Search Results

Search found 13727 results on 550 pages for 'oo design'.

Page 106/550 | < Previous Page | 102 103 104 105 106 107 108 109 110 111 112 113  | Next Page >

  • Generic and type safe I/O model in any language

    - by Eduardo León
    I am looking for an I/O model, in any programming language, that is generic and type safe. By genericity, I mean there should not be separate functions for performing the same operations on different devices (read_file, read_socket, read_terminal). Instead, a single read operation works on all read-able devices, a single write operation works on all write-able devices, and so on. By type safety, I mean operations that do not make sense should not even be expressible in first place. Using the read operation on a non-read-able device ought to cause a type error at compile time, similarly for using the write operation on a non-write-able device, and so on. Is there any generic and type safe I/O model?

    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

  • Adventures in the Land of CloudDB/NoSQL/NoAcid

    - by KKline
    Cloud, Bunny, or CloudBunny? Last year, some of my friends from Quest Software attended Hadoop World in New York. In 2009, I never would've guessed that Quest would be there with products, community initiatives, as a major sponsor and with presenters? There were just under 1,000 attendees who weren’t the typical devheads and geekasaurs you'd normally see at very techie events like Code Camps, SQL Saturdays, Cloud Camps and or even other NoSQL events such as the Cassandra Summit. We're talkin' enterprise...(read more)

    Read the article

  • C# XNA - Sky Sphere Question

    - by Wade
    I have been banging my head against the wall trying to get a sky sphere to work appropriately in XNA 4.0. I have the sphere loading correctly, and even textured, but i would like something a little more dynamic that can support a day/night cycle. My issue is that, while i know a good amount of C# and XNA, i know next to nothing about HLSL. (I could make an ambient light shader if my life depended on it...) I also have not been able to find a tutorial on how to build a sky sphere like this. Of course i don't expect to be able to make an amazing one right off the bat, i would like to start small, with a dynamic coloring sky i'll work out the clouds and sun later. My first question: Does anyone know of any good tutorial sites that could help me get a decent grasp around HLSL? Second: Does anyone have a good example of or know where to find one of a gradient sky using XNA and C#?

    Read the article

  • Procedural landscape generation but not just fractals

    - by Richard Fabian
    In large procedural landscape games, the land seems dull, but that's probably because the real world is largely dull, with only limited places where the scenery is dramatic or tactical. Looking at world generation from this point of view, a landscape generator for a game needs to not follow the rules of landscaping, but instead some rules married to the expectations of the gamer. For example, there could be a choke point / route generator that creates hills ravines, rivers and mountains between cities, rather than cities plotted on the land based on the resources or conditions generated by the mountains and rainfall patterns. Is there any existing work being done like this? Start with cities or population centres and then add in terrain afterwards?

    Read the article

  • genetic algorithm for leveling/build test

    - by Renan Malke Stigliani
    I'm starting o build a online PVP (duel like, one-to-one) game, where there is leveling, skill points, special attacks and all the common stuff. Since I never did anything like that, I'm still thinking about the maths behind the level/skill/special balances. So I thought good way of testing the best/combo builds would implement a Genetic Algorith. It'd be like that: Generate a big portion of random characters Make them fight, level them up accordingly to the victories(more XP)/losses(less XP) Mate the winners, crossing their builds, to try to make even best characters Add some more random chars, emulating new players Repeat the process for some time, or util find some chars who can beat everyone butts So I could play with the math and try to find the balance where the top x% chars would be a mix of various build types. So, is it a good idea, or there are some other easier method to do the balance? PS: I like this also, because it sounds funny

    Read the article

  • A talk about observer pattern

    - by Martin
    As part of a university course I'm taking, I have to hold a 10 minute talk about the observer pattern. So far these are my points: What is it? (defenition) Polling is an alternative Polling VS Observer When Observer is better When Polling is better (taken from here) A statement that Mediator pattern is worth checking out. (I won't have time to cover it in 10 minutes) I would be happy to hear about: Any suggestions to add something? Another alternative (if exists)

