Search Results

Search found 47799 results on 1912 pages for 'class attributes'.

Page 492/1912 | < Previous Page | 488 489 490 491 492 493 494 495 496 497 498 499  | Next Page >

• C# 4.0: Covariance And Contravariance In Generics Made Easy

  - by Paulo Morgado

  In my last post, I went through what is variance in .NET 4.0 and C# 4.0 in a rather theoretical way. Now, I’m going to try to make it a bit more down to earth. Given: class Base { } class Derived : Base { } Such that: Trace.Assert(typeof(Base).IsClass && typeof(Derived).IsClass && typeof(Base).IsGreaterOrEqualTo(typeof(Derived))); Covariance interface ICovariantIn<out T> { } Trace.Assert(typeof(ICovariantIn<Base>).IsGreaterOrEqualTo(typeof(ICovariantIn<Derived>))); Contravariance interface ICovariantIn<out T> { } Trace.Assert(typeof(IContravariantIn<Derived>).IsGreaterOrEqualTo(typeof(IContravariantIn<Base>))); Invariance interface IInvariantIn<T> { } Trace.Assert(!typeof(IInvariantIn<Base>).IsGreaterOrEqualTo(typeof(IInvariantIn<Derived>)) && !typeof(IInvariantIn<Derived>).IsGreaterOrEqualTo(typeof(IInvariantIn<Base>))); Where: public static class TypeExtensions { public static bool IsGreaterOrEqualTo(this Type self, Type other) { return self.IsAssignableFrom(other); } }

  Read the article

• WPF Login Verification Using Active Directory

  - by psheriff

  Back in October of 2009 I created a WPF login screen (Figure 1) that just showed how to create the layout for a login screen. That one sample is probably the most downloaded sample we have. So in this blog post, I thought I would update that screen and also hook it up to show how to authenticate your user against Active Directory. Figure 1: Original WPF Login Screen I have updated not only the code behind for this login screen, but also the look and feel as shown in Figure 2. Figure 2: An Updated WPF Login Screen The UI To create the UI for this login screen you can refer to my October of 2009 blog post to see how to create the borderless window. You can then look at the sample code to see how I created the linear gradient brush for the background. There are just a few differences in this screen compared to the old version. First, I changed the key image and instead of using words for the Cancel and Login buttons, I used some icons. Secondly I added a text box to hold the Domain name that you wish to authenticate against. This text box is automatically filled in if you are connected to a network. In the Window_Loaded event procedure of the winLogin window you can retrieve the user’s domain name from the Environment.UserDomainName property. For example: txtDomain.Text = Environment.UserDomainName The ADHelper Class Instead of coding the call to authenticate the user directly in the login screen I created an ADHelper class. This will make it easier if you want to add additional AD calls in the future. The ADHelper class contains just one method at this time called AuthenticateUser. This method authenticates a user name and password against the specified domain. The login screen will gather the credentials from the user such as their user name and password, and also the domain name to authenticate against. To use this ADHelper class you will need to add a reference to the System.DirectoryServices.dll in .NET. The AuthenticateUser Method In order to authenticate a user against your Active Directory you will need to supply a valid LDAP path string to the constructor of the DirectoryEntry class. The LDAP path string will be in the format LDAP://DomainName. You will also pass in the user name and password to the constructor of the DirectoryEntry class as well. With a DirectoryEntry object populated with this LDAP path string, the user name and password you will now pass this object to the constructor of a DirectorySearcher object. You then perform the FindOne method on the DirectorySearcher object. If the DirectorySearcher object returns a SearchResult then the credentials supplied are valid. If the credentials are not valid on the Active Directory then an exception is thrown. C#public bool AuthenticateUser(string domainName, string userName,  string password){  bool ret = false;   try  {    DirectoryEntry de = new DirectoryEntry("LDAP://" + domainName,                                           userName, password);    DirectorySearcher dsearch = new DirectorySearcher(de);    SearchResult results = null;     results = dsearch.FindOne();     ret = true;  }  catch  {    ret = false;  }   return ret;} Visual Basic Public Function AuthenticateUser(ByVal domainName As String, _ ByVal userName As String, ByVal password As String) As Boolean  Dim ret As Boolean = False   Try    Dim de As New DirectoryEntry("LDAP://" & domainName, _                                 userName, password)    Dim dsearch As New DirectorySearcher(de)    Dim results As SearchResult = Nothing     results = dsearch.FindOne()     ret = True  Catch    ret = False  End Try   Return retEnd Function In the Click event procedure under the Login button you will find the following code that will validate the credentials that the user types into the login window. C#private void btnLogin_Click(object sender, RoutedEventArgs e){  ADHelper ad = new ADHelper();   if(ad.AuthenticateUser(txtDomain.Text,         txtUserName.Text, txtPassword.Password))    DialogResult = true;  else    MessageBox.Show("Unable to Authenticate Using the                      Supplied Credentials");} Visual BasicPrivate Sub btnLogin_Click(ByVal sender As Object, _ ByVal e As RoutedEventArgs)  Dim ad As New ADHelper()   If ad.AuthenticateUser(txtDomain.Text, txtUserName.Text, _                         txtPassword.Password) Then    DialogResult = True  Else    MessageBox.Show("Unable to Authenticate Using the                      Supplied Credentials")  End IfEnd Sub Displaying the Login Screen At some point when your application launches, you will need to display your login screen modally. Below is the code that you would call to display the login form (named winLogin in my sample application). This code is called from the main application form, and thus the owner of the login screen is set to “this”. You then call the ShowDialog method on the login screen to have this form displayed modally. After the user clicks on one of the two buttons you need to check to see what the DialogResult property was set to. The DialogResult property is a nullable type and thus you first need to check to see if the value has been set. C# private void DisplayLoginScreen(){  winLogin win = new winLogin();   win.Owner = this;  win.ShowDialog();  if (win.DialogResult.HasValue && win.DialogResult.Value)    MessageBox.Show("User Logged In");  else    this.Close();} Visual Basic Private Sub DisplayLoginScreen()  Dim win As New winLogin()   win.Owner = Me  win.ShowDialog()  If win.DialogResult.HasValue And win.DialogResult.Value Then    MessageBox.Show("User Logged In")  Else    Me.Close()  End IfEnd Sub Summary Creating a nice looking login screen is fairly simple to do in WPF. Using the Active Directory services from a WPF application should make your desktop programming task easier as you do not need to create your own user authentication system. I hope this article gave you some ideas on how to create a login screen in WPF. NOTE: You can download the complete sample code for this blog entry at my website: http://www.pdsa.com/downloads. Click on Tips & Tricks, then select 'WPF Login Verification Using Active Directory' from the drop down list. Good Luck with your Coding,Paul Sheriff ** SPECIAL OFFER FOR MY BLOG READERS **We frequently offer a FREE gift for readers of my blog. Visit http://www.pdsa.com/Event/Blog for your FREE gift!

  Read the article

• How I understood monads, part 1/2: sleepless and self-loathing in Seattle

  - by Bertrand Le Roy

  For some time now, I had been noticing some interest for monads, mostly in the form of unintelligible (to me) blog posts and comments saying “oh, yeah, that’s a monad” about random stuff as if it were absolutely obvious and if I didn’t know what they were talking about, I was probably an uneducated idiot, ignorant about the simplest and most fundamental concepts of functional programming. Fair enough, I am pretty much exactly that. Being the kind of guy who can spend eight years in college just to understand a few interesting concepts about the universe, I had to check it out and try to understand monads so that I too can say “oh, yeah, that’s a monad”. Man, was I hit hard in the face with the limitations of my own abstract thinking abilities. All the articles I could find about the subject seemed to be vaguely understandable at first but very quickly overloaded the very few concept slots I have available in my brain. They also seemed to be consistently using arcane notation that I was entirely unfamiliar with. It finally all clicked together one Friday afternoon during the team’s beer symposium when Louis was patient enough to break it down for me in a language I could understand (C#). I don’t know if being intoxicated helped. Feel free to read this with or without a drink in hand. So here it is in a nutshell: a monad allows you to manipulate stuff in interesting ways. Oh, OK, you might say. Yeah. Exactly. Let’s start with a trivial case: public static class Trivial { public static TResult Execute<T, TResult>( this T argument, Func<T, TResult> operation) { return operation(argument); } } This is not a monad. I removed most concepts here to start with something very simple. There is only one concept here: the idea of executing an operation on an object. This is of course trivial and it would actually be simpler to just apply that operation directly on the object. But please bear with me, this is our first baby step. Here’s how you use that thing: "some string" .Execute(s => s + " processed by trivial proto-monad.") .Execute(s => s + " And it's chainable!"); What we’re doing here is analogous to having an assembly chain in a factory: you can feed it raw material (the string here) and a number of machines that each implement a step in the manufacturing process and you can start building stuff. The Trivial class here represents the empty assembly chain, the conveyor belt if you will, but it doesn’t care what kind of raw material gets in, what gets out or what each machine is doing. It is pure process. A real monad will need a couple of additional concepts. Let’s say the conveyor belt needs the material to be processed to be contained in standardized boxes, just so that it can safely and efficiently be transported from machine to machine or so that tracking information can be attached to it. Each machine knows how to treat raw material or partly processed material, but it doesn’t know how to treat the boxes so the conveyor belt will have to extract the material from the box before feeding it into each machine, and it will have to box it back afterwards. This conveyor belt with boxes is essentially what a monad is. It has one method to box stuff, one to extract stuff from its box and one to feed stuff into a machine. So let’s reformulate the previous example but this time with the boxes, which will do nothing for the moment except containing stuff. public class Identity<T> { public Identity(T value) { Value = value; } public T Value { get; private set;} public static Identity<T> Unit(T value) { return new Identity<T>(value); } public static Identity<U> Bind<U>( Identity<T> argument, Func<T, Identity<U>> operation) { return operation(argument.Value); } } Now this is a true to the definition Monad, including the weird naming of the methods. It is the simplest monad, called the identity monad and of course it does nothing useful. Here’s how you use it: Identity<string>.Bind( Identity<string>.Unit("some string"), s => Identity<string>.Unit( s + " was processed by identity monad.")).Value That of course is seriously ugly. Note that the operation is responsible for re-boxing its result. That is a part of strict monads that I don’t quite get and I’ll take the liberty to lift that strange constraint in the next examples. To make this more readable and easier to use, let’s build a few extension methods: public static class IdentityExtensions { public static Identity<T> ToIdentity<T>(this T value) { return new Identity<T>(value); } public static Identity<U> Bind<T, U>( this Identity<T> argument, Func<T, U> operation) { return operation(argument.Value).ToIdentity(); } } With those, we can rewrite our code as follows: "some string".ToIdentity() .Bind(s => s + " was processed by monad extensions.") .Bind(s => s + " And it's chainable...") .Value; This is considerably simpler but still retains the qualities of a monad. But it is still pointless. Let’s look at a more useful example, the state monad, which is basically a monad where the boxes have a label. It’s useful to perform operations on arbitrary objects that have been enriched with an attached state object. public class Stateful<TValue, TState> { public Stateful(TValue value, TState state) { Value = value; State = state; } public TValue Value { get; private set; } public TState State { get; set; } } public static class StateExtensions { public static Stateful<TValue, TState> ToStateful<TValue, TState>( this TValue value, TState state) { return new Stateful<TValue, TState>(value, state); } public static Stateful<TResult, TState> Execute<TValue, TState, TResult>( this Stateful<TValue, TState> argument, Func<TValue, TResult> operation) { return operation(argument.Value) .ToStateful(argument.State); } } You can get a stateful version of any object by calling the ToStateful extension method, passing the state object in. You can then execute ordinary operations on the values while retaining the state: var statefulInt = 3.ToStateful("This is the state"); var processedStatefulInt = statefulInt .Execute(i => ++i) .Execute(i => i * 10) .Execute(i => i + 2); Console.WriteLine("Value: {0}; state: {1}", processedStatefulInt.Value, processedStatefulInt.State); This monad differs from the identity by enriching the boxes. There is another way to give value to the monad, which is to enrich the processing. An example of that is the writer monad, which can be typically used to log the operations that are being performed by the monad. Of course, the richest monads enrich both the boxes and the processing. That’s all for today. I hope with this you won’t have to go through the same process that I did to understand monads and that you haven’t gone into concept overload like I did. Next time, we’ll examine some examples that you already know but we will shine the monadic light, hopefully illuminating them in a whole new way. Realizing that this pattern is actually in many places but mostly unnoticed is what will enable the truly casual “oh, yes, that’s a monad” comments. Here’s the code for this article: http://weblogs.asp.net/blogs/bleroy/Samples/Monads.zip The Wikipedia article on monads: http://en.wikipedia.org/wiki/Monads_in_functional_programming This article was invaluable for me in understanding how to express the canonical monads in C# (interesting Linq stuff in there): http://blogs.msdn.com/b/wesdyer/archive/2008/01/11/the-marvels-of-monads.aspx

