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• Keep a programming language backwards compatible vs. fixing its flaws

  - by Radu Murzea

  First, some context (stuff that most of you know anyway): Every popular programming language has a clear evolution, most of the time marked by its version: you have Java 5, 6, 7 etc., PHP 5.1, 5.2, 5.3 etc. Releasing a new version makes new APIs available, fixes bugs, adds new features, new frameworks etc. So all in all: it's good. But what about the language's (or platform's) problems? If and when there's something wrong in a language, developers either avoid it (if they can) or they learn to live with it. Now, the developers of those languages get a lot of feedback from the programmers that use them. So it kind of makes sense that, as time (and version numbers) goes by, the problems in those languages will slowly but surely go away. Well, not really. Why? Backwards compatibility, that's why. But why is this so? Read below for a more concrete situation. The best way I can explain my question is to use PHP as an example: PHP is loved thousands of people and hated by just as many thousands. All languages have flaws, but apparently PHP is special. Check out this blog post. It has a very long list of so called flaws in PHP. Now, I'm not a PHP developer (not yet), but I read through all of it and I'm sure that a big chunk of that list are indeed real issues. (Not all of it, since it's potentially subjective). Now, if I was one of the guys who actively develops PHP, I would surely want to fix those problems, one by one. However, if I do that, then code that relies on a particular behaviour of the language will break if it runs on the new version. Summing it up in 2 words: backwards compatibility. What I don't understand is: why should I keep PHP backwards compatible? If I release PHP version 8 with all those problems fixed, can't I just put a big warning on it saying: "Don't run old code on this version !"? There is a thing called deprecation. We had it for years and it works. In the context of PHP: look at how these days people actively discourage the use of the mysql_* functions (and instead recommend mysqli_* and PDO). Deprecation works. We can use it. We should use it. If it works for functions, why shouldn't it work for entire languages? Let's say I (the developer of PHP) do this: Launch a new version of PHP (let's say 8) with all of those flaws fixed New projects will start using that version, since it's much better, clearer, more secure etc. However, in order not to abandon older versions of PHP, I keep releasing updates to it, fixing security issues, bugs etc. This makes sense for reasons that I'm not listing here. It's common practice: look for example at how Oracle kept updating version 5.1.x of MySQL, even though it mostly focused on version 5.5.x. After about 3 or 4 years, I stop updating old versions of PHP and leave them to die. This is fine, since in those 3 or 4 years, most projects will have switched to PHP 8 anyway. My question is: Do all these steps make sense? Would it be so hard to do? If it can be done, then why isn't it done? Yes, the downside is that you break backwards compatibility. But isn't that a price worth paying ? As an upside, in 3 or 4 years you'll have a language that has 90 % of its problems fixed.... a language much more pleasant to work with. Its name will ensure its popularity. EDIT: OK, so I didn't expressed myself correctly when I said that in 3 or 4 years people will move to the hypothetical PHP 8. What I meant was: in 3 or 4 years, people will use PHP 8 if they start a new project.

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• Why do we use Pythagoras in game physics?

  - by Starkers

  I've recently learned that we use Pythagoras a lot in our physics calculations and I'm afraid I don't really get the point. Here's an example from a book to make sure an object doesn't travel faster than a MAXIMUM_VELOCITY constant in the horizontal plane: MAXIMUM_VELOCITY = <any number>; SQUARED_MAXIMUM_VELOCITY = MAXIMUM_VELOCITY * MAXIMUM_VELOCITY; function animate(){ var squared_horizontal_velocity = (x_velocity * x_velocity) + (z_velocity * z_velocity); if( squared_horizontal_velocity <= SQUARED_MAXIMUM_VELOCITY ){ scalar = squared_horizontal_velocity / SQUARED_MAXIMUM_VELOCITY; x_velocity = x_velocity / scalar; z_velocity = x_velocity / scalar; } } Let's try this with some numbers: An object is attempting to move 5 units in x and 5 units in z. It should only be able to move 5 units horizontally in total! MAXIMUM_VELOCITY = 5; SQUARED_MAXIMUM_VELOCITY = 5 * 5; SQUARED_MAXIMUM_VELOCITY = 25; function animate(){ var x_velocity = 5; var z_velocity = 5; var squared_horizontal_velocity = (x_velocity * x_velocity) + (z_velocity * z_velocity); var squared_horizontal_velocity = 5 * 5 + 5 * 5; var squared_horizontal_velocity = 25 + 25; var squared_horizontal_velocity = 50; // if( squared_horizontal_velocity <= SQUARED_MAXIMUM_VELOCITY ){ if( 50 <= 25 ){ scalar = squared_horizontal_velocity / SQUARED_MAXIMUM_VELOCITY; scalar = 50 / 25; scalar = 2.0; x_velocity = x_velocity / scalar; x_velocity = 5 / 2.0; x_velocity = 2.5; z_velocity = z_velocity / scalar; z_velocity = 5 / 2.0; z_velocity = 2.5; // new_horizontal_velocity = x_velocity + z_velocity // new_horizontal_velocity = 2.5 + 2.5 // new_horizontal_velocity = 5 } } Now this works well, but we can do the same thing without Pythagoras: MAXIMUM_VELOCITY = 5; function animate(){ var x_velocity = 5; var z_velocity = 5; var horizontal_velocity = x_velocity + z_velocity; var horizontal_velocity = 5 + 5; var horizontal_velocity = 10; // if( horizontal_velocity >= MAXIMUM_VELOCITY ){ if( 10 >= 5 ){ scalar = horizontal_velocity / MAXIMUM_VELOCITY; scalar = 10 / 5; scalar = 2.0; x_velocity = x_velocity / scalar; x_velocity = 5 / 2.0; x_velocity = 2.5; z_velocity = z_velocity / scalar; z_velocity = 5 / 2.0; z_velocity = 2.5; // new_horizontal_velocity = x_velocity + z_velocity // new_horizontal_velocity = 2.5 + 2.5 // new_horizontal_velocity = 5 } } Benefits of doing it without Pythagoras: Less lines Within those lines, it's easier to read what's going on ...and it takes less time to compute, as there are less multiplications Seems to me like computers and humans get a better deal without Pythagoras! However, I'm sure I'm wrong as I've seen Pythagoras' theorem in a number of reputable places, so I'd like someone to explain me the benefit of using Pythagoras to a maths newbie. Does this have anything to do with unit vectors? To me a unit vector is when we normalize a vector and turn it into a fraction. We do this by dividing the vector by a larger constant. I'm not sure what constant it is. The total size of the graph? Anyway, because it's a fraction, I take it, a unit vector is basically a graph that can fit inside a 3D grid with the x-axis running from -1 to 1, z-axis running from -1 to 1, and the y-axis running from -1 to 1. That's literally everything I know about unit vectors... not much :P And I fail to see their usefulness. Also, we're not really creating a unit vector in the above examples. Should I be determining the scalar like this: // a mathematical work-around of my own invention. There may be a cleverer way to do this! I've also made up my own terms such as 'divisive_scalar' so don't bother googling var divisive_scalar = (squared_horizontal_velocity / SQUARED_MAXIMUM_VELOCITY); var divisive_scalar = ( 50 / 25 ); var divisive_scalar = 2; var multiplicative_scalar = (divisive_scalar / (2*divisive_scalar)); var multiplicative_scalar = (2 / (2*2)); var multiplicative_scalar = (2 / 4); var multiplicative_scalar = 0.5; x_velocity = x_velocity * multiplicative_scalar x_velocity = 5 * 0.5 x_velocity = 2.5 Again, I can't see why this is better, but it's more "unit-vector-y" because the multiplicative_scalar is a unit_vector? As you can see, I use words such as "unit-vector-y" so I'm really not a maths whiz! Also aware that unit vectors might have nothing to do with Pythagoras so ignore all of this if I'm barking up the wrong tree. I'm a very visual person (3D modeller and concept artist by trade!) and I find diagrams and graphs really, really helpful so as many as humanely possible please!

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• NDepend Evaluation: Part 3

  - by Anthony Trudeau

  NDepend is a Visual Studio add-in designed for intense code analysis with the goal of high code quality. NDepend uses a number of metrics and aggregates the data in pleasing static and active visual reports. My evaluation of NDepend will be broken up into several different parts. In the first part of the evaluation I looked at installing the add-in.  And in the last part I went over my first impressions including an overview of the features.  In this installment I provide a little more detail on a few of the features that I really like. Dependency Matrix The dependency matrix is one of the rich visual components provided with NDepend.  At a glance it lets you know where you have coupling problems including cycles.  It does this with number indicating the weight of the dependency and a color-coding that indicates the nature of the dependency. Green and blue cells are direct dependencies (with the difference being whether the relationship is from row-to-column or column-to-row).  Black cells are the ones that you really want to know about.  These indicate that you have a cycle.  That is, type A refers to type B and type B also refers to Type A. But, that’s not the end of the story.  A handy pop-up appears when you hover over the cell in question.  It explains the color, the dependency, and provides several interesting links that will teach you more than you want to know about the dependency. You can double-click the problem cells to explode the dependency.  That will show the dependencies on a method-by-method basis allowing you to more easily target and fix the problem.  When you’re done you can click the back button on the toolbar. Dependency Graph The dependency graph is another component provided.  It’s complementary to the dependency matrix, but it isn’t as easy to identify dependency issues using the window. On a positive note, it does provide more information than the matrix. My biggest issue with the dependency graph is determining what is shown.  This was not readily obvious.  I ended up using the navigation buttons to get an acceptable view.  I would have liked to choose what I see. Once you see the types you want you can get a decent idea of coupling strength based on the width of the dependency lines.  Double-arrowed lines are problematic and are shown in red.  The size of the boxes will be related to the metric being displayed.  This is controlled using the Box Size drop-down in the toolbar.  Personally, I don’t find the size of the box to be helpful, so I change it to Constant Font. One nice thing about the display is that you can see the entire path of dependencies when you hover over a type.  This is done by color-coding the dependencies and dependants.  It would be nice if selecting the box for the type would lock the highlighting in place. I did find a perhaps unintended work-around to the color-coding.  You can lock the color-coding in by hovering over the type, right-clicking, and then clicking on the canvas area to clear the pop-up menu.  You can then do whatever with it including saving it to an image file with the color-coding. CQL NDepend uses a code query language (CQL) to work with your code just like it was a database.  CQL cannot be confused with the robustness of T-SQL or even LINQ, but it represents an impressive attempt at providing an expressive way to enumerate and interrogate your code. There are two main windows you’ll use when working with CQL.  The CQL Query Explorer allows you to define what queries (rules) are run as part of a report – I immediately unselected rules that I don’t want in my results.  The CQL Query Edit window is where you can view or author your own rules.  The explorer window is pretty self-explanatory, so I won’t mention it further other than to say that any queries you author will appear in the custom group. Authoring your own queries is really hard to screw-up.  The Intellisense-like pop-ups tell you what you can do while making composition easy.  I was able to create a query within two minutes of playing with the editor.  My query warns if any types that are interfaces don’t start with an “I”. WARN IF Count > 0 IN SELECT TYPES WHERE IsInterface AND !NameLike “I” The results from the CQL Query Edit window are immediate. That fact makes it useful for ad hoc querying.  It’s worth mentioning two things that could make the experience smoother.  First, out of habit from using Visual Studio I expect to be able to scroll and press Tab to select an item in the list (like Intellisense).  You have to press Enter when you scroll to the item you want.  Second, the commands are case-sensitive.  I don’t see a really good reason to enforce that. CQL has a lot of potential not just in enforcing code quality, but also enforcing architectural constraints that your enterprise has defined. Up Next My next update will be the final part of the evaluation.  I will summarize my experience and provide my conclusions on the NDepend add-in. ** View Part 1 of the Evaluation ** ** View Part 2 of the Evaluation ** Disclaimer: Patrick Smacchia contacted me about reviewing NDepend. I received a free license in return for sharing my experiences and talking about the capabilities of the add-in on this site. There is no expectation of a positive review elicited from the author of NDepend.

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• Access Control Service v2: Registering Web Identities in your Applications [concepts]

  - by Your DisplayName here!

