Search Results

Search found 8776 results on 352 pages for 'boolean logic'.

Page 177/352 | < Previous Page | 173 174 175 176 177 178 179 180 181 182 183 184  | Next Page >

  • How do you plan your asynchronous code?

    - by NullOrEmpty
    I created a library that is a invoker for a web service somewhere else. The library exposes asynchronous methods, since web service calls are a good candidate for that matter. At the beginning everything was just fine, I had methods with easy to understand operations in a CRUD fashion, since the library is a kind of repository. But then business logic started to become complex, and some of the procedures involves the chaining of many of these asynchronous operations, sometimes with different paths depending on the result value, etc.. etc.. Suddenly, everything is very messy, to stop the execution in a break point it is not very helpful, to find out what is going on or where in the process timeline have you stopped become a pain... Development becomes less quick, less agile, and to catch those bugs that happens once in a 1000 times becomes a hell. From the technical point, a repository that exposes asynchronous methods looked like a good idea, because some persistence layers could have delays, and you can use the async approach to do the most of your hardware. But from the functional point of view, things became very complex, and considering those procedures where a dozen of different calls were needed... I don't know the real value of the improvement. After read about TPL for a while, it looked like a good idea for managing tasks, but in the moment you have to combine them and start to reuse existing functionality, things become very messy. I have had a good experience using it for very concrete scenarios, but bad experience using them broadly. How do you work asynchronously? Do you use it always? Or just for long running processes? Thanks.

    Read the article

  • Integrating Amazon EC2 in Java via NetBeans IDE

    - by Geertjan
    Next, having looked at Amazon Associates services and Amazon S3, let's take a look at Amazon EC2, the elastic compute cloud which provides remote computing services. I started by launching an instance of Ubuntu Server 14.04 on Amazon EC2, which looks a bit like this in the on-line AWS Management Console, though I whitened out most of the details: Now that I have at least one running instance available on Amazon EC2, it makes sense to use the services that are integrated into NetBeans IDE:  I created a new application with one class, named "AmazonEC2Demo". Then I dragged the "describeInstances" service that you see above, with the mouse, into the class. Then the IDE automatically created all the other files you see below, i.e., 4 Java classes and one properties file: In the properties file, register the access ID and secret keys. These are read by the other generated Java classes. Signing and authentication are done automatically by the code that is generated, i.e., there's nothing generic you need to do and you can immediately begin working on your domain-specific code. Finally, you're now able to rewrite the code in "AmazonEC2Demo" to connect to Amazon EC2 and obtain information about your running instance: public class AmazonEC2Demo { public static void main(String[] args) { String instanceId1 = "i-something"; RestResponse result; try { result = AmazonEC2Service.describeInstances(instanceId1); System.out.println(result.getDataAsString()); } catch (IOException ex) { Logger.getLogger(AmazonEC2Demo.class.getName()).log(Level.SEVERE, null, ex); } } } From the above, you'll receive a chunk of XML with data about the running instance, it's name, status, dates, etc. In other words, you're now ready to integrate Amazon EC2 features directly into the applications you're writing, without very much work to get started. Within about 5 minutes, you're working on your business logic, rather than on the generic code that anyone needs when integrating with Amazon EC2.

    Read the article

  • Persisting high score table in flash game without a network. (Featuring: HttpListenerException)

