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• How to restore curropted installation?

  - by nightweels

  I have a laptop with dead battery that when there is no current connected to it turns critical so fast and in the energy management in ubuntu, when the battery is critical, there are 2 options: shutdown and hibernate witch is in grey (unclickable), so I have no choice but to chose immediate shutdown, there is no standby even if it is an option in the screen behavior. An immediate shutdown (and I mean by immediate the one that we use when we ended using the computer) happened while I was installing a program called quickly, so after the power was restored, I tried to reinstall the program then I get this translated message: An untreatable error occurred: It seems there is a software error in aptdaemon, the program that lets you install and remove software and any other task related to package management. details: Traceback (most recent call last): File "/usr/lib/python2.7/dist-packages/aptdaemon/worker.py", line 968, in simulate trans.unauthenticated = self._simulate_helper(trans) File "/usr/lib/python2.7/dist-packages/aptdaemon/worker.py", line 1092, in _simulate_helper return depends, self._cache.required_download, \ File "/usr/lib/python2.7/dist-packages/apt/cache.py", line 235, in required_download pm.get_archives(fetcher, self._list, self._records) SystemError: E:I wasn't able to locate a file for the libpng12-dev package. This might mean you need to manually fix this package.

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• Integration error in high velocity

  - by Elektito

  I've implemented a simple simulation of two planets (simple 2D disks really) in which the only force is gravity and there is also collision detection/response (collisions are completely elastic). I can launch one planet into orbit of the other just fine. The collision detection code though does not work so well. I noticed that when one planet hits the other in a free fall it speeds backward and goes much higher than its original position. Some poking around convinced me that the simplistic Euler integration is causing the error. Consider this case. One object has a mass of 1kg and the other has a mass equal to earth. Say the object is 10 meters above ground. Assume that our dt (delta t) is 1 second. The object goes to the height of 9 meters at the end of the first iteration, 7 at the end of the second, 4 at the end of the third and 0 at the end of the fourth iteration. At this points it hits the ground and bounces back with the speed of 10 meters per second. The problem is with dt=1, on the first iteration it bounces back to a height of 10. It takes several more steps to make the object change its course. So my question is, what integration method can I use which fixes this problem. Should I split dt to smaller pieces when velocity is high? Or should I use another method altogether? What method do you suggest? EDIT: You can see the source code here at github:https://github.com/elektito/diskworld/

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• Efficient coding in Visual Studio (or another IDE), with touch typing

  - by cheeesus

  Moving the cursor to another position in code is one of the most frequent actions when coding. I don't write my programs from the beginning to the end, like a letter. However, moving the cursor requires me to move my right hand to the key arrows or to the mouse, which feels like an interruption to my writing rhythm, since I'm using touch typing. I want my hands to rest on the keyboard. It's difficult to explain what I mean, but I think every coder using touch typing knows what I mean. I tried many things, like defining some shortcuts as surrogate arrow keys (Shift+Alt+J, K, L, I), or buying a keyboard with a Trackpoint, Trackpad, or Trackball on it, but I have not yet found a satisfying solution to the problem. What is the best solution you know of, regardless of which IDE you use? Edit: Thank you for your answers. I am using a lot of shortkeys, but I think using a Vim plugin in Visual Studio would interfere too much with the shortkeys I am used to. Also, I have a keyboard with a built-in mouse, but I'm still looking for a better solution.

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• fglrx: No matching Device section for instance... found how to fix it?