  ACS v2 support two fundamental types of client identities– I like to call them “enterprise identities” (WS-*) and “web identities” (Google, LiveID, OpenId in general…). I also see two different “mind sets” when it comes to application design using the above identity types: Enterprise identities – often the fact that a client can present a token from a trusted identity provider means he is a legitimate user of the application. Trust relationships and authorization details have been negotiated out of band (often on paper). Web identities – the fact that a user can authenticate with Google et al does not necessarily mean he is a legitimate (or registered) user of an application. Typically additional steps are necessary (like filling out a form, email confirmation etc). Sometimes also a mixture of both approaches exist, for the sake of this post, I will focus on the web identity case. I got a number of questions how to implement the web identity scenario and after some conversations it turns out it is the old authentication vs. authorization problem that gets in the way. Many people use the IsAuthenticated property on IIdentity to make security decisions in their applications (or deny user=”?” in ASP.NET terms). That’s a very natural thing to do, because authentication was done inside the application and we knew exactly when the IsAuthenticated condition is true. Been there, done that. Guilty ;) The fundamental difference between these “old style” apps and federation is, that authentication is not done by the application anymore. It is done by a third party service, and in the case of web identity providers, in services that are not under our control (nor do we have a formal business relationship with these providers). Now the issue is, when you switch to ACS, and someone with a Google account authenticates, indeed IsAuthenticated is true – because that’s what he is! This does not mean, that he is also authorized to use the application. It just proves he was able to authenticate with Google. Now this obviously leads to confusion. How can we solve that? Easy answer: We have to deal with authentication and authorization separately. Job done ;) For many application types I see this general approach: Application uses ACS for authentication (maybe both enterprise and web identities, we focus on web identities but you could easily have a dual approach here) Application offers to authenticate (or sign in) via web identity accounts like LiveID, Google, Facebook etc. Application also maintains a database of its “own” users. Typically you want to store additional information about the user In such an application type it is important to have a unique identifier for your users (think the primary key of your user database). What would that be? Most web identity provider (and all the standard ACS v2 supported ones) emit a NameIdentifier claim. This is a stable ID for the client (scoped to the relying party – more on that later). Furthermore ACS emits a claims identifying the identity provider (like the original issuer concept in WIF). When you combine these two values together, you can be sure to have a unique identifier for the user, e.g.: Facebook-134952459903700\799880347 You can now check on incoming calls, if the user is already registered and if yes, swap the ACS claims with claims coming from your user database. One claims would maybe be a role like “Registered User” which can then be easily used to do authorization checks in the application. The WIF claims authentication manager is a perfect place to do the claims transformation. If the user is not registered, show a register form. Maybe you can use some claims from the identity provider to pre-fill form fields. (see here where I show how to use the Facebook API to fetch additional user properties). After successful registration (which may include other mechanisms like a confirmation email), flip the bit in your database to make the web identity a registered user. This is all very theoretical. In the next post I will show some code and provide a download link for the complete sample. More on NameIdentifier Identity providers “guarantee” that the name identifier for a given user in your application will always be the same. But different applications (in the case of ACS – different ACS namespaces) will see different name identifiers. This is by design to protect the privacy of users because identical name identifiers could be used to create “profiles” of some sort for that user. In technical terms they create the name identifier approximately like this: name identifier = Hash((Provider Internal User ID) + (Relying Party Address)) Why is this important to know? Well – when you change the name of your ACS namespace, the name identifiers will change as well and you will will lose your “connection” to your existing users. Oh an btw – never use any other claims (like email address or name) to form a unique ID – these can often be changed by users.

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• Rebuilding CoasterBuzz, Part II: Hot data objects

  - by Jeff

  This is the second post, originally from my personal blog, in a series about rebuilding one of my Web sites, which has been around for 12 years. More: Part I: Evolution, and death to WCF After the rush to get moving on stuff, I temporarily lost interest. I went almost two weeks without touching the project, in part because the next thing on my backlog was doing up a bunch of administrative pages. So boring. Unfortunately, because most of the site's content is user-generated, you need some facilities for editing data. CoasterBuzz has a database full of amusement parks and roller coasters. The entities enjoy the relationships that you would expect, though they're further defined by "instances" of a coaster, to define one that has moved between parks as one, with different names and operational dates. And of course, there are pictures and news items, too. It's not horribly complex, except when you have to account for a name change and display just the newest name. In all previous versions, data access was straight SQL. As so much of the old code was rooted in 2003, with some changes in 2008, there wasn't much in the way of ORM frameworks going on then. Let me rephrase that, I mostly wasn't interested in ORM's. Since that time, I used a little LINQ to SQL in some projects, and a whole bunch of nHibernate while at Microsoft. Through all of that experience, I have to admit that these frameworks are often a bigger pain in the ass than not. They're great for basic crud operations, but when you start having all kinds of exotic relationships, they get difficult, and generate all kinds of weird SQL under the covers. The black box can quickly turn into a black hole. Sometimes you end up having to build all kinds of new expertise to do things "right" with a framework. Still, despite my reservations, I used the newer version of Entity Framework, with the "code first" modeling, in a science project and I really liked it. Since it's just a right-click away with NuGet, I figured I'd give it a shot here. My initial effort was spent defining the context class, which requires a bit of work because I deviate quite a bit from the conventions that EF uses, starting with table names. Then throw some partial querying of certain tables (where you'll find image data), and you're splitting tables across several objects (navigation properties). I won't go into the details, because these are all things that are well documented around the Internet, but there was a minor learning curve there. The basics of reading data using EF are fantastic. For example, a roller coaster object has a park associated with it, as well as a number of instances (if it was ever relocated), and there also might be a big banner image for it. This is stupid easy to use because it takes one line of code in your repository class, and by the time you pass it to the view, you have a rich object graph that has everything you need to display stuff. Likewise, editing simple data is also, well, simple. For this goodness, thank the ASP.NET MVC framework. The UpdateModel() method on the controllers is very elegant. Remember the old days of assigning all kinds of properties to objects in your Webforms code-behind? What a time consuming mess that used to be. Even if you're not using an ORM tool, having hydrated objects come off the wire is such a time saver. Not everything is easy, though. When you have to persist a complex graph of objects, particularly if they were composed in the user interface with all kinds of AJAX elements and list boxes, it's not just a simple matter of submitting the form. There were a few instances where I ended up going back to "old-fashioned" SQL just in the interest of time. It's not that I couldn't do what I needed with EF, it's just that the efficiency, both my own and that of the generated SQL, wasn't good. Since EF context objects expose a database connection object, you can use that to do the old school ADO.NET stuff you've done for a decade. Using various extension methods from POP Forums' data project, it was a breeze. You just have to stick to your decision, in this case. When you start messing with SQL directly, you can't go back in the same code to messing with entities because EF doesn't know what you're changing. Not really a big deal. There are a number of take-aways from using EF. The first is that you write a lot less code, which has always been a desired outcome of ORM's. The other lesson, and I particularly learned this the hard way working on the MSDN forums back in the day, is that trying to retrofit an ORM framework into an existing schema isn't fun at all. The CoasterBuzz database isn't bad, but there are design decisions I'd make differently if I were starting from scratch. Now that I have some of this stuff done, I feel like I can start to move on to the more interesting things on the backlog. There's a lot to do, but at least it's fun stuff, and not more forms that will be used infrequently.

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• Rebuilding CoasterBuzz, Part IV: Dependency injection, it's what's for breakfast

  - by Jeff

  (Repost from my personal blog.) This is another post in a series about rebuilding one of my Web sites, which has been around for 12 years. I hope to relaunch soon. More: Part I: Evolution, and death to WCF Part II: Hot data objects Part III: The architecture using the "Web stack of love" If anything generally good for the craft has come out of the rise of ASP.NET MVC, it's that people are more likely to use dependency injection, and loosely couple the pieces parts of their applications. A lot of the emphasis on coding this way has been to facilitate unit testing, and that's awesome. Unit testing makes me feel a lot less like a hack, and a lot more confident in what I'm doing. Dependency injection is pretty straight forward. It says, "Given an instance of this class, I need instances of other classes, defined not by their concrete implementations, but their interfaces." Probably the first place a developer exercises this in when having a class talk to some kind of data repository. For a very simple example, pretend the FooService has to get some Foo. It looks like this: public class FooService {    public FooService(IFooRepository fooRepo)    {       _fooRepo = fooRepo;    }    private readonly IFooRepository _fooRepo;    public Foo GetMeFoo()    {       return _fooRepo.FooFromDatabase();    } } When we need the FooService, we ask the dependency container to get it for us. It says, "You'll need an IFooRepository in that, so let me see what that's mapped to, and put it in there for you." Why is this good for you? It's good because your FooService doesn't know or care about how you get some foo. You can stub out what the methods and properties on a fake IFooRepository might return, and test just the FooService. I don't want to get too far into unit testing, but it's the most commonly cited reason to use DI containers in MVC. What I wanted to mention is how there's another benefit in a project like mine, where I have to glue together a bunch of stuff. For example, when I have someone sign up for a new account on CoasterBuzz, I'm actually using POP Forums' new account mailer, which composes a bunch of text that includes a link to verify your account. The thing is, I want to use custom text and some other logic that's specific to CoasterBuzz. To accomplish this, I make a new class that inherits from the forum's NewAccountMailer, and override some stuff. Easy enough. Then I use Ninject, the DI container I'm using, to unbind the forum's implementation, and substitute my own. Ninject uses something called a NinjectModule to bind interfaces to concrete implementations. The forum has its own module, and then the CoasterBuzz module is loaded second. The CB module has two lines of code to swap out the mailer implementation: Unbind<PopForums.Email.INewAccountMailer>(); Bind<PopForums.Email.INewAccountMailer>().To<CbNewAccountMailer>(); Piece of cake! Now, when code asks the DI container for an INewAccountMailer, it gets my custom implementation instead. This is a lot easier to deal with than some of the alternatives. I could do some copy-paste, but then I'm not using well-tested code from the forum. I could write stuff from scratch, but then I'm throwing away a bunch of logic I've already written (in this case, stuff around e-mail, e-mail settings, mail delivery failures). There are other places where the DI container comes in handy. For example, CoasterBuzz does a number of custom things with user profiles, and special content for paid members. It uses the forum as the core piece to managing users, so I can ask the container to get me instances of classes that do user lookups, for example, and have zero care about how the forum handles database calls, configuration, etc. What a great world to live in, compared to ten years ago. Sure, the primary interest in DI is around the "separation of concerns" and facilitating unit testing, but as your library grows and you use more open source, it starts to be the glue that pulls everything together.