    Read the article

  • Cluster Nodes as RAID Drives

    - by BuckWoody
    I'm unable to sleep tonight so I thought I would push this post out VERY early. When you don't sleep your mind takes interesting turns, which can be a good thing. I was watching a briefing today by a couple of friends as they were talking about various ways to arrange a Windows Server Cluster for SQL Server. I often see an "active" node of a cluster with a "passive" node backing it up. That means one node is working and accepting transactions, and the other is not doing any work but simply "standing by" waiting for the first to fail over. The configuration in the demonstration I saw was a bit different. In this example, there were three nodes that were actively working, and a fourth standing by for all three. I've put configurations like this one into place before, but as I was looking at their architecture diagram, it looked familar - it looked like a RAID drive setup! And that's not a bad way to think about your cluster arrangements. The same concerns you might think about for a particular RAID configuration provides a good way to think about protecting your systems in general. So even if you're not staying awake all night thinking about SQL Server clusters, take this post as an opportunity for "lateral thinking" - a way of combining in your mind the concepts from one piece of knowledge to another. You might find a new way of making your technical environment a little better. Share this post: email it! | bookmark it! | digg it! | reddit! | kick it! | live it!

    Read the article

  • What are the best resources for learning about concurrency and multi-threaded applications?

    - by Zepee
    I realised I have a massive knowledge gap when it comes to multi-threaded applications and concurrent programming. I've covered some basics in the past, but most of it seems to be gone from my mind, and it is definitely a field that I want, and need, to be more knowledgeable about. What are the best resources for learning about building concurrent applications? I'm a very practical oriented person, so if said book contains concrete examples the better, but I'm open to suggestions. I personally prefer to work in pseudocode or C++, and a slant toward game development would be best, but not required.

    Read the article

  • Databinding to an Entity Framework in WPF

    - by King Chan
    Is it good to use databinding to Entity Framework's Entity in WPF? I created a singleton entity framework context: To have only one connection and it won't open and close all the time. So I can pass the Entity around to any class, and can modify the Entity and make changes to the database. All ViewModels getting the entity out from the same Context and databinding to the View saves me time from mapping new object, but now I imagine there is problem in not using the newest Context: A ViewModel databinding to a Entity, then someone else updated the data. The ViewModel will still display the old data, because the Context is never being dispose to refresh. I always create new Context and then dispose of it. If I want to pass the Entity around, then there will be conflicts between Context and Entity. What is the suggested way of doing this ?

    Read the article

  • How to document/verify consistent layering?

    - by Morten
    I have recently moved to the dark side: I am now a CUSTOMER of software development -- mainly websites. With this new role comes new concerns. As a programmer i know how solid an application becomes when it is properly layered, and I want to use this knowledge in my new job. I don't want business logic in my presentation layer, and certainly not presentation stuff in my data layer. Thus, I want to be able to demand from my supllier that they document the level of layering, and how neat and consistent the layering is. The big question is: How is the level of layering documented to me as a customer, and is that a reasonable demmand for me to have, so I don't have to look in the code (I'm not supposed to do that anymore)?

    Read the article

  • In retrospect, has it been a good idea to use three-valued logic for SQL NULL comparisons?

    - by Heinzi
    In SQL, NULL means "unknown value". Thus, every comparison with NULL yields NULL (unknown) rather than TRUE or FALSE. From a conceptional point of view, this three-valued logic makes sense. From a practical point of view, every learner of SQL has, one time or another, made the classic WHERE myField = NULL mistake or learned the hard way that NOT IN does not do what one would expect when NULL values are present. It is my impression (please correct me if I am wrong) that the cases where this three-valued logic helps (e.g. WHERE myField IS NOT NULL AND myField <> 2 can be shortened to WHERE myField <> 2) are rare and, in those cases, people tend to use the longer version anyway for clarity, just like you would add a comment when using a clever, non-obvious hack. Is there some obvious advantage that I am missing? Or is there a general consensus among the development community that this has been a mistake?

    Read the article

  • Advantages of Singleton Class over Static Class?

