't know how to implement that, it's pretty awkward also. It interferes with normal user experience so much that I would hardly consider it an option. What I know should be relatively easy to accomplish is adding write access to the specified Registry Key during installation. I created a separate question for that. This also very similar to accessing a shared file for storing the settings. My feeling is that there must be a way to accomplish what I need, in a way that is secure, straightforward and compatible with all OS'es. Any ideas?

  Read the article

• How do I create a new AnyType[] array?

  - by cb

  Which is the best practice in this situation? I would like an un-initialized array of the same type and length as the original. public static <AnyType extends Comparable<? super AnyType>> void someFunction(AnyType[] someArray) { AnyType[] anotherArray = (AnyType[]) new Comparable[someArray.length]; ...or... AnyType[] anotherArray = (AnyType[]) new Object[someArray.length]; ...some other code... } Thanks, CB

  Read the article

• Learning Javascript in one weekend?

  - by dueyfinster

  Similiar to this question, I am wondering if experienced Javascript developers have any websites they use with examples to get the basics of Javascript down in 24/28 hours? I have looked at Douglas Crockford's Google Tech Talk and I bought the book "Javascript: the good parts" but I haven't had time to read it.

  Read the article

• Simple network gaming, client-server architecture planning.

  - by michal

  Hi, I'm coding simple game which I plan to make multiplayer (over the network) as my university project. I'm considering two scenarios for client-server communication: The physics (they're trivial! I should call it "collision tests" in fact :) ) are processed on server machine only. Therefore the communication looks like Client1->Server: Pressed "UP" Server->Clients: here you go, Client1 position is now [X,Y] Client2->Server: Pressed "fire" Server->Clients: Client1 hit Client2, make Client2 disappear! server receives the event and broadcasts it to all the other clients. Client1->Server: Pressed "UP" Server->Clients: Client1 pressed "UP", recalculate his position!! [Client1 receives this one as well!] Which one is better? Or maybe none of them? :)

  Read the article

• Error handling inside or out of class?

  - by Rin

  Usually I do all what I can inside a class, in every method (try and catch). Am I doing it wrong? Recently I heard better way is handle error in program body... What is good habit?

  Read the article

• Is there a more correct type for passing in the file path and file name to a method

  - by Rihan Meij

  Hi What I mean by this question is, when you need to store or pass a URL around, using a string is probably a bad practice, and a better approach would be to use a URI type. However it is so easy to make complex things more complex and bloated. So if I am going to be writing to a file on disk, do I pass it a string, as the file name and file path, or is there a better type that will be better suited to the requirement? This code seems to be clunky, and error prone? I would also need to do a whole bit of checking if it is a valid file name, if the string contains data and the list goes on. private void SaveFile(string fileNameAndPath) { //The normal stuff to save the file }

  Read the article

• Giving the script tag an ID

  - by The Code Pimp

  Hi guys, i came across a scenario where giving a <script> element an "ID" would solve a problem easily. However, after reading about the script tag at w3schools and quirksmode, it seems doing so could have some unforeseen consequences. Has anyone come across any of these issues with modern browsers such as Chrome, Safari, FF3 up and IE 7 up? Thanks

  Read the article

• Do you have a hard time keeping to 80 columns with Python?

  - by ApplePieIsGood

  I find myself breaking strings constantly just to get them on the next line. And of course when I go to change those strings (think logging messages), I have to reformat the breaks to keep them within the 80 columns. How do most people deal with this?

  Read the article

• Ideal way to set global uncaught exception Handler in Android

  - by Samuh

  I want to set a global uncaught exception handler for all the threads in my Android application. So, in my Application subclass I set an implementation of Thread.UncaughtExceptionHandler as default handler for uncaught exceptions. Thread.setDefaultUncaughtExceptionHandler( new DefaultExceptionHandler(this)); In my implementation, I am trying to display an AlertDialog displaying appropriate exception message. However, this doesn't seem to work. Whenever, an exception is thrown for any thread which goes un-handled, I get the stock, OS-default dialog (Sorry!-Application-has-stopped-unexpectedly dialog). What is the correct and ideal way to set a default handler for uncaught exceptions? Thanks.

  Read the article

• Sequential Asynchronous calls are gross. Is there a more readable solution?

  - by Fletcher Moore

  The problem is this is hard to follow: ajaxOne(function() { // do something ajaxTwo(function() { // do something ajaxThree() }); }); I'm using a third party API to make the AJAX calls, so I need a generic solution.

  Read the article

• Is there a particular naming convention for Java methods that throw exceptions?

  - by lyates

  I'm tempted to add a suffix like "Ex" to differentiate methods (with similar signatures) that throw Exceptions from those that don't. Is there such a convention?

  Read the article

• What is the standard way to bundle OSGi dependent libraries?