    - by bearcdp
    Hi everyone, this question is very programming-centric, but it's for a game so I figured I might as well post it here. I'm doing polishing work on a GGJ '11 game because it will be shown at an indie arcade tomorrow afternoon, and they're expecting our final build in the morning. We'd like to have a high score table that displays during attract mode, but since it's Flash (Flixel) it would require some networking, Mochi, or something to keep a record of these scores. Only problem is the machine we'd be running on probably won't have network access. As a quick solution, I thought I'd just write up a dinky little high score server in C#/.NET that could take basic GET requests for submitting scores and getting the score list. We're talking REAL basic, like blocking while waiting for an incoming request, run & forget console app, etc. There's no guarantee that our .swf won't get reloaded, and we'd like the scores to persist, so this server would pretty much exists to keep a safe copy of the scores that the game can add to and request, and occasionally the server will write the scores to a flat text file. But, HttpListener is giving me Error Code 87 'The parameter is incorrect.' Have any idea what I'm doing wrong? Or better yet, am I barking up the wrong tree and missing an obviously simpler solution? This is all I've got so far in my Main(): HttpListener listener = new HttpListener(); listener.Prefixes.Add("http://localhost:66666/"); listener.Start(); The exception happens at listener.Start(); and the stack trace is: at System.Net.HttpListener.AddAllPrefixes() at System.Net.HttpListener.Start() at WOSEBCE_ScoreServer.Program.Main(String[] args) in C:\Users\Michael\Documents\Visual Studio 2010\VS2010 Projects\WOSEBCE_ScoreServer\WOSEBCE_ScoreServer\Program.cs:line 24 at System.AppDomain._nExecuteAssembly(RuntimeAssembly assembly, String[] args) at System.AppDomain.ExecuteAssembly(String assemblyFile, Evidence assemblySecurity, String[] args) at Microsoft.VisualStudio.HostingProcess.HostProc.RunUsersAssembly() at System.Threading.ThreadHelper.ThreadStart_Context(Object state) at System.Threading.ExecutionContext.Run(ExecutionContext executionContext, ContextCallback callback, Object state, Boolean ignoreSyncCtx) at System.Threading.ExecutionContext.Run(ExecutionContext executionContext, ContextCallback callback, Object state) at System.Threading.ThreadHelper.ThreadStart()

    Read the article

  • Access Control Service: Walkthrough Videos of Web Application, SOAP, REST and Silverlight Integration

    - by Your DisplayName here!
    Over the weekend I worked a little more on my ACS2 sample. Instead of writing it all down, I decided to quickly record four short videos that cover the relevant features and code. Have fun ;) Part 1 – Overview This video does a quick walkthrough of the solution and shows the web application part. This includes driving the sign in UI via JavaScript (thanks Matias) as well as the registration logic I wrote about here. watch Part 2 – SOAP Service and Client The sample app also exposes a WCF SOAP service. This video shows how to wire up the service to ACS and hows how to create a client that first requests a token from an IdP and then sends this token to ACS. watch Part 3 – REST Service and Client This part shows how to set up a WCF REST service that consumes SWT tokens from ACS. Unfortunately there is currently no standard WIF plumbing for REST. For the service integration I had to combine a lot of code from different sources (kzu, zulfiq) as well as the WIF SDK and OAuth CTPs together. But it is working. watch Part 4 – Silverlight and Web Identity Integration This part took by far the most time to write. The Silverlight Client shows ho to sign in to the application using a registered identity provider (including web identities) and using the resulting SWT token to call our REST service. This is designed to be a desktop (OOB) client application (thanks to Jörg for the UI magic). watch code download

    Read the article

  • Call DB Stored Procedure using @NamedStoredProcedureQuery Injection

    - by anwilson
    Oracle Database Stored Procedure can be called from EJB business layer to perform complex DB specific operations. This approach will avoid overhead from frequent network hits which could impact end-user result. DB Stored Procedure can be invoked from EJB Session Bean business logic using org.eclipse.persistence.queries.StoredProcedureCall API. Using this approach requires more coding to handle the Session and Arguments of the Stored Procedure, thereby increasing effort on maintenance. EJB 3.0 introduces @NamedStoredProcedureQuery Injection to call Database Stored Procedure as NamedQueries. This blog will take you through the steps to call Oracle Database Stored Procedure using @NamedStoredProcedureQuery.EMP_SAL_INCREMENT procedure available in HR schema will be used in this sample.Create Entity from EMPLOYEES table.Add @NamedStoredProcedureQuery above @NamedQueries to Employees.java with definition as given below - @NamedStoredProcedureQuery(name="Employees.increaseEmpSal", procedureName = "EMP_SAL_INCREMENT", resultClass=void.class, resultSetMapping = "", returnsResultSet = false, parameters = { @StoredProcedureParameter(name = "EMP_ID", queryParameter = "EMPID"), @StoredProcedureParameter(name = "SAL_INCR", queryParameter = "SALINCR")} ) Observe how Stored Procedure's arguments are handled easily in  @NamedStoredProcedureQuery using @StoredProcedureParameter.Expose Entity Bean by creating a Session Facade.Business method need to be added to Session Bean to access the Stored Procedure exposed as NamedQuery. public void salaryRaise(Long empId, Long salIncrease) throws Exception { try{ Query query = em.createNamedQuery("Employees.increaseEmpSal"); query.setParameter("EMPID", empId); query.setParameter("SALINCR", salIncrease); query.executeUpdate(); } catch(Exception ex){ throw ex; } } Expose business method through Session Bean Remote Interface. void salaryRaise(Long empId, Long salIncrease) throws Exception; Session Bean Client is required to invoke the method exposed through remote interface.Call exposed method in Session Bean Client main method. final Context context = getInitialContext(); SessionEJB sessionEJB = (SessionEJB)context.lookup("Your-JNDI-lookup"); sessionEJB.salaryRaise(new Long(200), new Long(1000)); Deploy Session BeanRun Session Bean Client.Salary of Employee with Id 200 will be increased by 1000.