  - by Lejo

  I have HD 4850 card, Ubuntu 12.10 and installed legacy drivers using makson96 ppa. The issue is, that FGLRX can not detect my device and loads vesa bios. I had the same problem on ubuntu 11.10, 12.04 versions. I want to manually help fglrx find a matching device to load as it shoudld do. It is interesting, why does fglrx search for a device in a PCI:0@1:0:1 Bus? in xorg.cof different bus is indicated: Section "Device" Identifier "aticonfig-Device[0]-0" Driver "fglrx" BusID "PCI:1:0:0" EndSection fglrxinfo display: :0.0 screen: 0 OpenGL vendor string: Advanced Micro Devices, Inc. OpenGL renderer string: ATI Radeon HD 4800 Series OpenGL version string: 3.3.11653 Compatibility Profile Context Here is a part of my xorg log: [ 3.846] (II) VESA: driver for VESA chipsets: vesa [ 3.846] (II) FBDEV: driver for framebuffer: fbdev [ 3.846] (++) using VT number 7 [ 3.846] (WW) Falling back to old probe method for fglrx [ 3.883] (II) Loading PCS database from /etc/ati/amdpcsdb [ 3.883] (--) Assigning device section with no busID to primary device [ 3.883] (--) Chipset Supported AMD Graphics Processor (0x9442) found [ 3.884] (WW) fglrx: No matching Device section for instance (BusID PCI:0@1:0:1) found [ 3.884] (II) AMD Video driver is running on a device belonging to a group targeted for this release [ 3.884] (II) AMD Video driver is signed [ 3.884] (II) fglrx(0): pEnt->device->identifier=0xb7791d8f [ 3.884] (WW) Falling back to old probe method for vesa [ 3.884] (WW) Falling back to old probe method for fbdev from lispci i foud out finally, that my video card is in 01:00.0 slot. logically, if fglrx searches for a vdeo card device in a wrong place, it will not find it. 01:00.0 VGA compatible controller: Advanced Micro Devices [AMD] nee ATI RV770 [Radeon HD 4850] Thanks in advance.

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• geomipmapping using displacement mapping (and glVertexAttribDivisor)

  - by Will

  I wake up with a clear vision, but sadly my laptop card doesn't do displacement mapping nor glVertexAttribDivisor so I can't test it out; I'm left sharing here: With geomipmapping, the grid at any factor is transposable - if you pass in an offset - say as a uniform - you can reuse the same vertex and index array again and again. If you also pass in the offset into the heightmap as a uniform, the vertex shader can do displacement mapping. If the displacement map is mipmapped, you get the advantages of trilinear filtering for distant maps. And, if the scenery is closer, rather than exposing that the you have a world made out of quads, you can use your transposable grid vertex array and indices to do vertex-shader interpolation (fancy splines) to do super-smooth infinite zoom? So I have some questions: does it work? In theory, in practice? does anyone do it? Does this technique have a name? Papers, demos, anything I can look at? does glVertexAttribDivisor mean that you can have a single glMultiDrawElementsEXT or similar approach to draw all your terrain tiles in one call rather than setting up the uniforms and emitting each tile? Would this offer any noticeable gains? does a heightmap that is GL_LUMINANCE take just one byte per pixel(=vertex)? (On mainstream cards, obviously. Does storage vary in practice?) Does going to the effort of reusing the same vertices and indices mean that you can basically fill the GPU RAM with heightmap and not a lot else, giving you either bigger landscapes or more detailed landscapes/meshes for the same bang? is mipmapping the displacement map going to work? On future cards? Is it going to introduce unsurmountable inaccuracies if it is enabled?

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• What is the difference between Callback<T> and Java 8's Supplier<T>?

  - by Dan Pantry

  I've been switching over to Java from C# after some recommendations from some over at CodeReview. So, when I was looking into LWJGL, one thing I remembered was that every call to Display must be executed on the same thread that the Display.create() method was invoked on. Remembering this, I whipped up a class that looks a bit like this. public class LwjglDisplayWindow implements DisplayWindow { private final static int TargetFramesPerSecond = 60; private final Scheduler _scheduler; public LwjglDisplayWindow(Scheduler displayScheduler, DisplayMode displayMode) throws LWJGLException { _scheduler = displayScheduler; Display.setDisplayMode(displayMode); Display.create(); } public void dispose() { Display.destroy(); } @Override public int getTargetFramesPerSecond() { return TargetFramesPerSecond; } @Override public Future<Boolean> isClosed() { return _scheduler.schedule(() -> Display.isCloseRequested()); } } While writing this class you'll notice that I created a method called isClosed() that returns a Future<Boolean>. This dispatches a function to my Scheduler interface (which is nothing more than a wrapper around an ScheduledExecutorService. While writing the schedule method on the Scheduler I noticed that I could either use a Supplier<T> argument or a Callable<T> argument to represent the function that is passed in. ScheduledExecutorService didn't contain an override for Supplier<T> but I noticed that the lambda expression () -> Display.isCloseRequested() is actually type compatible with both Callable<bool> and Supplier<bool>. My question is, is there a difference between those two, semantically or otherwise - and if so, what is it, so I can adhere to it?