  - by Chris

  Hi, I have a project that references a number of open source libraries, some new, some not so new. That said, they are all stable and I wish to stick with my chosen versions until I have time to migrate to the newer versions (I tested hsqldb 2.0 yesterday and it contains many api changes). One of the libraries I have wish to embed is Jasper Reports, but as you all surely know, it comes with a mountain of supporting jar files and I have only need a subset of the mountain (known) therefore I am planning to custom bundle all of my dependant libraries. So: Does everyone custom-make their own OSGi bundles for open-source libraries they are using or is there a master source of OSGi versions of common libraries? Also, I was thinking that it would be far simpler for each of my bundles simply to embed their dependent jars within the bundle itself. Is this possible? If I choose to embed the 3rd party foc libraries within a bundle, I assume I will need to produce 2 jar files, one without the embedded libraries (for libraries to be loaded via the classpath via standard classloader), and one osgi version that includes the embedded libraryy, therefore should I choose a bundle name like this <<myprojectname>>-<<subproject>>-osgi-.1.0.0.jar ? If I cannot embed the open source libraries and choose to custom bundle the open source libraries (via bnd), should I choose a unique bundle name to avoid conflict with a possible official bundle? e.g. <<myprojectname>>-<<3rdpartylibname>>-<<3rdpartylibversion>>.jar ? My non-OSGi enabled project currently scans for custom plugins via scanning the META-INF folders in my various plugin jars via Service.providers(...). If I go OSGi, will this mechanism still work?

  Read the article

• database design - empty fields

  - by imanc

  Hey, I am currently debating an issue with a guy on my dev team. He believes that empty fields are bad news. For instance, if we have a customer details table that stores data for customers from different countries, and each country has a slightly different address configuration - plus 1-2 extra fields, e.g. French customer details may also store details for entry code, and floor/level plus title fields (madamme, etc.). South Africa would have a security number. And so on. Given that we're talking about minor variances my idea is to put all of the fields into the table and use what is needed on each form. My colleague believes we should have a separate table with extra data. E.g. customer_info_fr. But this seams to totally defeat the purpose of a combined table in the first place. His argument is that empty fields / columns is bad - but I'm struggling to find justification in terms of database design principles for or against this argument and preferred solutions. Another option is a separate mini EAV table that stores extra data with parent_id, key, val fields. Or to serialise extra data into an extra_data column in the main customer_data table. I think I am confused because what I'm discussing is not covered by 3NF which is what I would typically use as a reference for how to structure data. So my question specifically: - if you have slight variances in data for each record (1-2 different fields for instance) what is the best way to proceed?

  Read the article

• How to evade writing a lot of repetitive code when mapping?

  - by JPCF

  I have a data access layer (DAL) using Entity Framework, and I want to use Automapper to communicate with upper layers. I will have to map data transfer objects (DTOs) to entities as the first operation on every method, process my inputs, then proceed to map from entities to DTOs. What would you do to skip writing this code? As an example, see this: //This is a common method in my DAL public CarDTO getCarByOwnerAndCreditStatus(OwnerDTO ownerDto, CreditDto creditDto) { //I want to automatize this code on all methods similar to this Mapper.CreateMap<OwnerDTO,Owner>(); Mapper.CreateMap<CreditDTO,Credit>(); Owner owner = Mapper.map(ownerDto); Owner credit = Mapper.map(creditDto) //... Some code processing the mapped DTOs //I want to automatize this code on all methods similar to this Mapper.CreateMap<Car,CarDTO>(); Car car = Mapper.map(ownedCar); return car; }

  Read the article

• Correct structure and way of website versioning

  - by Saif Bechan

  Recently I use GIT to version my website. It makes it all really easy to see how my project develops and I always have save backups on different places on the web. Now my main question is if it is recommended to version your whole root of the website. I have a basic structure that looks something like this: /httpdocs /config /media /application index.php .htaccess 1) Should I use the /httpdocs folder to version, or should I use the content of the folder. 2) Is it recommended to version the media folder. In the media version I have several images for the overall layout, and some other images for the website. These imagas can be quite large. I work on these images from time to time and so they change. I hardly never need the old image again, so is this not just taking up precious storage space. I would highly appreciate just some basic recommendation on this topic.

  Read the article

• typeof === "undefined" vs. != null

  - by Thor Thurn

  I often see JavaScript code which checks for undefined parameters etc. this way: if (typeof input !== "undefined") { // do stuff } This seems kind of wasteful, since it involves both a type lookup and a string comparison, not to mention its verbosity. It's needed because 'undefined' could be renamed, though. My question is: How is that code any better than this approach: if (input != null) { // do stuff } As far as I know, you can't redefine null, so it's not going to break unexpectedly. And, because of the type-coercion of the != operator, this checks for both undefined and null... which is often exactly what you want (e.g. for optional function parameters). Yet this form does not seem widespread, and it even causes JSLint to yell at you for using the evil != operator. Why is this considered bad style?

  Read the article

• Saving a Django form with a Many2Many field with through table

  - by PhilGo20

  So I have this model with multiple Many2Many relationship. 2 of those (EventCategorizing and EventLocation are through tables/intermediary models) class Event(models.Model): """ Event information for Way-finding and Navigator application""" categories = models.ManyToManyField('EventCategorizing', null=True, blank=True, help_text="categories associated with the location") #categories associated with the location images = models.ManyToManyField(KMSImageP, null=True, blank=True) #images related to the event creator = models.ForeignKey(User, verbose_name=_('creator'), related_name="%(class)s_created") locations = models.ManyToManyField('EventLocation', null=True, blank=True) In my view, I first need to save the creator as the request user, so I use the commit=False parameter to get the form values. if event_form.is_valid(): event = event_form.save(commit=False) #we save the request user as the creator event.creator = request.user event.save() event = event_form.save_m2m() event.save() I get the following error: *** TypeError: 'EventCategorizing' instance expected I can manually add the M2M relationship to my "event" instance, but I am sure there is a simpler way. Am I missing on something ?

  Read the article

< Previous Page | 193 194 195 196 197 198 199 200 201 202 203 204  | Next Page >