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• Using Definition of Done to Drive Agile Maturity

  - by Dylan Smith

  I’ve been an Agile Coach at a lot of different clients over the years, and I want to share an approach I use to help them adopt and mature over time. It’s important to realize that “Agile” is not a black/white yes/no thing. Teams can be varying degrees of agile. I think of this as their agile maturity level. When I coach teams I want them to start out being a little agile, and get more agile as they mature. The approach I teach them is to use the definition of done as a technique to continuously improve their agile maturity over time. We’re probably all familiar with the concept of “Done Done” that represents what *actually* being done a feature means. Not just when a developer says he’s done right after he writes that last line of code that makes the feature kind-of work. Done Done means the coding is done, it’s been tested, installers and deployment packages have been created, user manuals have been updated, architecture docs have been updated, etc. To enable teams to internalize the concept of “Done Done”, they usually get together and come up with their Definition of Done (DoD) that defines all the activities that need to be completed before a feature is considered Done Done. The Done Done technique typically is applied only to features (aka User Stories). What I do is extend this to apply to several concepts such as User Stories, Sprints, Releases (and sometimes Check-Ins). During project kick-off I’ll usually sit down with the team and go through an exercise of creating DoD’s for each of these concepts (Stories/Sprints/Releases). We’ll usually start by just brainstorming a bunch of activities that could end up in these various DoD’s. Here’s some examples: Code Reviews StyleCop FxCop User Manuals Updated Architecture Docs Updated Tested by QA Tested by UAT Installers Created Support Knowledge Base Updated Deployment Instructions (for Ops) written Automated Unit Tests Run Automated Integration Tests Run Then we start by arranging these activities into the place they occur today (e.g. Do you do UAT testing only once per release? every sprint? every feature?). If the team was previously Waterfall most of these activities probably end up in the Release DoD. An extremely mature agile team would probably have most of these activities in the DoD for the User Stories (because an extremely mature agile team will probably do continuous deployment and release every story). So what we need to do as a team, is work to move these activities from their current home (Release DoD) down into the Sprint DoD and eventually into the User Story DoD (and maybe into the lower-level Check-In DoD if we decide to use that). We don’t have to move them all down to User Story immediately, but as a team we figure out what we think we’re capable of moving down to the Sprint cycle, and Story cycle immediately, and that becomes our starting DoD’s. Over time the team makes an effort to continue moving activities down from Release->Sprint->Story as they become more agile and more mature. I try to encourage them to envision a world in which they deploy to production as each User Story is completed. They would need to be updating User Manuals, creating installers, doing UAT testing (typical Release cycle activities) on every single User Story. They may never actually reach that point, but they should envision that, and strive to keep driving the activities down closer to the User Story cycle s they mature. This is a great technique to give a team an easy-to-follow roadmap to mature their agile practices over time. Sure there’s other aspects to maturity outside of this, but it’s a great technique, that’s easy to visualize, to drive agility into the team. Just keep moving those activities (aka “gates”) down the board from Release->Sprint->Story. I’ll try to give an example of what a recent client of mine had for their DoD’s (this is from memory, so probably not 100% accurate): Release Create/Update deployment Instructions For Ops Instructional Videos Updated Run manual regression test suite UAT Testing In this case that meant deploying to an environment shared across the enterprise that mirrored production and asking other business groups to test their own apps to ensure we didn’t break anything outside our system Sprint Deploy to UAT Environment But not necessarily actually request UAT testing occur User Guides updated Sprint Features Video Created In this case we decided to create a video each sprint showing off the progress (video version of Sprint Demo) User Story Manual Test scripts developed and run Tested by BA Deployed in shared QA environment Using automated deployment process Peer Code Review Code Check-In Compiled (warning-free) Passes StyleCop Passes FxCop Create installer packages Run Automated Tests Run Automated Integration Tests PS – One of my clients had a great question when we went through this activity. They said that if a Sprint is by definition done when the end-date rolls around (time-boxed), isn’t a DoD on a sprint meaningless – it’s done on the end-date regardless of whether those other activities are complete or not? My answer is that while that statement is true – the sprint is done regardless when the end date rolls around – if the DoD activities haven’t been completed I would consider the Sprint a failure (similar to not completing what was committed/planned – failure may be too strong a word but you get the idea). In the Retrospective that will become an agenda item to discuss and understand why we weren’t able to complete the activities we agreed would need to be completed each Sprint.

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• My Feelings About Microsoft Surface

  - by Valter Minute

  Advice: read the title carefully, I’m talking about “feelings” and not about advanced technical points proved in a scientific and objective way I still haven’t had a chance to play with a MS Surface tablet (I would love to, of course) and so my ideas just came from reading different articles on the net and MS official statements. Remember also that the MVP motto begins with “Independent” (“Independent Experts. Real World Answers.”) and this is just my humble opinion about a product and a technology. I know that, being an MS MVP you can be called an “MS-fanboy”, I don’t care, I hope that people can appreciate my opinion, even if it doesn’t match theirs. The “Surface” brand can be confusing for techies that knew the “original” surface concept but I think that will be a fresh new brand name for most of the people out there. But marketing department are here to confuse people… so I can understand this “recycle” of an existing name. So Microsoft is entering the hardware arena… for me this is good news. Microsoft developed some nice hardware in the past: the xbox, zune (even if the commercial success was quite limited) and, last but not least, the two arc mices (old and new model) that I use and appreciate. In the past Microsoft worked with OEMs and that model lead to good and bad things. Good thing (for microsoft, at least) is market domination by windows-based PCs that only in the last years has been reduced by the return of the Mac and tablets. Google is also moving in the hardware business with its acquisition of Motorola, and Apple leveraged his control of both the hardware and software sides to develop innovative products. Microsoft can scare OEMs and make them fly away from windows (but where?) or just lead the pack, showing how devices should be designed to compete in the market and bring back some of the innovation that disappeared from recent PC products (look at the shelves of your favorite electronics store and try to distinguish a laptop between the huge mass of anonymous PCs on displays… only Macs shine out there…). Having to compete with MS “official” hardware will force OEMs to develop better product and bring back some real competition in a market that was ruled only by prices (the lower the better even when that means low quality) and no innovative features at all (when it was the last time that a new PC surprised you?). Moving into a new market is a big and risky move, but with Windows 8 Microsoft is playing a crucial move for its future, trying to be back in the innovation run against apple and google. MS can’t afford to fail this time. I saw the new devices (the WinRT and Pro) and the specifications are scarce, misleading and confusing. The first impression is that the device looks like an iPad with a nice keyboard cover… Using “HD” and “full HD” to define display resolution instead of using the real figures and reviving the “ClearType” brand (now dead on Win8 as reported here and missed by people who hate to read text on displays, like myself) without providing clear figures (couldn’t you count those damned pixels?) seems to imply that MS was caught by surprise by apple recent “retina” displays that brought very high definition screens on tablets.Also there are no specifications about the processors used (even if some sources report NVidia Tegra for the ARM tablet and i5 for the x86 one) and expected battery life (a critical point for tablets and the point that killed Windows7 x86 based tablets). Also nothing about the price, and this will be another critical point because other platform out there already provide lots of applications and have a good user base, if MS want to enter this market tablets pricing must be competitive. There are some expansion ports (SD and USB), so no fixed storage model (even if the specs talks about 32-64GB for RT and 128-256GB for pro). I like this and don’t like the apple model where flash memory (that it’s dirt cheap used in thumdrives or SD cards) is as expensive as gold (or cocaine to have a more accurate per gram measurement) when mounted inside a tablet/phone. For big files you’ll be able to use external media and an SD card could be used to store files that don’t require super-fast SSD-like access times, I hope. To be honest I really don’t like the marketplace model and the limitation of Windows RT APIs (no local database? from a company that based a good share of its success on VB6+Access!) and lack of desktop support on the ARM (even if the support is here and has been used to port office). It’s a step toward the consumer market (where competitors are making big money), but may impact enterprise (and embedded) users that may not appreciate Windows 8 new UI or the limitations of the new app model (if you aren’t connected you are dead ). Not having compatibility with the desktop will require brand new applications and honestly made all the CPU cycles spent to convert .NET IL into real machine code in the past like a huge waste of time… as soon as a new processor architecture is supported by Windows you still have to rewrite part of your application (and MS is pushing HTML5+JS and native code more than .NET in my perception). On the other side I believe that the development experience provided by Visual Studio is still miles (or kilometres) ahead of the competition and even the all-uppercase menu of VS2012 hasn’t changed this situation. The new metro UI got mixed reviews. On my side I should say that is very pleasant to use on a touch screen, I like the minimalist design (even if sometimes is too minimal and hides stuff that, in my opinion, should be visible) but I should also say that using it with mouse and keyboard is like trying to pick your nose with boxing gloves… Metro is also very interesting for embedded devices where touch screen usage is quite common and where having an application taking all the screen is the norm. For devices like kiosks, vending machines etc. this kind of UI can be a great selling point. I don’t need a new tablet (to be honest I’m pretty happy with my wife’s iPad and with my PC), but I may change my opinion after having a chance to play a little bit with those new devices and understand what’s hidden under all this mysterious and generic announcements and specifications!

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• "Imprinting" as a language feature?

  - by MKO

  Idea I had this idea for a language feature that I think would be useful, does anyone know of a language that implements something like this? The idea is that besides inheritance a class can also use something called "imprinting" (for lack of better term). A class can imprint one or several (non-abstract) classes. When a class imprints another class it gets all it's properties and all it's methods. It's like the class storing an instance of the imprinted class and redirecting it's methods/properties to it. A class that imprints another class therefore by definition also implements all it's interfaces and it's abstract class. So what's the point? Well, inheritance and polymorphism is hard to get right. Often composition gives far more flexibility. Multiple inheritance offers a slew of different problems without much benefits (IMO). I often write adapter classes (in C#) by implementing some interface and passing along the actual methods/properties to an encapsulated object. The downside to that approach is that if the interface changes the class breaks. You also you have to put in a lot of code that does nothing but pass things along to the encapsulated object. A classic example is that you have some class that implements IEnumerable or IList and contains an internal class it uses. With this technique things would be much easier Example (c#) [imprint List<Person> as peopleList] public class People : PersonBase { public void SomeMethod() { DoSomething(this.Count); //Count is from List } } //Now People can be treated as an List<Person> People people = new People(); foreach(Person person in people) { ... } peopleList is an alias/variablename (of your choice)used internally to alias the instance but can be skipped if not needed. One thing that's useful is to override an imprinted method, that could be achieved with the ordinary override syntax public override void Add(Person person) { DoSomething(); personList.Add(person); } note that the above is functional equivalent (and could be rewritten by the compiler) to: public class People : PersonBase , IList<Person> { private List<Person> personList = new List<Person>(); public override void Add(object obj) { this.personList.Add(obj) } public override int IndexOf(object obj) { return personList.IndexOf(obj) } //etc etc for each signature in the interface } only if IList changes your class will break. IList won't change but an interface that you, someone in your team, or a thirdparty has designed might just change. Also this saves you writing a whole lot of code for some interfaces/abstract classes. Caveats There's a couple of gotchas. First we, syntax must be added to call the imprinted classes's constructors from the imprinting class constructor. Also, what happends if a class imprints two classes which have the same method? In that case the compiler would detect it and force the class to define an override of that method (where you could chose if you wanted to call either imprinted class or both) So what do you think, would it be useful, any caveats? It seems it would be pretty straightforward to implement something like that in the C# language but I might be missing something :) Sidenote - Why is this different from multiple inheritance Ok, so some people have asked about this. Why is this different from multiple inheritance and why not multiple inheritance. In C# methods are either virtual or not. Say that we have ClassB who inherits from ClassA. ClassA has the methods MethodA and MethodB. ClassB overrides MethodA but not MethodB. Now say that MethodB has a call to MethodA. if MethodA is virtual it will call the implementation that ClassB has, if not it will use the base class, ClassA's MethodA and you'll end up wondering why your class doesn't work as it should. By the terminology sofar you might already confused. So what happens if ClassB inherits both from ClassA and another ClassC. I bet both programmers and compilers will be scratching their heads. The benefit of this approach IMO is that the imprinting classes are totally encapsulated and need not be designed with multiple inheritance in mind. You can basically imprint anything.