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• Pushing complete notifications to client

  - by ton.yeung

  So with cqrs, we accept that consistency is eventual. However, that doesn't mean that the user has to continually poll, or that eventual means an update has to take more then 500ms to sync. For the sake of UX, we want to at least give the illusion of consistency, or if not possible, be as transparent as possible. With that in mind, I have this setup: angularjs web client, consumes webapi restful services, sends commands to nservicebus command handlers, saves to neventstore, dispatches events to nservicebus event handlers, sends message to signalr hub, sends notifications to angularjs web client so with that setup, theoretically some initiates a request the server validates the request sends out the necessary commands In the mean time the client gets a 200 response updates the view: working on it gets message sometime later: done, here's the updated data Here's where things get interesting, each command could spawn multiple events. Not sure if this is a serious no, no, or not, but that's how it is currently. For example, a new customer spawns CustomerIDCreated, CustomerNameUpdated, CustomerAddressUpdated, etc... Which event handler needs to notify the client? Should all of them in a progress bar style update?

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• How to mange big amount users at server side?

  - by Rami

  I built a social android application in which users can see other users around them by gps location. at the beginning thing went well as i had low number of users, But now that I have increasing number of users (about 1500 +100 every day) I revealed a major problem in my design. In my Google App Engine servlet I have static HashMap that holding all the users profiles objects, currenty 1500 and this number will increase as more users register. Why I'm doing it Every user that requesting for the users around him compares his gps with other users and check if they are in his 10km radius, this happens every 5 min on average. That is why I can't get the users from db every time because GAE read/write operation quota will tare me apart. The problem with this desgin is As the number of users increased the Hashmap turns to null every 4-6 hours, I thing that this time is getting shorten but I'm not sure. I'm fixing this by reloading the users from the db every time I detect that it became null, But this causes DOS to my users for 30 sec, So I'm looking for better solution. I'm guessing that it happens because the size of the hashmap, Am I right? I have been advised to use spatial database, but that mean that I can't work with GAE any more and that mean that I need to build my big server all over again and lose my existing DB. Is there something I can do with the existing tools? Thanks.

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• Fan always on and overheating problems on HP G62

  - by Dave

  I have a HP G62 with i5 processor, 4G Ram and ATI HD 5470. Started using Ubuntu 4 months ago, first was 11.10 and after 12.04. Everything worked perfectly until some weeks ago when my cpu fan became "crazy" and I mean by this always on, noise and overheating problems, for sure if I put a glass with water in some minutes will boil (and I mean it). There can be a bug in the last kernel or any other Ubuntu's official update? And by the way CPU fan is cleaned like a new born baby; Used jupiter and all those stuff (lm-sensor, psensor...) - same problem; Don't ask me to install ATI drivers because will work like sh#t (interface laggy as HD 5470 isn't supported by Ubuntu) and I can't even open ATI Catalyst (error when I try to open it), more than this I always used open source drivers and as I said, worked perfectly (3d, effects). Right now I'm back to Windows and everything is working perfectly but my main problem is that I get used with Ubuntu and kinda weird to use windows again. I want back my nice and almost perfect Ubuntu. Thanks, Dave

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• Detecting collision between ball (circle) and brick(rectangle)?