  Read the article

• MySQL for Beginners Training-on-Demand First Hand Insight

  - by Antoinette O'Sullivan

  The MySQL for Beginners course is THE course to get you started with MySQL providing you a solid foundation in relational databases using MySQL as a learning tool. Oracle University recently released the Training-on-Demand option for this course.  Ben Krug from the MySQL product team is trying out the MySQL for Beginners Training-on-Demand course and reporting on his experience. You can follow Ben on MySQL Support Blogs. The MySQL for Beginners course is available as: Training-on-Demand: Follow streaming video of instructor delivery and perform hands-on exercises as your own pace. You can start training with 24 hours of purchase. Live-Virtual: Attend a live-instructor led class from your own desk. Hundreds of events on the schedule across timezones. In-Class: Travel to an education center to attend this instructor-led class. Some events on the schedule below:  Location  Date  Delivery Language  Warsaw, Poland  24 September 2012  Polish  Dublin, Ireland  15 October 2012  English  London, United Kingdom  11 September 2012  English  Rome, Italy  5 November 2012  Italian  Hamburg, Germany  3 December 2012  German  Lisbon, Portugal  5 November 2012  European Portugese  Amsterdam, Netherlands  10 December 2012  Dutch  Nieuwegein, Netherlands  18 February 2013  Dutch  Nairobi, Kenya  12 November 2012  English  Barcelona, Spain  5 November 2012  Spanish  Madrid, Spain  8 January 2013  Spanish  Latvia, Riga  12 November 2012  Latvian  Petaling Jaya, Malaysia  22 October 2012  English  Ottawa, Toronto and Montreal Canada  17 December 2012  English  Sao Paulo, Brazil  11 September 2012  Brazilian Portugese  Sao Paulo, Brazil  5 November 2012  Brazilian Portugese  For more information on the Authentic MySQL Curriculum, go to the Oracle University Portal - http://oracle.com/education/mysql

  Read the article

• How can I resize a set of sprite images?

  - by Tyler J Fisher

  Hey StackExchange GameDev community, I'm attempting to resize series of sprites upon instantiation of the class they're located in. I've attempted to use the following code to resize the images, however my attempts have been unsuccessful. I have been unable to write an implementation that is even compilable, so no error codes yet. wLeft.getScaledInstance(wLeft.getWidth()*2, wLeft.getHeight()*2, Image.SCALE_FAST); I've heard that Graphics2D is the best option. Any suggestions? I think I'm probably best off loading the images into a Java project, resizing the images then outputting them to a new directory so as not to have to resize each sprite upon class instantiation. What do you think? Photoshopping each individual sprite is out of the question, unless I used a macro. Code: package game; //Import import java.awt.Image; import javax.swing.ImageIcon; public class Mario extends Human { Image wLeft = new ImageIcon("sprites\\mario\\wLeft.PNG").getImage(); //Constructor public Mario(){ super("Mario", 50); wLeft = wLeft.getScaledInstance(wLeft.getWidth()*2, wLeft.getHeight()*2, Image.SCALE_FAST); }

  Read the article

• Adding an Admin user to an ASP.NET MVC 4 application using a single drop-in file

  - by Jon Galloway

  I'm working on an ASP.NET MVC 4 tutorial and wanted to set it up so just dropping a file in App_Start would create a user named "Owner" and assign them to the "Administrator" role (more explanation at the end if you're interested). There are reasons why this wouldn't fit into most application scenarios: It's not efficient, as it checks for (and creates, if necessary) the user every time the app starts up The username, password, and role name are hardcoded in the app (although they could be pulled from config) Automatically creating an administrative account in code (without user interaction) could lead to obvious security issues if the user isn't informed However, with some modifications it might be more broadly useful - e.g. creating a test user with limited privileges, ensuring a required account isn't accidentally deleted, or - as in my case - setting up an account for demonstration or tutorial purposes. Challenge #1: Running on startup without requiring the user to install or configure anything I wanted to see if this could be done just by having the user drop a file into the App_Start folder and go. No copying code into Global.asax.cs, no installing addition NuGet packages, etc. That may not be the best approach - perhaps a NuGet package with a dependency on WebActivator would be better - but I wanted to see if this was possible and see if it offered the best experience. Fortunately ASP.NET 4 and later provide a PreApplicationStartMethod attribute which allows you to register a method which will run when the application starts up. You drop this attribute in your application and give it two parameters: a method name and the type that contains it. I created a static class named PreApplicationTasks with a static method named, then dropped this attribute in it: [assembly: PreApplicationStartMethod(typeof(PreApplicationTasks), "Initializer")] That's it. One small gotcha: the namespace can be a problem with assembly attributes. I decided my class didn't need a namespace. Challenge #2: Only one PreApplicationStartMethod per assembly In .NET 4, the PreApplicationStartMethod is marked as AllMultiple=false, so you can only have one PreApplicationStartMethod per assembly. This was fixed in .NET 4.5, as noted by Jon Skeet, so you can have as many PreApplicationStartMethods as you want (allowing you to keep your users waiting for the application to start indefinitely!). The WebActivator NuGet package solves the multiple instance problem if you're in .NET 4 - it registers as a PreApplicationStartMethod, then calls any methods you've indicated using [assembly: WebActivator.PreApplicationStartMethod(type, method)]. David Ebbo blogged about that here:  Light up your NuGets with startup code and WebActivator. In my scenario (bootstrapping a beginner level tutorial) I decided not to worry about this and stick with PreApplicationStartMethod. Challenge #3: PreApplicationStartMethod kicks in before configuration has been read This is by design, as Phil explains. It allows you to make changes that need to happen very early in the pipeline, well before Application_Start. That's fine in some cases, but it caused me problems when trying to add users, since the Membership Provider configuration hadn't yet been read - I got an exception stating that "Default Membership Provider could not be found." The solution here is to run code that requires configuration in a PostApplicationStart method. But how to do that? Challenge #4: Getting PostApplicationStartMethod without requiring WebActivator The WebActivator NuGet package, among other things, provides a PostApplicationStartMethod attribute. That's generally how I'd recommend running code that needs to happen after Application_Start: [assembly: WebActivator.PostApplicationStartMethod(typeof(TestLibrary.MyStartupCode), "CallMeAfterAppStart")] This works well, but I wanted to see if this would be possible without WebActivator. Hmm. Well, wait a minute - WebActivator works in .NET 4, so clearly it's registering and calling PostApplicationStartup tasks somehow. Off to the source code! Sure enough, there's even a handy comment in ActivationManager.cs which shows where PostApplicationStartup tasks are being registered: public static void Run() { if (!_hasInited) { RunPreStartMethods(); // Register our module to handle any Post Start methods. But outside of ASP.NET, just run them now if (HostingEnvironment.IsHosted) { Microsoft.Web.Infrastructure.DynamicModuleHelper.DynamicModuleUtility.RegisterModule(typeof(StartMethodCallingModule)); } else { RunPostStartMethods(); } _hasInited = true; } } Excellent. Hey, that DynamicModuleUtility seems familiar... Sure enough, K. Scott Allen mentioned it on his blog last year. This is really slick - a PreApplicationStartMethod can register a new HttpModule in code. Modules are run right after application startup, so that's a perfect time to do any startup stuff that requires configuration to be read. As K. Scott says, it's this easy: using System; using System.Web; using Microsoft.Web.Infrastructure.DynamicModuleHelper; [assembly:PreApplicationStartMethod(typeof(MyAppStart), "Start")] public class CoolModule : IHttpModule { // implementation not important // imagine something cool here } public static class MyAppStart { public static void Start() { DynamicModuleUtility.RegisterModule(typeof(CoolModule)); } } Challenge #5: Cooperating with SimpleMembership The ASP.NET MVC Internet template includes SimpleMembership. SimpleMembership is a big improvement over traditional ASP.NET Membership. For one thing, rather than forcing a database schema, it can work with your database schema. In the MVC 4 Internet template case, it uses Entity Framework Code First to define the user model. SimpleMembership bootstrap includes a call to InitializeDatabaseConnection, and I want to play nice with that. There's a new [InitializeSimpleMembership] attribute on the AccountController, which calls \Filters\InitializeSimpleMembershipAttribute.cs::OnActionExecuting(). That comment in that method that says "Ensure ASP.NET Simple Membership is initialized only once per app start" which sounds like good advice. I figured the best thing would be to call that directly: new Mvc4SampleApplication.Filters.InitializeSimpleMembershipAttribute().OnActionExecuting(null); I'm not 100% happy with this - in fact, it's my least favorite part of this solution. There are two problems - first, directly calling a method on a filter, while legal, seems odd. Worse, though, the Filter lives in the application's namespace, which means that this code no longer works well as a generic drop-in. The simplest workaround would be to duplicate the relevant SimpleMembership initialization code into my startup code, but I'd rather not. I'm interested in your suggestions here. Challenge #6: Module Init methods are called more than once When debugging, I noticed (and remembered) that the Init method may be called more than once per page request - it's run once per instance in the app pool, and an individual page request can cause multiple resource requests to the server. While SimpleMembership does have internal checks to prevent duplicate user or role entries, I'd rather not cause or handle those exceptions. So here's the standard single-use lock in the Module's init method: void IHttpModule.Init(HttpApplication context) { lock (lockObject) { if (!initialized) { //Do stuff } initialized = true; } } Putting it all together With all of that out of the way, here's the code I came up with: using Mvc4SampleApplication.Filters; using System.Web; using System.Web.Security; using WebMatrix.WebData; [assembly: PreApplicationStartMethod(typeof(PreApplicationTasks), "Initializer")] public static class PreApplicationTasks { public static void Initializer() { Microsoft.Web.Infrastructure.DynamicModuleHelper.DynamicModuleUtility .RegisterModule(typeof(UserInitializationModule)); } } public class UserInitializationModule : IHttpModule { private static bool initialized; private static object lockObject = new object(); private const string _username = "Owner"; private const string _password = "p@ssword123"; private const string _role = "Administrator"; void IHttpModule.Init(HttpApplication context) { lock (lockObject) { if (!initialized) { new InitializeSimpleMembershipAttribute().OnActionExecuting(null); if (!WebSecurity.UserExists(_username)) WebSecurity.CreateUserAndAccount(_username, _password); if (!Roles.RoleExists(_role)) Roles.CreateRole(_role); if (!Roles.IsUserInRole(_username, _role)) Roles.AddUserToRole(_username, _role); } initialized = true; } } void IHttpModule.Dispose() { } } The Verdict: Is this a good thing? Maybe. I think you'll agree that the journey was undoubtedly worthwhile, as it took us through some of the finer points of hooking into application startup, integrating with membership, and understanding why the WebActivator NuGet package is so useful Will I use this in the tutorial? I'm leaning towards no - I think a NuGet package with a dependency on WebActivator might work better: It's a little more clear what's going on Installing a NuGet package might be a little less error prone than copying a file A novice user could uninstall the package when complete It's a good introduction to NuGet, which is a good thing for beginners to see This code either requires either duplicating a little code from that filter or modifying the file to use the namespace Honestly I'm undecided at this point, but I'm glad that I can weigh the options. If you're interested: Why are you doing this? I'm updating the MVC Music Store tutorial to ASP.NET MVC 4, taking advantage of a lot of new ASP.NET MVC 4 features and trying to simplify areas that are giving people trouble. One change that addresses both needs us using the new OAuth support for membership as much as possible - it's a great new feature from an application perspective, and we get a fair amount of beginners struggling with setting up membership on a variety of database and development setups, which is a distraction from the focus of the tutorial - learning ASP.NET MVC. Side note: Thanks to some great help from Rick Anderson, we had a draft of the tutorial that was looking pretty good earlier this summer, but there were enough changes in ASP.NET MVC 4 all the way up to RTM that there's still some work to be done. It's high priority and should be out very soon. The one issue I ran into with OAuth is that we still need an Administrative user who can edit the store's inventory. I thought about a number of solutions for that - making the first user to register the admin, or the first user to use the username "Administrator" is assigned to the Administrator role - but they both ended up requiring extra code; also, I worried that people would use that code without understanding it or thinking about whether it was a good fit.

