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  • Portland Silverlight User Group: WP7 &amp; XNA &ndash; I survived.

    - by George Clingerman
    Last night I gave a talk to the Portland Silverlight User Group. http://www.portlandsilverlight.net/Meetings/Details/15 And I survived (which you should have probably already figured out since you’re reading this post AND that’s what I titled it…) Really though it was a fantastic time and I had a lot of fun! I was a little nervous getting ready for it, but I’m always a little nervous getting ready for things. I had the game all written,  I knew the general flow for what the talk was going to be. I read over Scott Hanselman’s 11 Top Tips for a Successful Technical presentation (which has become something I do EVERY time I’m preparing for a talk). I gave myself a brief list of points I wanted to make sure I covered or worked into the talk. But then I was ready and I waited. I hate the waiting. It makes me nervous. Once I was up in front of the room though with my laptop open and some XNA code in front of me, my nerves go away. Then I’m ready. I know XNA, I love talking about XNA and I love sharing what I know and hearing questions that make me think. And hopefully that came through while I was talking. I had a freaking blast. The swag went quickly (and I was even able to hand out some XNA 2.0 books that have been around forever!) and the pizza was been gobbled down. I started the talk at about 6:10 and managed to cover a very brief intro to programming against the game loop (it’s a different concept and one that seems to trip a lot of people up getting started with game development) and then rolled into making a basic 2D game for Windows Phone 7 using XNA. And I finished the whole thing before 8:30. Wahoo! I’m planning on posting the source code and assets on my site so those should be coming soon. And to make things even better, they recorded the whole thing on video so everyone will get to see me pretend I can speak! Just wait till you hear the new song I wrote for this talk…

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  • Creating a shared library that might be used with desktop applications and web projects

    - by dreza
    I have been involved in a number of MVC.NET and c# desktop projects in our company over the last year or so while also managing to kept my nose poked into other projects (in a read-only learning capacity of course). From this I've noticed that across the various projects and teams there is a-lot of functionality that has been well designed against good interfaces and abstractions. Because we tend to like our own work at times, I noticed a couple of projects had the exact same class, method copied into it as it had obviously worked on one and so was easily moved to a new project (probably by the same developer who originally wrote it) I mentioned this fact in one of our programmer meetings we have occasionally and suggested we pull some of this functionality into a core company library that we can build up over time and use across multiple projects. Everyone agreed and I started looking into this possibility. However, I've come across a stumbling block pretty early on. Our team primarily focuses on MVC at the moment and we have projects mainly in 2.0 but are starting to branch to 3.0. We also have a number of desktop applications that might benefit from some shared classes and basic helper methods. Initially when creating this DLL I included some shared classes that could be used across any project type (Web, Client etc) but then I started looking at adding some shared modules that would be useful in our MVC applications only. However this meant I had to include a reference to some Microsoft Web DLL's in order to leverage some of the classes I was creating (at this stage MVC 2.0). Now my issue is that we have a shared DLL that has references to web specific libraries that could also possibly be used in a client application. Not only that, our DLL referenced initially MVC 2.0 and we will eventually move onto MVC 3.0 for all projects. But alot of the classes in this library I expect to still be relevant to MVC 3 etc Our code within this DLL is separated into it's own namespaces such as: CompanyDLL.Primitives CompanyDLL.Web.Mvc CompanyDLL.Helpers etc etc So, my questions are: Is it OK to do a shared library like this, or if we have web specific features in it should we create a separate web DLL only targeted at a specific framework or MVC version? If it's OK, what kind of issues might we face when using the library that references MVC 2 in a MVC 3 project for example. I would be thinking that we might run into some sort of compatibility issue, or even issues where the developers using the library doesn't realize they need MVC 2.0 libraries. They might only want to use some of the generic classes etc The concept seemed like a good idea at the time, but I'm starting to think maybe it's not really a practical solution. But the number of times I've seen copied classes and methods across projects because they are proven tested code is a bit unnerving to be perfectly honest!

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  • Mutable Records in F#

    - by MarkPearl
    I’m loving my expert F# book – today I thought I would give a post on using mutable records as covered in Chapter 4 of Expert F#. So as they explain the simplest mutable data structures in F# are mutable records. The whole concept of things by default being immutable is a new one for me from my C# background. Anyhow… lets look at some C# code first. using System; using System.Collections.Generic; using System.Linq; using System.Text; namespace MutableRecords { public class DiscreteEventCounter { public int Total { get; set; } public int Positive { get; set; } public string Name { get; private set; } public DiscreteEventCounter(string name) { Name = name; } } class Program { private static void recordEvent(DiscreteEventCounter s, bool isPositive) { s.Total += 1; if (isPositive) s.Positive += 1; } private static void reportStatus (DiscreteEventCounter s) { Console.WriteLine("We have {0} {1} out of {2}", s.Positive, s.Name, s.Total); } static void Main(string[] args) { var longCounter = new DiscreteEventCounter("My Discrete Counter"); recordEvent(longCounter, true); recordEvent(longCounter, true); reportStatus(longCounter); Console.ReadLine(); } } } Quite simple, we have a class that has a few values. We instantiate an instance of the class and perform increments etc on the instance. Now lets look at an equivalent F# sample. namespace EncapsulationNS module Module1 = open System type DiscreteEventCounter = { mutable Total : int mutable Positive : int Name : string } let recordEvent (s: DiscreteEventCounter) isPositive = s.Total <- s.Total+1 if isPositive then s.Positive <- s.Positive+1 let reportStatus (s: DiscreteEventCounter) = printfn "We have %d %s out of %d" s.Positive s.Name s.Total let newCounter nm = { Total = 0; Positive = 0; Name = nm } // // Using it... // let longCounter = newCounter "My Discrete Counter" recordEvent longCounter (true) recordEvent longCounter (true) reportStatus longCounter System.Console.ReadLine() Notice in the type declaration of the DiscreteEventCounter we had to explicitly declare that the total and positive value holders were mutable. And that’s it – a very simple example of mutable types.

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  • Showrooming: What's the big deal?

