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  • User Produtivity Kit - Powerful Packages (Part 1)

    - by [email protected]
    User Productivity Kit provides the ability to create a variety of content types including robust topics on system process and web pages with formatted text and graphics. There are times when you want to enhance content with media types not naively created by User Productivity Kit, media types such as video, custom animations, forms, and more. One method of doing this is to maintain these media files on a web server - separate from the User Productivity Kit player content and link to the files using absolute URLs such as http://myserver/overview.html. While this will get you going, you won't benefit from the content management capabilities of the UPK Developer. Features such as check-in / check-out, history, document properties, folder permissions and more are not available to this external content. Further, if you ever need to move that content to a server with a different name or domain, you'd need to update all your links. UPK version 3.1 introduced a new document type - the package. A package is a group of folders and files that you manage in the Developer library as a single document. These package documents work in the same manner as any other document in the library and you can use all of the collaborative content development features you see with other document types. Packages can be used for anything from single Word documents, PDF files, and graphics to more intricate sets of inter-related files commonly seen with HTML files and their graphics, style sheets, and JavaScript files. The structure of the files and folders within a package will always be preserved so this means that any relative links between files in the package will work. For example, an HTML file containing an image tag with a relative link to a graphic elsewhere in the same package will continue to function properly both when viewed in the Developer and when published to outputs such as the UPK Player. Once you start to use packages, you'll soon discover that there is a lot of existing content that can be re-purposed by placing it into UPK packages. Packages are easily created by selecting File...New...Package. Files can be added in a number of ways including the "Add Files" button, copy & paste from Windows Explorer, and drag & drop. To use one of the files in the package, just create a link to the file in the package you want to target. This is supported throughout the Developer in places such as section & topic concepts, frame links and hyperlinks in web pages. A little more challenging is determining how to structure packages in your library. As I mentioned earlier, a package can contain anything from a single file to dozens of files and folders. So what should you do? You could create a package for each file. You could create one package for all your files. But which one is right? Well, there's not a right and wrong answer to this question. There are advantages and disadvantages to each. The right decision will be influenced by the package files themselves, the structure of the content in the library, the size and working style of the development team, how content is shared between different outlines and more. The first consideration can be assessed the quickest. If the content to be placed in the package is composed of multiple files and those files reference each other, they should be in the same package. There are loads of examples of this type of content. HTML files with graphics and style sheets, HTML files with embedded Flash movies, and Word documents saved as HTML are all examples where the content is composed of multiple files and the files reference each other in some way. Content like this should always be placed in a singe package such that these relative links between the files are preserved and play properly in the UPK Player. In upcoming posts, I'll explain additional considerations.

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  • Come see us at JavaU at JavaOne!

    - by tmcginn
    In just a little under a month, JavaOne will be in full swing (no pun intended) and thousands of Java developers will gather to hear the latest Java news, immerse themselves in Java technology and learn some new things. This year, I am fortunate enough to be able to attend, along with my Java curriculum development colleagues Matt Heimer and Mike Williams. We start our week at JavaOne teaching a one-day session at JavaU on Sunday morning. If you have never attended a training session through JavaU, you should check it out. There are some terrific sessions this year, and it might help to justify your trip to JavaOne if you can say it was for training! This year I am teaching a one day session on Java SE 7 New Features - a great session for anyone interested in the specific details of what is new in Java SE 7. Matt is teaching a one-day session on Developing Portable Java EE applications with the Enterprise JavaBeans 3.1 API and Java Persistence 2.0 API  EJB, and Mike is doing a one-day session on developing Rich Client applications with Java SE 7 using Java FX 2. I asked Matt and Mike to tell me what developers can expect from their sessions. Matt: "My session will get you up to speed on everything you need to know to create portable Java EE 6 applications using EJB 3.1 and JPA 2. I am going to cover why everyone can benefit from using EJBs (and why developers should relearn them if they haven't looked at them for years). Students who attend my session will see JPA examples showcasing how to use relational databases in an enterprise applications without programming to JDBC and without writing SQL statements. EJB and JPA benefit from being paired together, so I will also show how transaction management is easier in a container. I encourage students to bring a laptop and code as they learn!" Mike: "My session covers how to develop a rich client application using Java FX 2. Starting with the basic concepts of JavaFX, students will see how a JavaFX application is built from its layout, to its controls, to its data structures. In addition, more advanced controls like charts, smart tables, and transitions will be added to the application. Finally, a quick review of JavaFX concurrency and data binding is included. Blended with the core concepts the session will include some of the latest JavaFX technology. This includes using Scene Builder to create a JavaFX UI and connecting your XML UI definition to Java code.  In addition, packaging of the JavaFX application will be covered with some examples of the new native packaging features." As I mentioned, my session covers the changes in the Java for SE 7, including the  language changes that were voted into Java SE 7 from Project Coin. I will also look at how you can take advantage if the the new I/O library (NIO.2) for writing applications that work with files, directories and file systems. We will also look at the changes in Asynchronous I/O that are a part of the changes in NIO/2. We will spend some time looking at the changes to the Java Virtual Machine as well, including support for dynamically typed languages (JSR-292). We will spend some time looking at the Java Concurrency enhancements (JSR-166), including the new Fork/Join framework. And we'll round out the day with a look at changes in Swing, XML and a number of smaller changes in the API's. And, if these topics aren't grabbing your interest, take a look at the other 10 sessions that range from topics on architecture to how to pass the Oracle Certified Programmer I and II exams. See you soon!

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  • How does interpolation actually work to smooth out an object's movement?

