Search Results

Search found 56661 results on 2267 pages for 'class library'.

Page 417/2267 | < Previous Page | 413 414 415 416 417 418 419 420 421 422 423 424  | Next Page >

  • Should I use an interface when methods are only similar?

    - by Joshua Harris
    I was posed with the idea of creating an object that checks if a point will collide with a line: public class PointAndLineSegmentCollisionDetector { public void Collides(Point p, LineSegment s) { // ... } } This made me think that if I decided to create a Box object, then I would need a PointAndBoxCollisionDetector and a LineSegmentAndBoxCollisionDetector. I might even realize that I should have a BoxAndBoxCollisionDetector and a LineSegmentAndLineSegmentCollisionDetector. And, when I add new objects that can collide I would need to add even more of these. But, they all have a Collides method, so everything I learned about abstraction is telling me, "Make an interface." public interface CollisionDetector { public void Collides(Spatial s1, Spatial s2); } But now I have a function that only detects some abstract class or interface that is used by Point, LineSegment, Box, etc.. So if I did this then each implementation would have to to a type check to make sure that the types are the appropriate type because the collision algorithm is different for each different type match up. Another solution could be this: public class CollisionDetector { public void Collides(Point p, LineSegment s) { ... } public void Collides(LineSegment s, Box b) { ... } public void Collides(Point p, Box b) { ... } // ... } But, this could end up being a huge class that seems unwieldy, although it would have simplicity in that it is only a bunch of Collide methods. This is similar to C#'s Convert class. Which is nice because it is large, but it is simple to understand how it works. This seems to be the better solution, but I thought I should open it for discussion as a wiki to get other opinions.

    Read the article

  • Is this project Structure Valid?

    - by rafuru
    I have a dilemma: In the university we learn to create modular software (on java), but this modularity is explained using a single project with packages (a package for business, another one for DAOS and another one for the model, oh and a last package for frontend). But in my work we use the next structure: I will try to explain: First we create a java library project where the model (entities classes) are created in a package. Next we create an EJB named DAOS and using the netbeans wizard we store the DAOS interfaces in the library project in another package , these interfaces are implemented in the DAOS bean. So the next part is the business logic, we create a business EJB for each group of functions , again using the wizard we store the interface in the java library project in another package then is implemented on the business bean. The final part (for the backend) is a bean that I have suggested: a Facade bean who will gather every method of the business beans in a single bean and this has an interface too that is created in our library project and implemented in the bean. So the next part is call the facade module on the web project. But I don't know how valid or viable is this, maybe I'm doing everything wrong and I don't even know! so I want to ask your opinion about this.

    Read the article

  • Can't find gnutls ibrary when executing rpmbuild under non-root

    - by Rilindo
    I am trying to build ntgs from the latest source, using the .spec from rpmforge - as non-root via rpmbuild. During the compile, it fails at this step: checking for GNUTLS... no configure: error: ntfsprogs crypto code requires the gnutls library. error: Bad exit status from /var/tmp/rpm-tmp.78913 (%build) However, I can compile it successfully outside of rpmbuild. So it sounds like it just the matter of library being seen during the build. However, I can confirm that rpmbuild can see the library that gnutls resides: [foo@bar ~]$ rpmbuild -E '%{_libdir}' rpmbuild/SPECS/ntfsprogs.spec /usr/lib Library location: [foo@bar ntfs-3g_ntfsprogs-2012.1.15]$ /sbin/ldconfig -p | grep -i gnutls libgnutls.so.13 (libc6) => /usr/lib/libgnutls.so.13 libgnutls.so (libc6) => /usr/lib/libgnutls.so libgnutls-openssl.so.13 (libc6) => /usr/lib/libgnutls-openssl.so.13 libgnutls-openssl.so (libc6) => /usr/lib/libgnutls-openssl.so libgnutls-extra.so.13 (libc6) => /usr/lib/libgnutls-extra.so.13 libgnutls-extra.so (libc6) => /usr/lib/libgnutls-extra.so What would cause the problem of the library not being seen when you build a RPM? EDIT: Oh yeah, I am running Centos 5.5.

    Read the article

  • Windows 7 Media Player won't add MP3 files

    - by AnthonyWJones
    I have a set of MP3 files that Windows Media Player just refuses to add to the library. They are placed in the standard My Music folder. I play them in media player. They just won't be listed in the library. I've tried dragging them and dropping them on the media player but they still don't appear in the library. I have an identical laptop where I've also copied the mp3 files and they appear in the library fine. Any ideas what would cause this?