    - by David Dorf
    There's been lots of chatter recently on how retailers will combat showrooming this holiday season.  Best Buy and Target, for example, plan to price-match certain online sites.  But from my perspective, the whole showrooming concept is overblown.  Yes, mobile phones make is easier to comparison-shop, but consumers have been doing that all along.  Retailers have to work hard to merchandise their stores with the right products at the right price with the right promotions.  Its Retail 101. Yeah ok, many websites don't have to charge tax so they have an advantage, but they also have to cover shipping costs. Brick-and-mortar stores have the opportunity to provide expertise, fit, and instant gratification all of which are pretty big advantages. I see lots of studies that claim a large percentage of shoppers are showrooming.  Now I don't do much shopping, but when I do I rarely see anyone scanning UPC codes in the aisles.  If you dig into those studies, the question is usually something like, "have you used your mobile phone to price compare while shopping in the last year."  Well yeah, I did it once -- out of the 20 shopping trips.  And by the way, the in-store price was close enough to just buy the item.  Based on casual observation and informal surveys of friends, showrooming is not the modus-operandi for today's busy shoppers. I never see people showrooming in grocery stores, and most people don't bother for fashion.  For big purchases like appliances and furniture, I bet most people do their research online before entering the store.  The cases where I've done it was to see if a promotion was in fact a good deal.  Or even to make sure the in-store price is the same as the online price for the same brand. So, if you think you're a victim of showrooming, I suggest you look at the bigger picture.  Are you providing an engaging store experience?  Are you allowing customers to shop the way they want to shop, using various touchpoints?  Are you monitoring the competition to ensure prices are competitive?  Are your promotions attracting the right customers? Hubert Jolly, CEO of Best Buy, recently commented that showrooming might just get more people into his stores. "Once customers are in our stores, they're ours to lose."

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  • What is SOA ?

    - by llaszews
    First, let’s mention what SOA is not: • SOA is not the same thing as web services. Web Services implies the use of standard such as Java/JAX-RPC, .NET or REST. Web Services also implies the use of a WSDL, SOAP, and/or J2EE Connector Architecture (J2EE CA) and HTTP. SOA architectures can be implemented using J2EE CA, XML file transfer or Remote Procedural Call (RPC) over File Transfer Protocol (FTP), TCP/IP, Remote Method Invocation (RMI) or other protocols. In other words, Web Services are a very specific set of technologies. SOA is a concept and can be implemented in many different ways. Some very rudimentary, such as transfering flat files between applications. • SOA will not solve all of your problems. It will make your business more agile, increase business visibility, reduce integration costs and provide better reuse. However, if you don’t need help in these area or expect SOA to cure all of your IT problems, you are looking in the wrong place. • The concepts behind SOA are not new, but SOA is also not mature. SOA as it stands today has really only been around for 5 years. The concepts of standards based protocol handlers, predefined communication schemas and remote method invocation have been around for decades. So, what is SOA? SOA is an architectural blueprint, a way of developing applications, and a set of best practices. SOA is not an ‘out of the box’ solution you buy, install and then have up and running in a matter of months. SOA is a journey to a better way of doing business and the technology architecture to support this better way of doing business. SOA is also a broader set of technologies including more then just web services. Techologies like an Enterpirse Service Bus (ESB), Business Processs Execution Language (BPEL), message queues and Business Activity Monitoring (BAM) all are part of a SOA architecture. So, what is SOA? SOA is an architectural blueprint, a way of developing applications, and a set of best practices. SOA is not an ‘out of the box’ solution you buy, install and then have up and running in a matter of months. SOA is a journey to a better way of doing business and the technology architecture to support this better way of doing business. SOA is also a broader set of technologies including more then just web services. Techologies like an Enterpirse Service Bus (ESB), Business Processs Execution Language (BPEL), message queues and Business Activity Monitoring (BAM) all are part of a SOA architecture. Read more here: Oracle Modernization Solutions

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  • C++ and SDL resource management for 2D game

    - by KuruptedMagi
    My first question is about stateManagers. I do not use the singleton pattern (read many random posts with various reasons not to use it), I have gameStateManager which runs the pointer cCurrentGameState-render(), etc. I want to make a transitioning game, this engine should ideally cover both a platformer and a bird's eye RPG (with some recoding, I just mean the base engine), both of which will load different levels and events, such as world map, dungeon, shops, etc. So I then thought, rather then having to store all this data within all the states, I would break the engine into gameStates, and playStates... when gameState reaches gameStatePlay(), gameStatePlay simply runs the usual handleInput, logic, and render for the playStates, just as the low level gameStateManager does. This lets me store all the player data within the base playstate class without storing useless data in the gameStates. Now I have added a seperate mapEditor, which uses editorStates from gameStateEditor. Is this too much usage of the gameState concept? It seems to work pretty well for me, so I was wondering if I am too far off a common implementation of this. My second question is on image resources. I have my sprite class with nothing but static members, mainly loadImage, applySurface, and my screen pointer. I also have a map pairing imageName enums with actual SDL_Surface pointers, and one pairing clipNumber enums with a wrapper class for a vector of clips, so that each reference in the map can have different amounts of clips with different sizes. I thought it would be better to store all these images, and screen within one static body, since 20 different goblins all use the same sprite sheet, and all need to print to the same screen, and of course, this way I do not need to pass my screen reference to every little entity. The imageMap seems to work very well, I can even add the ability to search through the map at creation of entity type to see if a particular image at creation, creating if it doesnt exist, and destroying the image if the last entity that needs it was just destroyed. The vectored clip map however, seems to take too long to initialize, so if i run past the state that initializes them to fast, the game crashes <. Plus, the clip map call is half of this line =P SPRITE::applySurface( cEditorMap.cTiles[x][y].iX, cEditorMap.cTiles[x][y].iY, SPRITE::mImages[ IMAGE_TILEMAP ], SPRITE::screen, SPRITE::mImageClips[IMAGE_TILEMAP]->clips.at( cEditorMap.cTiles[x][y].iTileType ) ); Again, do I have the right idea? I like the imageMap, but am I better off with each entity storing its own clips? My last question is about collision detection. I only grasp the basics, will look at per-pixel and circular soon, but how can I determine which side the collision comes from with just the basic square collision detection, I tried breaking each entity into 4 collision zones, but that just gave me problems with walking through walls and the like <. Also, is per-pixel color collision a good way to decide what collision just occured, or is checking multiple colors for multiple entities too taxing each cycle?

