Search Results

Search found 8692 results on 348 pages for 'patterns and practices'.

Page 47/348 | < Previous Page | 43 44 45 46 47 48 49 50 51 52 53 54  | Next Page >

• Design pattern for isomorphic trees

  - by Peregring-lk

  I want to create a data structure to work with isomorphic tree. I don't search for a "algorithms" or methods to check if two or more trees are isomorphic each other. Just to create various trees with the same structure. Example: 2 - - - - - - - 'a' - - - - - - - 3.5 / \ / \ / \ 3 3 'f' 'y' 1.0 3.1 / \ / \ / \ 4 7 'e' 'f' 2.3 7.7 The first "layer" or tree is the "natural tree" (a tree with natural numbers), the second layer is the "character tree" and the third one is the "float tree". The data structure has a method or iterator to traverse the tree and to make diferent operations with its values. These operations could change the value of nodes, but never its structure (first I create the structure and then I configure the tree with its diferent layers). In case of that I add a new node, this would be applied to each layer. Which known design pattern fits with this description or is related with it?

  Read the article

• What are the consequences of immutable classes with references to mutable classes?

  - by glenviewjeff

  I've recently begun adopting the best practice of designing my classes to be immutable per Effective Java [Bloch2008]. I have a series of interrelated questions about degrees of mutability and their consequences. I have run into situations where a (Java) class I implemented is only "internally immutable" because it uses references to other mutable classes. In this case, the class under development appears from the external environment to have state. Do any of the benefits (see below) of immutable classes hold true even by only "internally immutable" classes? Is there an accepted term for the aforementioned "internal mutability"? Wikipedia's immutable object page uses the unsourced term "deep immutability" to describe an object whose references are also immutable. Is the distinction between mutability and side-effect-ness/state important? Josh Bloch lists the following benefits of immutable classes: are simple to construct, test, and use are automatically thread-safe and have no synchronization issues do not need a copy constructor do not need an implementation of clone allow hashCode to use lazy initialization, and to cache its return value do not need to be copied defensively when used as a field make good Map keys and Set elements (these objects must not change state while in the collection) have their class invariant established once upon construction, and it never needs to be checked again always have "failure atomicity" (a term used by Joshua Bloch) : if an immutable object throws an exception, it's never left in an undesirable or indeterminate state

  Read the article

• How to avoid code duplication for a system which has logic that may change year wise?

  - by aravind

  What would be the way to design a system which has logic that may change year wise? There is an application which conducts online exams. There are five questions for a particular subject. The questions may (or may not) change year wise. As per my current design, the questions in database are stored year wise. There are some year specific code logic as well. In order to enable the application for another year, the year specific database records and code will be copied or duplicated. How to avoid this code duplication?

  Read the article

• Given the presentation model pattern, is the view, presentation model, or model responsible for adding child views to an existing view at runtime?

  - by Ryan Taylor

  I am building a Flex 4 based application using the presentation model design pattern. This application will have several different components to it as shown in the image below. The MainView and DashboardView will always be visible and they each have corresponding presentation models and models as necessary. These views are easily created by declaring their MXML in the application root. <s:HGroup width="100%" height="100%"> <MainView width="75% height="100%"/> <DashboardView width="25%" height="100%"/> </s:HGroup> There will also be many WidgetViewN views that can be added to the DashboardView by the user at runtime through a simple drop down list. This will need to be accomplished via ActionScript. The drop down list should always show what WidgetViewN has already been added to the DashboardView. Therefore some state about which WidgetViewN's have been created needs to be stored. Since the list of available WidgetViewN and which ones are added to the DashboardView also need to be accessible from other components in the system I think this needs to be stored in a Model object. My understanding of the presentation model design pattern is that the view is very lean. It contains as close to zero logic as is practical. The view communicates/binds to the presentation model which contains all the necessary view logic. The presentation model is effectively an abstract representation of the view which supports low coupling and eases testability. The presentation model may have one or more models injected in in order to display the necessary information. The models themselves contain no view logic whatsoever. So I have a several questions around this design. Who should be responsible for creating the WidgetViewN components and adding these to the DashboardView? Is this the responsibility of the DashboardView, DashboardPresentationModel, DashboardModel or something else entirely? It seems like the DashboardPresentationModel would be responsible for creating/adding/removing any child views from it's display but how do you do this without passing in the DashboardView to the DashboardPresentationModel? The list of available and visible WidgetViewN components needs to be accessible to a few other components as well. Is it okay for a reference to a WidgetViewN to be stored/referenced in a model? Are there any good examples of the presentation model pattern online in Flex that also include creating child views at runtime?

