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  • WebAPI and MVC4 and OData

    - by Aligned
    I was looking closer into WebAPI, specificially how to use OData to avoid writing GetCustomerByCustomerId(int id) methods all over the place. I had problems just returning IQueryable<T> as some sites suggested in the WebpAPI (Assembly System.Web.Http.dll, v4.0.0.0).  I think things changed in the release version and the blog posts are still out of date. There is no [Queraable] as the answer to this question suggests. Once I get WebAPI.Odata Nuget package, and added the [Queryable] to the method http://localhost:57146/api/values/?$filter=Id%20eq%201 worked (don’t forget the ‘$’). Now the main question is whether I should do this and how to stop logged in users from sniffing the url and getting data for other users. I John V. Peterson has a post on securing WebAPI with headers and intercepting the call at that point. He had an update to use HttpMessageHandlers instead. I think I’ll use this to force the call to contain some kind of unique code for the user, but I’m still thinking about this. I will not expose this to the public, just to my calls with-in my Forms Authentication areas. Other links: http://robbincremers.me/2012/02/16/building-and-consuming-rest-services-with-asp-net-web-api-and-odata-support/ ~lots of good information John V Peterson example: https://github.com/johnvpetersen/ASPWebAPIExample ~ all data access goes through the WebApi and the web client doesn’t have a connection string ~ There is code library for calling the WebApi from MVC using the HttpClient. It’s a great starting point http://blogs.msdn.com/b/alexj/archive/2012/08/15/odata-support-in-asp-net-web-api.aspx ~ Beta (9/18/2012) Nuget package to help with what I want to do? ~ has a sample code project with examples http://blogs.msdn.com/b/alexj/archive/2012/08/15/odata-support-in-asp-net-web-api.aspx http://blogs.msdn.com/b/alexj/archive/2012/08/21/web-api-queryable-current-support-and-tentative-roadmap.aspx http://stackoverflow.com/questions/10885868/asp-net-mvc4-rc-web-api-odata-filter-not-working-with-iqueryable JSON, pass the correct format in the header (Accept: application/json). $format=JSON doesn’t appear to be working. Async methods built into WebApi! Look for the GetAsync methods.

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  • What can I do to make sure my code gets maintained in a developer light environment?

    - by asjohnson
    I am a contract data analyst, so I bounce between jobs every 3-6 months, which I find to be a good fit for me, but it leads to some problems when it comes to coding. I mostly do statistics (I've asked a similar question on cross validated, but the answers there are not relevant here), but I have also found out that the business world loves excel and loves copying and pasting the same thing over and over again even more. This led me to learn how to write VBA scripts and then VB.NET programs to automate as many of these reports as I can. I am certain my programs are not the most elegant, but I put a good bit of effort into making sure they work under as many cases as I can test, I add in exceptions and try to code so the program can handle changes in the files that it processes, but there is a limit, if you remove a huge portion of the data, there is a good chance my program is going to trip up, which I accept will inevitably happen. Usually a pretty minor change in the code fixes the problem and I do try and comment my code and make it readable under the assumption that some other person will have to read it some day. My problem is that I generally get put on teams of folks with essentially no experience with programming (like VBA would be a huge stretch for anyone I work directly with). I am wondering what I should be doing as the person that wrote the code to do my best to keep it maintained. I have two approaches in mind (outlined next), but would be very happy to get any advice. Solution 1: Find the more tech savvy coworkers and run them through the programs and what basic changes can be made. Honestly automating excel is about as easy as it can get when it comes to programming, so I feel like I could teach someone the basics of maintaining it pretty quick. Solution 2: Get in touch with the IT department and show them what is going on and maybe they will be able to help. The problem here is that the IT department is constantly swamped (as I'm sure many of you know) and I feel like kind of a jerk for dumping more things on them. I do leave my personal email address with places and am willing to answer quick questions via email, but I view the need for more exhaustive maintenance as something of an inevitability and would like to make sure I do my due diligence to make sure it gets done. I imagine some combination of the two approaches outlined there, but is there any kind of heads up I should give IT? I feel like I would be annoyed if I started getting requests to fix a program that I had never seen from some random guy that is no longer there.