    Point 1)Singleton We can get the object of singleton and then pass to other methods.Static Class We can not pass static class to other methods as we pass objectsPoint 2) Singleton In future, it is easy to change the logic of of creating objects to some pooling mechanism. Static Class Very difficult to implement some pooling logic in case of static class. We would need to make that class as non-static and then make all the methods non-static methods, So entire your code needs to be changed.Point3:) Singleton Can Singletone class be inherited to subclass? Singleton class does not say any restriction of Inheritence. So we should be able to do this as long as subclass is also inheritence.There's nothing fundamentally wrong with subclassing a class that is intended to be a singleton. There are many reasons you might want to do it. and there are many ways to accomplish it. It depends on language you use.Static Class We can not inherit Static class to another Static class in C#. Think about it this way: you access static members via type name, like this: MyStaticType.MyStaticMember(); Were you to inherit from that class, you would have to access it via the new type name: MyNewType.MyStaticMember(); Thus, the new item bears no relationships to the original when used in code. There would be no way to take advantage of any inheritance relationship for things like polymorphism. span.fullpost {display:none;}

    Read the article

  • Scene Graph Traversing Techniques

    - by Bunkai.Satori
    Scene Graph seems to be the most effective way of representing the game world. The game world usually tends to be as large as the memory and device can handle. In contrast, the screen of the device captures only a fraction of the Game World/Scene Graph. Ideally, I wish to process(update and render) only the visible game objects/nodes on per-frame basis. My question therefore is, how to traverse the scene graph so, that I will focus only on the game notes that are in the camera frustum? How to organize data so that I can easily focus only on the scene graph nodes visible to me? What are techniques to minimize scenegraph traversal time? Is there such way as more effective traversal, or do I have to traverse whole scene graph on per-frame basis?

    Read the article

  • Is it a "pattern smell" to put getters like "FullName" or "FormattedPhoneNumber" in your model?

    - by DanM
    I'm working on an ASP.NET MVC app, and I've been getting into the habit of putting what seem like helpful and convenient getters into my model/entity classes. For example: public class Member { public int Id { get; set; } public string FirstName { get; set; } public string LastName { get; set; } public string PhoneNumber { get; set; } public string FullName { get { return FirstName + " " + LastName; } } public string FormattedPhoneNumber { get { return "(" + PhoneNumber.Substring(0, 3) + ") " + PhoneNumber.Substring(3, 3) + "-" + PhoneNumber.Substring(6); } } } I'm wondering people think about the FullName and FormattedPhoneNumber getters. They make it very easy to create standardized data formats throughout the app, and they seem to save a lot of repeated code, but it could definitely be argued that data format is something that should be handled in mapping from model to view-model. In fact, I was originally applying these data formats in my service layer where I do my mapping, but it was becoming a burden to constantly have to write formatters then apply them in many different places. E.g., I use "Full Name" in most views, and having to type something like model.FullName = MappingUtilities.GetFullName(entity.FirstName, entity.LastName); all over the place seemed a lot less elegant than just typing model.FullName = entity.FullName (or, if you use something like AutoMapper, potentially not typing anything at all). So, where do you draw the line when it comes to data formatting. Is it "okay" to do data formatting in your model or is that a "pattern smell"? Note: I definitely do not have any html in my model. I use html helpers for that. I'm strictly talking about formatting or combining data (and especially data that is frequently used).

    Read the article

  • Designing a large database with multiple sources

    - by CatchingMonkey
    I have been tasked with redesigning, or at worst optimising the structure of a database for a data warehouse. Currently, the database has 4 other source databases (which is due to expand to X number of others), all of which have their own data structures, naming conventions etc. At the moment an overnight SSIS package pulls the data from the various source and then for each source coverts the data into a standardised, usable format. These tables are then appended to each other creating a 60m row, 40 column beast!. This table is then used in a variety of ways from an OLAP cube to a web front end. The structure has been in place for a very long time, and the work I have been able to prove the advantages of normalisation, and this is the way I would like to go. The problem for me is that the overnight process takes so long I don't then want to spend additional time normalising the last table into something usable. Can anyone offer any insight or ideas into the best way to restructure or optimise the database efficiently? Edit: All the databases are MS SQL Server 2008 R2 Thanks in advance CM

    Read the article

  • What's wrong with JavaScript

    - by ts01
    There is a lot of buzz around Dart recently, often questioning Google motivations and utility of Dart as replacement for JavaScript. I was searching for rationale of creating Dart rather than investing more effort in ECMAScript. In well known leaked mail its author is saying that Javascript has historical baggage that cannot be solved without a clean break. But there is only one concrete example given (apart of performance concerns) of "fundamental language problems", which is an existence of a single Number primitive So, my questions are: How an existence of a single Number primitive can be a "fundamental problem"? Are there other known "fundamental problems" in JavaScript?