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  • Releasing the new Sample Browser Phone app

    - by Jialiang
    Originally posted on: http://geekswithblogs.net/Jialiang/archive/2014/06/05/releasing-the-new-sample-browser-phone-app.aspx Starting its journey in 2010, Sample Browser is achieving its tetralogy by releasing a Windows Phone version Sample Browser today. The new Windows Phone app is the fourth milestone of Sample Browser since we released the desktop version and the Visual Studio version in 2012 and the Windows Store version in 2013. This time, by providing a sample browser designed for a ‘walking’ platform in response to MVPs’ suggestions during last year’s MVP Global Summit, we are literally putting a world of code samples "at developers’ fingertips”. If you like to have a code gallery of over 7000 quality code samples in your pocket, then click here to download our Windows Phone Sample Browser and start a fantastic mobile experience. With Windows Phone version Sample Browser and the Internet, you can search for code samples on MSDN at anytime and anywhere you want, 24/7 and–even to bed. You can also check code sample details and share them with your friends. Compared to the other 3 pieces in the tetralogy (desktop version, Visual Studio version, and the Windows Store version), the Windows Phone version Sample Browser sells itself for convenience and instant connectivity. For those who need to reach code samples under mobile circumstances where no PCs is available, Windows Phone version Sample Browser will definitely be the right service you are seeking for. Aside from sharing samples via emails as the other 3 do, the Windows Phone version Sample Browser also allows you to share the sample via SMS and Near Field Communication (NFC).   What's Next Currently, the Windows Phone Sample Browser only supports online MSDN code searching, but we already plan to upgrade Sample Browser to allow users to do ‘Bing code search’, and add and manage their private code snippets.  We will also upgrade the app to universal app. Universal App is a new concept brought up in the Microsoft Build Developer Conference 2014. It is a new development model that allows for a single app to be deployed across multiple Windows devices such as Windows Phone, Windows 8.1, and XBox. Therefore, once we finish upgrading Sample Browser to a universal app, you can synchronize your own code snippets across different devices; You can also mark a code sample as favorite on your Windows Phone and continue to study the sample when you are on your desktop. By then, sharing data between platforms will be a piece of cake. Also, the user experience of Sample Browser on different platforms will be more consistent.  The best is yet to come!   We sincerely suggest you give Sample Browser a try (click here to download). If you love what you see in Sample Browser, please recommend it to your friends and colleagues. If you encounter any problems or have any suggestions for us, please contact us at [email protected]. Your precious opinions and comments are more than welcome.

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  • PL/SQL to delete invalid data from token Strings

    - by Jie Chen
    Previous article describes how to delete the duplicated values from token string in bulk mode. This one extends it and shows the way to delete invalid data. Scenario Support we have page_two and manufacturers tables in database and the table DDL is: SQL> desc page_two; Name NULL? TYPE ----------------------------------------- -------- ------------------------ MULTILIST04 VARCHAR2(765) SQL> SQL> desc manufacturers; Name NULL? TYPE ----------------------------------------- -------- ------ ID NOT NULL NUMBER NAME VARCHAR In table page_two, column multilist04 stores a token string splitted with common. Each token represent a valid ID in manufacturers table. My expectation is to delete invalid token strings from page_two.multilist04, which have no mapping id in manufacturers.id. For example in below SQL result: ,6295728,33,6295729,6295730,6295731,22, , value 33 and 22 are invalid data because there is no ID equals to 33 or 22 in manufacturers table. So I need to delete 33 and 22. SQL> col rowid format a20; SQL> col multilist04 format a50; SQL> select rowid, multilist04 from page_two; ROWID MULTILIST04 -------------------- -------------------------------------------------- AAB+UrADfAAAAhUAAI ,6295728,6295729,6295730,6295731, AAB+UrADfAAAAhUAAJ ,1111,6295728,6295729,6295730,6295731, AAB+UrADfAAAAhUAAK ,6295728,111,6295729,6295730,6295731, AAB+UrADfAAAAhUAAL ,6295728,6295729,6295730,6295731,22, AAB+UrADfAAAAhUAAM ,6295728,33,6295729,6295730,6295731,22, SQL> select id, encode_name from manufacturers where id in (1111,11,22,33); No rows selected SQL> Solution As there is no existing SPLIT function or related in PL/SQL, I should program it by myself. I code Split intermediate function which is used to get the token value between current splitter and next splitter. Next program is main entry point, it get each column value from page_two.multilist04, process each row based on cursor. When it get each multilist04 value, it uses above Split function to get each token string stored to singValue variant, then check if it exists in manufacturers.id. If not found, set fixFlag to 1, pending to be deleted.

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  • Develop web site from existing software or cherry pick and use a web framework?

    - by erisco
    A small team and I are tasked with developing a web site. The client has referenced a particular open source project (we'll call it X) when describing some of the features. Because of this, the team wants to start with X and adapt it to satisfy the client. I have looked at X and its code and, in my opinion, it would be unwise. However, my experience is limited, and could really benefit from the insights of others so that I can figure out what I should be asserting as the right direction for the team. My red flags are going up and this is why. X was developed in the earlier days of PHP; 500 line blocks of code are the norm; global variables are abundant; giant switch cases are the norm for switching between which page is shown. There is no clear mapping between URL and where the code for that page sits. From a feature-set standpoint, X is actually software specialized for a different task and has dozens of features we don't need or have use for that come as core assumptions. We will be unable to adapt X through its plugin system. That said, there are a few features which can be mapped, with some modification, to suit our purposes. I believe this is the attraction the team feels. I would feel comfortable if, instead of using X directly, we lifted what is salvageable and useful to us. We can then use that code, and the same 3rd party libraries X is using, in a new code base built on top of a PHP web framework (particularly Agavi, so you understand what I mean by 'web framework'). The web framework gives us a strong MVC structure and provides the common facilities for web development, or adapters to work with 3rd party libraries that do so. We will also have a clean slate feature-wise to work from, which means we can work additively instead of subtractively. Because the code base is better structured, and contains none of what we don't need, it will be easier to document, which is a critical requirement of our client. So to summarize, the team wants to use X, whereas I want to take the bits we can from X and use a web framework instead. I want to bounce this opinion off of other's experiences so that I can be more informed. Thanks for your insight.