  Read the article

• Mapping between 4+1 architectural view model & UML

  - by Sadeq Dousti

  I'm a bit confused about how the 4+1 architectural view model maps to UML. Wikipedia gives the following mapping: Logical view: Class diagram, Communication diagram, Sequence diagram. Development view: Component diagram, Package diagram Process view: Activity diagram Physical view: Deployment diagram Scenarios: Use-case diagram The paper Role of UML Sequence Diagram Constructs in Object Lifecycle Concept gives the following mapping: Logical view (class diagram (CD), object diagram (OD), sequence diagram (SD), collaboration diagram (COD), state chart diagram (SCD), activity diagram (AD)) Development view (package diagram, component diagram), Process view (use case diagram, CD, OD, SD, COD, SCD, AD), Physical view (deployment diagram), and Use case view (use case diagram, OD, SD, COD, SCD, AD) which combines the four mentioned above. The web page UML 4+1 View Materials presents the following mapping: Finally, the white paper Applying 4+1 View Architecture with UML 2 gives yet another mapping: Logical view class diagrams, object diagrams, state charts, and composite structures Process view sequence diagrams, communication diagrams, activity diagrams, timing diagrams, interaction overview diagrams Development view component diagrams Physical view deployment diagram Use case view use case diagram, activity diagrams I'm sure further search will reveal other mappings as well. While various people usually have different perspectives, I don't see why this is the case here. Specially, each UML diagram describes the system from a particular aspect. So, for instance, why the "sequence diagram" is considered as describing the "logical view" of the system by one author, while another author considers it as describing the "process view"? Could you please help me clarify the confusion?

  Read the article

• My View on ASP.NET Web Forms versus MVC

  - by Ricardo Peres

  Introduction A lot has been said on Web Forms and MVC, but since I was recently asked about my opinion on the subject, here it is. First, I have to say that I really like both technologies and I don’t think any is going away – just remember SharePoint, which is built on top of Web Forms. I see them as complementary, targeting different needs and leveraging different skills. Let’s go through some of their differences. Rapid Application Development Rapid Application Development (RAD) is the development process by which you have an Integrated Development Environment (IDE), a visual design surface and a toolbox, and you drag components from the toolbox to the design surface and set their properties through a property inspector. It was introduced with some of the earliest Windows graphical IDEs such as Visual Basic and Delphi. With Web Forms you have RAD out of the box. Visual Studio offers a generally good (and extensible) designer for the layout of pages and web user controls. Designing a page may simply be about dragging controls from the toolbox, setting their properties and wiring up some events to event handlers, which are implemented in code behind .NET classes. Most people will be familiar with this kind of development and enjoy it. You can see what you are doing from the beginning. MVC also has designable pages – called views in MVC terminology – the problem is that they can be built using different technologies, some of which, at the moment (MVC 4) do not support RAD – Razor, for example. I believe it is just a matter of time for that to be implemented in Visual Studio, but it will mostly consist on HTML editing, and until that day comes, you have to live with source editing. Development Model Web Forms features the same development model that you are used to from Windows Forms and other similar technologies: events fired by controls and automatic persistence of their properties between postbacks. For that, it uses concepts such as view state, which some may love and others may hate, because it may be misused quite easily, but otherwise does its job well. Another fundamental concept is data binding, by which a collection of data can be fed to a control and have it render that data somehow – just thing of the GridView control. The focus is on the page, that’s where it all starts, and you can place everything in the same code behind class: data access, business logic, layout, etc. The controls take care of generating a great part of the HTML and JavaScript for you. With MVC there is no free lunch when it comes to data persistence between requests, you have to implement it yourself. As for event handling, that is at the core of MVC, in the form of controllers and action methods, you just don’t think of them as event handlers. In MVC you need to think more in HTTP terms, so action methods such as POST and GET are relevant to you, and may write actions to handle one or the other. Also of crucial importance is model binding: the way by which MVC converts your posted data into a .NET class. This is something that ASP.NET 4.5 Web Forms has introduced as well, but it is a cornerstone in MVC. MVC also has built-in validation of these .NET classes, which out of the box uses the Data Annotations API. You have full control of the generated HTML - except for that coming from the helper methods, usually small fragments - which requires a greater familiarity with the specifications. You normally rely much more on JavaScript APIs, they are even included in the Visual Studio template, that is because much less is done for you. Reuse It is difficult to accept a professional company/project that does not employ reuse. It can save a lot of time thus cutting costs significantly. Code reused in several projects matures as time goes by and helps developers learn from past experiences. ASP.NET Web Forms was built with reuse in mind, in the form of controls. Controls encapsulate functionality and are generally portable from project to project (with the notable exception of web user controls, those with an associated .ASCX markup file). ASP.NET has dozens of controls and it is very easy to develop new ones, so I believe this is a great advantage. A control can inject JavaScript code and external references as well as generate HTML an CSS. MVC on the other hand does not use controls – it is possible to use them, with some view engines like ASPX, but it is just not advisable because it breaks the flow – where do Init, Load, PreRender, etc, fit? The most similar to controls is extension methods, or helpers. They serve the same purpose – generating HTML, CSS or JavaScript – and can be reused between different projects. What differentiates them from controls is that there is no inheritance and no context – an extension method is just a static method which doesn’t know where it is being called. You also have partial views, which you can reuse in the same project, but there is no inheritance as well. This, in my view, is a weakness of MVC. Architecture Both technologies are highly extensible. I have writtenstarted writing a series of posts on ASP.NET Web Forms extensibility and will probably write another series on MVC extensibility as well. A number of scenarios are covered in any of these models, and some extensibility points apply to both, because, of course both stand upon ASP.NET. With Web Forms, if you’re like me, you start by defining you master pages, pages and controls, with some helper classes to glue everything. You may as well throw in some JavaScript, but probably you’re main work will be with plain old .NET code. The controls you define have the chance to inject JavaScript code and references, through either the ScriptManager or the page’s ClientScript object, as well as generating HTML and CSS code. The master page and page model with code behind classes offer a number of “hooks” by which you can change the normal way of things, for example, in a page you can access any control on the master page, add script or stylesheet references to its head and even change the page’s title. Also, with Web Forms, you typically have URLs in the form “/SomePath/SomePage.aspx?SomeParameter=SomeValue”, which isn’t really SEO friendly, no to mention the HTML that some controls produce, far from standards, optimization and best practices. In MVC, you also normally start by defining the master page (or layout) and views, which are the visible parts, and then define controllers on separate files. These controllers do not know anything about the views, except the names and types of the parameters that will be passed to and from them. The controller will be responsible for the data access and business logic, eventually relying on additional classes for this purpose. On a controller you only receive parameters and return a result, which may be a request for the rendering of a view, a redirection to another URL or a JSON object, to name just a few. The controller class does not know anything about the web, so you can effectively reuse it in a non-web project. This separation and the lack of programmatic access to the UI elements, makes it very difficult to implement, for example, something like SharePoint with MVC. OK, I know about Orchard, but it isn’t really a general purpose development framework, but instead, a CMS that happens to use MVC. Not having controls render HTML for you gives you in turn much more control over it – it is your responsibility to create it, which you can either consider a blessing or a curse, in the later case, you probably shouldn’t be using MVC at all. Also MVC URLs tend to be much more SEO-oriented, if you design your controllers and actions properly. Testing In a well defined architecture, you should separate business logic, data access logic and presentation logic, because these are all different things and it might even be the need to switch one implementation for another: for example, you might design a system which includes a data access layer, a business logic layer and two presentation layers, one on top of ASP.NET and the other with WPF; and the data access layer might be implemented first using NHibernate and later on switched for Entity Framework Code First. These changes are not that rare, so care should be taken in designing the system to make them possible. Web Forms are difficult to test, because it relies on event handlers which are only fired in web contexts, when a form is submitted or a page is requested. You can call them with reflection, but you have to set up a number of mocking objects first, HttpContext.Current first coming to my mind. MVC, on the other hand, makes testing controllers a breeze, so much that it even includes a template option for generating boilerplate unit test classes up from start. A well designed – from the unit test point of view - controller will receive everything it needs to work as parameters to its action methods, so you can pass whatever values you need very easily. That doesn’t mean, of course, that everything can be tested: views, for instance, are difficult to test without actually accessing the site, but MVC offers the possibility to compile views at build time, so that, at least, you know you don’t have syntax errors beforehand. Myths Some popular but unfounded myths around MVC include: You cannot use controls in MVC: not true, actually, you can, at least with the Web Forms (ASPX) view engine; the declaration and usage is exactly the same as with Web Forms; You cannot specify a base class for a view: with the ASPX view engine you can use the Inherits Page directive, with this and all the others you can use the pageBaseType and userControlBaseType attributes of the <page> element; MVC shields you from doing “bad things” on your views: well, you can place any code on a code block, at least with the ASPX view engine (you may be starting to see a pattern here), even data access code; The model is the entity model, tied to an O/RM: the model is actually any class that you use to pass values to a view, including (but generally not recommended) an entity model; Unit tests come with no cost: unit tests generally don’t cover the UI, although there are frameworks just for that (see WatiN, for example); also, for some tests, you will have to mock or replace either the HttpContext.Current property or the HttpContextBase class yourself; Everything is testable: views aren’t, without accessing the site; MVC relies on HTML5/some_cool_new_javascript_framework: there is no relation whatsoever, MVC renders whatever you want it to render and does not require any framework to be present. The thing is, the subsequent releases of MVC happened in a time when Microsoft has become much more involved in standards, so the files and technologies included in the Visual Studio templates reflect this, and it just happens to work well with jQuery, for example. Conclusion Well, this is how I see it. Some folks may think that I am being too rude on MVC, probably because I don’t like it, but that’s not true: like I said, I do like MVC and I am starting my new projects with it. I just don’t want to go along with that those that say that MVC is much superior to Web Forms, in fact, some things you can do much more easily with Web Forms than with MVC. I will be more than happy to hear what you think on this!