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  • #SSAS #Tabular Workshop and Community Events in Netherlands and Denmark

    - by Marco Russo (SQLBI)
    Next week I will finally start the roadshow of the SSAS Tabular Workshop, a 2-day seminar about the new BISM Tabular model for Analysis Services that has been introduced in SQL Server 2012. During these roadshows, we always try to arrange some speeches at local community events in the evening - we already defined for Copenhagen, we have some logistic issue in Amsterdam that we're trying to solve. Here is the timetable: Netherlands SSAS Workshop in Amsterdam, NL – April 16-17, 2012 2-day seminar, I and Alberto will be the trainers for this event, register here We're trying to manage a Community event but we still don't have a confirmation, stay tuned        Denmark SSAS Workshop in Copenhagen, DK – April 26-27, 2012 2-day seminar, I and Alberto will be the trainers for this event, register here Community event on April 26, 2012 This event will run in Hellerup, at Microsoft venue All details available here: http://msbip.dk/events/26/msbip-mode-nr-5/ People from Sweden are welcome! Just register to this private group on LinkedIn in order to announce your presence, so we’ll know how many people will attend In community events we’ll deliver two speeches – here are the descriptions: Inside xVelocity (VertiPaq) PowerPivot and BISM Tabular models in Analysis Services share a great columnar-based database engine called xVelocity in-memory analytics engine (VertiPaq). If you want to improve performance and optimize memory used, you have to understand some basic principles about how this engine works, how data is compressed, and how you can design a data model for better optimization. Prepare yourself to change your mind. xVelocity optimization techniques might seem counterintuitive and are absolutely different than OLAP and SQL ones! Choosing between Tabular and Multidimensional You have a new project and you have to make an important decision upfront. Should you use Tabular or Multidimensional? It is not easy to answer, because sometime there is a clear choice, but most of the times both decisions might be correct, at least at the beginning. In this session we’ll help you making an informed decision, correctly evaluating pros and cons of each one according to common scenarios, considering both short-term and long-term consequences of your choice. I hope to meet many people in this first dates. We have many other events coming in May and June, including an online event (for US time zones), and you can also attend our PreCon Day at TechEd US in Orland (PRC06) or TechEd Europe in Amsterdam. I’ll be a good customer for airline companies in the next three months! I’m just sorry that I hadn’t time to write other articles in the last month, but I’m accumulating material that I will need to write down during some flight – stay tuned…

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  • Why is it necessary to install EFI/rEFInd/UEFI/... on a SD Card since the Macbook Pro seems to already have it?

    - by user170794
    Dear askubuntu members, I own a Macbook Pro (late 2009) and when I boot the laptop and hold the alt key meanwhile, there is a EFI screen, so EFI is installed on... the firmware? I had a few troubles with my hard disk, so I had to change it, but I haven't installed OS X, I have only installed Ubuntu and still the EFI screen is there which is surely a good thing. As the new hard disk is making troubles again, I am using Puppy Linux, booting from a CD each time, which is unconfortable. So I am trying to have Ubuntu installed on a SD Card. After having spent many months on the internet grabing informations anywhere I can and trying several things, I applied this method: http://www.weihermueller.de/mac/ I succeeded in making one SD Card recognizable by the EFI of my laptop (holding alt key @ boot), but nothing installed on it yet as I fear to lose the recognizable-by-EFI part. I haven't succeded in producing the same result on another SD Card. I have a bootable USB key of Ubuntu (yipee) which works like a live CD, made with the help of Universal Linux UDF Creator, found there: http://www.pendrivelinux.com/universal-usb-installer-easy-as-1-2-3/ on which I have put Ubuntu 13.04 64bit, retrieved from the official deposits. Eventhough I have to add the "nouveau.noaccel=1" option to the grub command line launching Linux, it works (yipee again) properly as a live cd. When installing Ubuntu I come across the "where do I wanna put Ubuntu" window, I partition another SD Card in: the EFI part (40MB) the Linux part (15GB< <16GB) The installation works fine and finishes with no problem. But at the reboot, the SD Card where Linux is installed is not recognized by the EFI, the icons are : the CD (Puppy Linux), the USB stick (from Linux UDF Creator), the hard drive (the formerly-working Ubuntu 12) but no fourth icon of the SD Card whatsoever. As the title of this thread suggests, I am wondering: why there is a need for EFI to be installed on the SD Card since EFI seems to be on my laptop anyway? why EFI has to be on a different partition than the Linux's one? How do both parts communicate? why the EFI part on the SD Card made with the help of the live-USB key isn't recognized? on the EFI partition, there is a folder named "EFI" which contains another folder named "ubuntu" which contains a file named "grubx64.efi", why is there a thing called grub? Is it the Linux's grub where one can chose either to boot, to boot in safe mode, etc.? Thank you for your patience, looking forward for any kind of answer, Julien