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  • OpenGL ES 2 jittery camera movement

    - by user16547
    First of all, I am aware that there's no camera in OpenGL (ES 2), but from my understanding proper manipulation of the projection matrix can simulate the concept of a camera. What I'm trying to do is make my camera follow my character. My game is 2D, btw. I think the principle is the following (take Super Mario Bros or Doodle Jump as reference - actually I'm trying to replicate the mechanics of the latter): when the caracter goes beyond the center of the screen (in the positive axis/direction), update the camera to be centred on the character. Else keep the camera still. I did accomplish that, however the camera movement is noticeably jittery and I ran out of ideas how to make it smoother. First of all, my game loop (following this article): private int TICKS_PER_SECOND = 30; private int SKIP_TICKS = 1000 / TICKS_PER_SECOND; private int MAX_FRAMESKIP = 5; @Override public void run() { loops = 0; if(firstLoop) { nextGameTick = SystemClock.elapsedRealtime(); firstLoop = false; } while(SystemClock.elapsedRealtime() > nextGameTick && loops < MAX_FRAMESKIP) { step(); nextGameTick += SKIP_TICKS; loops++; } interpolation = ( SystemClock.elapsedRealtime() + SKIP_TICKS - nextGameTick ) / (float)SKIP_TICKS; draw(); } And the following code deals with moving the camera. I was unsure whether to place it in step() or draw(), but it doesn't make a difference to my problem at the moment, as I tried both and neither seemed to fix it. center just represents the y coordinate of the centre of the screen at any time. Initially it is 0. The camera object is my own custom "camera" which basically is a class that just manipulates the view and projection matrices. if(character.getVerticalSpeed() >= 0) { //only update camera if going up float[] projectionMatrix = camera.getProjectionMatrix(); if( character.getY() > center) { center += character.getVerticalSpeed(); cameraBottom = center + camera.getBottom(); cameraTop = center + camera.getTop(); Matrix.orthoM(projectionMatrix, 0, camera.getLeft(), camera.getRight(), center + camera.getBottom(), center + camera.getTop(), camera.getNear(), camera.getFar()); } } Any thought about what I should try or what I am doing wrong? Update 1: I think I updated every value you can see on screen to check whether the jittery movement is affected by that, but nothing changed, so something must be fundamentally flawed with my approach/calculations.

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  • eSTEP Newsletter for October 2013 Now Available

    - by Cinzia Mascanzoni
    The October'13 issue of our Newsletter is now available. The issue contains information on the following topics: Oracle Open World Summary Oracle Cloud: Oracle Engineered Systems Oracle Database and Middleware Oracle Applications and Software as a Service Oracle Industries Oracle Partners and the "Internet of Things" JavaOne News MySQL News Corporate News Create Your HR Strategic Vision at Oracle HCM World Oracle Database Protection Redefined A Preview: Oracle Database Backup Logging Recovery Appliance Oracle closed Tekelec acquisition Congratulations to ORACLE TEAM USA! Tech sectionARC M6 Oracle's SPARC M6 Oracle SuperCluster M6-32 - Oracle’s Most Scalable Engineered System Oracle Multitenant on SPARC Servers and Oracle Solaris Oracle Database 12c Enterprise Edition: Plug into the Cloud Oracle In-Memory Database Cache Oracle Virtual Compute Appliance New Benchmark-Results published (Sept. 2013) Video Interview: Elasticity, the Biggest Challenge Facing Data Centers Today Tech blog Announcing New Sun Storage 2500-M2 Drives SPARC Product Line Update ZFS RAID Calculator v6 What ships with ODA X3-2? Tech Article: Oracle Multitenant on SPARC Servers and Oracle Solaris New release of Sun Rack II capacity calculator available Announcing: Oracle Solaris Cluster Product Bulletin, September 2013 Learning & events Planned TechCasts Quarterly Partner Update Live Webcast: Simplify and Accelerate Oracle Database deployment with Oracle VM Templates Join us for OTN's Virtual Developer Day - Harnessing the Power of Oracle WebLogic and Oracle Coherence. Learn from OOW 2013 what is going on in Virtualization How to Implementing Early Arriving Facts in ODI, Part I and Part II: Proof of Concept Overview Multi-Factor Authentication in Oracle WebLogic Using multi-factor authentication to protect web applications deployed on Oracle WebLogic. If Virtualization Is Free, It Can't Be Any Good—Right? Looking beyond System/HW SOA and User Interfaces Overcoming the challenges to developing user interfaces in a service oriented References Vodafone Romania Improves Business Agility and Customer Satisfaction, with 10x Faster Business Intelligence Delivery and 12x Faster Processing Emirates Integrated Telecommunications Captures 47% Market Share in a Competitive Market, Thanks to 24/7 Availability Home Credit and Finance Bank Accelerates Getting New Banking Products to Market Extra A Conversation with Java Champion Johan Vos You can find the Newsletter on our portal under eSTEP News ---> Latest Newsletter. You will need to provide your email address and the pin below to get access. Link to the portal is shown below. URL: http://launch.oracle.com/ PIN: eSTEP_2011 Previous published Newsletters can be found under the Archived Newsletters section and more useful information under the Events, Download and Links tab.

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  • Changing Your Design for Testability

    Sometimes I come across a way of putting something that it is pithy good, not Hallmark trite, but an impactful and concise way of clarifying a previously obscure concept. A recent one of these happy occurrences was when I was reading the excellent Art of Unit Testing by Roy Osherove. After going through the basics of why youd want to test code and how to do it, Roy confronts a frequent objection to having unit tests, that it ends up changing how you design your components: When we write unit tests for our code, we are adding another end user (the test) to the object model. That end user is just as important as the original one, but it has different goals when using the model.  The test has specific requirements from the object model that seem to defy the basic logic behind a couple of object-oriented principles, mainly encapsulation. [emphasis added by me] When I read this, something clicked for me. I used to find it persuasive that because unit tests caused you to change your design they were more disruptive than they were worth. The counter argument I heard is that the disruption was OK, because testable design was just obviously better. That argument was not convincing as it seemed like delusional arrogance to suggest that any one of type of design was just inherently better for the particular applications I was building. What was missing was that I was not thinking of unit tests as an additional and equal end user to my design. If I accepted that proposition, than it was indeed obvious that a testable design was better because now all users of my component would be satisfied. Have I accepted that proposition? Id phrase it slightly different. I find more and more that having unit tests helps me write better, less buggy code before it gets to production or QA. As I write more unit tests, it gets easier to see how to create testable components, so I dont feel like its taking me as much extra time up front. I pick and choose components that seem most likely to benefit from automated tests and it is working out nicely. If you already implement Test Driven Development, this whole post was probably a waste of your time <g> If you hate the idea of unit tests, well, probably not a great value prop for you either. However, if you are somewhere in between, at least take a minute and check out a sample chapter from Roys book at: http://www.manning.com/osherove/.Did you know that DotNetSlackers also publishes .net articles written by top known .net Authors? We already have over 80 articles in several categories including Silverlight. Take a look: here.