  - by James Harrison

  Ok so this is for a small uni project. My lecturer provided me with a framework for a simple brickbreaker game. I am currently trying to overcome to problem of detecting a collision between the two game objects. One object is always the ball and the other objects can either be the bricks or the bat. public Collision hitBy( GameObject obj ) { //obj is the bat or the bricks //the current object is the ball // if ball hits top of object if(topX + width >= obj.topX && topX <= obj.topX + obj.width && topY + height >= obj.topY - 2 && topY + height <= obj.topY){ return Collision.HITY; } //if ball hits left hand side else if(topY + height >= obj.topY && topY <= obj.topY + obj.height && topX + width >= obj.topX -2 && topX + width <= obj.topX){ return Collision.HITX; } else return Collision.NO_HIT; } So far I have a method that is used to detect this collision. The the current obj is a ball and the obj passed into the method is the the bricks. At the moment I have only added statement to check for left and top collisions but do not want to continue as I have a few problems. The ball reacts perfectly if it hits the top of the bricks or bat but when it hits the ball often does not change directing. It seems that it is happening toward the top of the left hand edge but I cannot figure out why. I would like to know if there is another way of approaching this or if people know where I'm going wrong. Lastly the collision.HITX calls another method later on the changes the x direction likewise with y.

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• Rails: Law of Demeter Confusion

  - by user2158382

  I am reading a book called Rails AntiPatterns and they talk about using delegation to to avoid breaking the Law of Demeter. Here is their prime example: They believe that calling something like this in the controller is bad (and I agree) @street = @invoice.customer.address.street Their proposed solution is to do the following: class Customer has_one :address belongs_to :invoice def street address.street end end class Invoice has_one :customer def customer_street customer.street end end @street = @invoice.customer_street They are stating that since you only use one dot, you are not breaking the Law of Demeter here. I think this is incorrect, because you are still going through customer to go through address to get the invoice's street. I primarily got this idea from a blog post I read: http://www.dan-manges.com/blog/37 In the blog post the prime example is class Wallet attr_accessor :cash end class Customer has_one :wallet # attribute delegation def cash @wallet.cash end end class Paperboy def collect_money(customer, due_amount) if customer.cash < due_ammount raise InsufficientFundsError else customer.cash -= due_amount @collected_amount += due_amount end end end The blog post states that although there is only one dot customer.cash instead of customer.wallet.cash, this code still violates the Law of Demeter. Now in the Paperboy collect_money method, we don't have two dots, we just have one in "customer.cash". Has this delegation solved our problem? Not at all. If we look at the behavior, a paperboy is still reaching directly into a customer's wallet to get cash out. EDIT I completely understand and agree that this is still a violation and I need to create a method in Wallet called withdraw that handles the payment for me and that I should call that method inside the Customer class. What I don't get is that according to this process, my first example still violates the Law of Demeter because Invoice is still reaching directly into Customer to get the street. Can somebody help me clear the confusion. I have been searching for the past 2 days trying to let this topic sink in, but it is still confusing.

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• Should I modify an entity with many parameters or with the entity itself?

  - by Saeed Neamati

  We have a SOA-based system. The service methods are like: UpdateEntity(Entity entity) For small entities, it's all fine. However, when entities get bigger and bigger, to update one property we should follow this pattern in UI: Get parameters from UI (user) Create an instance of the Entity, using those parameters Get the entity from service Write code to fill the unchanged properties Give the result entity to the service Another option that I've experienced in previous experiences is to create semantic update methods for each update scenario. In other words instead of having one global all-encompasing update method, we had many ad-hoc parametric methods. For example, for the User entity, instead of having UpdateUser (User user) method, we had these methods: ChangeUserPassword(int userId, string newPassword) AddEmailToUserAccount(int userId, string email) ChangeProfilePicture(int userId, Image image) ... Now, I don't know which method is truly better, and for each approach, we encounter problems. I mean, I'm going to design the infrastructure for a new system, and I don't have enough reasons to pick any of these approaches. I couldn't find good resources on the Internet, because of the lack of keywords I could provide. What approach is better? What pitfalls each has? What benefits can we get from each one?