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• Data Binding to Attached Properties

  - by Chris Gardner

  Originally posted on: http://geekswithblogs.net/freestylecoding/archive/2013/06/14/data-binding-to-attached-properties.aspx When I was working on my C#/XAML game framework, I discovered I wanted to try to data bind my sprites to background objects. That way, I could update my objects and the draw functionality would take care of the work for me. After a little experimenting and web searching, it appeared this concept was an impossible dream. Of course, when has that ever stopped me? In my typical way, I started to massively dive down the rabbit hole. I created a sprite on a canvas, and I bound it to a background object. <Canvas Name="GameField" Background="Black"> <Image Name="PlayerStrite" Source="Assets/Ship.png" Width="50" Height="50" Canvas.Left="{Binding X}" Canvas.Top="{Binding Y}"/> </Canvas> Now, we wire the UI item to the background item. public MainPage() { this.InitializeComponent(); this.Loaded += StartGame; }   void StartGame( object sender, RoutedEventArgs e ) { BindingPlayer _Player = new BindingPlayer(); _Player.X = Window.Current.Bounds.Height - PlayerSprite.Height; _Player.X = ( Window.Current.Bounds.Width - PlayerSprite.Width ) / 2.0; } Of course, now we need to actually have our background object. public class BindingPlayer : INotifyPropertyChanged { private double m_X; public double X { get { return m_X; } set { m_X = value; NotifyPropertyChanged(); } }   private double m_Y; public double Y { get { return m_Y; } set { m_Y = value; NotifyPropertyChanged(); } }   public event PropertyChangedEventHandler PropertyChanged; protected void NotifyPropertyChanged( [CallerMemberName] string p_PropertyName = null ) { if( PropertyChanged != null ) PropertyChanged( this, new PropertyChangedEventArgs( p_PropertyName ) ); } } I fired this baby up, and my sprite was correctly positioned on the screen. Maybe the sky wasn't falling after all. Wouldn't it be great if that was the case? I created some code to allow me to move the sprite, but nothing happened. This seems odd. So, I start debugging the application and stepping through code. Everything appears to be working. Time to dig a little deeper. After much profanity was spewed, I stumbled upon a breakthrough. The code only looked like it was working. What was really happening is that there was an exception being thrown in the background thread that I never saw. Apparently, the key call was the one to PropertyChanged. If PropertyChanged is not called on the UI thread, the UI thread ignores the call. Actually, it throws an exception and the background thread silently crashes. Of course, you'll never see this unless you're looking REALLY carefully. This seemed to be a simple problem. I just need to marshal this to the UI thread. Unfortunately, this object has no knowledge of this mythical UI Thread in which we speak. So, I had to pull the UI Thread out of thin air. Let's change our PropertyChanged call to look this. public event PropertyChangedEventHandler PropertyChanged; protected void NotifyPropertyChanged( [CallerMemberName] string p_PropertyName = null ) { if( PropertyChanged != null ) Windows.ApplicationModel.Core.CoreApplication.MainView.CoreWindow.Dispatcher.RunAsync( Windows.UI.Core.CoreDispatcherPriority.Normal, new Windows.UI.Core.DispatchedHandler( () => { PropertyChanged( this, new PropertyChangedEventArgs( p_PropertyName ) ); } ) ); } Now, we raised our notification on the UI thread. Everything is fine, people are happy, and the world moves on. You may have noticed that I didn't await my call to the dispatcher. This was intentional. If I am trying to update a slew of sprites, I don't want thread being hung while I wait my turn. Thus, I send the message and move on. It is worth nothing that this is NOT the most efficient way to do this for game programming. We'll get to that in another blog post. However, it is perfectly acceptable for a business app that is running a background task that would like to notify the UI thread of progress on a periodic basis. It is worth noting that this code was written for a Windows Store App. You can do the same thing with WP8 and WPF. The call to the marshaler changes, but it is the same idea.

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• Better way to load level content in XNA?

  - by user2002495

  Currently I loaded all my assets in XNA in the main Game class. What I want to achieve later is that I only load specific assets for specific levels (the game will consist of many levels). Here is how I load my main assets into the main class: protected override void LoadContent() { spriteBatch = new SpriteBatch(GraphicsDevice); plane = new Player(Content.Load<Texture2D>(@"Player/playerSprite"), 6, 8); plane.animation = "down"; plane.pos = new Vector2(400, 500); plane.fps = 15; Global.currentPos = plane.pos; lvl1 = new Level1(Content.Load<Texture2D>(@"Levels/bgLvl1"), Content.Load<Texture2D>(@"Levels/bgLvl1-other"), new Vector2(0, 0), new Vector2(0, -600)); CommonBullet.LoadContent(Content); CommonEnemyBullet.LoadContent(Content); } protected override void UnloadContent() { } protected override void Update(GameTime gameTime) { if (GamePad.GetState(PlayerIndex.One).Buttons.Back == ButtonState.Pressed) this.Exit(); plane.Update(gameTime); lvl1.Update(gameTime); foreach (CommonEnemy ce in cel) { if (ce.CollidesWith(plane)) { ce.hasSpawn = false; } foreach (CommonBullet b in plane.commonBulletList) { if (b.CollidesWith(ce)) { ce.hasSpawn = false; } } ce.Update(gameTime); } LoadCommonEnemy(); base.Update(gameTime); } private void LoadCommonEnemy() { int randY = rand.Next(-600, -10); int randX = rand.Next(0, 750); if (cel.Count < 3) { cel.Add(new CommonEnemy(Content.Load<Texture2D>(@"Enemy/Common/commonEnemySprite"), 7, 2, "left", randX, randY)); } for (int i = 0; i < cel.Count; i++) { if (!cel[i].hasSpawn) { cel.RemoveAt(i); i--; } } } protected override void Draw(GameTime gameTime) { GraphicsDevice.Clear(Color.Black); spriteBatch.Begin(); lvl1.Draw(spriteBatch); plane.Draw(spriteBatch); foreach (CommonEnemy ce in cel) { ce.Draw(spriteBatch); } spriteBatch.End(); base.Draw(gameTime); } I wish to load my players, enemies, all in Level1 class. However, when I move my player & enemy code into the Level1 class, the gameTime returns null. Here is my Level1 class: using System; using System.Collections.Generic; using System.Linq; using System.Text; using Microsoft.Xna.Framework; using Microsoft.Xna.Framework.Audio; using Microsoft.Xna.Framework.Content; using Microsoft.Xna.Framework.Graphics; using Microsoft.Xna.Framework.Media; using Microsoft.Xna.Framework.Input; using SpaceShooter_Beta.Animation.PlayerCollection; using SpaceShooter_Beta.Animation.EnemyCollection.Common; namespace SpaceShooter_Beta.Levels { public class Level1 { public Texture2D bgTexture1, bgTexture2; public Vector2 bgPos1, bgPos2; public float speed = 5f; Player plane; public Level1(Texture2D texture1, Texture2D texture2, Vector2 pos1, Vector2 pos2) { this.bgTexture1 = texture1; this.bgTexture2 = texture2; this.bgPos1 = pos1; this.bgPos2 = pos2; } public void LoadContent(ContentManager cm) { plane = new Player(cm.Load<Texture2D>(@"Player/playerSprite"), 6, 8); plane.animation = "down"; plane.pos = new Vector2(400, 500); plane.fps = 15; Global.currentPos = plane.pos; } public void Draw(SpriteBatch sb) { sb.Draw(bgTexture1, bgPos1, Color.White); sb.Draw(bgTexture2, bgPos2, Color.White); plane.Draw(sb); } public void Update(GameTime gt) { bgPos1.Y += speed; bgPos2.Y += speed; if (bgPos1.Y >= 600) { bgPos1.Y = -600; } if (bgPos2.Y >= 600) { bgPos2.Y = -600; } plane.Update(gt); } } } Of course when I did this, I delete all my player's code in the main Game class. All of that works fine (no errors) except that the game cannot start. The debugger says that plane.Update(gt); in Level 1 class has null GameTime, same thing with the Draw method in the Level class. Please help, I appreciate for the time. [EDIT] I know that using switch in the main class can be a solution. But I prefer a cleaner solution than that, since using switch still means I need to load all the assets through the main class, the code will be A LOT later on for each levels

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• Performance triage

  - by Dave

  Folks often ask me how to approach a suspected performance issue. My personal strategy is informed by the fact that I work on concurrency issues. (When you have a hammer everything looks like a nail, but I'll try to keep this general). A good starting point is to ask yourself if the observed performance matches your expectations. Expectations might be derived from known system performance limits, prototypes, and other software or environments that are comparable to your particular system-under-test. Some simple comparisons and microbenchmarks can be useful at this stage. It's also useful to write some very simple programs to validate some of the reported or expected system limits. Can that disk controller really tolerate and sustain 500 reads per second? To reduce the number of confounding factors it's better to try to answer that question with a very simple targeted program. And finally, nothing beats having familiarity with the technologies that underlying your particular layer. On the topic of confounding factors, as our technology stacks become deeper and less transparent, we often find our own technology working against us in some unexpected way to choke performance rather than simply running into some fundamental system limit. A good example is the warm-up time needed by just-in-time compilers in Java Virtual Machines. I won't delve too far into that particular hole except to say that it's rare to find good benchmarks and methodology for java code. Another example is power management on x86. Power management is great, but it can take a while for the CPUs to throttle up from low(er) frequencies to full throttle. And while I love "turbo" mode, it makes benchmarking applications with multiple threads a chore as you have to remember to turn it off and then back on otherwise short single-threaded runs may look abnormally fast compared to runs with higher thread counts. In general for performance characterization I disable turbo mode and fix the power governor at "performance" state. Another source of complexity is the scheduler, which I've discussed in prior blog entries. Lets say I have a running application and I want to better understand its behavior and performance. We'll presume it's warmed up, is under load, and is an execution mode representative of what we think the norm would be. It should be in steady-state, if a steady-state mode even exists. On Solaris the very first thing I'll do is take a set of "pstack" samples. Pstack briefly stops the process and walks each of the stacks, reporting symbolic information (if available) for each frame. For Java, pstack has been augmented to understand java frames, and even report inlining. A few pstack samples can provide powerful insight into what's actually going on inside the program. You'll be able to see calling patterns, which threads are blocked on what system calls or synchronization constructs, memory allocation, etc. If your code is CPU-bound then you'll get a good sense where the cycles are being spent. (I should caution that normal C/C++ inlining can diffuse an otherwise "hot" method into other methods. This is a rare instance where pstack sampling might not immediately point to the key problem). At this point you'll need to reconcile what you're seeing with pstack and your mental model of what you think the program should be doing. They're often rather different. And generally if there's a key performance issue, you'll spot it with a moderate number of samples. I'll also use OS-level observability tools to lock for the existence of bottlenecks where threads contend for locks; other situations where threads are blocked; and the distribution of threads over the system. On Solaris some good tools are mpstat and too a lesser degree, vmstat. Try running "mpstat -a 5" in one window while the application program runs concurrently. One key measure is the voluntary context switch rate "vctx" or "csw" which reflects threads descheduling themselves. It's also good to look at the user; system; and idle CPU percentages. This can give a broad but useful understanding if your threads are mostly parked or mostly running. For instance if your program makes heavy use of malloc/free, then it might be the case you're contending on the central malloc lock in the default allocator. In that case you'd see malloc calling lock in the stack traces, observe a high csw/vctx rate as threads block for the malloc lock, and your "usr" time would be less than expected. Solaris dtrace is a wonderful and invaluable performance tool as well, but in a sense you have to frame and articulate a meaningful and specific question to get a useful answer, so I tend not to use it for first-order screening of problems. It's also most effective for OS and software-level performance issues as opposed to HW-level issues. For that reason I recommend mpstat & pstack as my the 1st step in performance triage. If some other OS-level issue is evident then it's good to switch to dtrace to drill more deeply into the problem. Only after I've ruled out OS-level issues do I switch to using hardware performance counters to look for architectural impediments.

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• Speakers, Please Check Your Time

  - by AjarnMark

  Woodrow Wilson was once asked how long it would take him to prepare for a 10 minute speech. He replied "Two weeks". He was then asked how long it would take for a 1 hour speech. "One week", he replied. 2 hour speech? "I'm ready right now," he replied.  Whether that is a true story or an urban legend, I don’t really know, but either way, it is a poignant reminder for all speakers, and particularly apropos this week leading up to the PASS Community Summit. (Cross-posted to the PASS Professional Development Virtual Chapter blog #PASSProfDev.) What’s the point of that story?  Simply this…if you have plenty of time to do your presentation, you don’t need to prepare much because it is easy to throw in more and more material to stretch out to your allotted time.  But if you are on a tight time constraint, then it will take significant preparation to distill your talk down to only the essential points. I have attended seven of the last eight North American Summit events, and every one of them has been fantastic.  The speakers are great, the material is timely and relevant, and the networking opportunities are awesome.  And every year, there is one little thing that just bugs me…speakers going over their allotted time.  Why does it bother me so?  Well, if you look at a typical schedule for a Summit, you’ll see that there are six or more sessions going on at the same time, and only 15 minutes to move from one to another.  If you’re trying to maximize your training dollar by attending something during every session time slot, and you don’t want to be the last guy trying to squeeze into the middle of the row, then those 15 minutes can be critical.  All the more so if you need to stop and use the bathroom or if you have to hike to the opposite end of the convention center.  It is really a bad position to find yourself having to choose between learning the last key points of Speaker A who is going over time, and getting over to Speaker B on time so you don’t miss her key opening remarks. And frankly, I think it is just rude.  Yes, the speakers are the function, after all they are bringing the content that the rest of us are paying to learn.  But it is also an honor to be given the opportunity to speak at a conference like this, and no one speaker is so important that the conference would be a disaster without him.  Speakers know when they submit their abstract, long before the conference, how much time they will have.  It has been the same pattern at the Summit for at least the last eight years.  Program Sessions are 75 minutes long.  Some speakers who have a good track record, and meet other qualifying criteria, are extended an invitation to present a Spotlight Session which is 90 minutes (a 20% increase).  So there really is no excuse.  It’s not like you were promised a 2-hour segment and then discovered when you got here that it was only 75 minutes.  In fact, it’s not like PASS advertised 90-minute sessions for everyone and then a select few were cut back to only 75.  As a speaker, you know well before you get here which type of session you are doing and how long it is, so as a professional, you should plan accordingly. Now you might think that this only happens to rookies, but I’ll tell you that some of the worst offenders are big-name veterans who draw huge attendance numbers for their sessions.  Some attendees blow this off as, “Hey, it’s so-and-so, and I’d stay here for hours and listen to him/her talk.”  To which I would reply, “Then they should have submitted for a pre- or post-conference day-long seminar instead, but don’t try to squeeze your day-long talk into a 90-minute session.”  Now I don’t really believe that these speakers are being malicious or just selfishly trying to extend their time in the spotlight.  I think that most of them are merely being undisciplined and did not trim their presentation sufficiently, or allowed themselves to get off-track (often in a generous attempt to help someone in the audience with a question or problem that really should have been noted for further discussion after the session). So here is my recommendation…my plea, even.  TRIM THE FAT!  Now.  Before it’s too late.  Before you even get on the airplane, take a long, hard look at your presentation and eliminate some of the points that you originally thought you had to make, but in reality are not truly crucial to your main topic.  Delete a few slides.  Test your demos and have them already scripted rather than typing them during your talk.  It is better to cut out too much and end up with plenty of time at the end for Questions & Answers.  And you can always keep some notes on the stuff that you cut out so that you could fill it back in at the end as bonus material if you really do end up with a whole bunch of time on your hands.  But I don’t think you will.  And if you do, that will look even better to the audience as it will look like you’re giving them something extra that not every audience gets.  And they will thank you for that.