  Read the article

• Understanding Process Scheduling in Oracle Solaris

  - by rickramsey

  The process scheduler in the Oracle Solaris kernel allocates CPU resources to processes. By default, the scheduler tries to give every process relatively equal access to the available CPUs. However, you might want to specify that certain processes be given more resources than others. That's where classes come in. A process class defines a scheduling policy for a set of processes. These three resources will help you understand and manage it process classes: Blog: Overview of Process Scheduling Classes in the Oracle Solaris Kernel by Brian Bream Timesharing, interactive, fair-share scheduler, fixed priority, system, and real time. What are these? Scheduling classes in the Solaris kernel. Brian Bream describes them and how the kernel manages them through context switching. Blog: Process Scheduling at the Thread Level by Brian Bream The Fair Share Scheduler allows you to dispatch processes not just to a particular CPU, but to CPU threads. Brian Bream explains how to use and provides examples. Docs: Overview of the Fair Share Scheduler by Oracle Solaris Documentation Team This official Oracle Solaris documentation set provides the nitty-gritty details for setting up classes and managing your processes. Covers: Introduction to the Scheduler CPU Share Definition CPU Shares and Process State CPU Share Versus Utilization CPU Share Examples FSS Configuration FSS and Processor Sets Combining FSS With Other Scheduling Classes Setting the Scheduling Class for the System Scheduling Class on a System with Zones Installed Commands Used With FSS -Rick Follow me on: Blog | Facebook | Twitter | Personal Twitter | YouTube | The Great Peruvian Novel

  Read the article

• Java Slick2d - How to translate mouse coordinates to world coordinates

  - by Corey

  I am translating in my main class render. How do I get the mouse position where my mouse actually is after I scroll the screen public void render(GameContainer gc, Graphics g) throws SlickException { float centerX = 800/2; float centerY = 600/2; g.translate(centerX, centerY); g.translate(-player.playerX, -player.playerY); gen.render(g); player.render(g); } playerX = 800 /2 - sprite.getWidth(); playerY = 600 /2 - sprite.getHeight(); Image to help with explanation I tried implementing a camera but it seems no matter what I can't get the mouse position. I was told to do this worldX = mouseX + camX; but it didn't work the mouse was still off. Here is my Camera class if that helps: public class Camera { public float camX; public float camY; Player player; public void init() { player = new Player(); } public void update(GameContainer gc, int delta) { Input input = gc.getInput(); if(input.isKeyDown(Input.KEY_W)) { camY -= player.speed * delta; } if(input.isKeyDown(Input.KEY_S)) { camY += player.speed * delta; } if(input.isKeyDown(Input.KEY_A)) { camX -= player.speed * delta; } if(input.isKeyDown(Input.KEY_D)) { camX += player.speed * delta; } } Code used to convert mouse worldX = (int) (mouseX + cam.camX); worldY = (int) (mouseY + cam.camY);

  Read the article

• Due to the Classes

  - by Ratman21

  Why does it seem that I am always saying sorry (or in Japanese Gomennasi)?  Well I am late again for blog as you can see. The CCNA class’s part 1 (also known as CCENT) was, well more intense than all of the certification classes before it.   The teacher was cramming as much as he could into us during the week and it was hard to come home and do much more than fall into bed (Well I was doing still doing my Job search and checking up on my web sites and groups).   But I didn’t have much left in the way of blogging (Which by the way is now in 3 different sites). Even though it was hard some times, I really liked the fact I was getting back to something like (and mean really like, in fact I like Cisco routers than some people I know). At the class, I got some software that allows me to simulate setting up and troubles shoot Lan’s or Wan’s.   When we weren’t getting facts for the test thrown at us, we were doing labs with this software. It was fun for me to be able to use the CISCO router commands and trouble shoot router issues. Even if it was just a sim. So now it is study, study, take practices tests and do the labs. I took the week end and more off after cram CCENT week but, now I am back at it.  Also I could not keep up with my Love Dare book during week of the class. No I did not stop or forget what I already learned. I just put the next dare on hold. Well the hold is off starting tomorrow and tonight I think I am going to write a new cover letter. Let’s see what else I can get done tonight. Hmm I think I will try to do a sim of my home wireless LAN and study for CCENT test in about 3 weeks.   So see you tomorrow (I hope).

  Read the article

• Organizing an entity system with external component managers?

  - by Gustav

  I'm designing a game engine for a top-down multiplayer 2D shooter game, which I want to be reasonably reuseable for other top-down shooter games. At the moment I'm thinking about how something like an entity system in it should be designed. First I thought about this: I have a class called EntityManager. It should implement a method called Update and another one called Draw. The reason for me separating Logic and Rendering is because then I can omit the Draw method if running a standalone server. EntityManager owns a list of objects of type BaseEntity. Each entity owns a list of components such as EntityModel (the drawable representation of an entity), EntityNetworkInterface, and EntityPhysicalBody. EntityManager also owns a list of component managers like EntityRenderManager, EntityNetworkManager and EntityPhysicsManager. Each component manager keeps references to the entity components. There are various reasons for moving this code out of the entity's own class and do it collectively instead. For example, I'm using an external physics library, Box2D, for the game. In Box2D, you first add the bodies and shapes to a world (owned by the EntityPhysicsManager in this case) and add collision callbacks (which would be dispatched to the entity object itself in my system). Then you run a function which simulates everything in the system. I find it hard to find a better solution to do this than doing it in an external component manager like this. Entity creation is done like this: EntityManager implements the method RegisterEntity(entityClass, factory) which registers how to create an entity if that class. It also implements the method CreateEntity(entityClass) which would return an object of type BaseEntity. Well now comes my problem: How would the reference to a component be registered to the component managers? I have no idea how I would reference the component managers from a factory/closure.