    Read the article

  • OData &ndash; The easiest service I can create

    - by Jon Dalberg
    I wanted to create an OData service with the least amount of code so I fired up Visual Studio and got cracking. I decided to serve up a list of naughty words and make them read-only. Create a new web project. I created an empty MVC 2 application but MVC is not required for OData. Add a new WCF Data Service to the project. I named mine NastyWords.svc since I’m serving up a list of nasty words. Add a class to expose via the service: NastyWord 1: [DataServiceKey("Word")] 2: public class NastyWord 3: { 4: public string Word { get; set; } 5: }   I need to be able to uniquely identify instances of NastyWords for the DataService so I used the DataServiceKey attribute with the “Word” property as the key. I could have added an “ID” property which would have uniquely identified them and would then not need the “DataServiceKey” attribute because the DataService would apply some reflection and heuristics to guess at which property would be the unique identifier. However, the words themselves are unique so adding an “ID” property would be redundantly repetitive. Then I created a data source to expose my NastyWord objects to the service. This is just a simple class with IQueryable<T> properties exposing the entities for my service: 1: public class NastyWordsDataSource 2: { 3: private static IList<NastyWord> words = new List<NastyWord> 4: { 5: new NastyWord{ Word="crap"}, 6: new NastyWord{ Word="darn"}, 7: new NastyWord{ Word="hell"}, 8: new NastyWord{ Word="shucks"} 9: }; 10:   11: public NastyWordsDataSource() 12: { 13: NastyWords = words.AsQueryable(); 14: } 15:   16: public IQueryable<NastyWord> NastyWords { get; private set; } 17: }   Now I can go to the NastyWords.svc class and tell it which data source to use and which entities to expose: 1: public class NastyWords : DataService<NastyWordsDataSource> 2: { 3: // This method is called only once to initialize service-wide policies. 4: public static void InitializeService(DataServiceConfiguration config) 5: { 6: config.SetEntitySetAccessRule("*", EntitySetRights.AllRead); 7: config.DataServiceBehavior.MaxProtocolVersion = DataServiceProtocolVersion.V2; 8: } 9: }   Compile and browse to my NastWords.svc and weep with joy Now I can query my service just like any other OData service. Next time, I’ll modify this service to allow updates to sent so I can build up my list of nasty words. Enjoy!

    Read the article

  • Refactoring and Open / Closed principle

    - by Giorgio
    I have recently being reading a web site about clean code development (I do not put a link here because it is not in English). One of the principles advertised by this site is the Open Closed Principle: each software component should be open for extension and closed for modification. E.g., when we have implemented and tested a class, we should only modify it to fix bugs or to add new functionality (e.g. new methods that do not influence the existing ones). The existing functionality and implementation should not be changed. I normally apply this principle by defining an interface I and a corresponding implementation class A. When class A has become stable (implemented and tested), I normally do not modify it too much (possibly, not at all), i.e. If new requirements arrive (e.g. performance, or a totally new implementation of the interface) that require big changes to the code, I write a new implementation B, and keep using A as long as B is not mature. When B is mature, all that is needed is to change how I is instantiated. If the new requirements suggest a change to the interface as well, I define a new interface I' and a new implementation A'. So I, A are frozen and remain the implementation for the production system as long as I' and A' are not stable enough to replace them. So, in view of these observation, I was a bit surprised that the web page then suggested the use of complex refactorings, "... because it is not possible to write code directly in its final form." Isn't there a contradiction / conflict between enforcing the Open / Closed Principle and suggesting the use of complex refactorings as a best practice? Or the idea here is that one can use complex refactorings during the development of a class A, but when that class has been tested successfully it should be frozen?

    Read the article

  • Augmenting functionality of subclasses without code duplication in C++

    - by Rob W
    I have to add common functionality to some classes that share the same superclass, preferably without bloating the superclass. The simplified inheritance chain looks like this: Element -> HTMLElement -> HTMLAnchorElement Element -> SVGElement -> SVGAlement The default doSomething() method on Element is no-op by default, but there are some subclasses that need an actual implementation that requires some extra overridden methods and instance members. I cannot put a full implementation of doSomething() in Element because 1) it is only relevant for some of the subclasses, 2) its implementation has a performance impact and 3) it depends on a method that could be overridden by a class in the inheritance chain between the superclass and a subclass, e.g. SVGElement in my example. Especially because of the third point, I wanted to solve the problem using a template class, as follows (it is a kind of decorator for classes): struct Element { virtual void doSomething() {} }; // T should be an instance of Element template<class T> struct AugmentedElement : public T { // doSomething is expensive and uses T virtual void doSomething() override {} // Used by doSomething virtual bool shouldDoSomething() = 0; }; class SVGElement : public Element { /* ... */ }; class SVGAElement : public AugmentedElement<SVGElement> { // some non-trivial check bool shouldDoSomething() { /* ... */ return true; } }; // Similarly for HTMLAElement and others I looked around (in the existing (huge) codebase and on the internet), but didn't find any similar code snippets, let alone an evaluation of the effectiveness and pitfalls of this approach. Is my design the right way to go, or is there a better way to add common functionality to some subclasses of a given superclass?

    Read the article

  • Confusion about inheritance

    - by Samuel Adam
    I know I might get downvoted for this, but I'm really curious. I was taught that inheritance is a very powerful polymorphism tool, but I can't seem to use it well in real cases. So far, I can only use inheritance when the base class is an abstract class. Examples : If we're talking about Product and Inventory, I quickly assumed that a Product is an Inventory because a Product must be inventorized as well. But a problem occured when user wanted to sell their Inventory item. It just doesn't seem to be right to change an Inventory object to it's subtype (Product), it's almost like trying to convert a parent to it's child. Another case is Customer and Member. It is logical (at least for me) to think that a Member is a Customer with some more privileges. Same problem occurred when user wanted to upgrade an existing Customer to become a Member. A very trivial case is the Employee case. Where Manager, Clerk, etc can be derived from Employee. Still, the same upgrading issue. I tried to use composition instead for some cases, but I really wanted to know if I'm missing something for inheritance solution here. My composition solution for those cases : Create a reference of Inventory inside a Product. Here I'm making an assumption about that Product and Inventory is talking in a different context. While Product is in the context of sales (price, volume, discount, etc), Inventory is in the context of physical management (stock, movement, etc). Make a reference of Membership instead inside Customer class instead of previous inheritance solution. Therefor upgrading a Customer is only about instantiating the Customer's Membership property. This example is keep being taught in basic programming classes, but I think it's more proper to have those Manager, Clerk, etc derived from an abstract Role class and make it a property in Employee. I found it difficult to find an example of a concrete class deriving from another concrete class. Is there any inheritance solution in which I can solve those cases? Being new in this OOP thing, I really really need a guidance. Thanks!