    - by user22241
    I've asked a few similar questions over the past 8 months or so with no real joy, so I am going make the question more general. I have an Android game which is OpenGL ES 2.0. within it I have the following Game Loop: My loop works on a fixed time step principle (dt = 1 / ticksPerSecond) loops=0; while(System.currentTimeMillis() > nextGameTick && loops < maxFrameskip){ updateLogic(dt); nextGameTick+=skipTicks; timeCorrection += (1000d/ticksPerSecond) % 1; nextGameTick+=timeCorrection; timeCorrection %=1; loops++; } render(); My intergration works like this: sprite.posX+=sprite.xVel*dt; sprite.posXDrawAt=sprite.posX*width; Now, everything works pretty much as I would like. I can specify that I would like an object to move across a certain distance (screen width say) in 2.5 seconds and it will do just that. Also because of the frame skipping that I allow in my game loop, I can do this on pretty much any device and it will always take 2.5 seconds. Problem However, the problem is that when a render frame skips, the graphic stutter. It's extremely annoying. If I remove the ability to skip frames, then everything is smooth as you like, but will run at different speeds on different devices. So it's not an option. I'm still not sure why the frame skips, but I would like to point out that this is Nothing to do with poor performance, I've taken the code right back to 1 tiny sprite and no logic (apart from the logic required to move the sprite) and I still get skipped frames. And this is on a Google Nexus 10 tablet (and as mentioned above, I need frame skipping to keep the speed consistent across devices anyway). So, the only other option I have is to use interpolation (or extrapolation), I've read every article there is out there but none have really helped me to understand how it works and all of my attempted implementations have failed. Using one method I was able to get things moving smoothly but it was unworkable because it messed up my collision. I can foresee the same issue with any similar method because the interpolation is passed to (and acted upon within) the rendering method - at render time. So if Collision corrects position (character now standing right next to wall), then the renderer can alter it's position and draw it in the wall. So I'm really confused. People have said that you should never alter an object's position from within the rendering method, but all of the examples online show this. So I'm asking for a push in the right direction, please do not link to the popular game loop articles (deWitters, Fix your timestep, etc) as I've read these multiple times. I'm not asking anyone to write my code for me. Just explain please in simple terms how Interpolation actually works with some examples. I will then go and try to integrate any ideas into my code and will ask more specific questions if need-be further down the line. (I'm sure this is a problem many people struggle with).

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  • Administer, manage, monitor, and fine tune the performance of your Oracle SOA Suite 11g Service Infrastructure and SOA composite applications.

    - by JuergenKress
    Key Features of the book If you are an Oracle SOA suite administrator, then this book is your bible. It gives you everything you need to know about all your tasks and help you to apply what you learn in your everyday life right from the first chapter. The book walks through promoting code across environments, performance tuning the service infrastructure, monitoring the environment, configuring security policies, managing the dehydration store, backing and restoring environments and so on. Packed with real-world examples from authors' own experiences, this books offers a unique insight into Oracle SOA Suite Administration. Detailed description The book begins with an introduction of SOA and quickly moves on to management of SOA composite applications. Readers will learn how to manage composite applications, their deployments and lifecycles. Equipped with this knowledge, readers will be introduced to monitoring and performance tuning SOA Suite, monitoring instances, messages, and composite applications, managing faults and exceptions, configuring audit levels of composite applications to include end-to-end monitoring through the use of extended logging as well as administering and configuring all SOA Suite components. A very important aspect of administration is tuning and optimizing the infrastructure for performance and book offers real work recommendations to monitor and performance tune service engines, the underlying WebLogic server, threads and timeouts, files systems, and composite applications. It also covers detailed administration of individual service components, configuring the infrastructure MBeans using both Oracle Enterprise Manager Fusion Middleware Control and WLST based scripts, migrating worklist preferences and BAM data across environments, setting up Email, LDAP and custom XPath. An administrator is always trusted with troubleshooting and root causing problems in the infrastructure and this book will help you through the troubleshooting approaches as how to identify faults and exception through extended logging and thread dumps and find solutions to common startup problems and deployment issues. The advanced contents of this book explains OWSM security framework and how to secure components deployed to the infrastructure along with the details of all groundwork needed to ready the environment. Last few chapters help you to understand and deal with managing the metadata services repository and dehydration store, backup and recovery and concluding with advanced topics such as silent/scripted installations, cloning, upgrading, patching and high availability installations. Packed with real-world examples, and tips straight from the trench; this book offers insights into SOA Suite administration that you will not find elsewhere. Part of our writing style in this book draws heavily on the philosophy of reuse and as such the book provide an ample of executable SQL queries and WLST scripts that administrators can reuse and extend to perform most of the administration tasks such as monitoring instances, processing times, instance states and perform automatic deployments, tuning, migration, and installation. These scripts are spread over each of the chapters in the book and can also be downloaded from here. The book is available in different formats at the following websites: Paperback and eBook versions & Kindle version. It is available for order and signed copies are available through our web site. SOA & BPM Partner Community For regular information on Oracle SOA Suite become a member in the SOA & BPM Partner Community for registration please visit  www.oracle.com/goto/emea/soa (OPN account required) If you need support with your account please contact the Oracle Partner Business Center. Blog Twitter LinkedIn Mix Forum Technorati Tags: SOA book,SOA Suite Adminsitration,SOA Community,Oracle SOA,Oracle BPM,Community,OPN,Jürgen Kress

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  • Simple MVVM Walkthrough – Refactored