    Read the article

  • Java game design question (graphical objects)

    - by vemalsar
    Hello Guys, I'm beginner in game development, in Java and here on this site too and I have a game design question. Please comment my idea: I have a main loop which call update and draw method. I want to use an ArrayList which store graphical objects, they have coordinate and image or text to draw and my game objects extends this class. In update, I can choose which objects should be put in the array and in draw method I'll display the elements of array on the screen. I'm using a buffer and draw first there, but it is not important now I guess...Here is a simple (not full) code, only the logic: public class GamePanel extends JPanel implements KeyListener { ArrayList<graphicalObjects> graphArray = new ArrayList<graphicalObjects>(); public void update() { //change the game scene, update the graphArray, process input etc. } public void draw() { //draws every element of graphArray to a JPanel } public static main(String[] args) { while(true) { update(); draw(); } } } My questions: Should have I use interface or abstract class for graphicalObjects? graphicalObjects class and the ArrayList really needs or there is some better solution? How to draw objects? They draw themself with their own method or in the draw method I have to draw manually based on graphicalObjects variables (x,y coordinates, image etc.)? If this conception is wrong, please suggest another one! All comments are welcome and sorry if this is dumb question, thanks!

    Read the article

  • How to choose between Tell don't Ask and Command Query Separation?

    - by Dakotah North
    The principle Tell Don't Ask says: you should endeavor to tell objects what you want them to do; do not ask them questions about their state, make a decision, and then tell them what to do. The problem is that, as the caller, you should not be making decisions based on the state of the called object that result in you then changing the state of the object. The logic you are implementing is probably the called object’s responsibility, not yours. For you to make decisions outside the object violates its encapsulation. A simple example of "Tell, don't Ask" is Widget w = ...; if (w.getParent() != null) { Panel parent = w.getParent(); parent.remove(w); } and the tell version is ... Widget w = ...; w.removeFromParent(); But what if I need to know the result from the removeFromParent method? My first reaction was just to change the removeFromParent to return a boolean denoting if the parent was removed or not. But then I came across Command Query Separation Pattern which says NOT to do this. It states that every method should either be a command that performs an action, or a query that returns data to the caller, but not both. In other words, asking a question should not change the answer. More formally, methods should return a value only if they are referentially transparent and hence possess no side effects. Are these two really at odds with each other and how do I choose between the two? Do I go with the Pragmatic Programmer or Bertrand Meyer on this?

    Read the article

  • how to rotate a sprite using multi touch (andengine) in android?

    - by 786
    I am new to android game development. I am using andengine GLES-2. i have created sprite as a box. this box is now draggable by using this coding. it works fine. but i want multitouch on this which i want to rotate a sprite with 2 finger in that box and even it should be draggable. .... plz help someone by overwriting this code or by giving exact example of this doubt... i am trying this many days but no idea. final float centerX = (CAMERA_WIDTH - this.mBox.getWidth()) / 2; final float centerY = (CAMERA_HEIGHT - this.mBox.getHeight()) / 2; Box= new Sprite(centerX, centerY, this.mBox, this.getVertexBufferObjectManager()) { public boolean onAreaTouched(TouchEvent pSceneTouchEvent, float pTouchAreaLocalX, float pTouchAreaLocalY) { this.setPosition(pSceneTouchEvent.getX() - this.getWidth()/ 2, pSceneTouchEvent.getY() - this.getHeight() / 2); float pValueX = pSceneTouchEvent.getX(); float pValueY = CAMERA_HEIGHT-pSceneTouchEvent.getY(); float dx = pValueX - gun.getX(); float dy = pValueY - gun.getY(); double Radius = Math.atan2(dy,dx); double Angle = Radius * 360 ; Box.setRotation((float)Math.toDegrees(Angle)); return true; } thanks

    Read the article

  • What is better for the overall performance and feel of the game: one setInterval performing all the work, or many of them doing individual tasks?