    Read the article

  • Confused about implementing Single Responsibility Principle

    - by HichemSeeSharp
    Please bear with me if the question looks not well structured. To put you in the context of my issue: I am building an application that invoices vehicles stay duration in a parking. In addition to the stay service there are some other services. Each service has its own calculation logic. Here is an illustration (please correct me if the design is wrong): public abstract class Service { public int Id { get; set; } public bool IsActivated { get; set; } public string Name { get; set } public decimal Price { get; set; } } public class VehicleService : Service { //MTM : many to many public virtual ICollection<MTMVehicleService> Vehicles { get; set; } } public class StayService : VehicleService { } public class Vehicle { public int Id { get; set; } public string ChassisNumber { get; set; } public DateTime? EntryDate { get; set; } public DateTime? DeliveryDate { get; set; } //... public virtual ICollection<MTMVehicleService> Services{ get; set; } } Now, I am focusing on the stay service as an example: I would like to know at invoicing time which class(es) would be responsible for generating the invoice item for the service and for each vehicle? This should calculate the duration cost knowing that the duration could be invoiced partially so the like is as follows: not yet invoiced stay days * stay price per day. At this moment I have InvoiceItemsGenerator do everything but I am aware that there is a better design.

    Read the article

  • Fixed Sized Buffer or Variable Buffers with C# Sockets

    - by Keagan Ladds
    I am busy designing a TCP Server class in C# that has events and allows the user of the class to define packets that the server can send a receive by registering a class that is derived from my "GenericPacket" class. My TCPListener uses Async methods such as .BeginReceive(..); My issue is that because I am using the .BeginReceive(); I need to specify a buffer size when I call the function. This means I cant read the whole packet if one of my defined packets is too big. I have thought of creating a fixed sized Header that gets read using .BeginRead(); and the read the rest using Stream.Read(); but this will lead to the whole server having to wait for this operation to complete. I would like to know if anyone has come across this before and I would appreciate any suggestions.

    Read the article

  • Designing a plug-in system

    - by madflame991
    I'm working on a Java project and I would like to add a plug-in system. More precisely, I would like to let the user design his own module, pack it into a jar, leave it in a "plugins/" subfolder of my application and be done with it. I've managed to get a child classloader to instantiate objects of classes located in external jars, but now I'm facing a design dilemma: Say Joe makes a plug-in and he packs it in joeplugin.jar. I would really like Joe to have a class named "instantiation.Factory" and I would also like everyone to have this class with this exact location and name. (This factory class obviously implements a interface that I provide and through it I get what I want from the plug-in.) If Joe wouldn't be restricted in this way I would have to look into his entire jar for some class that implements my factory interface and I don't want to imagine how complicated things get. So my question is: should I enforce a strict naming convention for this single class? I have no idea how plug-in systems work.

    Read the article

  • Spring + JSR 303 Validation group is ignored [closed]

    - by nsideras
    we have a simple bean with JSR annotations public class CustomerDTO { private static final long serialVersionUID = 1L; private Integer id; @NotEmpty(message = "{customer.firstname.empty}") private String firstName; @NotEmpty(message = "{customer.lastname.empty}") private String lastName; @NotEmpty(groups={PasswordChange.class}, message="{password.empty}") private String password; @NotEmpty(groups={PasswordChange.class}, message="{confirmation.password.empty}") private String password2; } and we have a Spring Controller @RequestMapping(value="/changePassword", method = RequestMethod.POST) public String changePassword(@Validated({ PasswordChange.class }) @ModelAttribute("customerdto") CustomerDTO customerDTO, BindingResult result, Locale locale) { logger.debug("Change Password was submitted with information: " + customerDTO.toString()); try { passwordStrengthPolicy.checkPasswordStrength(locale, customerDTO.getPassword()); if (result.hasErrors()) { return "changePassword"; } logger.debug("Calling customer service changePassword: " + customerDTO); customerOnlineNewService.changePassword(customerDTO); } catch (PasswordNotChangedException e) { logger.error("Could not change password PasswordNotChangedException: " + customerDTO.toString()); return "changePassword"; } catch (PasswordNotSecureException e) { return "changePassword"; } return createRedirectViewPath("changePassword"); } Our problem is that when changePassword is invoked the validator ignores the group(PasswordChange.class) and validates only firstName and lastName which are not in the group. Any idea? Thank you very much for your time.

    Read the article

  • Group method parameter or individual parameter?

    - by Nassign
    I would like to ask on method parameters design consideration. I am usually deciding between using individual variables as parameters versus grouping them to a class or dictionary as one parameter. Is there such a rule when you should use individual parameter against using a class or a dictionary to group the parameter? Individual parameter - Straight forward, strongly typed Dictionary parameter - Very extensible, like HTTP request but cannot be strongly typed. Class parameter - Extensible by adding member to the class parameter, strongly typed. I am looking for a design reference on when to use which? Note: I am not sure if this question is valid in programmers but I definitely think it would be closed in stackoverflow, If it is still not valid, please point me to the proper page.