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• CheckMemoryAllocationGame Sample

  - by Michael B. McLaughlin

  Many times I’ve found myself wondering how much GC memory some operation allocates. This is primarily in the context of XNA games due to the desire to avoid generating garbage and thus triggering a GC collection. Many times I’ve written simple programs to check allocations. I did it again recently. It occurred to me that many XNA developers find themselves asking this question from time to time. So I cleaned up my sample and published it on my website. Feel free to download it and put it to use. It’s rather thoroughly commented. The location where you insert the code you wish to check is in the Update method found in Game1.cs. The default that I put in is a line of code that generates a new Guid using Guid.NewGuid (which, if you’re curious, does not create any heap allocations). Read all of the comments in the Update method (at the very least) to make sure that your code is measured properly. It’s important to make sure that you meaningfully reference any thing you create after the second call to get the memory or else (in Release configuration at least) you will likely get incorrect results. Anyway, it should make sense when you read the comments and if not, feel free to post a comment here or ask me on Twitter. You can find my utilities and code samples page here: http://www.bobtacoindustries.com/developers/utils/Default.aspx To download CheckMemoryAllocationGame’s source code directly: http://www.bobtacoindustries.com/developers/utils/CheckMemoryAllocationGame.zip (If you’re looking to do this outside of the context of an XNA game, the measurement code in the Update method can easily be adapted into, e.g., a C# Windows Console application. In the past I mostly did that, actually. But I didn’t feel like adding references to all the XNA assemblies this time and… anyway, if you want you can easily convert it to a console application. If there’s any demand for it, I’ll do it myself and update this post when I get a chance.)

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• Strategies for managUse of types in Python

  - by dave

  I'm a long time programmer in C# but have been coding in Python for the past year. One of the big hurdles for me was the lack of type definitions for variables and parameters. Whereas I totally get the idea of duck typing, I do find it frustrating that I can't tell the type of a variable just by looking at it. This is an issue when you look at someone else's code where they've used ambiguous names for method parameters (see edit below). In a few cases, I've added asserts to ensure parameters comply with an expected type but this goes against the whole duck typing thing. On some methods, I'll document the expected type of parameters (eg: list of user objects), but even this seems to go against the idea of just using an object and let the runtime deal with exceptions. What strategies do you use to avoid typing problems in Python? Edit: Example of the parameter naming issues: If our code base we have a task object (ORM object) and a task_obj object (higher level object that embeds a task). Needless to say, many methods accept a parameter named 'task'. The method might expect a task or a task_obj or some other construct such as a dictionary of task properties - it is not clear. It is them up to be to look at how that parameter is used in order to work out what the method expects.

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• XNA CustomModelAnimationSample problem

  - by Mentoliptus

  I downloaded the official tutorial from:CustomModelAnimationSample It works fine but when I try to replicate it in my project, it fails to load the Tag property in my model. Is found that the probelm is in the line: skinnedModel = Content.Load<Model>("DudeWalk"); This line loads the model from the DudeWalk.fbx file and with the custom SkinnedModelProcessor. It loads the animations data in the model. After the line the Tag property is full. I stepped into the method and it went to the custom ModelData class. I copied everything from the projects CustomModelAnimationWindows and CustomModelAnimationPipeline to my solution and set all the references. I tried the same line of code and couldn't step in the method. It called the default method or model constructor and after the line the model's Tag propetry was null. I have to load the model through my custom SkinnedModelProcessor class, but how I tell the game to use this class? In the tutroail CustomModelClass the line is changed to: model = Content.Load<CustomModel>("tank"); So I assumed that I have to set the generic type to a custom model class, but the first example works without it. If anyone has some useful advice or some other helpful link, I'll be happy to try it.