    - by Sean Feldman
    JR has put together a good introduction post into MVVM pattern. I love kick start examples that serve the purpose well. And even more than that I love examples that also can pass the real world projects check. So I took the sample code and refactored it slightly for a few aspects that a lot of developers might raise a brow. Michael has mentioned model (entity) visibility from view. I agree on that. A few other items that don’t settle are using property names as string (magical strings) and Saver class internal casting of a parameter (custom code for each Saver command). Fixing a property names usage is a straight forward exercise – leverage expressions. Something simple like this would do the initial job: class PropertyOf<T> { public static string Resolve(Expression<Func<T, object>> expression) { var member = expression.Body as MemberExpression; return member.Member.Name; } } With this, refactoring of properties names becomes an easy task, with confidence that an old property name string will not get left behind. An updated Invoice would look like this: public class Invoice : INotifyPropertyChanged { private int id; private string receiver; public event PropertyChangedEventHandler PropertyChanged; private void OnPropertyChanged(string propertyName) { if (PropertyChanged != null) { PropertyChanged(this, new PropertyChangedEventArgs(propertyName)); } } public int Id { get { return id; } set { if (id != value) { id = value; OnPropertyChanged(PropertyOf<Invoice>.Resolve(x => x.Id)); } } } public string Receiver { get { return receiver; } set { receiver = value; OnPropertyChanged(PropertyOf<Invoice>.Resolve(x => x.Receiver)); } } } For the saver, I decided to change it a little so now it becomes a “view-model agnostic” command, one that can be used for multiple commands/view-models. Updated Saver code now accepts an action at construction time and executes that action. No more black magic internal class Command : ICommand { private readonly Action executeAction; public Command(Action executeAction) { this.executeAction = executeAction; } public bool CanExecute(object parameter) { return true; } public event EventHandler CanExecuteChanged; public void Execute(object parameter) { // no more black magic executeAction(); } } Change in InvoiceViewModel is instantiation of Saver command and execution action for the specific command. public ICommand SaveCommand { get { if (saveCommand == null) saveCommand = new Command(ExecuteAction); return saveCommand; } set { saveCommand = value; } } private void ExecuteAction() { DisplayMessage = string.Format("Thanks for creating invoice: {0} {1}", Invoice.Id, Invoice.Receiver); } This way internal knowledge of InvoiceViewModel remains in InvoiceViewModel and Command (ex-Saver) is view-model agnostic. Now the sample is not only a good introduction, but also has some practicality in it. My 5 cents on the subject. Sample code MvvmSimple2.zip

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  • How would I handle input with a Game Component?

    - by Aufziehvogel
    I am currently having problems from finding my way into the component-oriented XNA design. I read an overview over the general design pattern and googled a lot of XNA examples. However, they seem to be right on the opposite site. In the general design pattern, an object (my current player) is passed to InputComponent::update(Player). This means the class will know what to do and how this will affect the game (e.g. move person vs. scroll text in a menu). Yet, in XNA GameComponent::update(GameTime) is called automatically without a reference to the current player. The only XNA examples I found built some sort of higher-level Keyboard engine into the game component like this: class InputComponent: GameComponent { public void keyReleased(Keys); public void keyPressed(Keys); public bool keyDown(Keys); public void override update(GameTime gameTime) { // compare previous state with current state and // determine if released, pressed, down or nothing } } Some others went a bit further making it possible to use a Service Locator by a design like this: interface IInputComponent { public void downwardsMovement(Keys); public void upwardsMovement(Keys); public bool pausedGame(Keys); // determine which keys pressed and what that means // can be done for different inputs in different implementations public void override update(GameTime); } Yet, then I am wondering if it is possible to design an input class to resolve all possible situations. Like in a menu a mouse click can mean "click that button", but in game play it can mean "shoot that weapon". So if I am using such a modular design with game components for input, how much logic is to be put into the InputComponent / KeyboardComponent / GamepadComponent and where is the rest handled? What I had in mind, when I heard about Game Components and Service Locator in XNA was something like this: use Game Components to run the InputHandler automatically in the loop use Service Locator to be able to switch input at runtime (i.e. let player choose if he wants to use a gamepad or a keyboard; or which shall be player 1 and which player 2). However, now I cannot see how this can be done. First code example does not seem flexible enough, as on a game pad you could require some combination of buttons for something that is possible on keyboard with only one button or with the mouse) The second code example seems really hard to implement, because the InputComponent has to know in which context we are currently. Moreover, you could imagine your application to be multi-layered and let the key-stroke go through all layers to the bottom-layer which requires a different behaviour than the InputComponent would have guessed from the top-layer. The general design pattern with passing the Player to update() does not have a representation in XNA and I also cannot see how and where to decide which class should be passed to update(). At most time of course the player, but sometimes there could be menu items you have to or can click I see that the question in general is already dealt with here, but probably from a more elobate point-of-view. At least, I am not smart enough in game development to understand it. I am searching for a rather code-based example directly for XNA. And the answer there leaves (a noob like) me still alone in how the object that should receive the detected event is chosen. Like if I have a key-up event, should it go to the text box or to the player?

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  • How do you formulate the Domain Model in Domain Driven Design properly (Bounded Contexts, Domains)?

    - by lko
    Say you have a few applications which deal with a few different Core Domains. The examples are made up and it's hard to put a real example with meaningful data together (concisely). In Domain Driven Design (DDD) when you start looking at Bounded Contexts and Domains/Sub Domains, it says that a Bounded Context is a "phase" in a lifecycle. An example of Context here would be within an ecommerce system. Although you could model this as a single system, it would also warrant splitting into separate Contexts. Each of these areas within the application have their own Ubiquitous Language, their own Model, and a way to talk to other Bounded Contexts to obtain the information they need. The Core, Sub, and Generic Domains are the area of expertise and can be numerous in complex applications. Say there is a long process dealing with an Entity for example a Book in a core domain. Now looking at the Bounded Contexts there can be a number of phases in the books life-cycle. Say outline, creation, correction, publish, sale phases. Now imagine a second core domain, perhaps a store domain. The publisher has its own branch of stores to sell books. The store can have a number of Bounded Contexts (life-cycle phases) for example a "Stock" or "Inventory" context. In the first domain there is probably a Book database table with basically just an ID to track the different book Entities in the different life-cycles. Now suppose you have 10+ supporting domains e.g. Users, Catalogs, Inventory, .. (hard to think of relevant examples). For example a DomainModel for the Book Outline phase, the Creation phase, Correction phase, Publish phase, Sale phase. Then for the Store core domain it probably has a number of life-cycle phases. public class BookId : Entity { public long Id { get; set; } } In the creation phase (Bounded Context) the book could be a simple class. public class Book : BookId { public string Title { get; set; } public List<string> Chapters { get; set; } //... } Whereas in the publish phase (Bounded Context) it would have all the text, release date etc. public class Book : BookId { public DateTime ReleaseDate { get; set; } //... } The immediate benefit I can see in separating by "life-cycle phase" is that it's a great way to separate business logic so there aren't mammoth all-encompassing Entities nor Domain Services. A problem I have is figuring out how to concretely define the rules to the physical layout of the Domain Model. A. Does the Domain Model get "modeled" so there are as many bounded contexts (separate projects etc.) as there are life-cycle phases across the core domains in a complex application? Edit: Answer to A. Yes, according to the answer by Alexey Zimarev there should be an entire "Domain" for each bounded context. B. Is the Domain Model typically arranged by Bounded Contexts (or Domains, or both)? Edit: Answer to B. Each Bounded Context should have its own complete "Domain" (Service/Entities/VO's/Repositories) C. Does it mean there can easily be 10's of "segregated" Domain Models and multiple projects can use it (the Entities/Value Objects)? Edit: Answer to C. There is a complete "Domain" for each Bounded Context and the Domain Model (Entity/VO layer/project) isn't "used" by the other Bounded Contexts directly, only via chosen paths (i.e. via Domain Events). The part that I am trying to figure out is how the Domain Model is actually implemented once you start to figure out your Bounded Contexts and Core/Sub Domains, particularly in complex applications. The goal is to establish the definitions which can help to separate Entities between the Bounded Contexts and Domains.