    Read the article

  • compile ntp without ssl

    - by Zulakis
    I need to deploy ntp to a very space-critical pxe-imaging-system. (Yes, each KB matters.) Footprint needs to be as small as possible, so I want to compile ntp without linking openssl. According to the manual this is should be possible: If available, the OpenSSL library from http://www.openssl.org is used to support public key cryptography. The library must be built and installed prior to building NTP. The procedures for doing that are included in the OpenSSL documentation. The library is found during the normal NTP configure phase and the interface routines compiled automatically. Only the libcrypto.a library file and openssl header files are needed. If the library is not available or disabled, this step is not required. I already tried out ./configure --without-openssl however, this didn't help. This is my ldd output: ldd ntpd/ntpd linux-gate.so.1 => (0xb7706000) libm.so.6 => /lib/i686/cmov/libm.so.6 (0xb76d5000) libcrypto.so.0.9.8 => /usr/lib/i686/cmov/libcrypto.so.0.9.8 (0xb7582000) librt.so.1 => /lib/i686/cmov/librt.so.1 (0xb7578000) libc.so.6 => /lib/i686/cmov/libc.so.6 (0xb741d000) /lib/ld-linux.so.2 (0xb7707000) libdl.so.2 => /lib/i686/cmov/libdl.so.2 (0xb7419000) libz.so.1 => /usr/lib/libz.so.1 (0xb7404000) libpthread.so.0 => /lib/i686/cmov/libpthread.so.0 (0xb73eb000) The system I am compiling on is 32-bit debian lenny using openssl 0.9.8g-15+lenny16. What is the correct configure option to compile ntp without openssl?

    Read the article

  • Web Services Example - Part 2: Programmatic

    - by Denis T
    In this edition of the ADF Mobile blog we'll tackle part 2 of our Web Service examples.  In this posting we'll take a look at using a SOAP Web Service but calling it programmatically in code and parsing the return into a bean. Getting the sample code: Just click here to download a zip of the entire project.  You can unzip it and load it into JDeveloper and deploy it either to iOS or Android.  Please follow the previous blog posts if you need help getting JDeveloper or ADF Mobile installed.  Note: This is a different workspace than WS-Part1 Defining our Web Service: Just like our first installment, we are using the same public weather forecast web service provided free by CDYNE Corporation.  Sometimes this service goes down so please ensure you know it's up before reporting this example isn't working. We're going to concentrate on the same two web service methods, GetCityForecastByZIP and GetWeatherInformation. Defing the Application: The application setup is identical to the Weather1 version.  There are some improvements to the data that is displayed as part of this example though.  Now we are able to show the associated image along with each forecast line when using the Forecast By Zip feature.  We've also added the temperature Hi/Low values into the UI. Summary of Fundamental Changes In This Application The most fundamental change is that we're binding the UI to the Bean Data Controls instead of directly to the Web Service Data Controls.  This gives us much more flexibility to control the shape of the data and allows us to do caching of the data outside of the Web Service.  This way if your application is, say offline, your bean could still populate with data from a local cache and still show you some UI as opposed to completely failing because you don't have any connectivity. In general we promote this type of programming technique with ADF Mobile to insulate your application from any issues with network connectivity. What's different with this example? We have setup the Web Service DC the same way but now we have managed beans to process the data.  The following classes define the "Model" of our application:  CityInformation-CityForecast-Forecast, WeatherInformation-WeatherDescription.  We use WeatherBean for UI interaction to the model layer.  If you look through this example, we don't really do that much with the java code except use it to grab the image URL from the weather description.  In a more realistic example, you might be using some JDBC classes to persist the data to a local database. To have a good architecture it is always good to keep your model and UI layers separate.  This gets muddied if you start to use bindings on a page invoked from Java code and this java code starts to become your "model" layer.  Since bindings are page specific, your model layer starts to become entwined with your UI.  Not good!  To help with this, we've added some utility functions that let you invoke DC methods without having a binding and thus execute methods from your "model" layer without requiring a binding in your page definition.  We do this with the invokeDataControlMethod of the AdfmfJavaUtilities class.  An example of this method call is available in line 95 of WeatherInformation.java and line 93 of CityInformation.Java. What's a GenericType? Because Web Service Data Controls (and also URL Data Controls AKA REST) use generic name/value pairs to define their structure and don't have strongly typed objects, these are actually stored internally as GenericType objects.  The GenericType class is simply a property map of name/value pairs that can be hierarchical.  There are methods like getAttribute where you supply the index of the attribute or it's string property name.  Why is this important to know?  Because invokeDataControlMethod returns GenericType objects and developers either need to parse these GenericType objects themselves or use one of our helper functions. GenericTypeBeanSerializationHelper This class does exactly what it's name implies.  It's a helper class for developers to aid in serialization of GenericTypes to/from java objects.  This is extremely handy if you have a large GenericType object with many attributes (or you're just lazy like me!) and you just want to parse it out into a real java object you can use more easily.  Here you would use the fromGenericType method.  This method takes the class of the Java object you wish to return and the GenericType as parameters.  The method then parses through each attribute in the GenericType and uses reflection to set that same attribute in the Java class.  Then the method returns that new object of the class you specified.  This is obviously very handy to avoid a lot of shuffling code between GenericType and your own Java classes.  The reverse method, toGenericType is also available when you want to go the other way.  In this case you supply the string that represents the package location in the DataControl definition (Example: "MyDC.myParams.MyCollection") and then pass in the Java object you have that holds the data and a GenericType is returned to you.  Again, it will use reflection to calculate the attributes that match between the java class and the GenericType and call the getters/setters on those. Issues and Possible Improvements: In the next installment we'll show you how to make your web service calls asynchronously so your UI will fill dynamically when the service call returns but in the meantime you show the data you have locally in your bean fed from some local cache.  This gives your users instant delivery of some data while you fetch other data in the background.