  Read the article

• IIM Calcutta &ndash; EPBM 14 &ndash; Campus Visit &ndash; Day 4 &ndash; Managing Self, SDCC and Gari

  - by Ram Shankar Yadav

  …I’m becoming more of an addict of writing about my experiences, here in Kolkata! Today we started a bit of late at around 8 AM, did our breakfast and reached in class a bit late at around 9:50 AM, and here goes the surprise…. Today we had two lectures on “Managing Self” and two lectures on “Sustainable Development and Climate Change” (SDCC). Some of us got few self discipline lessons the moment they entered class and asked to “get out” :D So frankly speaking it was a nostalgic moment, which reminded us of Collage ;) We did a FIRO-B test as and got very good tips on managing ourselves and differentiate between “manager” and “leader” After the lunch we had our session on SDCC, in which the prof started by explaining “Credit Crisis”, and moved on to Sustainable Development and few great examples from industry and life~! After the class we went for shopping at Garihat Market, we ate Pani Puri and Moodi :P ..one more surprise…my room got flooded with lot of my new ePBM friends to take the copy of the pictures and we did lot of chit chat around anything and everything :D …so far so good…it’s an amazing experience for me and hopefully for others….who came out of their daily chores and went back to the nostalgic lanes of friendship, learning and most importantly “Happyness” ~~~ Cheers, ram :) EPBM 14 pics : http://epbm14.shutterfly.com/pictures

  Read the article

• Understanding C# async / await (2) Awaitable / Awaiter Pattern

  - by Dixin

  What is awaitable Part 1 shows that any Task is awaitable. Actually there are other awaitable types. Here is an example: Task<int> task = new Task<int>(() => 0); int result = await task.ConfigureAwait(false); // Returns a ConfiguredTaskAwaitable<TResult>. The returned ConfiguredTaskAwaitable<TResult> struct is awaitable. And it is not Task at all: public struct ConfiguredTaskAwaitable<TResult> { private readonly ConfiguredTaskAwaiter m_configuredTaskAwaiter; internal ConfiguredTaskAwaitable(Task<TResult> task, bool continueOnCapturedContext) { this.m_configuredTaskAwaiter = new ConfiguredTaskAwaiter(task, continueOnCapturedContext); } public ConfiguredTaskAwaiter GetAwaiter() { return this.m_configuredTaskAwaiter; } } It has one GetAwaiter() method. Actually in part 1 we have seen that Task has GetAwaiter() method too: public class Task { public TaskAwaiter GetAwaiter() { return new TaskAwaiter(this); } } public class Task<TResult> : Task { public new TaskAwaiter<TResult> GetAwaiter() { return new TaskAwaiter<TResult>(this); } } Task.Yield() is a another example: await Task.Yield(); // Returns a YieldAwaitable. The returned YieldAwaitable is not Task either: public struct YieldAwaitable { public YieldAwaiter GetAwaiter() { return default(YieldAwaiter); } } Again, it just has one GetAwaiter() method. In this article, we will look at what is awaitable. The awaitable / awaiter pattern By observing different awaitable / awaiter types, we can tell that an object is awaitable if It has a GetAwaiter() method (instance method or extension method); Its GetAwaiter() method returns an awaiter. An object is an awaiter if: It implements INotifyCompletion or ICriticalNotifyCompletion interface; It has an IsCompleted, which has a getter and returns a Boolean; it has a GetResult() method, which returns void, or a result. This awaitable / awaiter pattern is very similar to the iteratable / iterator pattern. Here is the interface definitions of iteratable / iterator: public interface IEnumerable { IEnumerator GetEnumerator(); } public interface IEnumerator { object Current { get; } bool MoveNext(); void Reset(); } public interface IEnumerable<out T> : IEnumerable { IEnumerator<T> GetEnumerator(); } public interface IEnumerator<out T> : IDisposable, IEnumerator { T Current { get; } } In case you are not familiar with the out keyword, please find out the explanation in Understanding C# Covariance And Contravariance (2) Interfaces. The “missing” IAwaitable / IAwaiter interfaces Similar to IEnumerable and IEnumerator interfaces, awaitable / awaiter can be visualized by IAwaitable / IAwaiter interfaces too. This is the non-generic version: public interface IAwaitable { IAwaiter GetAwaiter(); } public interface IAwaiter : INotifyCompletion // or ICriticalNotifyCompletion { // INotifyCompletion has one method: void OnCompleted(Action continuation); // ICriticalNotifyCompletion implements INotifyCompletion, // also has this method: void UnsafeOnCompleted(Action continuation); bool IsCompleted { get; } void GetResult(); } Please notice GetResult() returns void here. Task.GetAwaiter() / TaskAwaiter.GetResult() is of such case. And this is the generic version: public interface IAwaitable<out TResult> { IAwaiter<TResult> GetAwaiter(); } public interface IAwaiter<out TResult> : INotifyCompletion // or ICriticalNotifyCompletion { bool IsCompleted { get; } TResult GetResult(); } Here the only difference is, GetResult() return a result. Task<TResult>.GetAwaiter() / TaskAwaiter<TResult>.GetResult() is of this case. Please notice .NET does not define these IAwaitable / IAwaiter interfaces at all. As an UI designer, I guess the reason is, IAwaitable interface will constraint GetAwaiter() to be instance method. Actually C# supports both GetAwaiter() instance method and GetAwaiter() extension method. Here I use these interfaces only for better visualizing what is awaitable / awaiter. Now, if looking at above ConfiguredTaskAwaitable / ConfiguredTaskAwaiter, YieldAwaitable / YieldAwaiter, Task / TaskAwaiter pairs again, they all “implicitly” implement these “missing” IAwaitable / IAwaiter interfaces. In the next part, we will see how to implement awaitable / awaiter. Await any function / action In C# await cannot be used with lambda. This code: int result = await (() => 0); will cause a compiler error: Cannot await 'lambda expression' This is easy to understand because this lambda expression (() => 0) may be a function or a expression tree. Obviously we mean function here, and we can tell compiler in this way: int result = await new Func<int>(() => 0); It causes an different error: Cannot await 'System.Func<int>' OK, now the compiler is complaining the type instead of syntax. With the understanding of the awaitable / awaiter pattern, Func<TResult> type can be easily made into awaitable. GetAwaiter() instance method, using IAwaitable / IAwaiter interfaces First, similar to above ConfiguredTaskAwaitable<TResult>, a FuncAwaitable<TResult> can be implemented to wrap Func<TResult>: internal struct FuncAwaitable<TResult> : IAwaitable<TResult> { private readonly Func<TResult> function; public FuncAwaitable(Func<TResult> function) { this.function = function; } public IAwaiter<TResult> GetAwaiter() { return new FuncAwaiter<TResult>(this.function); } } FuncAwaitable<TResult> wrapper is used to implement IAwaitable<TResult>, so it has one instance method, GetAwaiter(), which returns a IAwaiter<TResult>, which wraps that Func<TResult> too. FuncAwaiter<TResult> is used to implement IAwaiter<TResult>: public struct FuncAwaiter<TResult> : IAwaiter<TResult> { private readonly Task<TResult> task; public FuncAwaiter(Func<TResult> function) { this.task = new Task<TResult>(function); this.task.Start(); } bool IAwaiter<TResult>.IsCompleted { get { return this.task.IsCompleted; } } TResult IAwaiter<TResult>.GetResult() { return this.task.Result; } void INotifyCompletion.OnCompleted(Action continuation) { new Task(continuation).Start(); } } Now a function can be awaited in this way: int result = await new FuncAwaitable<int>(() => 0); GetAwaiter() extension method As IAwaitable shows, all that an awaitable needs is just a GetAwaiter() method. In above code, FuncAwaitable<TResult> is created as a wrapper of Func<TResult> and implements IAwaitable<TResult>, so that there is a  GetAwaiter() instance method. If a GetAwaiter() extension method  can be defined for Func<TResult>, then FuncAwaitable<TResult> is no longer needed: public static class FuncExtensions { public static IAwaiter<TResult> GetAwaiter<TResult>(this Func<TResult> function) { return new FuncAwaiter<TResult>(function); } } So a Func<TResult> function can be directly awaited: int result = await new Func<int>(() => 0); Using the existing awaitable / awaiter - Task / TaskAwaiter Remember the most frequently used awaitable / awaiter - Task / TaskAwaiter. With Task / TaskAwaiter, FuncAwaitable / FuncAwaiter are no longer needed: public static class FuncExtensions { public static TaskAwaiter<TResult> GetAwaiter<TResult>(this Func<TResult> function) { Task<TResult> task = new Task<TResult>(function); task.Start(); return task.GetAwaiter(); // Returns a TaskAwaiter<TResult>. } } Similarly, with this extension method: public static class ActionExtensions { public static TaskAwaiter GetAwaiter(this Action action) { Task task = new Task(action); task.Start(); return task.GetAwaiter(); // Returns a TaskAwaiter. } } an action can be awaited as well: await new Action(() => { }); Now any function / action can be awaited: await new Action(() => HelperMethods.IO()); // or: await new Action(HelperMethods.IO); If function / action has parameter(s), closure can be used: int arg0 = 0; int arg1 = 1; int result = await new Action(() => HelperMethods.IO(arg0, arg1)); Using Task.Run() The above code is used to demonstrate how awaitable / awaiter can be implemented. Because it is a common scenario to await a function / action, so .NET provides a built-in API: Task.Run(): public class Task2 { public static Task Run(Action action) { // The implementation is similar to: Task task = new Task(action); task.Start(); return task; } public static Task<TResult> Run<TResult>(Func<TResult> function) { // The implementation is similar to: Task<TResult> task = new Task<TResult>(function); task.Start(); return task; } } In reality, this is how we await a function: int result = await Task.Run(() => HelperMethods.IO(arg0, arg1)); and await a action: await Task.Run(() => HelperMethods.IO());