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  • PASS Summit for SQL Starters

    - by Davide Mauri
    I’ve received a buch of emails from PASS Summit “First Timers” that are also somehow new to SQL Server (for “somehow” I mean people with less than 6 month experience but with some basic knowledge of SQL Server engine) or are catching up from SQL Server 2000. The common question regards the session one should not miss to have a broad view of the entire SQL Server platform have some insight into some specific areas of SQL Server Given that I’m on (semi-)vacantion and that I have more free time (not true, I have to prepare slides & demos for several conferences, PASS Summit  - Building the Agile Data Warehouse with SQL Server 2012 - and PASS 24H - Agile Data Warehousing with SQL Server 2012 - among them…but let’s pretend it to be true), I’ve decided to make a post to answer to this common questions. Of course this is my personal point of view and given the fact that the number and quality of session that will be delivered at PASS Summit is so high that is very difficoult to make a choice, fell free to jump into the discussion and leave your feedback or – even better – answer with another post. I’m sure it will be very helpful to all the SQL Server beginners out there. I’ve imposed to myself to choose 6 session at maximum for each Track. Why 6? Because it’s the maximum number of session you can follow in one day, and given that all the session will be on the Summit DVD, they are the answer to the following question: “If I have one day to spend in training, which session I should watch?”. Of course a Summit is not like a Course so a lot of very basics concept of well-established technologies won’t be found here. Analysis Services, Integration Services, MDX are not part of the Summit this time (at least for the basic part of them). Enough with that, let’s start with the session list ideal to have a good Overview of all the SQL Server Platform: Geospatial Data Types in SQL Server 2012 Inside Unstructured Data: SQL Server 2012 FileTable and Semantic Search XQuery and XML in SQL Server: Common Problems and Best Practice Solutions Microsoft's Big Play for Big Data Dashboards: When to Choose Which MSBI Tool Microsoft BI End-User Tools 360° for what concern Database Development, I recommend the following sessions Understanding Transaction Isolation Levels What to Look for in Execution Plans Improve Query Performance by Fixing Bad Parameter Sniffing A Window into Your Data: Using SQL Window Functions Practical Uses and Optimization of New T-SQL Features in SQL Server 2012 Taking MERGE Beyond the Basics For Business Intelligence Information Delivery Analyzing SSAS Data with Excel Building Compelling Power View Reports Managed Self-Service BI PowerPivot 101  SharePoint for Business Intelligence The Best Microsoft BI Tools You've Never Heard Of and for Business Intelligence Architecture & Development BI Power Hour Building a Tabular Model Database Enterprise Information Management: Bringing Together SSIS, DQS, and MDS SSIS Design Patterns Storing Columnstore Indexes Hadoop and Its Ecosystem Components in Action Beside the listed sessions, First Timers should also take a look the the page PASS set up for them: http://www.sqlpass.org/summit/2012/Connect/FirstTimers.aspx See you at PASS Summit!

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  • Oracle Brings Java to iOS Devices (and Android too)

    - by Shay Shmeltzer
    Java developer, did you ever wish that you can take your Java skills and apply them to building applications for iOS mobile devices? Well, now you can! With the new Oracle ADF Mobile solution, Oracle has created a unique technology that allows developers to use the Java language and develop applications that install and run on both iOS and Android mobile devices. The solution is based on a thin native container that installs as part of your application. The container is able to run the same application you develop unchanged on both Android and iOS devices. One part of the container is a headless lightweight JVM based on the Java ME CDC technology. This allows the execution of Java code on your mobile device. Java is used for building business logic, accessing local SQLite encrypted database, and invoking and interacting with remote services. Java concept on the UI too To further help transition Java developers to mobile developers, ADF Mobile borrows familiar concepts from the world of JSF to make the UI development experience simpler. The user interface layer of Oracle ADF Mobile is rendered with HTML5 which delivers native user experience on the devices, including animations and gesture support. Using a set of rich components, developers can create mobile pages without needing to write low level HTML5 and JavaScript code. The components cover everything from simple controls such as text fields, date pickers, buttons and links, to advanced data visualization components such as graphs, gauges and maps, and including unique mobile UI patterns such as lists, and toggle selectors. Want to see the components in action? Access this demo instance from your mobile device. Need to further customize the look and feel? You can use CSS3 to achieve this. A controller layer - similar in functionality to the JSF controller - allows developer to simplify the way they build navigation between pages. The logic behind the pages is written in managed beans with various scopes – again similar to the JSF approach. Need to interact with device features like camera, SMS, Contacts etc? Oracle conveniently packaged access to these services in a set of services that you can just drag and drop into your pages as buttons and links, or code into your managed beans Java calls to activate. Underneath the covers this layer is implemented using the open source phonegap solution. With the new Oracle ADF Mobile solution, transferring your Java skills into the Mobile world has become much easier. Check out this development experience demo. And then go and download JDeveloper and the ADF Mobile extension and try it out on your own. For more on ADF Mobile, see the ADF Mobile OTN page.

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  • All hail the Excel Queen

    - by Tim Dexter
    An excellent question this past week from dear ol Blighty; actually from Brian at Nextgen Clearing Ltd in the big smoke (London). Brian was developing an excel template and wanted to be able to reference the data fields multiple times inside the Excel template. Damn good question and I of course has some wacky solutions, from macros and cell referencing in Excel to pre-processing the data with an XSL stylesheet to copy the data multiple times so it could be referenced multiple times. All completely outlandish, enter our Queen of Excel, Shirley from the development team. Shirley is singlehandedly responsible for the Excel templates, I put her through six months of hell a few years back, with a host of Excel template requirements. She was more than up to the challenge and has developed some great features. One of those, is the ability to use the hidden XDO_METADATA sheet to map the data to custom named fields so they can be used multiple times in the template. So simple and very neat! Excel template and regular Excel users will know that you can only use the naming function once ie the names have to be unique across the workbook so you can not reuse a cell/group name. To get around this you can just come up with as many cell names as you want and map them in the XDO_METADATA sheet to the data columns/fields in your XML data set:. For example: XDO_?DEPTNO_SUMMARY?  <?DEPTNO?> XDO_?DNAME_SUMMARY?  <?DNAME?> XDO_GROUP_?G_D_DETAIL? <xsl:for-each-group select=".//G_D" group-by="./DEPTNO"> XDO_?DEPTNO_DETAIL? <?DEPTNO?> As you can see DEPTNO has been referenced twice and mapped to different named values in the left hand column. These values can then be used to name individual cells in the Excel template. You'll also notice a mix of Publisher <? ...?> and native XSL commands. So the world is your oyster on the mapping and the complexity you might need for calculations or string manipulation. Shirley has kindly built out a sample Excel template, data and result here so you can see how it all hangs together. the XDO_METADATA sheet is hidden, just right click on the sheet names and use the Unhide command to show it.