    Read the article

  • Microsoft Public License Question

    - by ryanzec
    Let preface this by saying that I understand that any advice I may receive is not to be taken as 100% correct, I am just looking for what people's understand of what this license is. I have been looking for a library that allow be to deal with archived compressed files (like zip files) and so far the best one I have found is DotNetZip. The only concern I have is that I am not familiar with the Microsoft Public License. While I plan to release a portion of my project (a web application platform) freely (MIT/BSD style) there are a few things. One is that I don't plan on actually releasing the source code, just the compiled project. Another thing is that I don't plan on releasing everything freely, only a subset of the application. Those are reason why I stay away form (L)GPL code. Is this something allowed while using 3rd party libraries that are licensed under the Microsoft Public License? EDIT The part about the Microsoft license that concerns me is Section 3 (D) which says (full license here): If you distribute any portion of the software in source code form, you may do so only under this license by including a complete copy of this license with your distribution. If you distribute any portion of the software in compiled or object code form, you may only do so under a license that complies with this license. I don't know what is meant by 'software'. My assumption would be that 'software' only refers to the library included under the license (being DotNetZip) and that is doesn't extends over to my code which includes the DotNetZip library. If that is the case then everything is fine as I have no issues keeping the license for DotNetZip when release this project in compiled form while having my code under its own license. If 'software' also include my code that include the DotNetZip library then that would be an issue (as it would basically act like GPL with the copyleft sense).

    Read the article

  • Name user object and user table correctly

    - by Marc
    It's maybe simple but I think about this every time I build a new application. How do you name the class for the current user of the application and for the orm class of the user table? Usually I have something like CurrentUser: Logged-in user, stored in session, info for last activity etc User: ORM Class (C# EF CodeFirst, but it doesn't matter) And yes, they could have the same name in different namespaces, but I don't really like that.

    Read the article

  • How do I separate codes with classes?

    - by Trycon
    I have this main class: package javagame; import org.newdawn.slick.GameContainer; import org.newdawn.slick.Graphics; import org.newdawn.slick.SlickException; import org.newdawn.slick.state.BasicGameState; import org.newdawn.slick.state.StateBasedGame; public class tests extends BasicGameState{ public boolean render=false; tests1 test = new tests1(); public tests(int test) { // TODO Auto-generated constructor stub } @Override public void init(GameContainer arg0, StateBasedGame arg1) throws SlickException { // TODO Auto-generated method stub } @Override public void render(GameContainer arg0, StateBasedGame arg1, Graphics g) throws SlickException { // TODO Auto-generated method stub if(render==true) { g.drawString("Hello",100,100); } } @Override public void update(GameContainer gc, StateBasedGame s, int delta) throws SlickException { // TODO Auto-generated method stub test.render=render; test.update(gc, s, delta); } @Override public int getID() { // TODO Auto-generated method stub return 1000; } } and its sub-class: package javagame; import org.newdawn.slick.GameContainer; import org.newdawn.slick.Input; import org.newdawn.slick.state.StateBasedGame; public class tests1 { public boolean render; public void update(GameContainer gc, StateBasedGame s, int delta) { Input input = gc.getInput(); if(input.isKeyPressed(Input.KEY_X)) { render=true; } } } I was finding a way to prevent many codes in one class. I'm new to java. When I try running my game, then when I press X, it does not work. How am I suppose to fix that?