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  • Using ASP.NET Membership Provider with an ACL

    - by geekrutherford
    Up until recently one of my applications has used the membership provider within ASP.NET exclusively. However, it has been proposed that while the currently defined roles are beneficial, security needs to be more granular to restrict both access to certain pages and functionality present within a given page.   Unfortunately, the role based security ASP.NET gives you out of the box falls down in this area. This is not due to a lack of foresight by Microsoft, but rather it was simply not designed for implementing both role based security and any inherent ACL you may define within these roles. Mind you some would say an ACL is independent of the role to which a user belongs and is assigned to the user directly.   The application mentioned here has it's own User object (which encapsulates the membership provider user object as a property) and SQL Server table to store extended information not present in the aspnet_users table. While I could have modified the aspnet membership schema to suit the applications needs, it seemed smarter to simply create a separate table with a foreign key back to the aspnet_users table.   Since I have a separate object to store extended user information, I simply created an ACL object and expose it as a property of my user object.   This is all well and good, but it does not help in regards to the SiteMapProvider and restricting access at the page level based on the users ACL.   The straightforward answer would be to develop some code within the databound event for the menu that checks the page title and has hardcoded logic that dictates a user must have certain permissions turned on. The problem with this approach is that it's HARDCODED!!! If you need to change access to a page you'd need to do a build and go through your normal deployment process....ugh!!!   An alternative method, albeit not perfect, is to utilize the resourceKey property on the SiteMapNodes in the SiteMap file with the name of the required permission to view the page. Within the databound event for your menu you iterate the SiteMapNodes in the menus SiteMapProvider looking for a match at the page level based on title. When a match is detected, you have a switch/case on the SiteMapNodes resourceKey (the name of the ACL permission required). The case for the resourceKey ensures the users ACL permission is turned on and viola!!!   This is noteably not perfect in that it is using the resourceKey in a manner other than intended.  Since the application is not localized, using it in the manner described it not an issue.   Below is a sample SiteMap file with the resourceKey used as the ACL permission identifier:     Below is the ItemDataBound event. This application uses the Telerik Menu control:

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  • Phone number in meta description bad or good for local rankings NAP

    - by bybe
    Once again I'm at it with increasing people's local rankings and I've learnt so much about local rankings in the past 2 weeks it feels like my brain is gonna pop anyway, question is fairly simple for someone who engages in local rankings and I appreciate the question may be a little guess work but isn't SEO mostly guessing anyway? From what I've read and learned that Google works of a system called nap for local rankings (With many other factors but this question is purely based on NAP). For people who care about local rankings NAP stands for Name of Business / Address of Business / Phone Number for Business. Now what what I've read you don't need the whole NAP to be on one website, a P or just a N can help towards your local rankings. It's believed that NAP rewards more than just P and N for example but knowing Google they might have a diversity checker which is my concern what your get to in a moment. Now of course sites weight differently where your business is posted, it's certainly going to be more credible if your NAP details are on your national phone book than say a blog site, so taking in this consideration too. Pure Guess (Not apart of the question but none the less makes a good read on my belief). Now my guess work would make me believe that the formula would look something like (N)+(A)+(P)x(T) So (N)name would be 1 or 0 to indicate present or not So (A)dress would be 1 or 0 to indicate present or not So (P)hone would be 1 or 0 to indicate present or not So (T)rust would be 1-100 to indicate level of trust So a phone number appearing on youtube might look something like 0+0+1x95= 95 and a NAP appearing on your national phone book might look something like 1+1+1x100= 300 Please note that I'm not saying this is the sole factor and I'm sure its way more complex that this with things like other factors on the page, off the page (Reviews, Links, Clicks) and so on but its still a contributor). The Question My question is fairly simple and I'd imagine hard to impossible to have an actual definite answer to this but maybe someone has seen official wording else where on this, is it bad to include address or phone number in the Meta Description? The reason I ask is that one of my competitors has these elements in the meta descriptions and their local rankings are absolutely superb, the problem I have with this is scrap bot sites like 'Similar Too' 'Seo Rankings' and 1,000's of the other scrap box networks that scrap site and then make urls with your site information are mostly limited to your meta description what this means that your phone number, address and sometimes even your company name if the domain is exact will appear as AP, and even NAP on thousands of websites. So, is it a bad strategy to include phone number and address in meta description, everything I read into would suggest its good of course with the downside of maybe lowering quality of description for click thoughts but top rankings would increase this 10 folds anyhow..