    Read the article

  • Configuration data: single-row table vs. name-value-pair table

    - by Heinzi
    Let's say you write an application that can be configured by the user. For storing this "configuration data" into a database, two patterns are commonly used. The single-row table CompanyName | StartFullScreen | RefreshSeconds | ... ---------------+-------------------+------------------+-------- ACME Inc. | true | 20 | ... The name-value-pair table ConfigOption | Value -----------------+------------- CompanyName | ACME Inc. StartFullScreen | true (or 1, or Y, ...) RefreshSeconds | 20 ... | ... I've seen both options in the wild, and both have obvious advantages and disadvantages, for example: The single-row tables limits the number of configuration options you can have (since the number of columns in a row is usually limited). Every additional configuration option requires a DB schema change. In a name-value-pair table everything is "stringly typed" (you have to encode/decode your Boolean/Date/etc. parameters). (many more) Is there some consensus within the development community about which option is preferable?

    Read the article

  • Can I use access used by Visual Basic for building a database [on hold]

    - by user3413537
    I am the only programmer where I work (summer job) and I am a student with only a few years of programming experience. So I was asked to build a database and I am very excited about this project because hopefully I can learn a lot from this. Using this database my manager is supposed to be able to assign work (dealing with businesses) to different people within the company using an interface (all workers have a shared drive). When workers are done with that paperwork related to the business, they can check off that its done, add comments at the bottom of the interface, and then move on to the next business. The only experience I've had with databases is some querying with SQL, and I've built GUI interfaces with JAVA. The information on the interface will be populated from Excel so workers know what businesses they are dealing with. I've done some research and I believe the best way to build this would be building a GUI using Microsoft Visual Studio (Visual Basic) first, then figuring out a way to populate the Interface from Excel. Also because the data is pretty straight forward and not complicated I will be using MS Access to store and track the database. I know this won't be easy, but for all you geniuses out there, is this on the right path? Thanks.

    Read the article

  • Dapper and object validation/business rules enforcement

    - by Eugene
    This isn't really Dapper-specific, actually, as it relates to any XML-serializeable object.. but it came up when I was storing an object using Dapper. Anyways, say I have a user class. Normally, I'd do something like this: class User { public string SIN {get; private set;} public string DisplayName {get;set;} public User(string sin) { if (string.IsNullOrWhiteSpace(sin)) throw new ArgumentException("SIN must be specified"); this.SIN = sin; } } Since a SIN is required, I'd just create a constructor with a sin parameter, and make it read-only. However, with a Dapper (and probably any other ORM), I need to provide a parameterless constructor, and make all properties writeable. So now I have this: class User: IValidatableObject { public int Id { get; set; } public string SIN { get; set; } public string DisplayName { get; set; } public IEnumerable<ValidationResult> Validate(ValidationContext validationContext) { // implementation } } This seems.. can't really pick the word, a bad smell? A) I'm allowing to change properties that should not be changed ever after an object has been created (SIN, userid) B) Now I have to implement IValidatableObject or something like that to test those properties before updating them to db. So how do you go about it ?

    Read the article

  • Circular dependency and object creation when attempting DDD

    - by Matthew
    I have a domain where an Organization has People. Organization Entity public class Organization { private readonly List<Person> _people = new List<Person>(); public Person CreatePerson(string name) { var person = new Person(organization, name); _people.Add(person); return person; } public IEnumerable<Person> People { get { return _people; } } } Person Entity public class Person { public Person(Organization organization, string name) { if (organization == null) { throw new ArgumentNullException("organization"); } Organization = organization; Name = name; } public Organization { get; private set; } public Name { get; private set; } } The rule for this relationship is that a Person must belong to exactly one Organization. The invariants I want to guarantee are: A person must have an organization this is enforced via the Person's constuctor An organization must know of its people this is why the Organization has a CreatePerson method A person must belong to only one organization this is why the organization's people list is not publicly mutable (ignoring the casting to List, maybe ToEnumerable can enforce that, not too concerned about it though) What I want out of this is that if a person is created, that the organization knows about its creation. However, the problem with the model currently is that you are able to create a person without ever adding it to the organizations collection. Here's a failing unit-test to describe my problem [Test] public void AnOrganizationMustKnowOfItsPeople() { var organization = new Organization(); var person = new Person(organization, "Steve McQueen"); CollectionAssert.Contains(organization.People, person); } What is the most idiomatic way to enforce the invariants and the circular relationship?