  Read the article

• DDD: Service or Repository

  - by tikhop

  I am developing an app in DDD manner. And I have a little problem with it. I have a Fare (airline fare) and FareRepository objects. And at some point I should load additional fare information and set this information to existing Fare. I guess that I need to create an Application Service (FareAdditionalInformationService) that will deal with obtaining data from the server and than update existing Fare. However, some people said me that it is necessary to use FareRepository for this problem. I don't know wich place is better for my problem Service or Repository.

  Read the article

• Using IComparable<T> Interface

  - by Pawan_Mishra

  Level : Beginner to Intermediate C# language has constantly evolved over a constant period of time.Each new version introduced new features which changed the way we programmed and solved the problems. Whether it was introduction of generics in C# 2.0 , LINQ in C# 3.0 or concept of dynamic programming in C# 4.0 , each of them had or will have greater impact on our programming style.As a developer we don’t have much option but to evolve and redefine our self in this constantly changing environment...(read more)

  Read the article

• Why do programmers seem to be such bad spellers?

  - by Joel Etherton

  Programming languages are very precise tools based on explicit grammars. They're very picky, and when being used they require an exacting amount of detail. C#, for instance, is case sensitive so even getting the case of an argument wrong will cause an error. Questions asked all over the StackExchange are replete with misspellings, grammatical errors, and other problems that seem to indicate a lack of attention to detail when it comes to the language itself. Now, I understand there are a lot of programmers out there whose native language is not English, and I am not directing this question (rant one might say) at them. I'm referring to the individuals who are clearly from an English speaking background who refuse to pay attention to these simple details. I am not perfect by any means, but I try to use the language correctly so that my meaning will be understood correctly. I find programmers misspelling variable names, classes, and all manner of words in any kind of technical documentation they might write. I have had to withstand code where I am repeatedly referring to the subit[sic] button or HttpWebResponse reponse. The general complaint about bad spelling is one thing, and it will always be there. I accept that. But my question/comment is about the proclivity of bad spelling within the programming community. I would think that people who deal with such exacting tools to be more naturally predisposed towards proper spelling. Yet this doesn't seem to be the case.

  Read the article

• Non-zero exit status for clean exit

  - by trinithis

  Is it acceptable to return a non-zero exit code if the program in question ran properly? For example, say I have a simple program that (only) does the following: Program takes N arguments. It returns an exit code of min(N, 255). Note that any N is valid for the program. A more realistic program might return different codes for successfully ran programs that signify different things. Should these programs instead write this information to a stream instead, such as to stdout?

  Read the article

• The use of Test-Driven Development in Non-Greenfield Projects?

  - by JHarley1

  So here is a question for you, having read some great answers to questions such as "Test-Driven Development - Convince Me". So my question is: "Can Test-Driven Development be used effectively on non-Greenfield projects?" To specify: I would really like to know if people have had experience in using TDD in projects where there was already non-TDD elements present? And the problems that they then faced.

  Read the article

• AdventureWorks 2014 Sample Databases Are Now Available

  - by aspiringgeek

    Where in the World is AdventureWorks? Recently, SQL Community feedback from twitter prompted me to look in vain for SQL Server 2014 versions of the AdventureWorks sample databases we’ve all grown to know & love. I searched Codeplex, then used the bing & even the google in an effort to locate them, yet all I could find were samples on different sites highlighting specific technologies, an incomplete collection inconsistent with the experience we users had learned to expect.  I began pinging internally & learned that an update to AdventureWorks wasn’t even on the road map.  Fortunately, SQL Marketing manager Luis Daniel Soto Maldonado (t) lent a sympathetic ear & got the update ball rolling; his direct report Darmodi Komo recently announced the release of the shiny new sample databases for OLTP, DW, Tabular, and Multidimensional models to supplement the extant In-Memory OLTP sample DB.  What Success Looks Like In my correspondence with the team, here’s how I defined success: 1. Sample AdventureWorks DBs hosted on Codeplex showcasing SQL Server 2014’s latest-&-greatest features, including:  In-Memory OLTP (aka Hekaton) Clustered Columnstore Online Operations Resource Governor IO 2. Where it makes sense to do so, consolidate the DBs (e.g., showcasing Columnstore likely involves a separate DW DB) 3. Documentation to support experimenting with these features As Microsoft Senior SDE Bonnie Feinberg (b) stated, “I think it would be great to see an AdventureWorks for SQL 2014.  It would be super helpful for third-party book authors and trainers.  It also provides a common way to share examples in blog posts and forum discussions, for example.”  Exactly.  We’ve established a rich & robust tradition of sample databases on Codeplex.  This is what our community & our customers expect.  The prompt response achieves what we all aim to do, i.e., manifests the Service Design Engineering mantra of “delighting the customer”.  Kudos to Luis’s team in SQL Server Marketing & Kevin Liu’s team in SQL Server Engineering for doing so. Download AdventureWorks 2014 Download your copies of SQL Server 2014 AdventureWorks sample databases here.