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  • Skyrim Creation Kit with Xbox 360

    - by funseiki
    I posted this on stackoverflow but was advised to post here (here is a link to the stackoverflow question). I'm hoping for constructive feedback on its plausibility. Update on progress: It looks like there are ways to stuff files back onto the console (horizon, modio, xplorer360, etc) and they do require some form of signing. As of now, though, I've had no luck. I was hoping I could get away with just placing the ".esp" into the directory containing marketplace downloads for Skyrim, along with the signed ".bsa" file (basically a zipped up file containing any extra content the .esp will need to refer that doesn't exist in the basic game). This doesn't work, at least not in the ways I've tried, so next I'm going to try install the entire game to my flash drive (if possible) and attempt to traverse through the game's directory (this is probably unlikely). If anyone else has suggestions or luck or wants more detail on my failures comment/answer away. Here is the question: I'm thinking about buying the PC version of Skyrim to get the Creation Kit (I already own a copy for the Xbox). I have read the faq and scoured plenty of forums to see if there was some way to mod Skyrim for a console (Xbox 360, in particular), but they are generally coming up negative. I realize the CreationKit is on the PC, but I was wondering if there was a way to set up the '.esp' (hopefully I'm interpreting this correctly) files to be placed on the Xbox 360 file system in a similar manner to how game add-ons are downloaded from the Xbox Live Marketplace. I believe it is possible to transfer saves between the console and the PC (e.g. google: 'skyrim mod xbox360'), but these are referencing items that already exist in the game (e.g. a console command for maximum carry weight does not require reference to new animations or models). It would probably be easier if one could navigate through the xbox's file system to see where the games' files are placed, but with the current setup, the file system is abstracted away. Any help or insight on the matter would be much appreciated. I would love to work on a project that would make it possible to let console gamers experience and enjoy all the great mods available to the PC community.

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  • ASP.NET Web Forms is bad, or what am I missing?

    - by iveqy
    Being a PHP guy myself I recently had to write a spider to an asp.net site. I was really surprised by the different approach to ajax and form-handling. For example, in the PHP sites I've worked with, a deletion of a database entry would be something like: GET delete.php?id=&confirm=yes and get a "success" back in some form (in the ajax case, probably a json reply). In this asp.net application you would instead post a form, including all inputs on the page, with a huge __VIEWSTATE and __EVENTVALIDATION. This would be more than 10 times as big as above. The reply would be the complete side again, with a footer containing some structured data for javascript to parse and display the result. Again, the whole page is sent, and then throwed away(?) since it's already displayed. Why not just send the footer with the data to parse (it's not json nor xml but a | separated list). I really can't see why you would design a system that way. Usually you've a fast client, and a somewhat fast server but a really slow connection. Why not keep the datatransfer to a minimum? Why those huge __VIEWSTATE and __EVENTVALIDATION? It seems that everything is done way to chatty and way to complicated. I really can't see the point and that usually means that I'm missing something. So please tell me, what are the reasons for this design and what benefits (and weaknesses) does it have? (Yes I know that __VIEWSTATE is used to tell what type of form-konfiguration should be sent back to the server. But WHY is this needed?) Please keep this discussion strictly technical and avoid flamewars. Update: Please excuse the somewhat rantish question. I tried to explain my view to be able to get a better answer. I am not saying that asp.net is bad, I am saying that I don't understand the meaning of those concepts. Usually that means that I've things to learn instead of the concepts beeing wrong. I appreciate the explanations about that "you don't have to do this way in asp.net", I'll read up on MVC and other .net technologies. However, there most be a reason for this site (the one I referred to) to be written the way it is. It's written by professionals for a big organisation with far more experience than what I've. Any explanation about their (possible) design choice would be welcome.