    - by Bane
    This question is, I suppose, not limited to Javascript, but it is the language I use to create my game, so I'll use it as an example. For now, I have structured my HTML5 game like this: var fps = 60; var game = new Game(); setInterval(game.update, 1000/fps); And game.update looks like this: this.update = function() { this.parseInput(); this.logic(); this.physics(); this.draw(); } This seems a bit inefficient, maybe I don't need to do all of those things at once. An obvious alternative would be to have more intervals performing individual tasks, but is it worth it? var fps = 60; var game = new Game(); setInterval(game.draw, 1000/fps); setInterval(game.physics, 1000/a); //where "a" is some constant, performing the same function as "fps" ... With which approach should I go and why? Is there a better alternative? Also, in case the second approach is the best, how frequently should I perform the tasks?

    Read the article

  • How to define implementation details?

    - by woni
    In our project, an assembly combines logic for the IoC-Container, the project internals and the communication layer. The current version evolved to have only internal classes in addin assemblies. My main problem with this approach is, that the entry point is only available over the IoC-Container. It is not possible to use anything else than reflection to initialize the assembly. Everything behind the IoC-Interface is defined as implementation detail and therefore not intended for usages outside. It is well known that you should not test implementation detail (such as private and internal methods), because they should be tested through the public interface. It is also well known, that your tests should not use the IoC-Container to setup the SUTs, because that would result in too much dependencies. So we are using the InternalsVisibleTo-Attribute to make internals visible to our test assemblies and test the so called implementation details. I recognized that one problem could be the mixup between different concerns in that assembly, changing this would make this discussion useless, because classes have to be defined public. Ignoring my concerns with this, isn't the need to test a class enough reason to make it public, the usages of InternalsVisibleTo seems unintended, and a little bit "hacky". The approach to test only against the publicly available IoC-Container is too costly and would result in integration style tests. The pros of using internals are, that the usages are well known and do not have to be implemented like a public method would have to be (documentation, completeness, versioning,...). Is there a solution, to not test against internals, but keep their advantages over public classes, or do we have to redefine what an implementation detail is.

    Read the article

  • PyQt application architecture

    - by L. De Leo
    I'm trying to give a sound structure to a PyQt application that implements a card game. So far I have the following classes: Ui_Game: this describes the ui of course and is responsible of reacting to the events emitted by my CardWidget instances MainController: this is responsible for managing the whole application: setup and all the subsequent states of the application (like starting a new hand, displaying the notification of state changes on the ui or ending the game) GameEngine: this is a set of classes that implement the whole game logic Now, the way I concretely coded this in Python is the following: class CardWidget(QtGui.QLabel): def __init__(self, filename, *args, **kwargs): QtGui.QLabel.__init__(self, *args, **kwargs) self.setPixmap(QtGui.QPixmap(':/res/res/' + filename)) def mouseReleaseEvent(self, ev): self.emit(QtCore.SIGNAL('card_clicked'), self) class Ui_Game(QtGui.QWidget): def __init__(self, window, *args, **kwargs): QtGui.QWidget.__init__(self, *args, **kwargs) self.setupUi(window) self.controller = None def place_card(self, card): cards_on_table = self.played_cards.count() + 1 print cards_on_table if cards_on_table <= 2: self.played_cards.addWidget(card) if cards_on_table == 2: self.controller.play_hand() class MainController(object): def __init__(self): self.app = QtGui.QApplication(sys.argv) self.window = QtGui.QMainWindow() self.ui = Ui_Game(self.window) self.ui.controller = self self.game_setup() Is there a better way other than injecting the controller into the Ui_Game class in the Ui_Game.controller? Or am I totally off-road?