  Read the article

• Implementing game rules in a tactical battle board game

  - by Setzer22

  I'm trying to create a game similar to what one would find in a typical D&D board game combat. For mor examples you could think of games like Advance Wars, Fire Emblem or Disgaea. I should say that I'm using design by component so far, but I can't find a nice way to fit components into the part I want to ask. I'm struggling right now with the "game rules" logic. That is, the code that displays the menu, allows the player to select units, and command them, then tells the unit game objects what to do given the player input. The best way I could thing of handling this was using a big state machine, so everything that could be done in a "turn" is handled by this state machine, and the update code of this state machine does different things depending on the state. This approach, though, leads to a large amount of code (anything not model-related) to go into a big class. Of course I can subdivide this big class into more classes, but it doesn't feel modular and upgradable enough. I'd like to know of better systems to handle this in order to be able to upgrade the game with new rules without having a monstruous if/else chain (or switch / case, for that matter). So, any ideas? I'd also like to ask that if you recommend me a specific design pattern to also provide some kind of example or further explanation and not stick to "Yeah you should use MVC and it'll work".

  Read the article

• Testing loses its effectiveness if all programmers don't use them

  - by Jeff O

  Let's assume you are convinced that the extra time spent unit testing has merit and improves production. Does that still hold up when everyone working on the same code doesn't use them? This question makes me wonder if fixing tests that everyone doesn't use is a waste of time. If you correct a test so the new code will pass, you're assuming the new code is correct. The person updating the test better have a firm understanding of the reasoning behind the code change and decide if the test or the new code needs to be fixed. This much inconsistency in a team when it comes to testing is probably an indication of other problems as well. There is a certain amount of risk involved that someone else on the team will alter code that is covered by testing. Is this the point where testing becomes counter-productive?

  Read the article

• How do you think about an Application Generator? [closed]

  - by Mehdi Sheyda

  I'm designing an application-generating application. It is an application that takes the requirements of customer as inputs , analyzes the requirements, creates classes and produces program files in C#. I am at the beginning of this project and have a long way to go with this application. Do you have an experience with designing similar kinds of projects? What risks might I encounter with this project?

  Read the article

• Am I missing a pattern?

  - by Ryan Pedersen

  I have a class that is a singleton and off of the singleton are properties that hold the instances of all the performance counters in my application. public interface IPerformanceCounters { IPerformanceCounter AccountServiceCallRate { get; } IPerformanceCounter AccountServiceCallDuration { get; } Above is an incomplete snippet of the interface for the class "PerformanceCounters" that is the singleton. I really don't like the plural part of the name and thought about changing it to "PerformanceCounterCollection" but stopped because it really isn't a collection. I also thought about "PerformanceCounterFactory" but it is really a factory either. After failing with these two names and a couple more that aren't worth mentioning I thought that I might be missing a pattern. Is there a name that make sense or a change that I could make towards a standardized pattern that would help me put some polish on this object and get rid of the plural name? I understand that I might be splitting hairs here but that is why I thought that the "Programmers" exchange was the place for this kind of thing. If it is not... I am sorry and I will not make that mistake again. Thanks!

  Read the article

• Developing a feature which sole purpose to be taken out?

  - by adib

  What is the name of the pattern in which individual contributors (programmers/designers) developed an artifact for the sole purpose is to serve as a diversion so that management can remove that feature in the final product? This is a folklore I heard from an ex-colleague who used to work at a large game development company. At that company, it is well known that middle management is pressurized to "give inputs" and "make changes" to the product otherwise they risk being seen as not contributing to the project. This situation have delayed many projects because of these superfluous "management inputs". In one project at the above company, the artists and developers created a supernumerary animated character that appears in every cutscene and sticks out like a sore thumb. They designed it in such a way that it can be easily removed before the game is shipped (this was when games were still sold in physical media and not a downloadable product). Obviously the management then voted to remove the animation. On the positive side, management didn't introduced any unnecessary changes that would have delayed the project because they have shown that they provided constructive inputs to the product. This process pattern has a name among game programmers that work in corporates, but I forgot what was the actual name. I believe it's duck-something. Anybody can help pointing out the name and perhaps some rather credible reference to how the pattern develops?.