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• JPRT: A Build & Test System

  - by kto

  DRAFT A while back I did a little blogging on a system called JPRT, the hardware used and a summary on my java.net weblog. This is an update on the JPRT system. JPRT ("JDK Putback Reliablity Testing", but ignore what the letters stand for, I change what they mean every day, just to annoy people :\^) is a build and test system for the JDK, or any source base that has been configured for JPRT. As I mentioned in the above blog, JPRT is a major modification to a system called PRT that the HotSpot VM development team has been using for many years, very successfully I might add. Keeping the source base always buildable and reliable is the first step in the 12 steps of dealing with your product quality... or was the 12 steps from Alcoholics Anonymous... oh well, anyway, it's the first of many steps. ;\^) Internally when we make changes to any part of the JDK, there are certain procedures we are required to perform prior to any putback or commit of the changes. The procedures often vary from team to team, depending on many factors, such as whether native code is changed, or if the change could impact other areas of the JDK. But a common requirement is a verification that the source base with the changes (and merged with the very latest source base) will build on many of not all 8 platforms, and a full 'from scratch' build, not an incremental build, which can hide full build problems. The testing needed varies, depending on what has been changed. Anyone that was worked on a project where multiple engineers or groups are submitting changes to a shared source base knows how disruptive a 'bad commit' can be on everyone. How many times have you heard: "So And So made a bunch of changes and now I can't build!". But multiply the number of platforms by 8, and make all the platforms old and antiquated OS versions with bizarre system setup requirements and you have a pretty complicated situation (see http://download.java.net/jdk6/docs/build/README-builds.html). We don't tolerate bad commits, but our enforcement is somewhat lacking, usually it's an 'after the fact' correction. Luckily the Source Code Management system we use (another antique called TeamWare) allows for a tree of repositories and 'bad commits' are usually isolated to a small team. Punishment to date has been pretty drastic, the Queen of Hearts in 'Alice in Wonderland' said 'Off With Their Heads', well trust me, you don't want to be the engineer doing a 'bad commit' to the JDK. With JPRT, hopefully this will become a thing of the past, not that we have had many 'bad commits' to the master source base, in general the teams doing the integrations know how important their jobs are and they rarely make 'bad commits'. So for these JDK integrators, maybe what JPRT does is keep them from chewing their finger nails at night. ;\^) Over the years each of the teams have accumulated sets of machines they use for building, or they use some of the shared machines available to all of us. But the hunt for build machines is just part of the job, or has been. And although the issues with consistency of the build machines hasn't been a horrible problem, often you never know if the Solaris build machine you are using has all the right patches, or if the Linux machine has the right service pack, or if the Windows machine has it's latest updates. Hopefully the JPRT system can solve this problem. When we ship the binary JDK bits, it is SO very important that the build machines are correct, and we know how difficult it is to get them setup. Sure, if you need to debug a JDK problem that only shows up on Windows XP or Solaris 9, you'll still need to hunt down a machine, but not as a regular everyday occurance. I'm a big fan of a regular nightly build and test system, constantly verifying that a source base builds and tests out. There are many examples of automated build/tests, some that trigger on any change to the source base, some that just run every night. Some provide a protection gateway to the 'golden' source base which only gets changes that the nightly process has verified are good. The JPRT (and PRT) system is meant to guard the source base before anything is sent to it, guarding all source bases from the evil developer, well maybe 'evil' isn't the right word, I haven't met many 'evil' developers, more like 'error prone' developers. ;\^) Humm, come to think about it, I may be one from time to time. :\^{ But the point is that by spreading the build up over a set of machines, and getting the turnaround down to under an hour, it becomes realistic to completely build on all platforms and test it, on every putback. We have the technology, we can build and rebuild and rebuild, and it will be better than it was before, ha ha... Anybody remember the Six Million Dollar Man? Man, I gotta get out more often.. Anyway, now the nightly build and test can become a 'fetch the latest JPRT build bits' and start extensive testing (the testing not done by JPRT, or the platforms not tested by JPRT). Is it Open Source? No, not yet. Would you like to be? Let me know. Or is it more important that you have the ability to use such a system for JDK changes? So enough blabbering on about this JPRT system, tell me what you think. And let me know if you want to hear more about it or not. Stay tuned for the next episode, same Bloody Bat time, same Bloody Bat channel. ;\^) -kto

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• Orchard shapeshifting

  - by Bertrand Le Roy

  I've shown in a previous post how to make it easier to change the layout template for specific contents or areas. But what if you want to change another shape template for specific pages, for example the main Content shape on the home page? Here's how. When we changed the layout, we had the problem that layout is created very early, so early that in fact it can't know what content is going to be rendered. For that reason, we had to rely on a filter and on the routing information to determine what layout template alternates to add. This time around, we are dealing with a content shape, a shape that is directly related to a content item. That makes things a little easier as we have access to a lot more information. What I'm going to do here is handle an event that is triggered every time a shape named "Content" is about to be displayed: public class ContentShapeProvider : IShapeTableProvider { public void Discover(ShapeTableBuilder builder) { builder.Describe("Content") .OnDisplaying(displaying => { // do stuff to the shape }); } } .csharpcode, .csharpcode pre { font-size: small; color: black; font-family: consolas, "Courier New", courier, monospace; background-color: #ffffff; /*white-space: pre;*/ } .csharpcode pre { margin: 0em; } .csharpcode .rem { color: #008000; } .csharpcode .kwrd { color: #0000ff; } .csharpcode .str { color: #006080; } .csharpcode .op { color: #0000c0; } .csharpcode .preproc { color: #cc6633; } .csharpcode .asp { background-color: #ffff00; } .csharpcode .html { color: #800000; } .csharpcode .attr { color: #ff0000; } .csharpcode .alt { background-color: #f4f4f4; width: 100%; margin: 0em; } .csharpcode .lnum { color: #606060; } This handler is implemented in a shape table provider which is where you do all shape related site-wide operations. The first thing we want to do in this event handler is check that we are on the front-end, displaying the "Detail" version, and not the "Summary" or the admin editor: if (displaying.ShapeMetadata.DisplayType == "Detail") { Now I want to provide the ability for the theme developer to provide an alternative template named "Content-HomePage.cshtml" for the home page. In order to determine if we are indeed on the home page I can look at the current site's home page property, which for the default home page provider contains the home page item's id at the end after a semicolon. Compare that with the content item id for the shape we are looking at and you can know if that's the homepage content item. Please note that if that content is also displayed on another page than the home page it will also get the alternate: we are altering at the shape level and not at the URL/routing level like we did with the layout. ContentItem contentItem = displaying.Shape.ContentItem; if (_workContextAccessor.GetContext().CurrentSite .HomePage.EndsWith(';' + contentItem.Id.ToString())) { _workContextAccessor is an injected instance of IWorkContextAccessor from which we can get the current site and its home page. Finally, once we've determined that we are in the specific conditions that we want to alter, we can add the alternate: displaying.ShapeMetadata.Alternates.Add("Content__HomePage"); And that's it really. Here's the full code for the shape provider that I added to a custom theme (but it could really live in any module or theme): using Orchard; using Orchard.ContentManagement; using Orchard.DisplayManagement.Descriptors; namespace CustomLayoutMachine.ShapeProviders { public class ContentShapeProvider : IShapeTableProvider { private readonly IWorkContextAccessor _workContextAccessor; public ContentShapeProvider( IWorkContextAccessor workContextAccessor) { _workContextAccessor = workContextAccessor; } public void Discover(ShapeTableBuilder builder) { builder.Describe("Content") .OnDisplaying(displaying => { if (displaying.ShapeMetadata.DisplayType == "Detail") { ContentItem contentItem = displaying.Shape.ContentItem; if (_workContextAccessor.GetContext() .CurrentSite.HomePage.EndsWith( ';' + contentItem.Id.ToString())) { displaying.ShapeMetadata.Alternates.Add( "Content__HomePage"); } } }); } } } The code for the custom theme, with layout and content alternates, can be downloaded from the following link: Orchard.Themes.CustomLayoutMachine.1.0.nupkg Note: this code is going to be used in the Contoso theme that should be available soon from the theme gallery.

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• What is Happening vs. What is Interesting

  - by Geertjan

  Devoxx 2011 was yet another confirmation that all development everywhere is either on the web or on mobile phones. Whether you looked at the conference schedule or attended sessions or talked to speakers at any point at all, it was very clear that no development whatsoever is done anymore on the desktop. In fact, that's something Tim Bray himself told me to my face at the speakers dinner. No new developments of any kind are happening on the desktop. Everyone who is currently on the desktop is working overtime to move all of their applications to the web. They're probably also creating a small subset of their application on an Android tablet, with an even smaller subset on their Android phone. Then you scratch that monolithic surface and find some interesting results. Without naming any names, I asked one of these prominent "ah, forget about the desktop" people at the Devoxx speakers dinner (and I have a witness): "Yes, the desktop is dead, but what about air traffic control, stock trading, oil analysis, risk management applications? In fact, what about any back office application that needs to be usable across all operating systems? Here there is no concern whatsoever with 100% accessibility which is, after all, the only thing that the web has over the desktop, (except when there's a network failure, of course, or when you find yourself in the 3/4 of the world where there's bandwidth problems)? There are 1000's of hidden applications out there that have processing requirements, security requirements, and the requirement that they'll be available even when the network is down or even completely unavailable. Isn't that a valid use case and aren't there 1000's of applications that fall into this so-called niche category? Are you not, in fact, confusing consumer applications, which are increasingly web-based and mobile-based, with high-end corporate applications, which typically need to do massive processing, of one kind or another, for which the web and mobile worlds are completely unsuited?" And you will not believe what the reply to the above question was. (Again, I have a witness to this discussion.) But here it is: "Yes. But those applications are not interesting. I do not want to spend any of my time or work in any way on those applications. They are boring." I'm sad to say that the leaders of the software development community, including those in the Java world, either share the above opinion or are led by it. Because they find something that is not new to be boring, they move on to what is interesting and start talking like the supposedly-boring developments don't even exist. (Kind of like a rapper pretending classical music doesn't exist.) Time and time again I find myself giving Java desktop development courses (at companies, i.e., not hobbyists, or students, but companies, i.e., the places where dollars are earned), where developers say to me: "The course you're giving about creating cross-platform, loosely coupled, and highly cohesive applications is really useful to us. Why do we never find information about this topic at conferences? Why can we never attend a session at a conference where the story about pluggable cross-platform Java is told? Why do we get the impression that we are uncool because we're not on the web and because we're not on a mobile phone, while the reason for that is because we're creating $1000,000 simulation software which has nothing to gain from being on the web or on the mobile phone?" And then I say: "Because nobody knows you exist. Because you're not submitting abstracts to conferences about your very interesting use cases. And because conferences tend to focus on what is new, which tends to be web related (especially HTML 5) or mobile related (especially Android). Because you're not taking the responsibility on yourself to tell the real stories about the real applications being developed all the time and every day. Because you yourself think your work is boring, while in fact it is fascinating. Because desktop developers are working from 9 to 5 on the desktop, in secure environments, such as banks and defense, where you can't spend time, nor have the interest in, blogging your latest tip or trick, as opposed to web developers, who tend to spend a lot of time on the web anyway and are therefore much more inclined to create buzz about the kind of work they're doing." So, next time you look at a conference program and wonder why there's no stories about large desktop development projects in the program, here's the short answer: "No one is going to put those items on the program until you start submitting those kinds of sessions. And until you start blogging. Until you start creating the buzz that the web developers have been creating around their work for the past 10 years or so. And, yes, indeed, programmers get the conference they deserve." And what about Tim Bray? Ask yourself, as Google's lead web technology evangelist, how many desktop developers do you think he talks to and, more generally, what his frame of reference is and what, clearly, he considers to be most interesting.