    Read the article

  • What are current Biggest Challenges faced by Ecommerce Applications ?

    - by Rachel
    I am in the process to start Product Development for E-commerce and Online Retail domain but before starting I would like to know what are the biggest challenges faced by current state of Art E-Commerce Application ? Also I have not experience building e-commerce products and so what things should I keep in mind before developing one ? Is there are books, articles, blogs outside which I should refer to gain some knowledge before starting out ? Update: What are you thoughts on the recommendation engines for ecommerce applications ? What challenges we have with current state of recommendations engines for ecommerce web application and how can we overcome them ?

    Read the article

  • One page using querystring or many folders and pages?

    - by ClarkeyBoy
    I have an application where I have the 'core' code in one folder for which there is a virtual directory in the root, such that I can include any core files using /myApp/core/bla.asp. I then have two folders outside of this with a default.asp which currently use the querystring to define what page should be displayed. One page is for general users, the other will only be accessible to users who have permission to manage users / usergroups / permissions. The core code checks the querystring and then checks the permissions for that user. An example of this as it is now is default.asp?action=view&viewtype=list&objectid=server. I am not worried about SEO as this is an internal app and uses Windows Auth. My question is, is it better the way it is now or would it be better to have something like the following: /server/view/list/ /server/view/?id=123 /server/create/ /server/edit/?id=123 /server/remove/?id=123 In the above folders I would have a home page which defines all the variables which are currently determined by the querystring - in /server/create/ for example, I would define the action as 'create', object name as 'server' and so on. In terms of future development, I really have no idea which method would be best. I think the 2nd method would be best in terms of following what page does what but this is such a huge change to make at this stage that I would really like some opinions, preferably based on experience. PS Sorry if the tags are wrong - I am new to this forum and thought this was a bit too much of a discussion for StackOverflow as that is very much right / wrong answer based. I got the idea SE is more discussion based.

    Read the article

  • Using virtual functions

    - by Tucker Morgan
    I am starting to use virtual functions, and i am programming a simple text game, my question is this, if i have a virtual function called spec_abil with in a Super class called rpg_class. If you allow the player to class what class they want to play, say a mage class, a archer class, and a warrior class, which all have their own spec_abil function. How do you write it so that the program knows which one to use depending on the chosen class.

    Read the article

  • Please recommend a patterns book for iOS development

    - by Brett Ryan
    I've read several books on iOS development and Objective-C, however what a lot of them teach is how to work with interfaces and all contain the model inside the view controller, i.e. a UITableViewController based view will simply have an NSArray as it's model. I'm interested in what the best practices are for designing the structure of an application. Specifically I'm interested in best practices for the following: How to separate a model from the view controller. I think I know how to do this by simply replacing the NSArray style example with a specific model object, however what I do not know how to do is alert the view when the model changes. For example in .NET I would solve this by conforming to INotifyPropertyChanged and databinding, and similarly with Java I would use PropertyChangeListener. How to create a service model for my domain objects. For example I want to learn the best way to create a service for a hypothetical Widget object to manage an internal DB and also services for communicating with remote endpoints. I need to learn the best ways to do this in a way that interface components can subscribe to events such as widgetUpdated. These services should be singleton classes and some how dependency injected into model/controller objects. Books I've read so far are: Programming in Objective-C (4th Edition) Beginning iOS 5 Development: Exploring the iOS SDK The iOS 5 Developer's Cookbook: Expanded Electronic Edition: Essentials and Advanced Recipes for iOS Programmers Learn Objective-C on the Mac: For OS X and iOS I've also purchased the following updated books but not yet read them. The Core iOS 6 Developer's Cookbook (4th edition Programming in Objective-C (5th Edition) I come from a Java and C# background with 15 years experience, I understand that many of the ways I would do things in these languages may not fit to the ObjC way of developing applications. Any guidance on the topic is very much appreciated.

    Read the article

< Previous Page | 102 103 104 105 106 107 108 109 110 111 112 113  | Next Page >