    Read the article

  • Using Unity – Part 4

    - by nmarun
    In this part, I’ll be discussing about constructor and property or setter injection. I’ve created a new class – Product3: 1: public class Product3 : IProduct 2: { 3: public string Name { get; set; } 4: [Dependency] 5: public IDistributor Distributor { get; set; } 6: public ILogger Logger { get; set; } 7:  8: public Product3(ILogger logger) 9: { 10: Logger = logger; 11: Name = "Product 1"; 12: } 13:  14: public string WriteProductDetails() 15: { 16: StringBuilder productDetails = new StringBuilder(); 17: productDetails.AppendFormat("{0}<br/>", Name); 18: productDetails.AppendFormat("{0}<br/>", Logger.WriteLog()); 19: productDetails.AppendFormat("{0}<br/>", Distributor.WriteDistributorDetails()); 20: return productDetails.ToString(); 21: } 22: } This version has a property of type IDistributor and takes a constructor parameter of type ILogger. The IDistributor property has a Dependency attribute (Microsoft.Practices.Unity namespace) applied to it. IDistributor and its implementation are shown below: 1: public interface IDistributor 2: { 3: string WriteDistributorDetails(); 4: } 5:  6: public class Distributor : IDistributor 7: { 8: public List<string> DistributorNames = new List<string>(); 9:  10: public Distributor() 11: { 12: DistributorNames.Add("Distributor1"); 13: DistributorNames.Add("Distributor2"); 14: DistributorNames.Add("Distributor3"); 15: DistributorNames.Add("Distributor4"); 16: } 17: public string WriteDistributorDetails() 18: { 19: StringBuilder distributors = new StringBuilder(); 20: for (int i = 0; i < DistributorNames.Count; i++) 21: { 22: distributors.AppendFormat("{0}<br/>", DistributorNames[i]); 23: } 24: return distributors.ToString(); 25: } 26: } ILogger and the FileLogger have the following definition: 1: public interface ILogger 2: { 3: string WriteLog(); 4: } 5:  6: public class FileLogger : ILogger 7: { 8: public string WriteLog() 9: { 10: return string.Format("Type: {0}", GetType()); 11: } 12: } The Unity container creates an instance of the dependent class (the Distributor class) within the scope of the target object (an instance of Product3 class that will be called by doing a Resolve<IProduct>() in the calling code) and assign this dependent object to the attributed property of the target object. To add to it, property injection is a form of optional injection of dependent objects.The dependent object instance is generated before the container returns the target object. Unlike constructor injection, you must apply the appropriate attribute in the target class to initiate property injection. Let’s see how to change the config file to make this work. The first step is to add all the type aliases: 1: <typeAlias alias="Product3" type="ProductModel.Product3, ProductModel"/> 2: <typeAlias alias="ILogger" type="ProductModel.ILogger, ProductModel"/> 3: <typeAlias alias="FileLogger" type="ProductModel.FileLogger, ProductModel"/> 4: <typeAlias alias="IDistributor" type="ProductModel.IDistributor, ProductModel"/> 5: <typeAlias alias="Distributor" type="ProductModel.Distributor, ProductModel"/> Now define mappings for these aliases: 1: <type type="ILogger" mapTo="FileLogger" /> 2: <type type="IDistributor" mapTo="Distributor" /> Next step is to define the constructor and property injection in the config file: 1: <type type="IProduct" mapTo="Product3" name="ComplexProduct"> 2: <typeConfig extensionType="Microsoft.Practices.Unity.Configuration.TypeInjectionElement, Microsoft.Practices.Unity.Configuration"> 3: <constructor> 4: <param name="logger" parameterType="ILogger" /> 5: </constructor> 6: <property name="Distributor" propertyType="IDistributor"> 7: <dependency /> 8: </property> 9: </typeConfig> 10: </type> There you see a constructor element that tells there’s a property named ‘logger’ that is of type ILogger. By default, the type of ILogger gets resolved to type FileLogger. There’s also a property named ‘Distributor’ which is of type IDistributor and which will get resolved to type Distributor. On the calling side, I’ve added a new button, whose click event does the following: 1: protected void InjectionButton_Click(object sender, EventArgs e) 2: { 3: unityContainer.RegisterType<IProduct, Product3>(); 4: IProduct product3 = unityContainer.Resolve<IProduct>(); 5: productDetailsLabel.Text = product3.WriteProductDetails(); 6: } This renders the following output: This completes the part for constructor and property injection. In the next blog, I’ll talk about Arrays and Generics. Please see the code used here.

    Read the article

  • Do you leverage the benefits of the open-closed principle?

    - by Kaleb Pederson
    The open-closed principle (OCP) states that an object should be open for extension but closed for modification. I believe I understand it and use it in conjunction with SRP to create classes that do only one thing. And, I try to create many small methods that make it possible to extract out all the behavior controls into methods that may be extended or overridden in some subclass. Thus, I end up with classes that have many extension points, be it through: dependency injection and composition, events, delegation, etc. Consider the following a simple, extendable class: class PaycheckCalculator { // ... protected decimal GetOvertimeFactor() { return 2.0M; } } Now say, for example, that the OvertimeFactor changes to 1.5. Since the above class was designed to be extended, I can easily subclass and return a different OvertimeFactor. But... despite the class being designed for extension and adhering to OCP, I'll modify the single method in question, rather than subclassing and overridding the method in question and then re-wiring my objects in my IoC container. As a result I've violated part of what OCP attempts to accomplish. It feels like I'm just being lazy because the above is a bit easier. Am I misunderstanding OCP? Should I really be doing something different? Do you leverage the benefits of OCP differently? Update: based on the answers it looks like this contrived example is a poor one for a number of different reasons. The main intent of the example was to demonstrate that the class was designed to be extended by providing methods that when overridden would alter the behavior of public methods without the need for changing internal or private code. Still, I definitely misunderstood OCP.

    Read the article

  • how should I design Objects around this business requirement?

    - by brainydexter
    This is the business requirement: " A Holiday Package (e.g. New York NY Holiday Package) can be offered in different ways based on the Origin city: From New Delhi to NY From Bombay to NY NY itself ( Land package ) (Bold implies default selection) a. and b. User can fly from either New Delhi or Bombay to NY. c. NY is a Land package, where a user can reach NY by himself and is a standalone holidayPackage. " Let's say I have a class that represents HolidayPackage, Destination (aka City). public class HolidayPackage{ Destination holidayCity; ArrayList<BaseHolidayPackageVariant> variants; BaseHolidayPackageVariant defaultVariant; } public abstract class BaseHolidayPackageVariant { private Integer variantId; private HolidayPackage holidayPackage; private String holidayPackageType; } public class LandHolidayPackageVariant extends BaseHolidayPackageVariant{ } public class FlightHolidayPackageVariant extends BaseHolidayPackageVariant{ private Destination originCity; } What data structure/objects should I design to support: options a default within those options Sidenote: A HolidayPackage can also be offered in different ways based on Hotel selections. I'd like to follow a design which I can leverage to support that use case in the future. This is the backend design I have in mind.