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  • OpenWorld: Our (Road) Maps are Looking Good!

    - by Tony Berk
    Wow, only one (or two) days down at Oracle OpenWorld! Are you on overload yet? I'm still trying to figure out how to be in 3 sessions at the same time... I guess everyone needs to prioritize! There was a lot to see in Monday's sessions, especially some great forward-looking roadmap sessions. In case you aren't here or you decided to go to other sessions, this is my quick summary of what I could capture from a couple of the roadmaps: In the Fusion CRM Strategy and Roadmap session, Anthony Lye provided an overview of the Fusion CRM strategy including the key design principles of 3 E's: Easy, Effective and Efficient. After an overview of how Oracle has deployed Fusion CRM internally to 25,000 users worldwide, Anthony discussed the features coming in the next release, the releases in the next 12 months and beyond. I can't detail too much since you haven't read Oracle's Safe Harbor statement, but check out Fusion Tap and look for new features and added functionality for sales prediction, marketing, social and integration with a number of the key Customer Experience products.  In the Oracle RightNow CX Cloud Service Vision and Roadmap session, Chris Hamilton presented the focus areas for the RightNow product. As a result of the large increase in development resources after the acquisition, the RightNow CX team is planning a lot of enhancements to the functionality, infrastructure and integrations. As a key piece of the Oracle Customer Experience (CX) strategy, RightNow will be integrated with Oracle Social Network, Oracle Commerce (ATG and Endeca), Oracle Knowledge, Oracle Policy Automation and, of course, further integration with Fusion Sales and Marketing. Look forward to seeing more on the Virtual Assistant, Smart Interaction Hub and Mobility. In addition to the roadmaps, I was looking forward to hearing from Oracle CRM customers. So, I sat in on two great Siebel customer panels: The Maximizing User Adoption Rates for Siebel Sales and Siebel Partner Relationship Management panel consisted of speakers from CSL Behring, McKesson and Intuit. It was great to get an overview of implementations for both B2B and B2C companies. It was great hearing that all of these companies have more than 1,000 sales users (Intuit has 4,000) and how the 360 degree view of the customer in Siebel is helping these customers improve their customers' experience (CX). They are all great examples of centralized implementations which have standardized processes across the globe and across business units.  Waste Management, Farmers Insurance and the US Citizenship & Immigration Services presented in the Driving Great Customer Experiences with Siebel Service Applications session. Talk about serving large customer bases! Is it possible that Farmers with only 10 million households is the smallest of these 3? All of them provided great examples of how they are improving the customer experience (CX) including 60-70% improvements in efficiency or reducing the number of applications the customer service reps (CSRs) need to use from 10 to 1 (Waste Management) and context aware call transfers to avoid the caller explaining their issue 3 times (USCIS). So that's my wrap up of only 4 sessions from Monday. In between sessions, I stopped by the Oracle DEMOgrounds and CRM Pavilion to visit with a group of great partners and see the products and partner integrations in action. Don't miss a recap of Mark Hurd's Keynote. I can't believe there were another 40+ sessions covering CRM, Fusion, Cloud, etc. that I missed today! Anyone else see any great sessions?

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  • Hopping/Tumbling Windows Could Introduce Latency.

    This is a pre-article to one I am going to be writing on adjusting an event’s time and duration to satisfy business process requirements but it is one that I think is really useful when understanding the way that Hopping/Tumbling windows work within StreamInsight.  A Tumbling window is just a special shortcut version of  a Hopping window where the width of the window is equal to the size of the hop Here is the simplest and often used definition for a Hopping Window.  You can find them all here public static CepWindowStream<CepWindow<TPayload>> HoppingWindow<TPayload>(     this CepStream<TPayload> source,     TimeSpan windowSize,     TimeSpan hopSize,     WindowInputPolicy inputPolicy,     HoppingWindowOutputPolicy outputPolicy )   And here is the definition for a Tumbling Window public static CepWindowStream<CepWindow<TPayload>> TumblingWindow<TPayload>(     this CepStream<TPayload> source,     TimeSpan windowSize,     WindowInputPolicy inputPolicy,     HoppingWindowOutputPolicy outputPolicy )   These methods allow you to group events into windows of a temporal size.  It is a really useful and simple feature in StreamInsight.  One of the downsides though is that the windows cannot be flushed until an event in a following window occurs.  This means that you will potentially never see some events or see them with a delay.  Let me explain. Remember that a stream is a potentially unbounded sequence of events. Events in StreamInsight are given a StartTime.  It is this StartTime that is used to calculate into which temporal window an event falls.  It is best practice to assign a timestamp from the source system and not one from the system clock on the processing server.  StreamInsight cannot know when a window is over.  It cannot tell whether you have received all events in the window or whether some events have been delayed which means that StreamInsight cannot flush the stream for you.   Imagine you have events with the following Timestamps 12:10:10 PM 12:10:20 PM 12:10:35 PM 12:10:45 PM 11:59:59 PM And imagine that you have defined a 1 minute Tumbling Window over this stream using the following syntax var HoppingStream = from shift in inputStream.TumblingWindow(TimeSpan.FromMinutes(1),HoppingWindowOutputPolicy.ClipToWindowEnd) select new WindowCountPayload { CountInWindow = (Int32)shift.Count() };   The events between 12:10:10 PM and 12:10:45 PM will not be seen until the event at 11:59:59 PM arrives.  This could be a real problem if you need to react to windows promptly This can always be worked around by using a different design pattern but a lot of the examples I see assume there is a constant, very frequent stream of events resulting in windows always being flushed. Further examples of using windowing in StreamInsight can be found here