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• Collision Detection problems in Voxel Engine (XNA)

  - by Darestium

  I am creating a minecraft like terrain engine in XNA and have had some collision problems for quite some time. I have checked and changed my code based on other peoples collision code and I still have the same problem. It always seems to be off by about a block. for instance, if I walk across a bridge which is one block high I fall through it. Also, if you walk towards a "row" of blocks like this: You are able to stand "inside" the left most one, and you collide with nothing in the right most side (where there is no block and is not visible on this image). Here is all my collision code: private void Move(GameTime gameTime, Vector3 direction) { float speed = playermovespeed * (float)gameTime.ElapsedGameTime.TotalSeconds; Matrix rotationMatrix = Matrix.CreateRotationY(player.Camera.LeftRightRotation); Vector3 rotatedVector = Vector3.Transform(direction, rotationMatrix); rotatedVector.Normalize(); Vector3 testVector = rotatedVector; testVector.Normalize(); Vector3 movePosition = player.position + testVector * speed; Vector3 midBodyPoint = movePosition + new Vector3(0, -0.7f, 0); Vector3 headPosition = movePosition + new Vector3(0, 0.1f, 0); if (!world.GetBlock(movePosition).IsSolid && !world.GetBlock(midBodyPoint).IsSolid && !world.GetBlock(headPosition).IsSolid) { player.position += rotatedVector * speed; } //player.position += rotatedVector * speed; } ... public void UpdatePosition(GameTime gameTime) { player.velocity.Y += playergravity * (float)gameTime.ElapsedGameTime.TotalSeconds; Vector3 footPosition = player.Position + new Vector3(0f, -1.5f, 0f); Vector3 headPosition = player.Position + new Vector3(0f, 0.1f, 0f); // If the block below the player is solid the Y velocity should be zero if (world.GetBlock(footPosition).IsSolid || world.GetBlock(headPosition).IsSolid) { player.velocity.Y = 0; } UpdateJump(gameTime); UpdateCounter(gameTime); ProcessInput(gameTime); player.Position = player.Position + player.velocity * (float)gameTime.ElapsedGameTime.TotalSeconds; velocity = Vector3.Zero; } and the one and only function in the camera class: protected void CalculateView() { Matrix rotationMatrix = Matrix.CreateRotationX(upDownRotation) * Matrix.CreateRotationY(leftRightRotation); lookVector = Vector3.Transform(Vector3.Forward, rotationMatrix); cameraFinalTarget = Position + lookVector; Vector3 cameraRotatedUpVector = Vector3.Transform(Vector3.Up, rotationMatrix); viewMatrix = Matrix.CreateLookAt(Position, cameraFinalTarget, cameraRotatedUpVector); } which is called when the rotation variables are changed: public float LeftRightRotation { get { return leftRightRotation; } set { leftRightRotation = value; CalculateView(); } } public float UpDownRotation { get { return upDownRotation; } set { upDownRotation = value; CalculateView(); } } World class: public Block GetBlock(int x, int y, int z) { if (InBounds(x, y, z)) { Vector3i regionalPosition = GetRegionalPosition(x, y, z); Vector3i region = GetRegionPosition(x, y, z); return regions[region.X, region.Y, region.Z].Blocks[regionalPosition.X, regionalPosition.Y, regionalPosition.Z]; } return new Block(BlockType.none); } public Vector3i GetRegionPosition(int x, int y, int z) { int regionx = x == 0 ? 0 : x / Variables.REGION_SIZE_X; int regiony = y == 0 ? 0 : y / Variables.REGION_SIZE_Y; int regionz = z == 0 ? 0 : z / Variables.REGION_SIZE_Z; return new Vector3i(regionx, regiony, regionz); } public Vector3i GetRegionalPosition(int x, int y, int z) { int regionx = x == 0 ? 0 : x / Variables.REGION_SIZE_X; int X = x % Variables.REGION_SIZE_X; int regiony = y == 0 ? 0 : y / Variables.REGION_SIZE_Y; int Y = y % Variables.REGION_SIZE_Y; int regionz = z == 0 ? 0 : z / Variables.REGION_SIZE_Z; int Z = z % Variables.REGION_SIZE_Z; return new Vector3i(X, Y, Z); } Any ideas how to fix this problem? EDIT 1: Graphic of the problem: EDIT 2 GetBlock, Vector3 version: public Block GetBlock(Vector3 position) { int x = (int)Math.Floor(position.X); int y = (int)Math.Floor(position.Y); int z = (int)Math.Ceiling(position.Z); Block block = GetBlock(x, y, z); return block; } Now, the thing is I tested the theroy that the Z is always "off by one" and by ceiling the value it actually works as intended. Altough it still could be greatly more accurate (when you go down holes you can see through the sides, and I doubt it will work with negitive positions). I also does not feel clean Flooring the X and Y values and just Ceiling the Z. I am surely not doing something correctly still.

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• Windows Phone 8 Announcement

  - by Tim Murphy

  As if the Surface announcement on Monday wasn’t exciting enough, today Microsoft announce that Windows Phone 8 will be coming this fall.  That itself is great news, but the features coming were like confetti flying in all different directions.  Given this speed I couldn’t capture every feature they covered.  A summary of what I did capture is listed below starting with their eight main features. Common Core The first thing that they covered is that Windows Phone 8 will share a core OS with Windows 8.  It will also run natively on multiple cores.  They mentioned that they have run it on up to 64 cores to this point.  The phones as you might expect will at least start as dual core.  If you remember there were metrics saying that Windows Phone 7 performed operations faster on a single core than other platforms did with dual cores.  The metrics they showed here indicate that Windows Phone 8 runs faster on comparable dual core hardware than other platforms. New Screen Resolutions Screen resolution has never been an issue for me, but it has been a criticism of Windows Phone 7 in the media.  Windows Phone 8 will supports three screen resolutions: WVGA 800 x 480, WXGA 1280 x 768, and 720 1280x720.  Hopefully this makes pixel counters a little happier. MicroSD Support This was one of my pet peeves when I got my Samsung Focus. With Windows Phone 8 the operating system will support adding MicroSD cards after initial setup.  Of course this is dependent on the hardware company on implementing it, but I think we have seen that even feature phone manufacturers have not had a problem supporting this in the past. NFC NFC has been an anticipated feature for some time.  What Microsoft showed today included the fact that they didn’t just want it to be for the phone.  There is cross platform NFC functionality between Windows Phone 8 and Windows 8.  The demos , while possibly a bit fanciful, showed would could be achieved even in a retail environment.  We are getting closer and closer to a Minority Report world with these technologies. Wallet Windows Phone 8 isn’t the first platform to have a wallet concept.  What they have done to differentiate themselves is to make it sot that it is not dependent on a SIM type chip like other platforms.  They have also expanded the concept beyond just banks to other types of credits such as airline miles. Nokia Mapping People have been envious of the Lumia phones having the Nokia mapping software.  Now all Windows Phone 8 devices will use NavTeq data and will have the capability to run in an offline fashion.  This is a major step forward from the Bing “touch for the next turn” maps. IT Administration The lack of features for enterprise administration and deployment was a complaint even before the Windows Phone 7 was released.  With the Windows Phone 8 release such features as Bitlocker and Secure boot will be baked into the OS. We will also have the ability to privately sign and distribute applications. Changing Start Screen Joe Belfiore made a big deal about this aspect of the new release.  Users will have more color themes available to them and the live tiles will be highly customizable. You will have the ability to resize and organize the tiles in a more dynamic way.  This allows for less important tiles or ones with less information to be made smaller.  And There Is More So what other tidbits came out of the presentation?  Later this summer the API for WP8 will be available.  There will be developer events coming to a city near you.  Another announcement of interest to developers is the ability to write applications at a native code level.  This is a boon for game developers and those who need highly efficient applications. As a topper on the cake there was mention of in app payment. On the consumer side we also found out that all updates will be available over the air.  Along with this came the fact that Microsoft will support all devices with updates for at least 18 month and you will be able to subscribe for early updates.  Update coming for Windows Phone 7.5 customers to WP7.8.  The main enhancement will be the new live tile features.  The big bonus is that the update will bypass the carriers.  I would assume though that you will be brought up to date with all previous patches that your carrier may not have released. There is so much more, but that is enough for one post.  Needless to say, EXCITING! del.icio.us Tags: Windows Phone 8,WP8,Windows Phone 7,WP7,Announcements,Microsoft

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• World Backup Day

  - by red(at)work

  Here at Red Gate Towers, the SQL Backup development team have been hunkered down in their shed for the last few months, with the toolbox, blowtorch and chamois leather out, upgrading SQL Backup. When we started, autumn leaves were falling. Now we're about to finish, spring flowers are budding. If not quite a gleaming new machine, at the very least a familiar, reliable engine with some shiny new bits on it will trundle magnificently out of the workshop. One of the interesting things I've noticed about working on software development teams is that the team is together for so long 'implementing' stuff - designing, coding, testing, fixing bugs and so on - that you occasionally forget why you're doing what you're doing. Doubt creeps in. It feels like a long time since we launched this project in a fanfare of optimism and enthusiasm, and all that clarity of purpose and mission "yee-haw" has dissipated with the daily pressures of development. Every now and again, we look up from our bunker and notice all those thousands of users out there, with their different configurations and working practices and each with their own set of problems and requirements, and we ask ourselves "does anyone care about what we're doing?" Has the world moved on while we've been busy? Could we have been doing something more useful with the time and talent of all these excellent people we've assembled? In truth, you can research and test and validate all you like, but you never really know if you've done the right thing (or at least, something valuable for some users) until you release. All projects suffer this insecurity. If they don't, maybe you're not worrying enough about what you're building. The two enemies of software development are certainty and complacency. Oh, and of course, rival teams with Nerf guns. The goal of SQL Backup 7 is to make it so easy to schedule regular restores of your backups that you have no excuse not to. Why schedule a restore? Because your data is not as good as your last backup. It's only as good as your last successful restore. If you're not checking your backups by restoring them and running an integrity check on the database, you're only doing half the job. It seems that most DBAs know that this is best practice, but it can be tricky and time-consuming to set up, so it's one of those tasks that can get forgotten in the midst all the other demands on their time. Sometimes, they're just too busy firefighting. But if it was simple to do? That was our inspiration for SQL Backup 7. So it was heartening to read Brent Ozar's blog post the other day about World Backup Day. To be honest, I'd never heard of World Backup Day (Talk Like a Pirate Day, yes, but not this one); however, its emphasis on not just backing up your data but checking the validity of those backups was exactly the same message we had in mind when building SQL Backup 7. It's printed on a piece of A3 above our planning board - "Make backup verification so easy to do that no DBA has an excuse for not doing it" It's the missing piece that completes the puzzle. Simple idea, great concept, useful feature, but, as it turned out, far from straightforward to implement. The problem is the future. As Marty McFly discovered over the course of three movies, the future is uncertain and hard to predict - so when you are scheduling a restore to take place an hour, day, week or month after the backup, there are all kinds of questions that you wouldn't normally have to consider. Where will this backup live? Will it even exist at the time? Will it be split into multiple files? What will the file names be? Will it be encrypted? What files should it be restored to? SQL Backup needs to know what to expect at the time the restore job is actually run. Of course, a DBA will know the answer to all these questions, but to deliver the whole point of version 7, we wanted to make it easy for them to input that information into SQL Backup. We think we've done that. When you create your scheduled backup job, there is now an option to create a "reminder" to follow it up with a scheduled restore to verify the resulting backups. Actually, it's much more than a reminder, as it stores all the relevant data so you can click it and pre-populate the wizard with all the right settings to set up your verification restores. Simple. But, what do you think? We'd love you to try it. Post by Brian Harris