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• What makes a person contribute to opensource? [duplicate]

  - by Jibin

  This question already has an answer here: Why develop free, open source programs? [closed] 14 answers I know this is controversial, but.. There are many great projects like Apache Webserver or Hadoop provided by the OpenSource Community. I often feel that the people that actually benefit (financially), from these projects are developers like me, sitting in India, working for MNCs, who has never contributed anything to any opensource project so far, but earn handsomely due to my basic googling skills & the community provided documentation. Is it fair ? I mean no other industry in the world face such dilemma.Those who work get paid. I mean I almost am starting to feel guilty of taking such advantage of some thing that I contribute nothing to. I had to do projects every semester in college (we could choose projects) & I used to enjoy coding then. I want to contribute. But contributing to opensource is not a task [unlike college or office work]. And life is so busy .. Are all these opensource contributors really jobless ?[just kidding..] Could someone please share some personal experiences on how you guys started contributing or any advice on why I should contribute or what attitude in life makes you keep aside time or is it that you just crazly love writing code or is it that you just love to see your name in the contributors list or do you have a local coding group you hang out with ? Do you feel I am destined to do this ? This is my part of contributing back to the world ? Whats that basic mentality that make you guys want to contribute, while I just want to finish my work and go home. What makes you guys tick ?

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• Initializing entities vs having a constructor parameter

  - by Vee

  I'm working on a turn-based tile-based puzzle game, and to create new entities, I use this code: Field.CreateEntity(10, 5, Factory.Player()); This creates a new Player at [10; 5]. I'm using a factory-like class to create entities via composition. This is what the CreateEntity method looks like: public void CreateEntity(int mX, int mY, Entity mEntity) { mEntity.Field = this; TileManager.AddEntity(mEntity, true); GetTile(mX, mY).AddEntity(mEntity); mEntity.Initialize(); InvokeOnEntityCreated(mEntity); } Since many of the components (and also logic) of the entities require to know what the tile they're in is, or what the field they belong to is, I need to have mEntity.Initialize(); to know when the entity knows its own field and tile. The Initialize(); method contains a call to an event handler, so that I can do stuff like this in the factory class: result.OnInitialize += () => result.AddTags(TDLibConstants.GroundWalkableTag, TDLibConstants.TrapdoorTag); result.OnInitialize += () => result.AddComponents(new RenderComponent(), new ElementComponent(), new DirectionComponent()); This works so far, but it is not elegant and it's very open to bugs. I'm also using the same idea with components: they have a parameterless constructor, and when you call the AddComponent(mComponent); method in an entity, it is the entity's job to set the component's entity to itself. The alternative would be having a Field, int, int parameters in the factory class, to do stuff like: new Entity(Field, 10, 5); But I also don't like the fact that I have to create new entities like this. I would prefer creating entities via the Field object itself. How can I make entity/component creation more elegant and less prone to bugs?

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• Adding tolerance to a point in polygon test

  - by David Gouveia

  I've been using this method which was taken from Game Coding Complete to detect whether a point is inside of a polygon. It works in almost every case, but is failing on a few edge cases, and I can't figure out the reason. For example, given a polygon with vertices at (0,0) (0,100) and (100,100), the algorithm is returning: True for any point strictly inside the polygon False for any of the vertices False for (0, 50) which lies on one of the edges of the polygon True (?) for (50,50) which is also on one of the edges of the polygon I'd actually like to relax the algorithm so that it returns true in all of these cases. In other words, it should return true for points that are strictly inside, for the vertices themselves, and for points on the edges of the polygon. If possible I'd also like to give it enough tolerance so that it always tend towards "true" in face of floating point fluctuations. For example, I have another method, that given a line segment and a point, returns the closest location on the line segment to the given point. Currently, given any point outside the polygon and one of its edges, there are cases where the result is categorized as being inside by the method above, while other points are considered outside. I'd like to give it enough tolerance so that it always returns true in this situation. The way I've currently solved the problem is an hack, which consists of using an external library to inflate the polygon by a few pixels, and performing the tests on the inflated polygon, but I'd really like to replace this with a proper solution.