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  • Geek Bike Ride JavaOne 2012

    - by Tori Wieldt
    "Geek Bike Ride?" the clerk at the bike rental shop asked. "Are you guys all from the same company?" "We aren't even from the same country!" we answered. "I'm from Russia." "We're from Germany."  "I'm from Belgium." "I'm from Palo Alto." "I'm from Japan."  "We're from Brazil." "We're from Brazil." "I'm from Sweden." "Coooool" was all she could say. She was right. The Geek Bike Ride was cooool. We had 39 bike riders and one skater show up Saturday for a great route from San Francisco's Fisherman's Wharf, across the Golden Gate bridge, to Saulsalito, and back to the city by ferry. Duke Bike jerseys, sponsored by OTN, were given out. To make sure Java developers got them, each person had to answer a Java question to get a jersey. The questions were really hard, like "Who is the Father of Java?" "What's the biggest Java conference in San Francisco?" The best was when the question was "Name one of Duke's Choice Award winner from this year," and Régina ten Bruggencate answered answered "Me!"  It was foggy throughout the day, with the sun poking out occasionally. The fog was thickest on the bridge, more that one rider commented that we were "in the cloud." It was a great day to meet new friends, and have a chat with old friends. We all had fun, though some of us may more a little more slowly during JavaOne. Ride on!  Photos by permission by Arun Gupta and Yoshio Terada. Thanks, guys!

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  • What is the difference between development and R&D?

    - by MainMa
    I was asked by a colleague to explain clearly the difference between ordinary development and research and development (R&D) and was unable to do it. After reading Wikipedia, I still don't have the precise answer. According to Wikipedia (slightly modified): There are two primary models: In one model, the primary function is to develop new products; in the other model, the primary function is to discover and create new knowledge about scientific and technological topics for the purpose of uncovering and enabling development of valuable new products, processes, and services. The first model is confusing. Does it mean that development (not R&D) consists exclusively in adding new features to a product, solving bugs and doing maintenance? What if something which was previously developed as a new feature becomes a separate product? The second model is less confusing, but still, how to qualify whether something is new knowledge or existent knowledge which is just rediscovered? Later, Wikipedia adds that ordinary development is different from R&D because of its: nearly immediate profit or immediate improvement. It's still not clear enough. How to qualify "nearly immediate profit"? What if a task has an immediate profit but requires heavy research? Or if it is basic but has uncertain profit, like the enforcement of a common style over the codebase? For example, does it belong to development or R&D to: Develop an engine which abstracts the access to the database, simplifying and shortening enormously the code of other applications (existent or ones which will be written in future) which should access to the database? Establish a new service-oriented architecture for the entire organization of company resources, in order to move from a bunch of separate and autonomous applications to a set of well-organized, interconnected web services, like what is used by Amazon? Design a new communication protocol to allow faster replication of data between two data centers of the company? Conceive a new type of software testing while working on a specific product, knowing that this type of testing will improve/simplify the testing process? Prove that Functional programming is more appropriate than OOP for a specific application, based on evidence, logic and previous experience? Enhance the existent application by adding gestures on tactile screens, after doing studies and testing that shows that those gestures improve the productivity of the users by a ratio of at least 1.4 for a precise set of tasks? Find a way to strongly enhance the Power usage effectiveness (PUE) of a data center? Create a Domain-Specific Language (DSL)? In short, how could I determine whether I'm doing R&D while working on something?

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  • Booting Ubuntu on HP Pavilion g7 - 13.04 [duplicate]

    - by death2040
    This question already has an answer here: My computer boots to a black screen, what options do I have to fix it? 24 answers I have a HP Pavilion G7 with an AMD A4 processor and Radeon graphics. I want to install Ubuntu on my laptop but whenever I put the Ubuntu live CD in it and boot to it, the screen shows the Ubuntu logo and the four little dots then after about a minute or two the screen goes black. I can tell the screen is still on but it doesn't have anything on it. I'm beginning to wonder if its a driver problem but I can't really install the drivers when I cant even get Ubuntu to show anything except a loading screen. I've already tried using 12.04 and 12.10 and all the others down to Ubuntu 10. none of them worked. All the other versions don't even show the Ubuntu logo. I'd prefer to have Ubuntu 13.04 on it if its possible but I haven't had any luck finding a solution. I've also tried using WUBI installer in Windows 7 but all that did was make my computer slower for windows and it does the same with the screen when i boot it to Ubuntu. I'm trying to use Ubuntu alongside Windows 7. I cant find any solution on Google. It wont load anything and I know that there is a program called grub on Ubuntu that I used on my desktop computer when it had graphics trouble but the trouble with my desktop was minor things like the screen would flash and then show weird patterns on the screen. But I can't find anything on what to do with the HP laptop. Please help. I use this laptop a lot for games on Windows 7 and I just want to use Ubuntu for when I take my laptop to school and for school stuff. Edit: I just tried booting it in nomodeset and some other things and still didn't work. It did boot up but now when it goes to install alongside windows it crashes and says Ubuntu is forcing reboot or something like that Also, this question is different from the black screen at boot issue because when I do use nomodeset on my computer and select install Ubuntu it will go as far as the screen where you can choose to replace Windows or run alongside Windows. Then after I click continue it ejects the live CD and turns off my computer without installing anything. The error message it shows when it ejects the disk says signal 15, shutting down - modem manager [1675]: <info> Caught nm-dispatcher.action: Caught signal 15, shutting down... *Deconfiguring network interfaces... Please remove installation media and close the tray (if any) then press ENTER *Deactivating swap... *Stopping remaining crypto disks... *stopping early crypto disks... unmount: /run/lock: not mounted unmount: /run/shm: not mounted