  Read the article

• Evil DRY

  - by StefanSteinegger

  DRY (Don't Repeat Yourself) is a basic software design and coding principle. But there is just no silver bullet. While DRY should increase maintainability by avoiding common design mistakes, it could lead to huge maintenance problems when misunderstood. The root of the problem is most probably that many developers believe that DRY means that any piece of code that is written more then once should be made reusable. But the principle is stated as "Every piece of knowledge must have a single, unambiguous, authoritative representation within a system." So the important thing here is "knowledge". Nobody ever said "every piece of code". I try to give some examples of misusing the DRY principle. Code Repetitions by Coincidence There is code that is repeated by pure coincidence. It is not the same code because it is based on the same piece of knowledge, it is just the same by coincidence. It's hard to give an example of such a case. Just think about some lines of code the developer thinks "I already wrote something similar". Then he takes the original code, puts it into a public method, even worse into a base class where none had been there before, puts some weird arguments and some if or switch statements into it to support all special cases and calls this "increasing maintainability based on the DRY principle". The resulting "reusable method" is usually something the developer not even can give a meaningful name, because its contents isn't anything specific, it is just a bunch of code. For the same reason, nobody will really understand this piece of code. Typically this method only makes sense to call after some other method had been called. All the symptoms of really bad design is evident. Fact is, writing this kind of "reusable methods" is worse then copy pasting! Believe me. What will happen when you change this weird piece of code? You can't say what'll happen, because you can't understand what the code is actually doing. So better don't touch it anymore. Maintainability just died. Of course this problem is with any badly designed code. But because the developer tried to make this method as reusable as possible, large parts of the system get dependent on it. Completely independent parts get tightly coupled by this common piece of code. Changing on the single common place will have effects anywhere in the system, a typical symptom of too tight coupling. Without trying to dogmatically (and wrongly) apply the DRY principle, you just had a system with a weak design. Now you get a system which just can't be maintained anymore. So what can you do against it? When making code reusable, always identify the generally reusable parts of it. Find the reason why the code is repeated, find the common "piece of knowledge". If you have to search too far, it's probably not really there. Explain it to a colleague, if you can't explain or the explanation is to complicated, it's probably not worth to reuse. If you identify the piece of knowledge, don't forget to carefully find the place where it should be implemented. Reusing code is never worth giving up a clean design. Methods always need to do something specific. If you can't give it a simple and explanatory name, you did probably something weird. If you can't find the common piece of knowledge, try to make the code simpler. For instance, if you have some complicated string or collection operations within this code, write some general-purpose operations into a helper class. If your code gets simple enough, its not so bad if it can't be reused. If you are not able to find anything simple and reasonable, copy paste it. Put a comment into the code to reference the other copies. You may find a solution later. Requirements Repetitions by Coincidence Let's assume that you need to implement complex tax calculations for many countries. It's possible that some countries have very similar tax rules. These rules are still completely independent from each other, since every country can change it of its own. (Assumed that this similarity is actually by coincidence and not by political membership. There might be basic rules applying to all European countries. etc.) Let's assume that there are similarities between an Asian country and an African country. Moving the common part to a central place will cause problems. What happens if one of the countries changes its rules? Or - more likely - what happens if users of one country complain about an error in the calculation? If there is shared code, it is very risky to change it, even for a bugfix. It is hard to find requirements to be repeated by coincidence. Then there is not much you can do against the repetition of the code. What you really should consider is to make coding of the rules as simple as possible. So this independent knowledge "Tax Rules in Timbuktu" or wherever should be as pure as possible, without much overhead and stuff that does not belong to it. So you can write every independent requirement short and clean. DRYing try-catch and using Blocks This is a technical issue. Blocks like try-catch or using (e.g. in C#) are very hard to DRY. Imagine a complex exception handling, including several catch blocks. When the contents of the try block as well as the contents of the individual catch block are trivial, but the whole structure is repeated on many places in the code, there is almost no reasonable way to DRY it. try { // trivial code here using (Thingy thing = new thingy) { //trivial, but always different line of code } } catch(FooException foo) { // trivial foo handling } catch (BarException bar) { // trivial bar handling } catch { // trivial common handling } finally { // trivial finally block } The key here is that every block is trivial, so there is nothing to just move into a separate method. The only part that differs from case to case is the line of code in the body of the using block (or any other block). The situation is especially interesting if the many occurrences of this structure are completely independent: they appear in classes with no common base class, they don't aggregate each other and so on. Let's assume that this is a common pattern in service methods within the whole system. Examples of Evil DRYing in this situation: Put a if or switch statement into the method to choose the line of code to execute. There are several reasons why this is not a good idea: The close coupling of the formerly independent implementation is the strongest. Also the readability of the code and the use of a parameter to control the logic. Put everything into a method which takes a delegate as argument to call. The caller just passes his "specific line of code" to this method. The code will be very unreadable. The same maintainability problems apply as for any "Code Repetition by Coincidence" situations. Enforce a base class to all the classes where this pattern appears and use the template method pattern. It's the same readability and maintainability problem as above, but additionally complex and tightly coupled because of the base class. I would call this "Inheritance by Coincidence" which will not lead to great software design. What can you do against it: Ideally, the individual line of code is a call to a class or interface, which could be made individual by inheritance. If this would be the case, it wouldn't be a problem at all. I assume that it is no such a trivial case. Consider to refactor the error concept to make error handling easier. The last but not worst option is to keep the replications. Some pattern of code must be maintained in consistency, there is nothing we can do against it. And no reason to make it unreadable. Conclusion The DRY-principle is an important and basic principle every software developer should master. The key is to identify the "pieces of knowledge". There is code which can't be reused easily because of technical reasons. This requires quite a bit flexibility and creativity to make code simple and maintainable. It's not the problem of the principle, it is the problem of blindly applying a principle without understanding the problem it should solve. The result is mostly much worse then ignoring the principle.

  Read the article

• Ruby on Rails - Belongs_to and Active Admin not creating foreign ID

  - by Milo

  I have the following setup: class Category < ActiveRecord::Base has_many :products end class Product < ActiveRecord::Base belongs_to :category has_attached_file :photo, :styles => { :medium => "300x300>", :thumb => "200x200>" } validates_attachment_content_type :photo, :content_type => /\Aimage\/.*\Z/ end ActiveAdmin.register Product do permit_params :title, :price, :slideshow, :photo, :category form do |f| f.inputs "Product Details" do f.input :title f.input :category f.input :price f.input :slideshow f.input :photo, :required => false, :as => :file end f.actions end show do |ad| attributes_table do row :title row :category row :photo do image_tag(ad.photo.url(:medium)) end end end index do column :id column :title column :category column :price do |product| number_to_currency product.price end actions end class ProductController < ApplicationController def create @product = Product.create(params[:id]) end end Every time I make a product item in activeadmin the category comes up empty. It wont populate the column category_id for the product. It just leaves it empty. What am I doing wrong?

  Read the article

• Metro: Dynamically Switching Templates with a WinJS ListView

  - by Stephen.Walther

  Imagine that you want to display a list of products using the WinJS ListView control. Imagine, furthermore, that you want to use different templates to display different products. In particular, when a product is on sale, you want to display the product using a special “On Sale” template. In this blog entry, I explain how you can switch templates dynamically when displaying items with a ListView control. In other words, you learn how to use more than one template when displaying items with a ListView control. Creating the Data Source Let’s start by creating the data source for the ListView. Nothing special here – our data source is a list of products. Two of the products, Oranges and Apples, are on sale. (function () { "use strict"; var products = new WinJS.Binding.List([ { name: "Milk", price: 2.44 }, { name: "Oranges", price: 1.99, onSale: true }, { name: "Wine", price: 8.55 }, { name: "Apples", price: 2.44, onSale: true }, { name: "Steak", price: 1.99 }, { name: "Eggs", price: 2.44 }, { name: "Mushrooms", price: 1.99 }, { name: "Yogurt", price: 2.44 }, { name: "Soup", price: 1.99 }, { name: "Cereal", price: 2.44 }, { name: "Pepsi", price: 1.99 } ]); WinJS.Namespace.define("ListViewDemos", { products: products }); })(); The file above is saved with the name products.js and referenced by the default.html page described below. Declaring the Templates and ListView Control Next, we need to declare the ListView control and the two Template controls which we will use to display template items. The markup below appears in the default.html file: <!-- Templates --> <div id="productItemTemplate" data-win-control="WinJS.Binding.Template"> <div class="product"> <span data-win-bind="innerText:name"></span> <span data-win-bind="innerText:price"></span> </div> </div> <div id="productOnSaleTemplate" data-win-control="WinJS.Binding.Template"> <div class="product onSale"> <span data-win-bind="innerText:name"></span> <span data-win-bind="innerText:price"></span> (On Sale!) </div> </div> <!-- ListView --> <div id="productsListView" data-win-control="WinJS.UI.ListView" data-win-options="{ itemDataSource: ListViewDemos.products.dataSource, layout: { type: WinJS.UI.ListLayout } }"> </div> In the markup above, two Template controls are declared. The first template is used when rendering a normal product and the second template is used when rendering a product which is on sale. The second template, unlike the first template, includes the text “(On Sale!)”. The ListView control is bound to the data source which we created in the previous section. The ListView itemDataSource property is set to the value ListViewDemos.products.dataSource. Notice that we do not set the ListView itemTemplate property. We set this property in the default.js file. Switching Between Templates All of the magic happens in the default.js file. The default.js file contains the JavaScript code used to switch templates dynamically. Here’s the entire contents of the default.js file: (function () { "use strict"; var app = WinJS.Application; app.onactivated = function (eventObject) { if (eventObject.detail.kind === Windows.ApplicationModel.Activation.ActivationKind.launch) { WinJS.UI.processAll().then(function () { var productsListView = document.getElementById("productsListView"); productsListView.winControl.itemTemplate = itemTemplateFunction; });; } }; function itemTemplateFunction(itemPromise) { return itemPromise.then(function (item) { // Select either normal product template or on sale template var itemTemplate = document.getElementById("productItemTemplate"); if (item.data.onSale) { itemTemplate = document.getElementById("productOnSaleTemplate"); }; // Render selected template to DIV container var container = document.createElement("div"); itemTemplate.winControl.render(item.data, container); return container; }); } app.start(); })(); In the code above, a function is assigned to the ListView itemTemplate property with the following line of code: productsListView.winControl.itemTemplate = itemTemplateFunction;   The itemTemplateFunction returns a DOM element which is used for the template item. Depending on the value of the product onSale property, the DOM element is generated from either the productItemTemplate or the productOnSaleTemplate template. Using Binding Converters instead of Multiple Templates In the previous sections, I explained how you can use different templates to render normal products and on sale products. There is an alternative approach to displaying different markup for normal products and on sale products. Instead of creating two templates, you can create a single template which contains separate DIV elements for a normal product and an on sale product. The following default.html file contains a single item template and a ListView control bound to the template. <!-- Template --> <div id="productItemTemplate" data-win-control="WinJS.Binding.Template"> <div class="product" data-win-bind="style.display: onSale ListViewDemos.displayNormalProduct"> <span data-win-bind="innerText:name"></span> <span data-win-bind="innerText:price"></span> </div> <div class="product onSale" data-win-bind="style.display: onSale ListViewDemos.displayOnSaleProduct"> <span data-win-bind="innerText:name"></span> <span data-win-bind="innerText:price"></span> (On Sale!) </div> </div> <!-- ListView --> <div id="productsListView" data-win-control="WinJS.UI.ListView" data-win-options="{ itemDataSource: ListViewDemos.products.dataSource, itemTemplate: select('#productItemTemplate'), layout: { type: WinJS.UI.ListLayout } }"> </div> The first DIV element is used to render a normal product: <div class="product" data-win-bind="style.display: onSale ListViewDemos.displayNormalProduct"> <span data-win-bind="innerText:name"></span> <span data-win-bind="innerText:price"></span> </div> The second DIV element is used to render an “on sale” product: <div class="product onSale" data-win-bind="style.display: onSale ListViewDemos.displayOnSaleProduct"> <span data-win-bind="innerText:name"></span> <span data-win-bind="innerText:price"></span> (On Sale!) </div> Notice that both templates include a data-win-bind attribute. These data-win-bind attributes are used to show the “normal” template when a product is not on sale and show the “on sale” template when a product is on sale. These attributes set the Cascading Style Sheet display attribute to either “none” or “block”. The data-win-bind attributes take advantage of binding converters. The binding converters are defined in the default.js file: (function () { "use strict"; var app = WinJS.Application; app.onactivated = function (eventObject) { if (eventObject.detail.kind === Windows.ApplicationModel.Activation.ActivationKind.launch) { WinJS.UI.processAll(); } }; WinJS.Namespace.define("ListViewDemos", { displayNormalProduct: WinJS.Binding.converter(function (onSale) { return onSale ? "none" : "block"; }), displayOnSaleProduct: WinJS.Binding.converter(function (onSale) { return onSale ? "block" : "none"; }) }); app.start(); })(); The ListViewDemos.displayNormalProduct binding converter converts the value true or false to the value “none” or “block”. The ListViewDemos.displayOnSaleProduct binding converter does the opposite; it converts the value true or false to the value “block” or “none” (Sadly, you cannot simply place a NOT operator before the onSale property in the binding expression – you need to create both converters). The end result is that you can display different markup depending on the value of the product onSale property. Either the contents of the first or second DIV element are displayed: Summary In this blog entry, I’ve explored two approaches to displaying different markup in a ListView depending on the value of a data item property. The bulk of this blog entry was devoted to explaining how you can assign a function to the ListView itemTemplate property which returns different templates. We created both a productItemTemplate and productOnSaleTemplate and displayed both templates with the same ListView control. We also discussed how you can create a single template and display different markup by using binding converters. The binding converters are used to set a DIV element’s display property to either “none” or “block”. We created a binding converter which displays normal products and a binding converter which displays “on sale” products.