    Read the article

  • Unzipping in Java and FileUtil.copy

    - by Geertjan
    Via NetBeans File Systems API, which provides FileUtil.copy below, which means a dependency on NetBeans Utilities API: private void unzipEpubFile(String folder, File file) throws IOException { final AtomicBoolean canceled = new AtomicBoolean(); //define and start progress bar here... // ProgressHandle handle = // ProgressHandleFactory.createHandle( // Bundle.MSG_unpacking(zip.getName()), // new Cancellable() { // @Override // public boolean cancel() { // return canceled.compareAndSet(false, true); // } // }); //then unzip 'file' into 'root": try { List folders = new ArrayList<>(); try (InputStream is = new FileInputStream(file)) { ZipInputStream zis = new ZipInputStream(is); ZipEntry entry; while ((entry = zis.getNextEntry()) != null) { if (canceled.get()) { return; } String n = entry.getName(); File f = new File(folder, n); if (n.endsWith("/")) { if (!f.isDirectory()) { if (!f.mkdirs()) { throw new IOException("could not make " + f); } if (entry.getTime() > 0) { if (!f.setLastModified(entry.getTime())) { // oh well } } } folders.add(f); } else { //handle.progress(Bundle.MSG_creating(n)); File p = f.getParentFile(); if (!p.isDirectory() && !p.mkdirs()) { throw new IOException("could not make " + p); } try (OutputStream os = new FileOutputStream(f)) { FileUtil.copy(zis, os); } if (entry.getTime() > 0) { if (!f.setLastModified(entry.getTime())) { // oh well } } } } } //handle.switchToDeterminate(folders.size()); if (canceled.get()) { } } finally { //stop progress bar } } Mostly from NetBeans IDE sources for working with projects and ZIP files.

    Read the article

  • [EF + Oracle]Object Context

    - by JTorrecilla
    Prologue After EF episodes I and II, we are going to see the Object Context. What is Object Context? It is a class which manages the DB connection, and the different Entities of our model. When Visual Studio creates the EF model, like I explain previously, also generates a Class that extends ObjectContext. ObjectContext provides: - DB connection - Add, update and delete functions. - Object Sets of Entities. - State of Pending Changes. This class will give a function, for each Entity, like  Esta clase va a contar con una función, para cada entidad, del tipo “AddTo{ENTITY}({Entity_Type } value)”, which are going to add a Entity to the related ObjectSet. In addition, it has a property, for each Entity, like “ObjectSet<TEntity> Entity”, does will keep the related record set. It will be filled with the CreateObjectSet<TEntity> function of Base class (ObjectContext). What is an ObjectSet? It is a class that allows us to manage the Entity Set from a Type. It inherits from: · ObjectQuery<TEntity> · IObjectSet<TEntity> · IQueryAble<TEntity · IEnumerable<TEntity · IQueryAble · IEnumerable An ObjectSet is a class property that allows query, insert, delete and update records from a determinate Entity. In following chapters we will see how to query Entities. LazyLoadingEnabled A very important property of the Context is “LazyLoadingEnabled”. This Boolean property lets indicate if the data loading is lazy, in other words, the Object will not be created and query until not be needed. Finally In this post we have seen what the VS generated context is, some of the characteristics, and where to see Entity data. In next chapters we will see, CRUD operations, and how to query ObjectSets.

    Read the article

  • TechEd 2012: Fast SQL Server

    - by Tim Murphy
    While I spend a certain amount of my time creating databases (coding around SQL Server and setup a server when I have to) it isn’t my bread and butter.  Since I have run into a number of time that SQL Server needed to be tuned I figured I would step out of my comfort zone and see what I can learn. Brent Ozar packed a mountain of information into his session on making SQL Server faster.  I’m not sure how he found time to hit all of his points since he was allowing the audience abuse him on Twitter instead of asking questions, but he managed it.  I also questioned his sanity since he appeared to be using a fruit laptop. He had my attention though when he stated that he had given up on telling people to not use “select *”. He posited that it could be fixed with hardware by caching the data in memory.  He continued by cautioning that having too many indexes could defeat this approach.  His logic was sound if not always practical, but it was a good place to start when determining the trade-offs you need to balance.  He was moving pretty fast, but I believe he was prescribing this solution predominately for OLTP database prior to moving on to data warehouse solutions. Much of the advice he gave for data warehouses is contained in the Microsoft Fast Track guidance so I won’t rehash it here.  To summarize the solution seems to be the proper balance memory, disk access speed and the speed of the pipes that get the data from storage to the CPU.  It appears to be sound guidance and the session gave enough information that going forward we should be able to find the details needed easily.  Just what the doctor ordered. del.icio.us Tags: SQL Server,TechEd,TechEd 2012,Database,Performance Tuning

    Read the article

  • What are most demanded web-development languages today for startups?