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  • Upstart: How does rc job work / order of (contradicting) "start on ..." and "stop on ..." stanzas

    - by Binarus
    Hi, I just can't understand how Upstart's rc job definition in Natty 11.04 works. To illustrate the problem, here is the definition (empty lines and comments are left out): start on runlevel [0123456] stop on runlevel [!$RUNLEVEL] export RUNLEVEL export PREVLEVEL console output env INIT_VERBOSE task exec /etc/init.d/rc $RUNLEVEL Let's suppose we currently are in runlevel 2 and the rc job is stopped (that is exactly the situation after booting my box and logging in via SSH). Now, let's assume that the system switches to runlevel 3, for example due to a command like "telinit 3" given by root. What will happen to the rc job? Obviously, the rc job will be started since it is currently stopped and the event runlevel 3 is matching the start events. But from now on, things are unclear to me: According to the manual $RUNLEVEL evaluates to the new runlevel when the job is started (that means 3 in our example). Therefore, the next stanza "stop on runlevel [!$RUNLEVEL]" translates to "stop on runlevel [!3]"; that means we have a first stanza which will trigger the job, but the second stanza will never stop the job and seems to be useless. Since I know that the Ubuntu / Upstart people won't do useless things, I must be heavily misunderstanding something. I would be grateful for any explanation. While trying to understand this, an additional question came to my mind. If I had contradicting start and stop triggers, for example start on foo stop on foo what would happen? I swear I never will do that, but I am nevertheless very interested in how Upstart handles that on the theoretical level. Thank you very much! Editing the question as a reaction on geekosaur's first answer: I can see the parallelism, but it is not that easy (at least, not to me). Let's assume the job aurrently is still running, and a new runlevel event comes in (of course, the new runlevel is different from the current one). Then, the following should happen: 1) The job is single instance. That means that "start on ..." won't be triggered since the job is currently running; $RUNLEVEL is not touched. 2) "stop on ..." will be triggered since the new runlevel is different from $RUNLEVEL, so the job will be aborted. 3) Now, the job is stopped and waiting. I can't see how it is restarted with the new runlevel. AFAIK, initctl emits events only once, so "start on ..." won't be triggered and the new runlevel won't be entered. I know that I still misunderstanding something, and I am grateful for explanations. Thank you very much!

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  • Rails - How to use modal form to add object in one model, then reflect that change on main page?

    - by Jim
    I'm working on a Rails app and I've come across a situation where I'm unsure of the cleanest way to proceed. I posted a question on SO with code samples and such - it has received no answers, and the more I think about the problem, the more I think I might be approaching this the wrong way. (See the SO question at http://stackoverflow.com/questions/9521319/how-to-reference-form-when-rendering-partial-from-js-erb-file) So, in more of a generic architecture type question: Right now I have a form where a user can add a new recipe. The form also allows the user to select ingredients (it uses a collection_select which contains Ingredient.all). The catch is - I'd like the user to be able to add a new ingredient on the fly, without leaving the recipe form. Using a hidden div and some jQuery/AJAX, I have a link the user can click to popup a modal form containing ingredients/new.html.erb which is a simple form. When that form is submitted, I call ingredients/create.js.erb to validate the ingredient was saved and hide the modal div. Now I am back to my recipe form, but my collection_select hasn't updated. It seems I have a few choices here: try and re-render the collection_select portion of the form so it grabs a new list of ingredients. This was the method I was attempting when I wrote the SO question. The problem I run into is the partial I use for the collection_select needs the parent form passed in, and when I try and render from the JS file I don't know how to pass it the form object. Reload the recipe form. This works (the collection_select now contains the new ingredient), but the user loses any progress they made on the recipe form. I would need a way to persist the form data - I thought about manually passing the values back and forth, but that is sloppy and there has to be a better way... Try and manually insert the tags using jQuery - this would be simple, but because I'm allowing for multiple ingredients to be added, I can't be certain what ID to target. Now, I can't be the only person to have this issue - so is there an easier way I'm missing? I like option 2 above, but I don't know if there's an easy way to grab the entire params hash as if I had submitted the main recipes form. Hopefully someone can point me in the right direction so I can find an answer to this... If this doesn't make any sense at all, let me know - I can post code samples if you want, but most of the pertinent code is up on the SO question. Thanks!