    Read the article

  • Object oriented wrapper around a dll

    - by Tom Davies
    So, I'm writing a C# managed wrapper around a native dll. The dll contains several hundred functions. In most cases, the first argument to each function is an opaque handle to a type internal to the dll. So, an obvious starting point for defining some classes in the wrapper would be to define classes corresponding to each of these opaque types, with each instance holding and managing the opaque handle (passed to its constructor) Things are a little awkward when dealing with callbacks from the dll. Naturally, the callback handlers in my wrapper have to be static, but the callbacks arguments invariable contain an opaque handle. In order to get from the static callback back to an object instance, I've created a static dictionary in each class, associating handles with class instances. In the constructor of each class, an entry is put into the dictionary, and this entry is then removed in the Destructors. When I receive a callback, I can then consult the dictionary to retrieve the class instance corresponding to the opaque reference. Are there any obvious flaws to this? Something that seems to be a problem is that the existence static dictionary means that the garbage collector will not act on my class instances that are otherwise unreachable. As they are never garbage collected, they never get removed from the dictionary, so the dictionary grows. It seems I might have to manually dispose of my objects, which is something absolutely would like to avoid. Can anyone suggest a good design that allows me to avoid having to do this?

    Read the article

  • Annotation Processor for Superclass Sensitive Actions

    - by Geertjan
    Someone creating superclass sensitive actions should need to specify only the following things: The condition under which the popup menu item should be available, i.e., the condition under which the action is relevant. And, for superclass sensitive actions, the condition is the name of a superclass. I.e., if I'm creating an action that should only be invokable if the class implements "org.openide.windows.TopComponent",  then that fully qualified name is the condition. The position in the list of Java class popup menus where the new menu item should be found, relative to the existing menu items. The display name. The path to the action folder where the new action is registered in the Central Registry. The code that should be executed when the action is invoked. In other words, the code for the enablement (which, in this case, means the visibility of the popup menu item when you right-click on the Java class) should be handled generically, under the hood, and not every time all over again in each action that needs this special kind of enablement. So, here's the usage of my newly created @SuperclassBasedActionAnnotation, where you should note that the DataObject must be in the Lookup, since the action will only be available to be invoked when you right-click on a Java source file (i.e., text/x-java) in an explorer view: import java.awt.event.ActionEvent; import java.awt.event.ActionListener; import org.netbeans.sbas.annotations.SuperclassBasedActionAnnotation; import org.openide.awt.StatusDisplayer; import org.openide.loaders.DataObject; import org.openide.util.NbBundle; import org.openide.util.Utilities; @SuperclassBasedActionAnnotation( position=30, displayName="#CTL_BrandTopComponentAction", path="File", type="org.openide.windows.TopComponent") @NbBundle.Messages("CTL_BrandTopComponentAction=Brand") public class BrandTopComponentAction implements ActionListener { private final DataObject context; public BrandTopComponentAction() { context = Utilities.actionsGlobalContext().lookup(DataObject.class); } @Override public void actionPerformed(ActionEvent ev) { String message = context.getPrimaryFile().getPath(); StatusDisplayer.getDefault().setStatusText(message); } } That implies I've created (in a separate module to where it is used) a new annotation. Here's the definition: package org.netbeans.sbas.annotations; import java.lang.annotation.ElementType; import java.lang.annotation.Retention; import java.lang.annotation.RetentionPolicy; import java.lang.annotation.Target; @Retention(RetentionPolicy.SOURCE) @Target(ElementType.TYPE) public @interface SuperclassBasedActionAnnotation { String type(); String path(); int position(); String displayName(); } And here's the processor: package org.netbeans.sbas.annotations; import java.util.Set; import javax.annotation.processing.Processor; import javax.annotation.processing.RoundEnvironment; import javax.annotation.processing.SupportedAnnotationTypes; import javax.annotation.processing.SupportedSourceVersion; import javax.lang.model.SourceVersion; import javax.lang.model.element.Element; import javax.lang.model.element.TypeElement; import javax.lang.model.util.Elements; import org.openide.filesystems.annotations.LayerBuilder.File; import org.openide.filesystems.annotations.LayerGeneratingProcessor; import org.openide.filesystems.annotations.LayerGenerationException; import org.openide.util.lookup.ServiceProvider; @ServiceProvider(service = Processor.class) @SupportedAnnotationTypes("org.netbeans.sbas.annotations.SuperclassBasedActionAnnotation") @SupportedSourceVersion(SourceVersion.RELEASE_6) public class SuperclassBasedActionProcessor extends LayerGeneratingProcessor { @Override protected boolean handleProcess(Set annotations, RoundEnvironment roundEnv) throws LayerGenerationException { Elements elements = processingEnv.getElementUtils(); for (Element e : roundEnv.getElementsAnnotatedWith(SuperclassBasedActionAnnotation.class)) { TypeElement clazz = (TypeElement) e; SuperclassBasedActionAnnotation mpm = clazz.getAnnotation(SuperclassBasedActionAnnotation.class); String teName = elements.getBinaryName(clazz).toString(); String originalFile = "Actions/" + mpm.path() + "/" + teName.replace('.', '-') + ".instance"; File actionFile = layer(e).file( originalFile). bundlevalue("displayName", mpm.displayName()). methodvalue("instanceCreate", "org.netbeans.sbas.annotations.SuperclassSensitiveAction", "create"). stringvalue("type", mpm.type()). newvalue("delegate", teName); actionFile.write(); File javaPopupFile = layer(e).file( "Loaders/text/x-java/Actions/" + teName.replace('.', '-') + ".shadow"). stringvalue("originalFile", originalFile). intvalue("position", mpm.position()); javaPopupFile.write(); } return true; } } The "SuperclassSensitiveAction" referred to in the code above is unchanged from how I had it in yesterday's blog entry. When I build the module containing two action listeners that use my new annotation, the generated layer file looks as follows, which is identical to the layer file entries I hard coded yesterday: <folder name="Actions"> <folder name="File"> <file name="org-netbeans-sbas-impl-ActionListenerSensitiveAction.instance"> <attr name="displayName" stringvalue="Process Action Listener"/> <attr methodvalue="org.netbeans.sbas.annotations.SuperclassSensitiveAction.create" name="instanceCreate"/> <attr name="type" stringvalue="java.awt.event.ActionListener"/> <attr name="delegate" newvalue="org.netbeans.sbas.impl.ActionListenerSensitiveAction"/> </file> <file name="org-netbeans-sbas-impl-BrandTopComponentAction.instance"> <attr bundlevalue="org.netbeans.sbas.impl.Bundle#CTL_BrandTopComponentAction" name="displayName"/> <attr methodvalue="org.netbeans.sbas.annotations.SuperclassSensitiveAction.create" name="instanceCreate"/> <attr name="type" stringvalue="org.openide.windows.TopComponent"/> <attr name="delegate" newvalue="org.netbeans.sbas.impl.BrandTopComponentAction"/> </file> </folder> </folder> <folder name="Loaders"> <folder name="text"> <folder name="x-java"> <folder name="Actions"> <file name="org-netbeans-sbas-impl-ActionListenerSensitiveAction.shadow"> <attr name="originalFile" stringvalue="Actions/File/org-netbeans-sbas-impl-ActionListenerSensitiveAction.instance"/> <attr intvalue="10" name="position"/> </file> <file name="org-netbeans-sbas-impl-BrandTopComponentAction.shadow"> <attr name="originalFile" stringvalue="Actions/File/org-netbeans-sbas-impl-BrandTopComponentAction.instance"/> <attr intvalue="30" name="position"/> </file> </folder> </folder> </folder> </folder>