    - by Liston Catch
    What technologies are in demand nowaydas for web-development for web-startups? For frontend its all clear: HTML5, JS, AJAX, JQuery. But what about backend? What languages (and frameworks) should I consider using? I am not asking "which language is best", I just need a list of modern languages and frameworks (and not Pascal, Delphi or Basic) which are demanded and well-payed. UPD: I totally decline the "it's all about logic, not about language. language is just a tool" concept. While THEORETICALLY it's true, in reality the time you need to study required frameworks is counted by months, so language DOES matter indeed. That's why I made this topic UPD 2: Mason Wheeler, so you seriously advice me to go for Delphi? You think its DEMANDED nowadays? Or you just tell me an exception which only confirms the rule? It's like "one guy won 100,000,000$ in lottery. Just for you to know that lottery is not a bad way to earn money."

    Read the article

  • what's a good approach to working with multiple databases?

    - by Riz
    I'm working on a project that has its own database call it InternalDb, but also it queries two other databases, call them ExternalDb1 and ExternalDb2. Both ExternalDb1 and ExternalDb2 are actually required by a few other projects. I'm wondering what the best approach for dealing with this is? Currently, I've just created a project for each of these external databases and then generated Edmx and entities using the entity-framework approach. My thought was that I could then include these projects in any of my solutions that require access to these databases. Also, I don't have any separate business layers. I just have a solution like below: Project.Domain ExternalDb1Project.Domain ExternalDb2Project.Domain Project.Web So my Domain projects contain the data access as well as the POCOs generated by Entity Framework and any business logic. But I'm not sure if this is a good approach. For example if I want to do Validation in my Project.Domain on the entities in the InternalDb, it's fine. But if I want to do Validation for entities from either of the ExternalDbs, then I wonder where it should go? To be more specific, I retrieve Employees from ExternalDb1Project.Domain. However, I want to make sure they are Active. Where should this Validation go? How to architect a project like this at a high level? Also, I want to make sure that I use IoC for my data contexts so I can create Fakes when writing tests. I wonder where the interfaces for these various data contexts would reside?

    Read the article

  • tips, guidelines, points to remember for rendering professional code?

    - by ronnieaka
    I'm talking about giving clients professional looking code. The whole nine yards, everything you hardcore professional highly experienced programmers here probably do when coding freelance or for the company you work in. I'm fresh out of college and I'm going into freelance. I just want to be sure that my first few projects leave a good after-taste of professionalism imprinted on the clients' minds. When I Googled what i'm asking here, I was given pages that showed various websites and tools that let you make flashy websites and templates etc. The $N package and such stuff. I can't recall the word experts use for it. Standard, framework [i know that's not it]. English isn't my first language so I'm sorry I don't really don't know the exact phrase for it. That abstract way of writing code so that you don't come across as a sloppy programmer. That above mentioned way for programming websites and desktop software [in python/C/C++/Java]. EDIT: i can work on the accruing vast knowledge and know-how and logic building etc. what i'm asking for is the programming standard/guidelines you guys follow so that the client on seeing code feels that its a professional solution. Like comment blocks, a particular indentation style something like that. Is there any book on it or specific list of points for enterprise type coding by them? Especially here as in my case, for building websites [php for now..], and desktop software [c/c++/java/python]

    Read the article

  • What’s ‘default’ for?