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  • Innovation for Retailers

    - by David Dorf
    One of my main objectives for this blog is to point out emerging technologies and how they might apply to the retail industry.  But ideas are just the beginning; retailers either have to rely on vendors or have their own lab to explore these ideas and see which ones work.  (A healthy dose of both is probably the best solution.)  The Nordstrom Innovation Lab is a fine example of dedicating resources to cultivate ideas and test prototypes. The video below, from 2011, is a case study in which the team builds an iPad app that helps customers purchase sunglasses in the store.  Customers take pictures of themselves wearing different sunglasses, then can do side-by-side comparisons. There are a few interesting take-aways from their process.  First, they are working in the store alongside employees and customers.  There's no concept of documenting all the requirements then building the product.  Instead, they work closely with those that will be using the app in order to fully understand what's needed.  When they find an issue, they change the software onsite and try again.  This iterative prototyping ensures their product hits the mark.  Feels like Extreme Programming if you recall that movement. Second, they have time-boxed the project to one week.  Either it works or it doesn't, and either way they've only expended a week's worth of resources.  Innovation always entails failure, and those that succeed are often good at detecting failure quickly then adjusting.  Fail fast and fail often. Third, its not always about technology.  I was impressed they used paper designs to walk through user stories and help understand the needs of the customer.  Pen and paper is the innovator's most powerful tool. Our Retail Applied Research (RAR) team uses some of these concepts in our development process.  (Calling it a process is probably overkill.)  We try to give life to concepts quickly so the rest of organization can help us decide if we're heading the right direction.  It takes many failures before finding a successful product.

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  • Are closures with side-effects considered "functional style"?

    - by Giorgio
    Many modern programming languages support some concept of closure, i.e. of a piece of code (a block or a function) that Can be treated as a value, and therefore stored in a variable, passed around to different parts of the code, be defined in one part of a program and invoked in a totally different part of the same program. Can capture variables from the context in which it is defined, and access them when it is later invoked (possibly in a totally different context). Here is an example of a closure written in Scala: def filterList(xs: List[Int], lowerBound: Int): List[Int] = xs.filter(x => x >= lowerBound) The function literal x => x >= lowerBound contains the free variable lowerBound, which is closed (bound) by the argument of the function filterList that has the same name. The closure is passed to the library method filter, which can invoke it repeatedly as a normal function. I have been reading a lot of questions and answers on this site and, as far as I understand, the term closure is often automatically associated with functional programming and functional programming style. The definition of function programming on wikipedia reads: In computer science, functional programming is a programming paradigm that treats computation as the evaluation of mathematical functions and avoids state and mutable data. It emphasizes the application of functions, in contrast to the imperative programming style, which emphasizes changes in state. and further on [...] in functional code, the output value of a function depends only on the arguments that are input to the function [...]. Eliminating side effects can make it much easier to understand and predict the behavior of a program, which is one of the key motivations for the development of functional programming. On the other hand, many closure constructs provided by programming languages allow a closure to capture non-local variables and change them when the closure is invoked, thus producing a side effect on the environment in which they were defined. In this case, closures implement the first idea of functional programming (functions are first-class entities that can be moved around like other values) but neglect the second idea (avoiding side-effects). Is this use of closures with side effects considered functional style or are closures considered a more general construct that can be used both for a functional and a non-functional programming style? Is there any literature on this topic? IMPORTANT NOTE I am not questioning the usefulness of side-effects or of having closures with side effects. Also, I am not interested in a discussion about the advantages / disadvantages of closures with or without side effects. I am only interested to know if using such closures is still considered functional style by the proponent of functional programming or if, on the contrary, their use is discouraged when using a functional style.

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  • How to get around the Circular Reference issue with JSON and Entity

    - by DanScan
    I have been experimenting with creating a website that leverages MVC with JSON for my presentation layer and Entity framework for data model/database. My Issue comes into play with serializing my Model objects into JSON. I am using the code first method to create my database. When doing the code first method a one to many relationship (parent/child) requires the child to have a reference back to the parent. (Example code my be a typo but you get the picture) class parent { public List<child> Children{get;set;} public int Id{get;set;} } class child { public int ParentId{get;set;} [ForeignKey("ParentId")] public parent MyParent{get;set;} public string name{get;set;} } When returning a "parent" object via a JsonResult a circular reference error is thrown because "child" has a property of class parent. I have tried the ScriptIgnore attribute but I lose the ability to look at the child objects. I will need to display information in a parent child view at some point. I have tried to make base classes for both parent and child that do not have a circular reference. Unfortunately when I attempt to send the baseParent and baseChild these are read by the JSON Parser as their derived classes (I am pretty sure this concept is escaping me). Base.baseParent basep = (Base.baseParent)parent; return Json(basep, JsonRequestBehavior.AllowGet); The one solution I have come up with is to create "View" Models. I create simple versions of the database models that do not include the reference to the parent class. These view models each have method to return the Database Version and a constructor that takes the database model as a parameter (viewmodel.name = databasemodel.name). This method seems forced although it works. NOTE:I am posting here because I think this is more discussion worthy. I could leverage a different design pattern to over come this issue or it could be as simple as using a different attribute on my model. In my searching I have not seen a good method to overcome this problem. My end goal would be to have a nice MVC application that heavily leverages JSON for communicating with the server and displaying data. While maintaining a consistant model across layers (or as best as I can come up with).

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  • Organization &amp; Architecture UNISA Studies &ndash; Chap 13

    - by MarkPearl
    Learning Outcomes Explain the advantages of using a large number of registers Discuss the way in which compilers optimize register usage Discuss the evolution of CISC machines Describe the characteristics of RISC architecture Discuss the RISC vs. CISC controversy Describe the way in which RISC and CISC design principles can be combined Instruction Execution Characteristics To understand the the line of reasoning of RISC advocates, we need a brief overview of instruction execution characteristics. These include… Operations Operands Procedure Calls These three sections can be studied in depth in the textbook at pages 503 - 505 A number of groups have come up with the conclusion that the attempt to make the instruction set architecture closer to HLLs (High Level Languages) is not the most effective design strategy. Rather HLL’s can be best supported by optimizing performance of the most time-consuming features of typical HLL programs. Generally 3 main characteristics came up to improve performance… Use a large number of registers or use a compiler to optimize register usage Careful attention needs to be paid to the design of instruction pipelines A simplified (reduced) instruction set is indicated The use of a large register optimization One of the most important design principles of RISC machines is the use of a large number of registers. The concept of register windows and the use of a large register file versus the use of cache memory are discussed. On the face of it, the use of a large set of registers should decrease the need to access memory. The design task is to organize the registers in such a fashion that this goal is realized. Read page 507 – 510 for a detailed explanation. Compiler-based register optimization   Reduced Instructions Set Architecture There are two advantages to smaller programs… Because the program takes up less memory, there is a savings in that resource (this was more compelling when memory was more expensive) Smaller programs should improve performance, and this will happen in two ways – fewer instructions means fewer instruction bytes to be fetched and in a paging environment smaller programs occupy fewer pages, reducing page faults. Certain characteristics are common to RISC processors… One instruction per cycle Register-to-register operations Simple addressing modes Simple instruction formats RISC vs. CISC After initial enthusiasm for RISC machines, there has been a growing realization that RISC designs may benefit from the inclusion of some CISC features CISC designs may benefit from the inclusion of some RISC features