    Read the article

  • jQuery open and close nested ul nav depending on location

    - by firefusion
    I'm making a sub nav in wordpress and have a nested list style menu. An example of the HTML is below. Whichever is the current item has the li class "current_page_item". I need all child menus collapsed unless there is a current_page_item class on the parent or one of the children. <ul> <li class="current_page_item"><a href="#">Parent Item</a> <ul class="children"> <li><a href="#">Child page</a></li> <li><a href="#">Child page</a></li> <li><a href="#">Child page</a></li> <li><a href="#">Child page</a></li> </ul> </li> <li><a href="#">Parent Item</a> <ul class="children"> <li><a href="#">Child page</a></li> <li><a href="#">Child page</a></li> </ul> </li> <li><a href="#">Parent Item</a> <ul class="children"> <li><a href="#">Child page</a></li> <li><a href="#">Child page</a></li> </ul> </li> <li><a href="#">Parent Item</a></li> <li><a href="#">Parent Item</a></li> </ul> This so far, which works but i wonder if it can be improved as there is some flashing open and then closed again.... jQuery('ul.children').slideUp(); jQuery('li.current_page_item ul.children').slideDown('medium'); jQuery('li.current_page_item').parent().slideDown('medium');

    Read the article

  • Thunderbird cant open due to GLiB Error

    - by Elli
    i recently updated Lubuntu to 13.10 and now after some days Thunderbird stopped working. It just won't open. When i try to open it with the terminal i get the following text: user@user-rechner:~$ thunderbird (process:6231): GLib-CRITICAL **: g_slice_set_config: assertion 'sys_page_size == 0' failed (thunderbird:6231): GLib-GObject-WARNING **: Attempt to add property GnomeProgram::sm-connect after class was initialised (thunderbird:6231): GLib-GObject-WARNING **: Attempt to add property GnomeProgram::show-crash-dialog after class was initialised (thunderbird:6231): GLib-GObject-WARNING **: Attempt to add property GnomeProgram::display after class was initialised (thunderbird:6231): GLib-GObject-WARNING **: Attempt to add property GnomeProgram::default-icon after class was initialised GNOME-Tastaturkürzel-Verzeichnis »/home/user/.gnome2/accels« konnte nicht angelegt werden: Keine Berechtigung (Translation: gnome shortcut-directory could not be created - no permission) Now i reinstalled it once, deleted this .thunderbird folder in my home directory and it still won't work. I hope someone can help me. Thanks.

    Read the article

< Previous Page | 413 414 415 416 417 418 419 420 421 422 423 424  | Next Page >