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• How to write PowerShell code part 2 (Using function)

  - by ybbest

  In the last post, I have showed you how to use external configuration file in your PowerShell script. In this post, I will show you how to create PowerShell function and call external PowerShell script.You can download the script here. 1. In the original script, I create the site directly using New-SPSite command. I will refactor it so that I will create a new function to create the site using New-SPSite. The PowerShell function is quite similar to a C# method. You put your function parameters in () and separate each parameter by a comma (,). Then you put your method body in {}. function add ([int] $num1 , [int] $num2){ $total=$num1+$num2 #Return $total $total } 2. The difference is you do not need semi-colon (;) at the end of each statement and when calling the method you do not need comma (,) to separate each parameter. function add ([int] $num1 , [int] $num2){ $total=$num1+$num2 #Return $total $total } #Calling the function [int] $num1=3 [int] $num2=4 $d= add $num1 $num2 Write-Host $d 3. If you like to return anything from the function, you just need to type in the object you like to return, not need to type return .e.g. $ObjectToReturn not return $ObjectToReturn

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• Custom field names in Rails error messages

  - by Madhan ayyasamy

  The defaults in Rails with ActiveRecord is beautiful when you are just getting started and are created everything for the first time. But once you get into it and your database schema becomes a little more solidified, the things that would have been easy to do by relying on the conventions of Rails require a little bit more work.In my case, I had a form where there was a database column named “num_guests”, representing the number of guests. When the field fails to pass validation, the error messages is something likeNum guests is not a numberNot quite the text that we want. It would be better if it saidNumber of guests is not a numberAfter doing a little bit of digging, I found the human_attribute_name method. You can override this method in your model class to provide alternative names for fields. To change our error message, I did the followingclass Reservation ... validates_presence_of :num_guests ... HUMAN_ATTRIBUTES = { :num_guests = "Number of guests" } def self.human_attribute_name(attr) HUMAN_ATTRIBUTES[attr.to_sym] || super endendSince Rails 2.2, this method is used to support internationalization (i18n). Looking at it, it reminds me of Java’s Resource Bundles and Spring MVC’s error messages. Messages are defined based off a key and there’s a chain of look ups that get applied to resolve an error’s message.Although, I don’t see myself doing any i18n work in the near-term, it is cool that we have that option now in Rails.

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• Ninject/DI: How to correctly pass initialisation data to injected type at runtime

  - by MrLane

  I have the following two classes: public class StoreService : IStoreService { private IEmailService _emailService; public StoreService(IEmailService emailService) { _emailService = emailService; } } public class EmailService : IEmailService { } Using Ninject I can set up bindings no problem to get it to inject a concrete implementation of IEmailService into the StoreService constructor. StoreService is actually injected into the code behind of an ASP.NET WebForm as so: [Ninject.Inject] public IStoreService StoreService { get; set; } But now I need to change EmailService to accept an object that contains SMTP related settings (that are pulled from the ApplicationSettings of the Web.config). So I changed EmailService to now look like this: public class EmailService : IEmailService { private SMTPSettings _smtpSettings; public void SetSMTPSettings(SMTPSettings smtpSettings) { _smtpSettings = smtpSettings; } } Setting SMTPSettings in this way also requires it to be passed into StoreService (via another public method). This has to be done in the Page_Load method in the WebForms code behind (I only have access to the Settings class in the UI layer). With manual/poor mans DI I could pass SMTPSettings directly into the constructor of EmailService and then inject EmailService into the StoreService constructor. With Ninject I don't have access to the instances of injected types outside of the objects they are injected to, so I have to set their data AFTER Ninject has already injected them via a separate public setter method. This to me seems wrong. How should I really be solving this scenario?