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  • OAuth with RestSharp in Windows Phone

    - by midoBB
    Nearly every major API provider uses OAuth for the user authentication and while it is easy to understand the concept, using it in a Windows Phone app isn’t pretty straightforward. So for this quick tutorial we will be using RestSharp for WP7 and the API from getglue.com (an entertainment site) to authorize the user. So the first step is to get the OAuth request token and then we redirect our browserControl to the authorization URL private void StartLogin() {   var client = new RestClient("https://api.getglue.com/"); client.Authenticator = OAuth1Authenticator.ForRequestToken("ConsumerKey", "ConsumerSecret"); var request = new RestRequest("oauth/request_token"); client.ExecuteAsync(request, response => { _oAuthToken = GetQueryParameter(response.Content, "oauth_token"); _oAuthTokenSecret = GetQueryParameter(response.Content, "oauth_token_secret"); string authorizeUrl = "http://getglue.com/oauth/authorize" + "?oauth_token=" + _oAuthToken + "&style=mobile"; Dispatcher.BeginInvoke(() => { browserControl.Navigate(new Uri(authorizeUrl)); }); }); } private static string GetQueryParameter(string input, string parameterName) { foreach (string item in input.Split('&')) { var parts = item.Split('='); if (parts[0] == parameterName) { return parts[1]; } } return String.Empty; } Then we listen to the browser’s Navigating Event private void Navigating(Microsoft.Phone.Controls.NavigatingEventArgs e) { if (e.Uri.AbsoluteUri.Contains("oauth_callback")) { var arguments = e.Uri.AbsoluteUri.Split('?'); if (arguments.Length < 1) return; GetAccessToken(arguments[1]); } } private void GetAccessToken(string uri) { var requestToken = GetQueryParameter(uri, "oauth_token"); var client = new RestClient("https://api.getglue.com/"); client.Authenticator = OAuth1Authenticator.ForAccessToken(ConsumerKey, ConsumerSecret, _oAuthToken, _oAuthTokenSecret); var request = new RestRequest("oauth/access_token"); client.ExecuteAsync(request, response => { AccessToken = GetQueryParameter(response.Content, "oauth_token"); AccessTokenSecret = GetQueryParameter(response.Content, "oauth_token_secret"); UserId = GetQueryParameter(response.Content, "glue_userId"); }); } Now to test it we can access the user’s friends list var client = new RestClient("http://api.getglue.com/v2"); client.Authenticator = OAuth1Authenticator.ForProtectedResource(ConsumerKey, ConsumerSecret, GAccessToken, AccessTokenSecret); var request = new RestRequest("/user/friends"); request.AddParameter("userId", UserId,ParameterType.GetOrPost); // request.AddParameter("category", "all",ParameterType.GetOrPost); client.ExecuteAsync(request, response => { TreatFreindsList(); }); And that’s it now we can access all OAuth methods using RestSharp.

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  • Drawing flaming letters in 3D with OpenGL ES 2.0

    - by Chiquis
    I am a bit confused about how to achieve this. What I want is to "draw with flames". I have achieved this with textures successfully, but now my concern is about doing this with particles to achieve the flaming effect. Am I supposed to create a path along which I should add many particle emitters that will be emitting flame particles? I understand the concept for 2D, but for 3D are the particles always supposed to be facing the user? Something else I'm worried about is the performance hit that will occur by having that many particle emitters, because there can be many letters and drawings at the same time, and each of these elements will have many particle emitters. More detailed explanation: I have a path of points, which is my model. Imagine a dotted letter "S" for example. I want make the "S" be on fire. The "S" is just an example it can be a circle, triangle, a line, pretty much any path described by my set of points. For achieving this fire effect I thought about using particles. So I am using a program called "Particle Designer" to create a fire style particle emitter. This emitter looks perfect on 2D on the iphone screen dimensions. So then I thought that I could probably draw an S or any other figure if i place many particle emitters next to each other following the path described. To move from the 2D version to the 3D version I thought about, scaling the emitter (with a scale matrix multiplication in its model matrix) and then moving it to a point in my 3D world. I did this and it works. So now I have 1 particle emitter in the 3D world. My question is, is this how you would achieve a flaming letter? Is this too inefficient if i expect to have many flaming paths on my world? Am i supposed to rotate the particle's quad so that its always looking at the user? (the last one is because i noticed that if u look at it from the side the particles start to flatten out)

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  • High-Powered Sites for low Cost

    - by HighAltitudeCoder
    Ahh, I am experiencing the intimidation of my very first post - visible by the whole world. Ok, here goes.   This first post is nothing exceptional.  It is simply a recommendation based (fittingly, I suppose) upon the job search you may be gearing up for.  I find myself in this very situation right now.  And, I will take my own recommendation after posting this entry. Job-Seekers: To the left you will notice two links under "Recommended Learning".  I have found these links to be invaluable when it comes to re-tooling, re-familiarizing, or otherwise resharping my skills when looking for that next job. Often, you will find job-postings with the text, usually posted after a laborious list of qualifications indicating the company's desire to hire candidates who know what they are doing: "...Looking for a candidate who can hit the ground running...".  The interesting thing about this post to me is I've encountered many individuals who, after speaking and working with them for some time, I've realized are perfectly capable of hitting the ground running - and FAST.  But what if they speed off in the wrong direction? The next time you spearhead a major task in your job, ask yourself: Am I headed in the wrong direction?  There are many ways to do this.  In fact, I've found in this new field there are more tempting ways to steer your project in the wrong direction than there are good ones.  I don't want to suggest that every one of my posts will fall into the "right direction" category, however I do think a healthy dose of introspection of the pros and cons will always be beneficial before you set off. That said, allow me to expound on the previously mentioned links. These web sites are invaluable.  They demonstrate the capabilities of existing as well as new and upcoming tools available in several IDE's.  I've viewed many tutorials in LearnVisualStudio.NET, and only one or two so far in TrainingSpot, however I've been delighted in their simplicity and straightforward approach to proper usage of the particular tool or concept being discussed.  They have not (so far in my experience) demonstrated ways in which to use the tools that become cumbersome, impractical, or error-prone. Each website has step-by-step videos that can be paused, replayed, and most importantly, they are done in real time.  As the author is typing, the viewer gets to experience the coding experience from a first-person perspective, including syntax errors, unexpected behaviors, IDE setup idiosyncracies, everything.  A subtle value I've gained from these videos is that a certain degree of confusion and introspection is normal when working with new tools and exploring new paths.  They (as well as your own experience) are not to be feared, but enjoyed.  I highly recommend them. Good work, guys!