  Read the article

• SQL Server for the Oracle DBA Links

  - by BuckWoody

  I do a presentation (and a class) called "SQL Server for the Oracle DBA". It's a non-marketing overview that gives you the basics of working with SQL Server if you're already familiar wtih how Oracle works. This class and these links DO NOT help you with "Why should I use Oracle/SQL Server instead of Oracle/SQL Server" - I'll assume you're already there, and if not, there are LOTS of sites to help you make that decision. Although these links might contain slight marketing slants (I don't control them) I've tried to get the best links I can. Feel free to comment here to add more/better links. As such, these aren't links that help you work with Oracle - they are links to help you work with SQL Server. Some of them contain more information than you actually need, others don't have near enough. Taken together (and with the class) you're able to get done what you need to do. "Practical SQL Server for Oracle Professionals" - A Microsoft Whitepaper, probably the best place to get started: http://download.microsoft.com/download/6/9/d/69d1fea7-5b42-437a-b3ba-a4ad13e34ef6/SQLServer2008forOracle.docx Free Training: http://technet.microsoft.com/en-us/sqlserver/dd548020.aspx Classroom training (will cost you): http://www.microsoft.com/learning/en/us/course.aspx?ID=50068A&locale=en-us Terminology Differences: http://www.associatedcontent.com/article/2383466/oracle_and_sql_server_basic_terminology.html Datatype mapping between Oracle and SQL Server: http://msdn.microsoft.com/en-us/library/ms151817.aspx The "other" direction - can still be useful for the Oracle professional to see the other side: http://blog.benday.com/archive/2008/10/23/23195.aspx Share this post: email it! | bookmark it! | digg it! | reddit! | kick it! | live it!

  Read the article

• Entity System with C++

  - by Dono

  I'm working on a game engine using the Entity System and I have some questions. How I see Entity System : Components : A class with attributs, set and get. Sprite Physicbody SpaceShip ... System : A class with a list of components. (Component logic) EntityManager Renderer Input Camera ... Entity : Just a empty class with a list of components. What I've done : Currently, I've got a program who allow me to do that : // Create a new entity/ Entity* entity = game.createEntity(); // Add some components. entity->addComponent( new TransformableComponent() ) ->setPosition( 15, 50 ) ->setRotation( 90 ) ->addComponent( new PhysicComponent() ) ->setMass( 70 ) ->addComponent( new SpriteComponent() ) ->setTexture( "name.png" ) ->addToSystem( new RendererSystem() ); My questions Did the system stock a list of components or a list of entities ? In the case where I stock a list of entities, I need to get the component of this entities on each frame, that's probably heavy isn't it ? Did the system stock a list of components or a list of entities ? In the case where I stock a list of entities, I need to get the component of this entities on each frame, that's probably heavy isn't it ?

  Read the article

• How to use T4 templates in WP7, Silverlight, Desktop or even MonoDroid apps

  - by Daniel Cazzulino

  In other words, how to use T4 templates without ANY runtime dependencies? Yes, it is possible, and quite simple and elegant actually. In a desktop project, just open the Add New Item dialog, and search for "text template": From the two available templates, the one that gives you a zero-dependency runtime-usable template is the first one: Preprocessed Text Template. Once unfolded, you get the .tt file, but also a dependent .cs file automatically generated. Note the Custom Tool associated with the file: If you open up the .cs file, you will see that it doesn't contain the rendered "Hello World!!!" I added in the .tt, but rather a full class named after the template file itself: namespace ConsoleApplication1 { using System; #line 1 "C:\Temp\ConsoleApplication1\ConsoleApplication1\PreTextTemplate1.tt" [System.CodeDom.Compiler.GeneratedCodeAttribute("Microsoft.VisualStudio.TextTemplating", "10.0.0.0")] public partial class PreTextTemplate1 : PreTextTemplate1Base { public virtual string TransformText() { this.GenerationEnvironment = null; this.Write("Hello World!!!"); return this.GenerationEnvironment.ToString(); } } #region Base class ... #endregion } ... Read full article

  Read the article

• Web workflow solution - how should I approach the design?

  - by Tom Pickles

  We've been tasked with creating a web based workflow tool to track change management. It has a single workflow with multiple synchronous tasks for the most part, but branch out at a point to tasks running in parallel which meet up later on. There will be all sorts of people using the application, and all of them will need to see their outstanding tasks for each change, but only theirs, not others. There will also be a high level group of people who oversee all changes, so need to see everything. They will need to see tasks which have not been done in the specified time, who's responsible etc. The data will be persisted to a SQL database. It'll all be put together using .Net. I've been trying to learn and implement OOP into my designs of late, but I'm wondering if this is moot in this instance as it may be better to have the business logic for this in stored procedures in the DB. I could use POCO's, a front end layer and a data access layer for the web application and just use it as a mechanism for CRUD actions on the DB, then use SP's fired in the DB to apply the business rules. On the other hand, I could use an object oriented design within the web app, but as the data in the app is state-less, is this a bad idea? I could try and model out the whole application into a class structure, implementing interfaces, base classes and all that good stuff. So I would create a change class, which contained a list of task classes/types, which defined each task, and implement an ITask interface etc. Put end-user types into the tasks to identify who should be doing what task. Then apply all the business logic in the respective class methods etc. What approach do you guys think I should be using for this solution?

  Read the article

• How add fog with pixel shader (HLSL) XNA?

  - by Mehdi Bugnard

  I started to make a small game in XNA . And recently i tried to add a "fog" on "pixel shader HLSL" with the class Effect from XNA . I search online about some tutorial and found many sample. But nothing want work on my game :-( . Before i already add a "fog" effect in my game and everything work, because i used the class "BasicEffect" but with the class "Effect" and HLSL, it's really more complicated. If somebody have an idea, it's will be wonderfull. Thanks again. Here is my code HLSL, i use. // Both techniques share this same pixel shader. float4 PixelShaderFunction(VertexShaderOutput input) : COLOR0 { //return tex2D(Sampler, input.TextureCoordinate) * input.Color; float d = length(input.TextureCoordinate - cameraPos); float l = saturate((d-fogNear)/(fogFar-fogNear)); float fogFactory = clamp((d - fogNear) / (fogFar - fogNear), 0, 1) * l; return tex2D(Sampler, input.TextureCoordinate) * lerp(input.Color, fogColor, fogFactory); } Here is the screenShot With effect Without effect