  Read the article

• Style bits vs. Separate bool's

  - by peterchen

  My main platform (WinAPI) still heavily uses bits for control styles etc. (example). When introducing custom controls, I'm permanently wondering whether to follow that style or rather use individual bool's. Let's pit them against each other: enum EMyCtrlStyles { mcsUseFileIcon = 1, mcsTruncateFileName = 2, mcsUseShellContextMenu = 4, }; void SetStyle(DWORD mcsStyle); void ModifyStyle(DWORD mcsRemove, DWORD mcsAdd); DWORD GetStyle() const; ... ctrl.SetStyle(mcsUseFileIcon | mcsUseShellContextMenu); vs. CMyCtrl & SetUseFileIcon(bool enable = true); bool GetUseFileIcon() const; CMyCtrl & SetTruncteFileName(bool enable = true); bool GetTruncteFileName() const; CMyCtrl & SetUseShellContextMenu(bool enable = true); bool GetUseShellContextMenu() const; ctrl.SetUseFileIcon().SetUseShellContextMenu(); As I see it, Pro Style Bits Consistent with platform less library code (without gaining complexity), less places to modify for adding a new style less caller code (without losing notable readability) easier to use in some scenarios (e.g. remembering / transferring settings) Binary API remains stable if new style bits are introduced Now, the first and the last are minor in most cases. Pro Individual booleans Intellisense and refactoring tools reduce the "less typing" effort Single Purpose Entities more literate code (as in "flows more like a sentence") No change of paradim for non-bool properties These sound more modern, but also "soft" advantages. I must admit the "platform consistency" is much more enticing than I could justify, the less code without losing much quality is a nice bonus. 1. What do you prefer? Subjectively, for writing the library, or for writing client code? 2. Any (semi-) objective statements, studies, etc.?

  Read the article

• How to avoid big and clumpsy UITableViewController on iOS?

  - by Johan Karlsson

  I have a problem when implementing the MVC-pattern on iOS. I have searched the Internet but seems not to find any nice solution to this problem. Many UITableViewController implementations seems to be rather big. Most example I have seen lets the UITableViewController implement UITableViewDelegate and UITableViewDataSource. These implementations are a big reason why UITableViewControlleris getting big. One solution would be to create separate classes that implements UITableViewDelegate and UITableViewDataSource. Of course these classes would have to have a reference to the UITableViewController. Are there any drawbacks using this solution? In general I think you should delegate the functionality to other "Helper" classes or similar, using the delegate pattern. Are there any well established ways of solving this problem? I do not want the model to contain to much functionality, nor the view. A believe that the logic should really be in the controller class, since this is one of the cornerstones of the MVC-pattern. But the big question is; How should you divide the controller of a MVC-implementation into smaller manageable pieces? (Applies to MVC in iOS in this case) There might be a general pattern for solving this, although I am specifically looking for a solution for iOS. Please give an example of a good pattern for solving this issue. Also an argument why this solution is awesome.

  Read the article

• Is the 'C' in MVC really necessary?

  - by Anne Nonimus

  I understand the role of the model and view in the Model-View-Controller pattern, but I have a hard time understanding why a controller is necessary. Let's assume we're creating a chess program using an MVC approach; the game state should be the model, and the GUI should be the view. What exactly is the controller in this case? Is it just a separate class that has all the functions that will be called when you, say, click on a tile? Why not just perform all the logic on the model in the view itself?

  Read the article

• How to protect a peer-to-peer network from inappropriate content?

  - by Mike

  I’m developing a simple peer-to-peer app in .Net which should enable users to share specific content (text and picture files). As I've learned with my last question, inappropriate content can “relatively” easily be identified / controlled in a centralized environment. But what about a peer-to-peer network, what are the best methods to protect a decentralized system from unwanted (illegal) content? At the moment I only see the following two methods: A protocol (a set of rules) defines what kind of data (e.g. only .txt and jpg-files, not bigger than 20KB etc.) can be shared over the p2p-network and all clients (peers) must implement this protocol. If a peer doesn’t, it gets blocked by other peers. Pro: easy to implement. Con: It’s not possible to define the perfect protocol (I think eMail-Spam filters have the same problem) Some kind of rating/reputation system must be implemented (similar to stackoverflow), so “bad guys” and inappropriate content can be identified / blocked by other users. Pro: Would be very accurate. Con: Would be slow and in my view technically very hard to implement. Are there other/better solutions? Any answer or comment is highly appreciated.