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• Extending Expression Blend 4 &amp; Blend for Visual Studio 2012

  - by Chris Skardon

  Just getting this off the bat, I presume this will also work for Blend 5, but I can’t confirm it… Anyhews, I imagine you’re here because you want to know how to create an addin for Blend, so let’s jump right in there! First, and foremost, we’re going to need to ensure our development environment has the right setup, so the checklist: Visual Studio 2012 Blend for Visual Studio 2012 OK, let’s create a new project (class library, .NET 4.5): Hello.Extension The ‘.Extension’ bit is very very important. The addin will not work unless it is named in this way. You can put whatever you want at the front, but it has to have the extension bit. OK, so now we have a solution with one project. To this project we need to add references to the following things: Microsoft.Expression.Extensibility (from c:\program files\Microsoft Visual Studio 11.0\Blend\   -- x86 folder if you are on an x64 windows install) Microsoft.Expression.Framework (same location as above) PresentationCore PresentationFramework WindowsBase System.ComponentModel.Composition Got them? ACE. Let’s now add a project to contain our control, so, create a new WPF Application project, cunningly named something like ‘Hello.Control’… (I’m creating a WPF application here, because I’m too lazy to dig up the correct references, and this will add all the ones I need ) Once that is created, delete the App.xaml and MainWindow.xaml files, we won’t be needing them. You will also need to change the properties of the project itself, so it is only a class library. Once that is done, let’s add a new UserControl, which will be this: <UserControl x:Class="Hello.Control.HelloControl" xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation" xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml" xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006" xmlns:d="http://schemas.microsoft.com/expression/blend/2008" mc:Ignorable="d" d:DesignHeight="300" d:DesignWidth="300"> <Grid> <TextBlock Text="HELLO!!!"/> </Grid> </UserControl> Impressive eh? Now, let’s reference the WPF project from the Extension library. All that’s left now is to code up our extension… So, add a class to the Extension project (name wise doesn’t matter), and make it implement the IPackage interface from the Microsoft.Expression.Extensibility library: public class HelloExtension : IPackage { /**/ } We’ll implement the two methods we need to: public class HelloExtension : IPackage { public void Load(IServices services) { } public void Unload() { } } We’re only really concerned about the Load method in this case, as let’s face it, the extension we have doesn’t need to do a lot to bog off. The interesting thing about the Load method is that it receives an IServices instance. This allows us to get access to all the services that Expression provides, in this case we’re interested in one in particular, the ‘IWindowService’ So, let’s get that bad boy… private IWindowService _windowService; public void Load(IServices services) { _windowService = services.GetService<IWindowService>(); } Nailed it… But why? The WindowService allows us to register our UserControl with Blend, which in turn allows people to activate and see it, which is a big plus point. So, let’s do that… We’ll create an ‘Initialize’ method to create our new control, and add it to the WindowService: private HelloControl _helloControl; public void Initialize() { _helloControl = new HelloControl(); if (_windowService.PaletteRegistry["HelloPanel"] == null) _windowService.RegisterPalette("HelloPanel", _helloControl, "Hello Window"); } First we check that we’re not already registered, and if we’re not we register, the first argument is the identifier used by the service to, well, identify your extension. The second argument is the actual control, the third argument is the name that people will see in the ‘Windows’ menu of Blend itself (so important note here – don’t put anything embarrassing or (need I say it?) sweary…) There are only two things to do now - Call ‘Initialize()’ from our Load method, and Export the class This is easy money – add [Export(typeof(IPackage))] to the top of our class… The full code will (should) look like this: [Export(typeof (IPackage))] public class HelloExtension : IPackage { private HelloControl _helloControl; private IWindowService _windowService; public void Load(IServices services) { _windowService = services.GetService<IWindowService>(); Initialize(); } public void Unload() { } public void Initialize() { _helloControl = new HelloControl(); if (_windowService.PaletteRegistry["HelloControl"] == null) _windowService.RegisterPalette("HelloControl", _helloControl, "Hello Window"); } } If you build this and copy it to your ‘Extensions’ folder in Blend (c:\program files\microsoft visual studio 11.0\blend\) and start Blend, you should see ‘Hello Window’ listed in the Window menu: That as they say is it!

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• Trouble with Samba Domain

  - by Arkevius

  I'm having a bit of trouble setting up this Samba domain correctly. I'm getting an Access Denied error when trying to add a Windows XP machine to the domain. I'll go through my scenario in detail, but for those of you wanting a TLDR summary it'll be at the bottom of this post. I have HP Proliant server with Ubuntu 12.04 LTS installed. For this particular environment, I need this server to act as a PDC, file server, and print server. I began by updating and upgrading the packages (of course). Then went to install samba, gnome-desktop, wine, and cpanm. Samba was, of course, for the PDC and file/print services. The GUI was needed because a certain software has to be installed on there that needs a GUI. Wine was needed because the software is Windows-native. And cpanm was for a perl script I have running. For Samba, I went into the smb.conf file and enabled domain logons, changed the workgroup/domain name, the logon script for a per-group basis (netlogon/%g), enabled the netlogon and profiles share, and setup a couple of custom shares for the file service. The printer was added later, and seems to be working just fine. I then restarted the services, and used the net groupmap command to ensure my unix groups were mapped correctly to the Windows groups. After this, I went to a Windows box, and was able to successfully join the domain without a problem. After some fidgeting with the software to get it running on the win boxes from the server (it's a records management system program, which stores it's database files on the server), I went to add another computer to the domain. But now it's saying Access Denied. Before when I had this trouble it was because I forgot to add the group "machines" so Samba could create machine accounts. Thinking this was the case, I manually created the machine account to test this theory. However, it would still give me an Access Denied error. That must mean it has something to do with permissions now, correct? I've been fighting with this server for the past two weeks. If it's not one thing that;s wrong, then it's something else completely different. This would be the third time I've actually reinstalled everything to start over. I'll post snippets of my system settings below. If anything else is needed, just say the word and I'll gather up the info. The unix group 'domadmin' is the Domain Admins group. Samba Administrator account administrator:x:1000:1000:Administrator,,,:/home/administrator:/bin/bash Adminstrator's groups administrator adm cdrom sudo dip plugdev lpadmin sambashare domadmin crimestar Samba's Configuration FIle (a snippet anyways) [global] workgroup = CITYPD server string = BPDServer dns proxy = no log file = /var/log/samba/log.%m max log size = 1000 syslog = 0 panic action = /usr/share/samba/panic-action %d security = user encrypt passwords = true passdb backend = tdbsam obey pam restrictions = yes unix password sync = yes passwd program = /usr/bin/passwd %u passwd chat = *Enter\snew\s*\spassword:* %n\n *Retype\snew\s*\spassword:* %n\n *password\supdated\ssuccessfully* . pam password change = yes map to guest = bad user domain logons = yes logon path = \\%L\srv\samba\profiles\%U logon script = logon.bat add machine script = /usr/sbin/useradd -g machines -c "%u machine account" -d /var/lib/samba -s /bin/false %u domain master = yes usershare allow guests = yes [netlogon] comment = Network Logon Service path = /srv/samba/netlogon/%g guest ok = yes read only = yes browseable = no [profiles] comment = All Printers browseable = no path = /var/spool/samba printable = yes guest ok = no read only = yes create mask = 0700 [print$] comment = Printer Drivers path = /var/lib/samba/printers browseable = yes read only = yes guest ok = no write list = root, @lpadmin [crimestar] comment = "Crimestar DB" path = /srv/crimestar/db valid users = @domadmin, @crimestar admin users = administrator writeable = yes guest ok = no browseable = no create mask = 0666 directory mask = 0777 [crimestarfiles] path = /home/administrator/.wine/drive_c/crimestar admin users = administrator browseable = yes ls -la on /srv/samba/profiles drwxrwxrwx 2 root machines 4096 Nov 21 15:27 . drwxr-xr-x 4 root root 4096 Nov 21 15:28 .. ls -la on /srv/samba/netlogon drwxr-xr-x 6 root root 4096 Nov 21 15:30 . drwxr-xr-x 4 root root 4096 Nov 21 15:28 .. drwxr-xr-x 2 root root 4096 Nov 21 15:30 crimestar drwxr-xr-x 2 root root 4096 Nov 21 18:13 domadmin drwxr-xr-x 3 root root 4096 Nov 21 15:30 guests drwxr-xr-x 2 root root 4096 Nov 21 15:29 users GrouMap list Domain Users (S-1-5-21-2978508755-2341913247-928297747-513) -> users Domain Admins (S-1-5-21-2978508755-2341913247-928297747-512) -> domadmin Domain Guests (S-1-5-21-2978508755-2341913247-928297747-514) -> nogroup TLDR I'm getting an Access Denied error message while trying to join a windows box to a samba domain, even after I successfully joined another computer without a problem. System settings / files are quoted above. Anyone have any ideas or suggestions?

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• Navigate Quickly with JustCode and Ctrl+Click

  Ctrl + Click is a widely used shortcut for Go To Definition in many development environments but not in Visual Studio. We, the JustCode team, find it really useful so we added it to Visual Studio. But we didn't stop there - we improved it even further. Read on to find the details. With JustCode you get an enhanced Go To Definition. By default you can execute it in the Visual Studio editor using one of the following shortcuts: Middle Click, Ctrl+Left Click, F12, Ctrl+Enter, Ctrl+B. The first usage of this feature is not much different from the default Visual Studio Go To Definition command use it where a member, type, method, property, etc is used to navigate to the definition of that item. For example, if you have this method:         public void Start()         {             lion = new Lion();             lion.Roar();         } If you hold Ctrl and click on the usage of the lion you will go to the lion member definition. If you hold Ctrl and click on the Lion you will go to the Lion class definition. What we added is the ability to easily find all the usages of the item you just navigated to. For example:     public class Lion     {         public void Roar()         {             Console.WriteLine("Rhaaaar");         }     }   If you hold Ctrl and click on the Lion definition you will see all the usages of the Lion type; if you click on the Roar method definition you will see all the usages of the Roar method: And if there is only one usage you will get automatically to that usage. In the examples I use C#, but it works also in VB.NET, JavaScript, ASP.NET and XAML. Why we like this feature? Let me first start with how the Ctrl+Click (or Go To Definition command) is used. We noticed that developers use it especially in what we call "code browsing sessions". In simple words this is when you browse around the code looking for a bug, just reading the code or searching for something. Sounds familiar? In our experience when you go to the definition of some item you often want to know more about it and the first thing you need is to find its usages. With JustCode this is just one click away. Why Ctrl+Click/Middle Click over F12/Ctrl+Enter/Ctrl+B? Actually you can use all of them. But during these "code browsing sessions" we noticed that most developers use the mouse. So the mouse is already in use and pressing Ctrl+Click (or the Middle Click) is so natural. During heavy coding sessions or if you are a keyboard type developer F12 (or any of the other keyboard shortcuts) is the key. We really use heavily this feature not only in our team but in the whole company. It saves us a bit of time many times a day. And it adds up. We hope you will like it too. Your feedback is more than welcome for us. P.S. If you dont want JustCode to capture the Ctrl+Click and the Middle Click in the editor, you can change that in JustCode->Options->General in the Navigation group. Keyboard shortcuts can be reassigned using the Visual Studio keyboard shortcuts editor.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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• Content in Context: The right medicine for your business applications