    - by Strenium
    Sometimes there's a need to communicate explicitly that value variable is yet to be "initialized" or in other words - we’ve never changed it from its' default value. Perhaps "initialized" is not the right word since a value type will always have some sort of value (even a nullable one) but it's just that - how do we tell? Of course an 'int' would be 0, an 'enum' would the first defined value of a given enum and so on – we sure can make this kind of check "by hand" but eventually it would get a bit messy. There's a more elegant way with a use of little-known functionality of: 'default'Let’s just say we have a simple Enum: Simple Enum namespace xxx.Common.Domain{    public enum SimpleEnum    {        White = 1,         Black = 2,         Red = 3    }}   In case below we set the value of the enum to ‘White’ which happens to be a first and therefore default value for the enum. So the snippet below will set value of the ‘isDefault’ Boolean to ‘true’. 'True' Case SimpleEnum simpleEnum = SimpleEnum.White;bool isDefault; /* btw this one is 'false' by default */ isDefault = simpleEnum == default(SimpleEnum) ? true : false; /* default value 'white' */   Here we set the value to ‘Red’ and ‘default’ will tell us whether or not this the default value for this enum type. In this case: ‘false’. 'False' Case simpleEnum = SimpleEnum.Red; /* change from default */isDefault = simpleEnum == default(SimpleEnum) ? true : false; /* value is not default any longer */ Same 'default' functionality can also be applied to DateTimes, value types and other custom types as well. Sweet ‘n Short. Happy Coding!

    Read the article

  • How to pause and resume a game in XNA using the same key?

    - by user13095
    I'm attempting to implement a really simple game state system, this is my first game - trying to make a Tetris clone. I'd consider myself a novice programmer at best. I've been testing it out by drawing different textures to the screen depending on the current state. The 'Not Playing' state seems to work fine, I press Space and it changes to 'Playing', but when I press 'P' to pause or resume the game nothing happens. I tried checking current and previous keyboard states thinking it was happening to fast for me to see, but again nothing seemed to happen. If I change either the pause or resume, so they're both different, it works as intended. I'm clearly missing something obvious, or completely lacking some know-how in regards to how update and/or the keyboard states work. Here's what I have in my Update method at the moment: protected override void Update(GameTime gameTime) { KeyboardState CurrentKeyboardState = Keyboard.GetState(); // Allows the game to exit if (CurrentKeyboardState.IsKeyDown(Keys.Escape)) this.Exit(); // TODO: Add your update logic here if (CurrentGameState == GameStates.NotPlaying) { if (CurrentKeyboardState.IsKeyDown(Keys.Space)) CurrentGameState = GameStates.Playing; } if (CurrentGameState == GameStates.Playing) { if (CurrentKeyboardState.IsKeyDown(Keys.P)) CurrentGameState = GameStates.Paused; } if (CurrentGameState == GameStates.Paused) { if (CurrentKeyboardState.IsKeyDown(Keys.P)) CurrentGameState = GameStates.Playing; } base.Update(gameTime); }

    Read the article

  • Common Substring of two strings

    - by Chander Shivdasani
    This particular interview-question stumped me: Given two Strings S1 and S2. Find the longest Substring which is a Prefix of S1 and suffix of S2. Through Google, I came across the following solution, but didnt quite understand what it was doing. public String findLongestSubstring(String s1, String s2) { List<Integer> occurs = new ArrayList<>(); for (int i = 0; i < s1.length(); i++) { if (s1.charAt(i) == s2.charAt(s2.length()-1)) { occurs.add(i); } } Collections.reverse(occurs); for(int index : occurs) { boolean equals = true; for(int i = index; i >= 0; i--) { if (s1.charAt(index-i) != s2.charAt(s2.length() - i - 1)) { equals = false; break; } } if(equals) { return s1.substring(0,index+1); } } return null; }

    Read the article

  • How to choose between using a Domain Event, or letting the application layer orchestrate everything

    - by Mr Happy
    I'm setting my first steps into domain driven design, bought the blue book and all, and I find myself seeing three ways to implement a certain solution. For the record: I'm not using CQRS or Event Sourcing. Let's say a user request comes into the application service layer. The business logic for that request is (for whatever reason) separated into a method on an entity, and a method on a domain service. How should I go about calling those methods? The options I have gathered so far are: Let the application service call both methods Use method injection/double dispatch to inject the domain service into the entity, letting the entity do it's thing and then let it call the method of the domain service (or the other way around, letting the domain service call the method on the entity) Raise a domain event in the entity method, a handler of which calls the domain service. (The kind of domain events I'm talking about are: http://www.udidahan.com/2009/06/14/domain-events-salvation/) I think these are all viable, but I'm unable to choose between them. I've been thinking about this a long time and I've come to a point where I no longer see the semantic differences between the three. Do you know of some guidelines when to use what?

    Read the article

  • Motivation for service layer (instead of just copying dlls)?