  Read the article

• CodePlex Daily Summary for Monday, December 17, 2012

  CodePlex Daily Summary for Monday, December 17, 2012Popular ReleasesMove Mouse: Move Mouse 2.5.3: FIXED - Issue where it errors on load if the screen saver interval is over 333 minutes.LINUX????????: LINUX????????: LINUX????????cnbeta: cnbeta: cnbetaCSDN ??: CSDN??????: CSDN??????PowerShell Community Extensions: 2.1.1 Production: PowerShell Community Extensions 2.1.1 Release NotesDec 16, 2012 This version of PSCX supports both Windows PowerShell 2.0 and 3.0. Bug fix for HelpUri error with the Get-Help proxy command. See the ReleaseNotes.txt download above for more information.CRM 2011 Navigation UI Record Counter: Navigation UI Record Counter v1.3.1: Fixes Bug with Chrome Bug with parseXml - reverted to good old indexOfVidCoder: 1.4.11 Beta: Added Hungarian translation, thanks to Brechler Zsolt. Update HandBrake core to SVN 5098. This update should fix crashes on some files. Updated the enqueue split button to fit in better with the active Windows theme. Updated presets to use x264 preset/profile/level.???: Cnblogs: CNBLOGSSandcastle Help File Builder: SHFB v1.9.6.0 with Visual Studio Package: General InformationIMPORTANT: On some systems, the content of the ZIP file is blocked and the installer may fail to run. Before extracting it, right click on the ZIP file, select Properties, and click on the Unblock button if it is present in the lower right corner of the General tab in the properties dialog. This new release contains bug fixes and feature enhancements. There are some potential breaking changes in this release as some features of the Help File Builder have been moved into...Electricity, Gas and Temperature Monitoring with Netduino Plus: V1.0.1 Netduino Plus Monitoring: This is the first stable release from the Netduino Plus Monitoring program. Bugfixing The code is enhanced at some places in respect to the V0.6.1 version There is a possibility to add multiple S0 meters Website for realtime display of data Website for configuring the Netduino Comments are welcome! Additions will not be made to this version. This is the first and last major Netduino Plus V1 release. The new development will take place with the Netduino Plus V2 development board in mi...CRM 2011 Visual Ribbon Editor: Visual Ribbon Editor (1.3.1116.8): [FIX] Fixed issue not displaying CRM system button images correctly (incorrect path in file VisualRibbonEditor.exe.config)My Expenses Windows Store LOB App Demo: My Expenses Version 1: This is version 1 of the MyExpenses Windows 8 line of business demo app. The app is written in XAML and C#. It calls a WCF service that works with a SQL Server database. The app uses the Callisto toolkit. You can get it at https://github.com/timheuer/callisto. The Expenses.sql file contains the SQL to create the Expenses database. The ExpensesWCFService.zip file contains the WCF service, also written in C#. You should create a WCF service. Create an Entity Framework model and point it to...BlackJumboDog: Ver5.7.4: 2012.12.13 Ver5.7.4 (1)Web???????、???????????????????????????????????????????VFPX: ssClasses A1.0: My initial release. See https://vfpx.codeplex.com/wikipage?title=ssClasses&referringTitle=Home for a brief description of what is inside this releaseLayered Architecture Solution Guidance (LASG): LASG 1.0.0.8 for Visual Studio 2012: PRE-REQUISITES Open GAX (Please install Oct 4, 2012 version) Microsoft® System CLR Types for Microsoft® SQL Server® 2012 Microsoft® SQL Server® 2012 Shared Management Objects Microsoft Enterprise Library 5.0 (for the generated code) Windows Azure SDK (for layered cloud applications) Silverlight 5 SDK (for Silverlight applications) THE RELEASE This release only works on Visual Studio 2012. Known Issue If you choose the Database project, the solution unfolding time will be slow....Fiskalizacija za developere: FiskalizacijaDev 2.0: Prva prava produkcijska verzija - Zakon je tu, ova je verzija uskladena sa trenutno važecom Tehnickom specifikacijom (v1.2. od 04.12.2012.) i spremna je za produkcijsko korištenje. Verzije iza ove ce ovisiti o naknadnim izmjenama Zakona i/ili Tehnicke specifikacije, odnosno, o eventualnim greškama u radu/zahtjevima community-a za novim feature-ima. Novosti u v2.0 su: - That assembly does not allow partially trusted callers (http://fiskalizacija.codeplex.com/workitem/699) - scheme IznosType...Bootstrap Helpers: Version 1: First releaseDirectX Tool Kit: December 11, 2012: December 11, 2012 Ex versions of DDSTextureLoader and WICTextureLoader Removed use of ATL's CComPtr in favor of WRL's ComPtr for all platforms to support VS Express editions Updated VS 2010 project for official 'property sheet' integration for Windows 8.0 SDK Minor fix to CommonStates for Feature Level 9.1 Tweaked AlphaTestEffect.cpp to work around ARM NEON compiler codegen bug Added dxguid.lib as a default library for Debug builds to resolve GUID link issuesArcGIS Editor for OpenStreetMap: ArcGIS Editor for OSM 2.1 Final for 10.1: We are proud to announce the release of ArcGIS Editor for OpenStreetMap version 2.1. This download is compatible with ArcGIS 10.1, and includes setups for the Desktop Component, Desktop Component when 64 bit Background Geoprocessing is installed, and the Server Component. Important: if you already have ArcGIS Editor for OSM installed but want to install this new version, you will need to uninstall your previous version and then install this one. This release includes support for the ArcGIS 1...SharpCompress - a fully native C# library for RAR, 7Zip, Zip, Tar, GZip, BZip2: SharpCompress 0.8.2: This release just contains some fixes that have been done since the last release. Plus, this is strong named as well. I apologize for the lack of updates but my free time is less these days.New ProjectsAzke: New: Azke is a portal developed with ASP.NET MVC and MySQL. Old: Azke is a portal developed with ASP.net and MySQL.BasicallyNot Visual Studio 2010 Extension: "BasicallyNot" is a new Visual Studio 2010 Extension. It is designed to "drastically improve your VB.Net productivity", and of course make you think happy thoughts about cookies.Beautiful Code: These are collections of random code that I have written, which I believe are "beautiful" in some respects (algorithm, usage of language features etc.).bjyxl2: a csla project for myself.Buscayasminas: Buscayasminas is an open source "Minesweeper" alike game totally written in DHTML (JavaScript, CSS and HTML) that uses mouse and keyboard optionally. This cross-platform and cross-browser game was tested under BeOS, Linux, *BSD, Windows and others.Check if Knowledge Base fix is installed script: A handy script that checks if a knowledge base fix is installed or not.cnbeta: CNBETA ???????CSDN ??: CSDN????????IT??DateTime Class: DateTime Class with several methods: -NumberOfBusinessDaysFrom -IsWorkDay -NextBusinessDay -PreviousBusinessDayECSE6770: An web application for Software Engineering at RPI Hartford.Google+ for Windows Phone 7: Nothing here now.Koch Curve in Silverlight: This program generates the Koch curve using the Silverlight browser plugin.LINUX????????: LINUX????????longchang capture project: this is the project of longchang traffic police capture.Luna Programming Editor: Luna Programming Editor aims to be a simple but very functional, open source programming editor for developers who want to be more productive.markgrovestest: Azure TestMerge PDF Files: This class implement the merge of PDF filesMetroWeb: Metro web is a new modern web browser that provide a different experience for web browsing it just show any traditional web site as a metro designed websiteMinecraft 1.4.4 -- Learning Java: But a simple attempt at modding Minecraft over two different computers not on the same network.Nhóm CKT11: chia s? code nhóm ckt11Orchard.DecoratorField: Orchard Module to add new fieldsPhysic Engine: Physic EnginePixentration: UIS projectPomidoro: Windows store app: timer, which can be used in the application of 'Pomodoro Technique'.ROBO XERO Control: ROBO XERO ??????????????????????。ruc: Buscar en RUC de Paraguay.Send Email Class: Generic class to send emailsServiceProcessManagement: ?????SPMSeven Zip Wrapper: This small application which allows to call 7zip to create an archive, but skip compression for specific file extensions, which are usually already compressed.SharpShell: SharpShell is a .NET class library that lets you build Windows Shell Extensions using C# or VB.Silverseed.Core: Silverseed.Core is planned to be a common library for a variety of tools I'm planning to write, one of which is already available at Codeplex: [url:RepoCop|http://repocop.codeplex.com].Sistemas De Seguridad: integrantes jorge sara marieta douglassSomeTD: someSourPresser: komprese zdrojoveho kodu, zakodovani do B64 a oznaceni jako "nekompiluj" pro CIL kompilator. ....nekdy uzitecne.....The Curse: The Curse UO. Helping make the runUO community better.TIF Manipulation (Image): Tif Image Manipulation (Split, GetPage, Save Tif format...)Tiny Image Filters: This is a basic image processing library for Windows Phone. It is going to help developing photo effect app on Windows Phone.TrainGroup: This LightSwitch Project aims to be a simple management tool for any kind of training groups.Windows 7 Logon Tweaker: A Simple Software Used To Change The Logon Background Of Windows 7Windows Disguiser: Windows Disguiser is a little program that allows to automatically disguise minimized windows into the system tray.Windows Forms Metro: This project aims to create a library of controls & templates of Windows 8 Metro Style UI elements, for those who still using/loves windows forms.WPF Open Dialog: WPF Open Dialog is a simple and free open file/folder dialog for WPF using MVVM pattern. ???: ????????

  Read the article

• links for 2010-12-15

  - by Bob Rhubart

  Pravin Janardanam: Security in OBIEE 11g, Part 1 Guest blogger Pravin Janardanam kicks off a two-part series in which he tackles the differences in security between OBIEE 11g and 10g, and provides some hints on security migration from a 10g environment. (tags: oracle otn businessintelligence obiee) HttpClusterServlet Configuration (Weblogic Server Acting as a Proxy) Quick tips from Divay Dureja. (tags: oracle weblogic servlet configuration) Accelerating Deployment of Virtualized Infrastructures with the Oracle VM Blade Cluster Reference Configuration "The Oracle VM blade cluster reference configuration is a single-vendor solution that addresses every layer of the virtualization stack with Oracle hardware and software components." - from the white paper. (tags: oracle otn oraclevm virtualization) A SOA Safari (Antony Reynolds' Blog) SOA author Antony Reynolds shares links to some of his favorite SOA titles available for reading on Safari. (tags: oracle otn soa) Using Crossbow and Solaris 11 Express Zones for a single machine proof of concept environment with Puppet "My last blog entry was about my debugging experience with Puppet and promise to share the setup that I used. I now follow up that previous entry with this one which describes my Crossbow + NAT + S11 Zones proof of concept." - Michael Tin (tags: oracle solaris crossbow) @myfear: One thing you did not know about Java EE class loading in GlassFish 2.x "Be careful migrating apps from one app server to the other. And don't expect to have a strong hierarchical class loader in place. That is especially true for GF 2.x class loading." Oracle ACE Director Markus Eisele (tags: oracle otn oracleace java glassfish weblogic)

  Read the article

• CSS and HTML incoherences when declaring multiple classes

  - by Cesco

  I'm learning CSS "seriously" for the first time, but I found the way you deal with multiple CSS classes in CSS and HTML quite incoherent. For example I learned that if I want to declare multiple CSS classes with a common style applied to them, I have to write: .style1, .style2, .style3 { color: red; } Then, if I have to declare an HTML tag that has multiple classes applied to it, I have to write: <div class="style1 style2 style3"></div> And I'm asking why? From my personal point of view it would be more coherent if both could be declared by using a comma to separate each class, or if both could be declared using a space; after all IMHO we're still talking about multiple classes, in both CSS and HTML. I think that it would make more sense if I could write this to declare a div with multiple classes applied: <div class="style1, style2, style3"></div> Am I'm missing something important? Could you explain me if there's a valid reason behind these two different syntaxes?

  Read the article

< Previous Page | 488 489 490 491 492 493 494 495 496 497 498 499  | Next Page >