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  • Practices for domain models in Javascript (with frameworks)

    - by AndyBursh
    This is a question I've to-and-fro'd with for a while, and searched for and found nothing on: what're the accepted practices surrounding duplicating domain models in Javascript for a web application, when using a framework like Backbone or Knockout? Given a web application of a non-trivial size with a set of domain models on the server side, should we duplicate these models in the web application (see the example at the bottom)? Or should we use the dynamic nature to load these models from the server? To my mind, the arguments for duplicating the models are in easing validation of fields, ensuring that fields that expected to be present are in fact present etc. My approach is to treat the client-side code like an almost separate application, doing trivial things itself and only relying on the server for data and complex operations (which require data the client-side doesn't have). I think treating the client-side code like this is akin to separation between entities from an ORM and the models used with the view in the UI layer: they may have the same fields and relate to the same domain concept, but they're distinct things. On the other hand, it seems to me that duplicating these models on the server side is a clear violation of DRY and likely to lead to differing results on the client- and server-side (where one piece gets updated but the other doesn't). To avoid this violation of DRY we can simply use Javascripts dynamism to get the field names and data from the server as and when they're neeed. So: are there any accepted guidelines around when (and when not) to repeat yourself in these situations? Or this a purely subjective thing, based on the project and developer(s)? Example Server-side model class M { int A DateTime B int C int D = (A*C) double SomeComplexCalculation = ServiceLayer.Call(); } Client-side model function M(){ this.A = ko.observable(); this.B = ko.observable(); this.C = ko.observable(); this.D = function() { return A() * C(); } this.SomeComplexCalculation = ko.observalbe(); return this; }l M.GetComplexValue = function(){ this.SomeComplexCalculation(Ajax.CallBackToServer()); }; I realise this question is quite similar to this one, but I think this is more about almost wholly untying the web application from the server, where that question is about doing this only in the case of complex calculation.

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  • "Whole-team" C++ features?

    - by Blaisorblade
    In C++, features like exceptions impact your whole program: you can either disable them in your whole program, or you need to deal with them throughout your code. As a famous article on C++ Report puts it: Counter-intuitively, the hard part of coding exceptions is not the explicit throws and catches. The really hard part of using exceptions is to write all the intervening code in such a way that an arbitrary exception can propagate from its throw site to its handler, arriving safely and without damaging other parts of the program along the way. Since even new throws exceptions, every function needs to provide basic exception safety — unless it only calls functions which guarantee throwing no exception — unless you disable exceptions altogether in your whole project. Hence, exceptions are a "whole-program" or "whole-team" feature, since they must be understood by everybody in a team using them. But not all C++ features are like that, as far as I know. A possible example is that if I don't get templates but I do not use them, I will still be able to write correct C++ — or will I not?. I can even call sort on an array of integers and enjoy its amazing speed advantage wrt. C's qsort (because no function pointer is called), without risking bugs — or not? It seems templates are not "whole-team". Are there other C++ features which impact code not directly using them, and are hence "whole-team"? I am especially interested in features not present in C. Update: I'm especially looking for features where there's no language-enforced sign you need to be aware of them. The first answer I got mentioned const-correctness, which is also whole-team, hence everybody needs to learn about it; however, AFAICS it will impact you only if you call a function which is marked const, and the compiler will prevent you from calling it on non-const objects, so you get something to google for. With exceptions, you don't even get that; moreover, they're always used as soon as you use new, hence exceptions are more "insidious". Since I can't phrase this as objectively, though, I will appreciate any whole-team feature. Appendix: Why this question is objective (if you wonder) C++ is a complex language, so many projects or coding guides try to select "simple" C++ features, and many people try to include or exclude some ones according to mostly subjective criteria. Questions about that get rightfully closed regularly here on SO. Above, instead, I defined (as precisely as possible) what a "whole-team" language feature is, provide an example (exceptions), together with extensive supporting evidence in the literature about C++, and ask for whole-team features in C++ beyond exceptions. Whether you should use "whole-team" features, or whether that's a relevant concept, might be subjective — but that only means the importance of this question is subjective, like always.

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  • EF Doesn't Like Same Named Tables

    - by Anthony Trudeau
    Originally posted on: http://geekswithblogs.net/tonyt/archive/2013/07/02/153327.aspxIt's another week and another restriction imposed by the Entity Framework (EF). Don't get me wrong. I like EF, but I don't like how it restricts you in different ways. At this point you may be asking yourself the question: how can you have more than one table with the same name?The answer is to have tables in different schemas. I do this to partition the data based on the area of concern. It allows security to be assigned conveniently. A lot of people don't use schemas. I love them. But this article isn't about schemas.In the situation I have two tables:Contact.PersonEmployee.PersonThe first contains the basic, more public information such as the name. The second contains mostly HR specific information. I then mapped these tables to two classes. I stuck to a Table per Class (TPC) mapping, because of problems I've had in the past implementing inheritance with EF. The following code gives you the basic contents of the classes.[Table("Person", Schema = "Employee")]public class Employee {   ...   public int PersonId { get; set; }   [ForeignKey("PersonId")]   public virtual Person Person { get; set; }}[Table("Person", Schema = "Contact")]public class Person {   [Key]   public int Id { get; set; }   ...}This seemingly simple scenario just doesn't work. The problem occurs when you try to add a Person to the DbContext. You get an InvalidOperationException with the following text:The entity types 'Employee' and 'Person' cannot share table 'People' because they are not in the same type hierarchy or do not have a valid one to one foreign key relationship with matching primary keys between them..This is interesting for a couple of reasons. First, there is no People table in my database. Second, I have used the SetInitializer method to stop a database from being created, so it shouldn't be thinking about new tables.The solution to my problem was to change the name of my Employee.Person table. I decided to name it Employee.Employee. It's not ideal, but it gets me past the EF limitation. I hope that this article will help someone else that has the same problem.

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