  Read the article

• How you return to a code when you don't remember what you were doing?

  - by speeder

  Well, I have some problems with procrastination and whatnot, but those get infinitely worse, when I cannot remember what I should be doing. I mean, I know my project, I wrote 100% of the code so far, and I knew more or less what I was doing, but I don't remember exactly what, I don't remember what file I was editing and why. How I get back on track? (because right now my technique of opening the source code and staring at it is not working)

  Read the article

• Looking for some OO design advice

  - by Andrew Stephens

  I'm developing an app that will be used to open and close valves in an industrial environment, and was thinking of something simple like this:- public static void ValveController { public static void OpenValve(string valveName) { // Implementation to open the valve } public static void CloseValve(string valveName) { // Implementation to close the valve } } (The implementation would write a few bytes of data to the serial port to control the valve - an "address" derived from the valve name, and either a "1" or "0" to open or close the valve). Another dev asked whether we should instead create a separate class for each physical valve, of which there are dozens. I agree it would be nicer to write code like PlasmaValve.Open() rather than ValveController.OpenValve("plasma"), but is this overkill? Also, I was wondering how best to tackle the design with a couple of hypothetical future requirements in mind:- We are asked to support a new type of valve requiring different values to open and close it (not 0 and 1). We are asked to support a valve that can be set to any position from 0-100, rather than simply "open" or "closed". Normally I would use inheritance for this kind of thing, but I've recently started to get my head around "composition over inheritance" and wonder if there is a slicker solution to be had using composition?

  Read the article

• Best practice settings Effect parameters in XNA

  - by hichaeretaqua

  I want to ask if there is a best practice settings effect parameters in XNA. Or in other words, what exactly happens when I call pass.Apply(). I can imagine multiple scenarios: Each time Apply() is called, all effect parameters are transferred to the GPU and therefor it has no real influence how often I set a parameter. Each time Apply() is called, only the parameters that got reset are transferred. So caching Set-operations that don't actually set a new value should be avoided. Each time Apply() is called, only the parameters that got changed are transferred. So caching Set-operations is useless. This whole questions is bootless because no one of the mentions ways has any noteworthy impact on game performance. So the final question: Is it useful to implement some caching of Set-operation like: private Matrix _world; public Matrix World { get{ return _world;} set { if(value == world)return; _effect.Parameters["xWorld"].SetValue(value); _world = value; } Thanking you in anticipation

  Read the article

• Is monkeypatching considered good programming practice?

  - by vartec

  I've been under impression, that monkeypatching is more in quick and dirty hack category, rather than standard, good programming practice. While I'd used from time to time to fix minor issues with 3rd party libs, I considered it temporary fix and I'd submit proper patch to the 3rd party project. However, I've seen this technique used as "the normal way" in mainstream projects, for example in Gevent's gevent.monkey module. Has monkeypatching became mainstream, normal, acceptable programming practice? See also: "Monkeypatching For Humans" by Jeff Atwood

  Read the article

• Back in Atlanta! Wed, Feb 9 2011

  - by KKline

  I always enjoy spending time with my friends from Atlanta, as well as meeting folks and making new friends. If you live in the Atlanta area, I hope you'll join me on the evening of Wednesday, February 9th, 2011. Details are at the Atlanta SQL Server user group website . It's common knowledge that I have a terrible memory for many things. However, one of the few things that my memory is usually really good at is remember names & faces (and remembering stories, but that is another story as well)....(read more)

  Read the article

• Filtering your offices IPs from Google Analytics when each has a dynamic IP?

  - by leeand00

  I found the documentation for filtering IPs from Google Analytics, but the address of the several locations of our company all have dynamic IP addresses that change every 30 days from what I'm told. I know from working with Dynamic DNS that the provider usually gives you a script that you configure your router to run when it's IP address changes or when it is restarted, which passes the new IP address to the DDNS server. I'm wondering if there might be a way to write or use a preexisting script to do the same thing with the Google Analytics API.

  Read the article

< Previous Page | 43 44 45 46 47 48 49 50 51 52 53 54  | Next Page >