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• (Abstract) Game engine design

  - by lukeluke

  I am writing a simple 2D game (for mobile platforms) for the first time. From an abstract point of view, i have the main player controlled by the human, the enemies, elments that will interact with the main player, other living elements that will be controlled by a simple AI (both enemies and non-enemies). The human player will be totally controlled by the player, the other actors will be controlled by AI. So i have a class CActor and a class CActorLogic to start with. I would define a CActor subclass CHero (the main player controlled with some input device). This class will probably implement some type of listener, in order to capture input events. The other players controlled by the AI will be probably a specific subclass of CActor (a subclass per-type, obviously). This seems to be reasonable. The CActor class should have a reference to a method of CActorLogic, that we will call something like CActorLogic::Advance() or similar. Actors should have a visual representation. I would introduce a CActorRepresentation class, with a method like Render() that will draw the actor (that is, the right frame of the right animation). Where to change the animation? Well, the actor logic method Advance() should take care of checking collisions and other things. I would like to discuss the design of a game engine (actors, entities, objects, messages, input handling, visualization of object states (that is, rendering, sound output and so on)) but not from a low level point of view, but from an high level point of view, like i have described above. My question is: is there any book/on line resource that will help me organize things (using an object oriented approach)? Thanks

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• How to write PowerShell code part 2 (Using function)

  - by ybbest

  In the last post, I have showed you how to use external configuration file in your PowerShell script. In this post, I will show you how to create PowerShell function and call external PowerShell script.You can download the script here. 1. In the original script, I create the site directly using New-SPSite command. I will refactor it so that I will create a new function to create the site using New-SPSite. The PowerShell function is quite similar to a C# method. You put your function parameters in () and separate each parameter by a comma (,). Then you put your method body in {}. function add ([int] $num1 , [int] $num2){ $total=$num1+$num2 #Return $total $total } 2. The difference is you do not need semi-colon (;) at the end of each statement and when calling the method you do not need comma (,) to separate each parameter. function add ([int] $num1 , [int] $num2){ $total=$num1+$num2 #Return $total $total } #Calling the function [int] $num1=3 [int] $num2=4 $d= add $num1 $num2 Write-Host $d 3. If you like to return anything from the function, you just need to type in the object you like to return, not need to type return .e.g. $ObjectToReturn not return $ObjectToReturn

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• For a Javascript library, what is the best or standard way to support extensibility

  - by Michael Best

  Specifically, I want to support "plugins" that modify the behavior of parts of the library. I couldn't find much information on the web about this subject. But here are my ideas for how a library could be extensible. The library exports an object with both public and "protected" functions. A plugin can replace any of those functions, thus modifying the library's behavior. Advantages of this method are that it's simple and that the plugin's functions can have full access to the library's "protected" functions. Disadvantages are that the library may be harder to maintain with a larger set of exposed functions and it could be hard to debug if multiple plugins are involved (how to know which plugin modified which function?). The library provides an "add plugin" function that accepts an object with a specific interface. Internally, the library will use the plugin instead of it's own code if appropriate. With this method, the internals of the library can be rearranged more freely as long as it still supports the same plugin interface. This could also support having different plugin interfaces to modify different parts of the library. A disadvantage of this method is that the plugins may have to re-implement code that is already part of the library since the library's internal functions are not exported. The library provides a "set implementation" function that accepts an object inherited from a specific base object. The library's public API calls functions in the implementation object for any functionality that can be modified and the base implementation object includes the core functionality, with both external (to the API) and internal functions. A plugin creates a new implementation object, which inherits from the base object and replaces any functions it wants to modify. This combines advantages and disadvantages of both the other methods.

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• Who is a CMS really for?

  - by Eirc man

  I have started lately discovering Content Management Systems, and I was wondering, who is really CMS for? What I mean by that: is it only for companies, small businesses or individuals, that pays a contractor to make a website that it's users can just upload content through a easy interface. Or is it used also by programmers, to build their own websites, projects? Would a Facebook, Tweeter, StackExhange ever started by using a CMS, a very powerful one for example. Would you as a programmer build your own "fancy" website on top of a CMS, for example like Typo3, or you would build it from scratch? P.S To be more clear is a summary: What I mean to begin with is, would I as a developer choose a CMS to develop a website that can be scaled with a big base of users, be stuck if I choose to start with a CMS system. What if I build a website using CMS, and the website explodes in popularity, and then I wanted to add much more functionality that I have planed, is it possible that the CMS will limit the growth, because it might have not been build for that kind of scale?

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