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  • Why is 0 false?

    - by Morwenn
    This question may sound dumb, but why does 0 evaluates to false and any other [integer] value to true is most of programming languages? String comparison Since the question seems a little bit too simple, I will explain myself a little bit more: first of all, it may seem evident to any programmer, but why wouldn't there be a programming language - there may actually be, but not any I used - where 0 evaluates to true and all the other [integer] values to false? That one remark may seem random, but I have a few examples where it may have been a good idea. First of all, let's take the example of strings three-way comparison, I will take C's strcmp as example: any programmer trying C as his first language may be tempted to write the following code: if (strcmp(str1, str2)) { // Do something... } Since strcmp returns 0 which evaluates to false when the strings are equal, what the beginning programmer tried to do fails miserably and he generally does not understand why at first. Had 0 evaluated to true instead, this function could have been used in its most simple expression - the one above - when comparing for equality, and the proper checks for -1 and 1 would have been done only when needed. We would have considered the return type as bool (in our minds I mean) most of the time. Moreover, let's introduce a new type, sign, that just takes values -1, 0 and 1. That can be pretty handy. Imagine there is a spaceship operator in C++ and we want it for std::string (well, there already is the compare function, but spaceship operator is more fun). The declaration would currently be the following one: sign operator<=>(const std::string& lhs, const std::string& rhs); Had 0 been evaluated to true, the spaceship operator wouldn't even exist, and we could have declared operator== that way: sign operator==(const std::string& lhs, const std::string& rhs); This operator== would have handled three-way comparison at once, and could still be used to perform the following check while still being able to check which string is lexicographically superior to the other when needed: if (str1 == str2) { // Do something... } Old errors handling We now have exceptions, so this part only applies to the old languages where no such thing exist (C for example). If we look at C's standard library (and POSIX one too), we can see for sure that maaaaany functions return 0 when successful and any integer otherwise. I have sadly seen some people do this kind of things: #define TRUE 0 // ... if (some_function() == TRUE) { // Here, TRUE would mean success... // Do something } If we think about how we think in programming, we often have the following reasoning pattern: Do something Did it work? Yes -> That's ok, one case to handle No -> Why? Many cases to handle If we think about it again, it would have made sense to put the only neutral value, 0, to yes (and that's how C's functions work), while all the other values can be there to solve the many cases of the no. However, in all the programming languages I know (except maybe some experimental esotheric languages), that yes evaluates to false in an if condition, while all the no cases evaluate to true. There are many situations when "it works" represents one case while "it does not work" represents many probable causes. If we think about it that way, having 0 evaluate to true and the rest to false would have made much more sense. Conclusion My conclusion is essentially my original question: why did we design languages where 0 is false and the other values are true, taking in account my few examples above and maybe some more I did not think of? Follow-up: It's nice to see there are many answers with many ideas and as many possible reasons for it to be like that. I love how passionate you seem to be about it. I originaly asked this question out of boredom, but since you seem so passionate, I decided to go a little further and ask about the rationale behind the Boolean choice for 0 and 1 on Math.SE :)

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  • Compressing IplImage to JPEG using libjpeg in OpenCV

    - by Petar
    Hi everybody. So I have this problem. I have an IplImage that i want to compress to JPEG and do something with it. I use libjpeg. I found a lot of answers "read through examples and docs" and such and did that. And successfully written a function for that. FILE* convert2jpeg(IplImage* frame) { FILE* outstream = NULL; outstream=malloc(frame-imageSize*frame-nChannels*sizeof(char)) unsigned char *outdata = (uchar *) frame->imageData; struct jpeg_error_mgr jerr; struct jpeg_compress_struct cinfo; int row_stride; JSAMPROW row_ptr[1]; jpeg_create_compress(&cinfo); jpeg_stdio_dest(&cinfo, outstream); cinfo.image_width = frame->width; cinfo.image_height = frame->height; cinfo.input_components = frame->nChannels; cinfo.in_color_space = JCS_RGB; jpeg_set_defaults(&cinfo); jpeg_start_compress(&cinfo, TRUE); row_stride = frame->width * frame->nChannels; while (cinfo.next_scanline < cinfo.image_height) { row_ptr[0] = &outdata[cinfo.next_scanline * row_stride]; jpeg_write_scanlines(&cinfo, row_ptr, 1); } jpeg_finish_compress(&cinfo); jpeg_destroy_compress(&cinfo); return outstream; } Now this function is straight from the examples (except the part of allocating memory, but i need that since i'm not writnig to a file), but it still doesn't work. It dies on jpeg_start_compress(&cinfo, TRUE); part? Can anybody help?