    - by BornToCode
    I'm creating an application which has 2 different UIs so I'm making it with a service layer which I understood is appropriate for such case. However I found myself just creating web methods for every single method I have in the BL layer, so the services basically built from methods that looks like this: return customers_bl.Get_Customer_Prices(customer_id); I understood that a main point of the service layer is to prevent duplication of code so I asked myself - well, why not just import the BL.dll (and the DAL.dll) to the other UI, and whenever making a change re-copy the dll files, it might not be so 'neat', but is the all purpose of the service layer to prevent this? {I know something is wrong in my approach, I'm probably missing the importance of service layer, I'd like to get more motivation to create another layer, especially because as it is I found that many of my BL functions ALREADY looks like: return customers_dal.Get_Customer_Prices(cust_id) which led me to ask: was it really necessary to create the BL just because on several functions I actually have LOGIC inside the BL?} so I'm looking for more motivation to creating ONE MORE layer, I'm sure it's not just to make it more convenient that I won't have to re-copy the dlls on changes? Am I grasping it wrong? Any simple guidelines on how to design service layer (corresponding to all the BL layer functions or not? any simple example?) any enlightenment on the subject?

    Read the article

  • How to populate a private container for unit test?

    - by Sardathrion
    I have a class that defines a private (well, __container to be exact since it is python) container. I am using the information within said container as part of the logic of what the class does and have the ability to add/delete the elements of said container. For unit tests, I need to populate this container with some data. That date depends on the test done and thus putting it all in setUp() would be impractical and bloated -- plus it could add unwanted side effects. Since the data is private, I can only add things via the public interface of the object. This run codes that need not be run during a unit test and in some case is just a copy and paste from another test. Currently, I am mocking the whole container but somehow it does not feel that elegant a solution. Due to Python mocking frame work (mock), this requires the container to be public -- so I can use patch.dict(). I would rather keep that data private. What pattern can one use to still populate the containers without excising the public method so I have data to test with? Is there a way to do this with mock' patch.dict() that I missed?

    Read the article

  • At what point does programming become a useful skill?

    - by Elip
    This is probably a very difficult question to answer, because of its subjectivity, but even a vague guess would help me out: Now that Khan Academy is beginning to offer Computer Science lectures I'm getting an itch to learn programming again. I maybe am a bit more technical than your average computer user, using Ubuntu as my OS, LaTeX for writing and I know some small tricks like regular expressions or boolean search for google. However from my previous attempts to learn programming, I realized I do not have a natural aptitude for it and I also don't seem to enjoy the process. But I am fairly certain that a basic proficiency in programming could prove to be very beneficial for me career wise; I also often get ideas for little scripts that I cannot implement. My question is: Let's say you study programming 1 hour / day on average. At what point will you become good enough so that programming can be used for automating tasks and actually saving time? Do you think programming is worth picking up if you never have the ambition to make it your career or even your hobby, but use it strictly for utility purposes?

    Read the article

  • Motivation for a service layer (instead of just copying dlls)?

    - by BornToCode
    I'm creating an application which has 2 different UIs so I'm making it with a service layer which I understood is appropriate for such scenario. However I found myself just creating web methods for every single method I have in the BL layer, so the services basically built from methods that looks like this: return customers_bl.Get_Customer_Prices(customer_id); I understood that a main point of the service layer is to prevent duplication of code so I asked myself - why not just import the BL.DLL (and the dal.dll) to the other UI, and whenever making a change re-copy the dlls, it might not be so 'neat', but still less hassle than one more layer? {I know something is wrong in my approach, I'm probably missing the importance of service layer, I'd like to get more motivation to create another layer, especially because as it is I found that many of my BL functions ALREADY looks like: return customers_dal.Get_Customer_Prices(cust_id) which led me to ask: was it really necessary to create the BL just because on several functions I actually have LOGIC inside the BL?} so I'm looking for more motivation to creating ONE MORE layer, I'm sure it's not just to make it more convenient that I won't have to re-copy the dlls on changes? Am I grasping it wrong? Any simple guidelines on how to design service layer (corresponding to all the BL layer functions or not? any simple example?) any enlightenment on the subject?

    Read the article

< Previous Page | 173 174 175 176 177 178 179 180 181 182 183 184  | Next Page >