  - by Lance Shaw

  For many of you, your companies have already invested in a number of applications that are critical to the way your business is run. HR, Payroll, Legal, Accounts Payable, and while they might need an upgrade in some cases, they are all there and handling the lifeblood of your business. But are they really running as efficiently as they could be? For many companies, the answer is no. The problem has to do with the important information caught up within documents and paper. It’s everywhere except where it truly needs to be – readily available right within the context of the application itself. When the right information cannot be easily found, business processes suffer significantly. The importance of this recently struck me when I recently went to meet my new doctor and get a routine physical. Walking into the office lobby, I couldn't help but notice rows and rows of manila folders in racks from floor to ceiling, filled with documents and sensitive, personal information about various patients like myself.  As I looked at all that paper and all that history, two things immediately popped into my head.  “How do they find anything?” and then the even more alarming, “So much for information security!” It sure looked to me like all those documents could be accessed by anyone with a key to the building. Now the truth is that the offices of many general practitioners look like this all over the United States and the world.  But it had me thinking, is the same thing going on in just about any company around the world, involving a wide variety of important business processes? Probably so. Think about all the various processes going on in your company right now. Invoice payments are being processed through Accounts Payable, contracts are being reviewed by Procurement, and Human Resources is reviewing job candidate submissions and doing background checks. All of these processes and many more like them rely on access to forms and documents, whether they are paper or digital. Now consider that it is estimated that employee’s spend nearly 9 hours a week searching for information and not finding it. That is a lot of very well paid employees, spending more than one day per week not doing their regular job while they search for or re-create what already exists. Back in the doctor’s office, I saw this trend exemplified as well. First, I had to fill out a new patient form, even though my previous doctor had transferred my records over months previously. After filling out the form, I was later introduced to my new doctor who then interviewed me and asked me the exact same questions that I had answered on the form. I understand that there is value in the interview process and it was great to meet my new doctor, but this simple process could have been so much more efficient if the information already on file could have been brought directly together with the new patient information I had provided. Instead of having a highly paid medical professional re-enter the same information into the records database, the form I filled out could have been immediately scanned into the system, associated with my previous information, discrepancies identified, and the entire process streamlined significantly. We won’t solve the health records management issues that exist in the United States in this blog post, but this example illustrates how the automation of information capture and classification can eliminate a lot of repetitive and costly human entry and re-creation, even in a simple process like new patient on-boarding. In a similar fashion, by taking a fresh look at the various processes in place today in your organization, you can likely spot points along the way where automating the capture and access to the right information could be significantly improved. As you evaluate how content-process flows through your organization, take a look at how departments and regions share information between the applications they are using. Business applications are often implemented on an individual department basis to solve specific problems but a holistic approach to overall information management is not taken at the same time. The end result over the years is disparate applications with separate information repositories and in many cases these contain duplicate information, or worse, slightly different versions of the same information. This is where Oracle WebCenter Content comes into the story. More and more companies are realizing that they can significantly improve their existing application processes by automating the capture of paper, forms and other content. This makes the right information immediately accessible in the context of the business process and making the same information accessible across departmental systems which has helped many organizations realize significant cost savings. Here on the Oracle WebCenter team, one of our primary goals is to help customers find new ways to be more effective, more cost-efficient and manage information as effectively as possible. We have a series of three webcasts occurring over the next few weeks that are focused on the integration of enterprise content management within the context of business applications. We hope you will join us for one or all three and that you will find them informative. Click here to learn more about these sessions and to register for them. There are many aspects of information management to consider as you look at integrating content management within your business applications. We've barely scratched the surface here but look for upcoming blog posts where we will discuss more specifics on the value of delivering documents, forms and images directly within applications like Oracle E-Business Suite, PeopleSoft Enterprise, JD Edwards Enterprise One, Siebel CRM and many others. What do you think?  Are your important business processes as healthy as they can be?  Do you have any insights to share on the value of delivering content directly within critical business processes? Please post a comment and let us know the value you have realized, the lessons learned and what specific areas you are interested in.

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• Why do we use the Pythagorean theorem in game physics?

  - by Starkers

  I've recently learned that we use Pythagorean theorem a lot in our physics calculations and I'm afraid I don't really get the point. Here's an example from a book to make sure an object doesn't travel faster than a MAXIMUM_VELOCITY constant in the horizontal plane: MAXIMUM_VELOCITY = <any number>; SQUARED_MAXIMUM_VELOCITY = MAXIMUM_VELOCITY * MAXIMUM_VELOCITY; function animate(){ var squared_horizontal_velocity = (x_velocity * x_velocity) + (z_velocity * z_velocity); if( squared_horizontal_velocity <= SQUARED_MAXIMUM_VELOCITY ){ scalar = squared_horizontal_velocity / SQUARED_MAXIMUM_VELOCITY; x_velocity = x_velocity / scalar; z_velocity = x_velocity / scalar; } } Let's try this with some numbers: An object is attempting to move 5 units in x and 5 units in z. It should only be able to move 5 units horizontally in total! MAXIMUM_VELOCITY = 5; SQUARED_MAXIMUM_VELOCITY = 5 * 5; SQUARED_MAXIMUM_VELOCITY = 25; function animate(){ var x_velocity = 5; var z_velocity = 5; var squared_horizontal_velocity = (x_velocity * x_velocity) + (z_velocity * z_velocity); var squared_horizontal_velocity = 5 * 5 + 5 * 5; var squared_horizontal_velocity = 25 + 25; var squared_horizontal_velocity = 50; // if( squared_horizontal_velocity <= SQUARED_MAXIMUM_VELOCITY ){ if( 50 <= 25 ){ scalar = squared_horizontal_velocity / SQUARED_MAXIMUM_VELOCITY; scalar = 50 / 25; scalar = 2.0; x_velocity = x_velocity / scalar; x_velocity = 5 / 2.0; x_velocity = 2.5; z_velocity = z_velocity / scalar; z_velocity = 5 / 2.0; z_velocity = 2.5; // new_horizontal_velocity = x_velocity + z_velocity // new_horizontal_velocity = 2.5 + 2.5 // new_horizontal_velocity = 5 } } Now this works well, but we can do the same thing without Pythagoras: MAXIMUM_VELOCITY = 5; function animate(){ var x_velocity = 5; var z_velocity = 5; var horizontal_velocity = x_velocity + z_velocity; var horizontal_velocity = 5 + 5; var horizontal_velocity = 10; // if( horizontal_velocity >= MAXIMUM_VELOCITY ){ if( 10 >= 5 ){ scalar = horizontal_velocity / MAXIMUM_VELOCITY; scalar = 10 / 5; scalar = 2.0; x_velocity = x_velocity / scalar; x_velocity = 5 / 2.0; x_velocity = 2.5; z_velocity = z_velocity / scalar; z_velocity = 5 / 2.0; z_velocity = 2.5; // new_horizontal_velocity = x_velocity + z_velocity // new_horizontal_velocity = 2.5 + 2.5 // new_horizontal_velocity = 5 } } Benefits of doing it without Pythagoras: Less lines Within those lines, it's easier to read what's going on ...and it takes less time to compute, as there are less multiplications Seems to me like computers and humans get a better deal without Pythagorean theorem! However, I'm sure I'm wrong as I've seen Pythagoras' theorem in a number of reputable places, so I'd like someone to explain me the benefit of using Pythagorean theorem to a maths newbie. Does this have anything to do with unit vectors? To me a unit vector is when we normalize a vector and turn it into a fraction. We do this by dividing the vector by a larger constant. I'm not sure what constant it is. The total size of the graph? Anyway, because it's a fraction, I take it, a unit vector is basically a graph that can fit inside a 3D grid with the x-axis running from -1 to 1, z-axis running from -1 to 1, and the y-axis running from -1 to 1. That's literally everything I know about unit vectors... not much :P And I fail to see their usefulness. Also, we're not really creating a unit vector in the above examples. Should I be determining the scalar like this: // a mathematical work-around of my own invention. There may be a cleverer way to do this! I've also made up my own terms such as 'divisive_scalar' so don't bother googling var divisive_scalar = (squared_horizontal_velocity / SQUARED_MAXIMUM_VELOCITY); var divisive_scalar = ( 50 / 25 ); var divisive_scalar = 2; var multiplicative_scalar = (divisive_scalar / (2*divisive_scalar)); var multiplicative_scalar = (2 / (2*2)); var multiplicative_scalar = (2 / 4); var multiplicative_scalar = 0.5; x_velocity = x_velocity * multiplicative_scalar x_velocity = 5 * 0.5 x_velocity = 2.5 Again, I can't see why this is better, but it's more "unit-vector-y" because the multiplicative_scalar is a unit_vector? As you can see, I use words such as "unit-vector-y" so I'm really not a maths whiz! Also aware that unit vectors might have nothing to do with Pythagorean theorem so ignore all of this if I'm barking up the wrong tree. I'm a very visual person (3D modeller and concept artist by trade!) and I find diagrams and graphs really, really helpful so as many as humanely possible please!

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• Waiting for Windows 8: A Long, Hot Summer

  - by andrewbrust

  Microsoft has revealed some things about Windows 8, and revealed a part of the developer story for new Windows 8 “tailored,” “immersive” applications.  In retrospect, very little was shared.  The bit that was revealed to us is that those applications can be developed using a combination of HTML 5 and JavaScript.  Not much else was said, except that additional details would be revealed at Microsoft’s //Build/ conference in Anaheim, California in September. This has left a lot of people in suspense, and it seems that suspended state is going to last all summer.  The problem, of course, is that in the absence of hard information, people fill the void with Speculation, Rumor and Gloom.  That’s a bit like Fear, Uncertainty and Doubt, except that it’s self-imposed by the Microsoft community and not planted by Microsoft’s competitors. This is a less-than-perfect situation.  Not only is it causing developers to worry about the value of their skill sets, but I am already hearing from consulting shops that customers are getting nervous too and, in extreme cases, opting for non-Microsoft tools for their projects as a result.  I’m also hearing from dev tool ISVs that sales have suffered as a result. It’s quite possible that the customers moving off .NET wanted to do so anyway and it’s also possible that dev tool ISVs are suffering slower sales this year due a slowed rate of economic recovery. Without hard information, tend to people interpret things negatively.  Actually, that’s the major point in all of this. While there is multitude of opinions about what the Windows 8 development platform will look like once fully revealed, there is an emerging consensus around one thing: it sure would help if Microsoft revealed more of its strategy…just enough to quash absurd rumors, stabilize the .NET ecosystem and get people to stay calm. We’ve had some reassurances thus far: there will be a Windows desktop mode; we’ll still have Windows Explorer, we’ll still run Office, we’ll still have a task bar, and all the skills and tools we use now will still work there.  But with reassurances like that…people still feel insecure.  Because telling us that Windows 8 will have what is essentially a “classic” mode sure makes it sound like today’s skill sets will soon be “classic” too…and then maybe they’ll just become obsolete. Humans find change scary; it’s natural.  And when left alone with their fears – because no one is saying anything to dispel them – people can go from frightened to paranoid, and can start to viewing things in a downright conspiratorial light.  It would be great if Microsoft stepped into the void now and told us what is coming – especially because whatever they tell us is bound to be at least a little better than what people think they are going to hear. I don’t know what the announcements will be, but I do have it on authority, from a number of sources, that Microsoft isn’t gong to talk until //Build/.  That means no news until September September 13th.  Nothing until after Labor Day.  You get zippo until after the Back-to-School sales are done. What to do?  Try not to let the dark voices of gloom and doom fill your head.  Even in the absence of answers, we still have some important facts: The .NET developer community is huge. Microsoft’s customers have major investments in .NET, and in .NET skills. Political infighting in Redmond might make for irrational decisions, but ultimately public companies can’t just alienate their advocates and piss off their customers.  Spite doesn’t trump fiduciary responsibility. The computing device markets are changing, software is changing, software business models are changing and developers are changing.  Microsoft has to keep up. The HTML + JavaScript community is huge too, and it includes many of the “changed” developers. Public companies can’t ignore new markets nor the popular standards that can help them enter those new markets.  Loyalty doesn’t trump fiduciary responsibility either. If Microsoft can appeal to new developers, then it should. If Microsoft can keep catering to its existing developers and customers -- not just through legacy support, but also through empowering futures -- then it probably will. You don’t have to shove your old friends out into the rain to make room for new ones; you can bring those new constituents in under a bigger tent.  I hope Microsoft will enlarge the tent, and I have trouble imagining why it would not.

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