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  • What is the standard convention for defining nested view:viewmodel mapping in MVVM Light

    - by firoso
    so in classic MVVM examples ive seen DataTemplate definitions are used to map up View Models to Views, what is the standard way to do this in MVVM Light framework, and where should the mappings be located? Following are examples of what I'm doing now and what I'm talking about, blendability is important to me! Main Window: <Window xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation" xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml" xmlns:d="http://schemas.microsoft.com/expression/blend/2008" xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006" mc:Ignorable="d" x:Class="STS2Editor.MainWindow" Title="{Binding ApplicationTitle, Mode=OneWay}" DataContext="{Binding RootViewModel, Source={StaticResource Locator}}"> <Window.Resources> <ResourceDictionary> <ResourceDictionary.MergedDictionaries> <ResourceDictionary Source="Skins/ApplicationSkin.xaml" /> <ResourceDictionary Source="Resources/ViewMappings.xaml" /> </ResourceDictionary.MergedDictionaries> </ResourceDictionary> </Window.Resources> <Grid> <ContentControl Content="{Binding ApplicationManagementViewModel}" HorizontalAlignment="Left" VerticalAlignment="Top"/> </Grid> </Window> In the above code, my RootViewModel class has an instance of the class ApplicationManagementViewModel with the same property name: public ApplicationManagementViewModel ApplicationManagementViewModel {get {...} set {...} } I reference the ResourceDictionary "ViewMappings.xaml" to specify how my view model is represented as a view. <ResourceDictionary xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation" xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml" xmlns:local="clr-namespace:STS2Editor.ViewModel"> <DataTemplate DataType="{x:Type local:ApplicationManagementViewModel}"> <local:ApplicationManagementView/> </DataTemplate> </ResourceDictionary> should I be doing things like this using ViewModelLocator? what about collections of view models?

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  • Using Freepascal\Lazarus JSON Libraries

    - by Gizmo_the_Great
    I'm hoping for a bit of a "simpletons" demo\explanation for using Lazarus\Freepascal JSON parsing. I've asked a question here but all the replies are "read this" and none of them are really helping me get a grasp because the examples are bit too in-depth and I'm seeking a very simple example to help me understand how it works. In brief, my program reads an untyped binary file in chunks of 4096 bytes. The raw data then gets converted to ASCII and stored in a string. It then goes through the variable looking for certain patterns, which, it turned out, are JSON data structures. I've currently coded the parsing the hard way using Pos and ExtractANSIString etc. But I'vesince learnt that there are JSON libraries for Lazarus & FPC, namely fcl-json, fpjson, jsonparser, jsonscanner etc. https://bitbucket.org/reiniero/fpctwit/src http://fossies.org/unix/misc/fpcbuild-2.6.0.tar.gz:a/fpcbuild-2.6.0/fpcsrc/packages/fcl-json/src/ http://svn.freepascal.org/cgi-bin/viewvc.cgi/trunk/packages/fcl-json/examples/ However, I still can't quite work out HOW I read my string variable and parse it for JSON data and then access those JSON structures. Can anyone give me a very simple example, to help getting me going? My code so far (without JSON) is something like this: try SourceFile.Position := 0; while TotalBytesRead < SourceFile.Size do begin BytesRead := SourceFile.Read(Buffer,sizeof(Buffer)); inc(TotalBytesRead, BytesRead); StringContent := StripNonAsciiExceptCRLF(Buffer); // A custom function to strip out binary garbage leaving just ASCII readable text if Pos('MySearchValue', StringContent) > 0 then begin // Do the parsing. This is where I need to do the JSON stuff ...

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  • WCF and Unity - Dependecy Injection

    - by Michael
    I'm trying to hock up WCF with dependecy injection. All the examples that I have found is based on the assumptions that you either uses a .svc (ServiceHostFactory) service or uses app.config to configure the container. Other examples is also based on that the container is passed around to the classes. I would like a solution where the container is not passed around (not tightly coupled to Unity). Where I don't uses a config file to configure the container and where I use self-hosted services. The problem is - as I see it - that the ServiceHost is taking the type of the service implementation as a parameter so what different does it do to use the InstanceProvider? The solution I have come up with at the moment is to register the ServiceHost (or a specialization) an register a Type with a name ( e.g. container.RegisterInstance<Type>("ServiceName", typeof(Service);). And then container.RegisterType<UnityServiceHost>(new InjectionConstructor(new ResolvedParameter<Type>("ServiceName"))); to register the ServiceHost. Any better solutions out there? I'm I perhaps way of in my assumptions. Best regards, Michael

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  • How to arrange models, views, controllers in a new Kohana 3 project

    - by Pekka
    I'm looking at how to set up a mid-sized web application with Kohana 3. I have implemented MVC patterns in the past but never worked against a "formalized" MVC framework so I'm still getting my head around the terminology - toying around with basic examples, building views and templates, and so on. I'm progressing fairly well but I want to set up a real-world web project (one of my own that I've been planning for quite some time now) as a learning object. Example-based documentation is a bit sparse for Kohana 3 right now - they say so themselves on the site. While I'm not worried about learning the framework soon enough, I'm a bit at a loss on how to arrange a healthy code base from the start - i.e. how to split up controllers, how to name them, and how to separate the functionality into the appropriate models. My application could, in its core, be described as a business directory with a main businesses table. Businesses can be listed by category and by street name. Each business has a detail page. Business owners can log in and edit their business's entry. Businesses can post offers into an offers table. I know this is pretty vague, I'll be more than happy to go into more detail on request. Supposing I have all the basic functionality worked out and in place already - list all businesses, edit business, list businesses by street name, create offer, and so on, and I'm just looking for how to fit the functionality into a Kohana application structure that can be easily extended: Do you know real-life, publicly accessible examples of applications built on Kohana 3 where I could take a peek how they do it? Are there conventions or best practices on how to structure an extendable login area for end users in a Kohana project that is not only able to handle a business directory page, but further products on separate pages as well? Do you know application structuring HOWTOs or best practices for Kohana 3 not mentioned in the user guide and the inofficial Wiki? Have you built something similar and could give me some recommendations?

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  • Creating a Custom Design-Time Environment

    - by Charlie
    Hello all, My question is related to the design-time support of WPF. From MSDN I read, The WPF Designer provides a framework and a public API which you can use to implement custom adorners, tools, property editors, and designers. But the vast majority of the examples I have found are trivial, and do not illustrate much concerning the creation of a customized designer in an existing WPF application. We have migrated our application from Windows Forms to WPF over the past year, and the next step will be to take an existing WinForms Panel designer, and rewrite it in WPF. Suffice it to say that this will be a huge project. But I don't even know where to begin. I am wondering if any of you have had similar experiences writing a customized designer for a WPF application, and what it was like. Even better, if you could compare and contrast the functionality between the WinForms designer and the WPF designer, or explain the transition from the former to the latter, that would be helpful. If you know of any simple examples that demonstrate a customized design environment (with custom controls, etc.) that would be extremely beneficial. All in all, I am just wondering if many people have undertaken this yet, and what their results have been. EDIT: To clarify, yes, I am talking about hosting a WPF designer. It appears that this may not even be possible, which is a huge setback. Here is a screenshot of our current WinForms designer. As you can see, it is used to create customized user interfaces. You can drag custom controls onto it and design them, then put the panel into a "run mode" in which all of the controls become functional. Short of spending months writing our designer, would this be possible in WPF? What about .NET 4.0 and VS2010? Will those add any designer functionality?

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  • picturebox image randomisation C#

    - by cheesebunz
    Hi everyone, i am working on a puzzle slider program and trying to randomize images inside of pictureboxes. I did some research on the internet can't find any examples i could work on. These are my code: Random r = new Random(); PictureBox[] picBox = new PictureBox[9]; picBox[0] = new PictureBox(); picBox[1] = new PictureBox(); picBox[2] = new PictureBox(); picBox[3] = new PictureBox(); picBox[4] = new PictureBox(); picBox[5] = new PictureBox(); picBox[6] = new PictureBox(); picBox[7] = new PictureBox(); picBox[8] = new PictureBox(); i have bitmap array too: Bitmap[] pictures = new Bitmap[9]; pictures[0] = new Bitmap(@"1.1Bright.jpg"); pictures[1] = new Bitmap(@"1.2Bright.jpg"); pictures[2] = new Bitmap(@"1.3Bright.jpg"); pictures[3] = new Bitmap(@"2.1Bright.jpg"); pictures[4] = new Bitmap(@"2.2Bright.jpg"); pictures[5] = new Bitmap(@"2.3Bright.jpg"); pictures[6] = new Bitmap(@"3.1Bright.jpg"); pictures[7] = new Bitmap(@"3.2Bright.jpg"); pictures[8] = new Bitmap(@"3.3Dark.jpg"); i tried a few ways but i don't know how to set random pictures[] into the picBox[]: for(int i=0; i<=8;i++) { picBox[i].Image= pictures[r.Next(0,9)]; } the problem here is that some pictureboxes e.g picBox[1] and picBox[6] are repeated pictures. How do i make them non repeats? Examples are greatly appreciated thanks.

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  • Core Data migration of to-one relationship to to-many relationship

    - by westsider
    I have a deployed app that samples measurements from sensors (e.g., Temp °C, Pressure kPa). The user can create Experiments and collect samples. Each sample is stored as a Run, such that there is a one-to-many relationship from Experiment to Run. In the interest of performance, Run has a to-one relationship with Data entity (which is where the actual raw data is stored); this allows some Run attributes to be loaded without necessarily loading lots of data. Most of our sensors have multiple measurements, so it would be nice to store all the data that is actually being sampled. But this means that the Run <--- Data relationship needs to become Run <-- Data (to use Xcode's convention). I am faced with trying to migrate data from old Run to-one Data model to new Run to-many Data model. Can this be done using Mapping Models? If so, does anyone have any pointers to examples? If not, does anyone have any pointers to examples of how to do that? Thanks for any pointers or advice.

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  • Using hibernate criteria, is there a way to escape special characters?

    - by Kevin Crowell
    For this question, we want to avoid having to write a special query since the query would have to be different across multiple databases. Using only hibernate criteria, we want to be able to escape special characters. This situation is the reason for needing the ability to escape special characters: Assume that we have table 'foo' in the database. Table 'foo' contains only 1 field, called 'name'. The 'name' field can contain characters that may be considered special in a database. Two examples of such a name are 'name_1' and 'name%1'. Both the '_' and '%' are special characters, at least in Oracle. If a user wants to search for one of these examples after they are entered in the database, problems may occur. criterion = Restrictions.ilike("name", searchValue, MatchMode.ANYWHERE); return findByCriteria(null, criterion); In this code, 'searchValue' is the value that the user has given the application to use for its search. If the user wants to search for '%', the user is going to be returned with every 'foo' entry in the database. This is because the '%' character represents the "any number of characters" wildcard for string matching and the SQL code that hibernate produces will look like: select * from foo where name like '%' Is there a way to tell hibernate to escape certain characters, or to create a workaround that is not database type sepecific?

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  • Where should I declare my CDI resources?

    - by Laird Nelson
    JSR-299 (CDI) introduces the (unfortunately named) concept of a resource: http://docs.jboss.org/weld/reference/1.0.0/en-US/html/resources.html#d0e4373 You can think of a resource in this nomenclature as a bridge between the Java EE 6 brand of dependency injection (@EJB, @Resource, @PersistenceContext and the like) and CDI's brand of dependency injection. The general gist seems to be that somewhere (and this will be the root of my question) you declare what amounts to a bridge class: it contains fields annotated both with Java EE's @EJB or @PersistenceContext or @Resource annotations and with CDI's @Produces annotations. The net effect is that Java EE 6 injects a persistence context, say, where it's called for, and CDI recognizes that injected PersistenceContext as a source for future injections down the line (handled by @Inject). My question is: what is the community's consensus--or is there one--on: what this bridge class should be named where this bridge class should live whether it's best to localize all this stuff into one class or make several of them ...? Left to my own devices, I was thinking of declaring a single class called CDIResources and using that as the One True Place to link Java EE's DI with CDI's DI. Many examples do something similar, but I'm not clear on whether they're "just" examples or whether that's a good way to do it. Thanks.

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  • HttpURLConnection: What is the minimum best-practice implementation?

    - by stormin986
    I've come across a lot of HttpURLConnection examples that are nothing more than openConnection(), getInputStream(), and then they just read the buffer and are done. It's simple but seems like it's not the best implementation ... it handles no problems. I don't yet know much about http, so I keep thinking I have everything covered until a new problem arises. I'm currently experiencing a similar problem to this one. Most times I try to read the same resource a second time (from a different HttpURLConnection object, after I .disconnect()'ed the previous one), the response code returns as -1 (but no exception is thrown!!). Before I knew to check the response code, I was baffled since I was throwing no exceptions. So, is there a minimum 'best practice' HttpURLConnection implementation? What are notable exceptions to handle? Request code checking? Any other error checks? What connection parameters do and don't need to be set (like doInput / doOutput, are these even necessary? Some examples have em, some don't). Etc. I realize this is kind of a broad question but I think it has potential to be a very useful resource if many of the common use cases and FAQs are addressed in one central place. This seems like the kind of thing a community wiki would be good for...

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  • How do I know if I have an unmanaged resource?

    - by Shiftbit
    I've read that unmanaged resource are considered file handles, streams, anything low level. Does MSDN or any other source explain how to recognize an unmanaged resource? I can't seem to find any examples on the net that show unmanaged code, all the examples just have comments that say unmanaged code here. Can someone perhaps provide a realworld example where I would handle an unmanaged resources in an IDispose interface? I provided the IDisposable interface for your convience. How do I identify an unmanaged resource? Thanks in advance! IDisposable Reference Public Class Sample : Implements IDisposable Private disposedValue As Boolean = False 'To detect redundant calls ' IDisposable Protected Overridable Sub Dispose(ByVal disposing As Boolean) If Not Me.disposedValue Then If disposing Then ' TODO: free other state (managed objects). End If ' TODO: free your own state (unmanaged objects). ' TODO: set large fields to null. End If Me.disposedValue = True End Sub ' This code added by Visual Basic to correctly implement the disposable pattern. Public Sub Dispose() Implements IDisposable.Dispose ' Do not change this code. Put cleanup code in Dispose(ByVal disposing As Boolean) above. Dispose(True) GC.SuppressFinalize(Me) End Sub End Class

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  • Any Red5 Working Example Project for 0.9 release

    - by Daryl
    I'm trying to find 1, just 1, working sample project for Red5 that's updated to work against the latest 0.9 release without missing jars and other nonsense. Right now, it's at v0.9 and the libs are different from other versions. They have 5 pathetic examples on their website, but all were built with the older versions, and who knows which version since they don't seem to be putting any effort into updating or marketing their open source project. For these 5 old examples, I could use the Add External JARS feature to try and add libs from previous versions, they don't mention which versions they were built against and I'm not going to try each previous version to see which works (I already did and nothing works). P.S. Voted the worst documented project on the planet. It's hilarious, one of their developers posted a few videos on youtube, without bothering to attach a sample zip for the get-started project he's demoing. No offense, but that's seriously #(#$$#($!@#*. Not a good start for any tech decision maker to assess a technology for commercial use. Anyone who's more intelligent and can shed some light on behalf of these fools?

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  • Auto switching databases from a rails app gracefully from the ApplicationController?

    - by Zaqintosh
    I've seen this post a few times, but haven't really found the answer to this specific question. I'd like to run a rails application that based on the detected request.host (imagine I have two subdomains points to the same rails app and server ip address: myapp1.domain.com and myapp2.domain.com). I'm trying to have myapp1 use the default "production" database, and myapp2 requests always use the alternative remote database. Here is an example of what I tried to do in Application controller that did not work: class ApplicationController < ActionController::Base helper :all before_filter :use_alternate_db private def use_alternate_db if request.host == 'myapp1.domain.com' regular_db elsif request.host == 'myapp2.domain.com' alternate_db end end def regular_db ActiveRecord::Base.establish_connection :production end def alternate_db ActiveRecord::Base.establish_connection( :adapter => 'mysql', :host => '...', :username => '...', :password => '...', :database => 'alternatedb' ) end end The problem is when it switches databases using this method, all connections (including valid sessions across the different subdomains get interrupted...). All examples online have people controlling database connectivity at the model level, but this would involve adding code all over my application. Is there some way to globally switch database connections on a per-request basis in the manner I'm suggesting above WITHOUT having to inject code all over my application? The added complexity here is I'm using Heroku as a hosting provider, so I have no control at the apache / rails application server level. I have looked at solutions like dbcharmer and magicmodels, but none seem to show examples of doing it in the manner that I'm trying to. Thanks for any help!

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  • General Drools Question

    - by El Guapo
    For the last few months my company has been using a product from a company called Informatica (previously AgentLogic) called RulePoint. This product has proven itself very easy to use with a well-developed and easy-to-use SDK for customization. The way we use the product for CEP is fairly trivial, we have 2 sources which we monitor for our rule data, the first being a JMS Queue, the second being a Jabber IM account. The product runs on any java-based application server (WebLogic, Tomcat, etc) and runs just about flawlessly. Last week my boss says, "Hey, I've heard that we may be able to do the same thing we are doing with RulePoint with an open-source product called Drools. Check it out and let me know what you think." I've heard of people using Drools for flow-based operations (validation, etc), however, I've never heard of anyone using their CEP product (Fusion) in practice. So, being the diligent worker, I have undertaken this task. I've downloaded all the files (version 5.0) and accompanying documentation and have started to read. I've read through just about all the docs and run most of the examples, but I still don't really see HOW drools works for CEP. While there are examples for using Data (or Facts, I guess) from JMS, I don't see how this thing stays "running", continuously monitoring a queue until the application is actually stopped. RulePoint pretty must just sits and listens, however, Drools seems to not. I could probably write a full-blown command-line application for our needs, however, I was hoping to leverage some of the benefits of using a application server provides. I guess I'm looking for some good tutorials or an example of how someone is using Drools and CEP in production. Thanks in advanced for any information, advice you may be able to provide.

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