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  • What to use C++ for?

    - by futlib
    I really love C++. However, I'm struggling to find good uses for it lately. It is still the language to use if you're building huge systems with huge performance requirements. Like backend/infrastructure code at Google and Facebook, or high-end games. But I don't get to do stuff like that. It's also a good choice for code that runs close to the hardware. I'd like to do more low-level stuff, but it isn't part of my job, and I can't think of useful private projects that would involve that. Traditionally, C++ was also a good choice for rich client applications, but those are mostly written in C# and Obj-C lately - and aren't really that important anymore, with everything being a web app. Or a mobile app, which are mostly written in Obj-C and Java. And of course, web-based desktop and mobile apps are quite prominent, too. At my job, I work mostly on web applications, using Java, JavaScript and Groovy. Java is a good/popular choice for non-Google-scale backends, Groovy (or Python, or Ruby or Node.js) is pretty good for the server-side of web apps and JavaScript is the only real choice for the client-side. Even the little games I'm writing in my spare time are lately mostly written in JavaScript, so they can run in the browser. So what would you suggest I could use C++ for? I'm aware that this question is very similar. However, I don't want to learn C++, I was a professional C++ programmer for years. I want to keep doing it and find good new use cases for it. I know that I can use C++ for web apps/games. I could even compile C++ to JavaScript with Emscripten. However, it doesn't seem like a good idea. I'm looking for something C++ is really good at to stay competent in the language. If your answer is: Just give up and forget C++, you'll probably never need it again, so be it.

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  • What does the Spring framework do? Should I use it? Why or why not?

    - by sangfroid
    So, I'm starting a brand-new project in Java, and am considering using Spring. Why am I considering Spring? Because lots of people tell me I should use Spring! Seriously, any time I've tried to get people to explain what exactly Spring is or what it does, they can never give me a straight answer. I've checked the intros on the SpringSource site, and they're either really complicated or really tutorial-focused, and none of them give me a good idea of why I should be using it, or how it will make my life easier. Sometimes people throw around the term "dependency injection", which just confuses me even more, because I think I have a different understanding of what that term means. Anyway, here's a little about my background and my app : Been developing in Java for a while, doing back-end web development. Yes, I do a ton of unit testing. To facilitate this, I typically make (at least) two versions of a method : one that uses instance variables, and one that only uses variables that are passed in to the method. The one that uses instance variables calls the other one, supplying the instance variables. When it comes time to unit test, I use Mockito to mock up the objects and then make calls to the method that doesn't use instance variables. This is what I've always understood "dependency injection" to be. My app is pretty simple, from a CS perspective. Small project, 1-2 developers to start with. Mostly CRUD-type operations with a a bunch of search thrown in. Basically a bunch of RESTful web services, plus a web front-end and then eventually some mobile clients. I'm thinking of doing the front-end in straight HTML/CSS/JS/JQuery, so no real plans to use JSP. Using Hibernate as an ORM, and Jersey to implement the webservices. I've already started coding, and am really eager to get a demo out there that I can shop around and see if anyone wants to invest. So obviously time is of the essence. I understand Spring has quite the learning curve, plus it looks like it necessitates a whole bunch of XML configuration, which I typically try to avoid like the plague. But if it can make my life easier and (especially) if make it can make development and testing faster, I'm willing to bite the bullet and learn Spring. So please. Educate me. Should I use Spring? Why or why not?

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  • Programming Language, Turing Completeness and Turing Machine

    - by Amumu
    A programming language is said to be Turing Completeness if it can successfully simulate a universal TM. Let's take functional programming language for example. In functional programming, function has highest priority over anything. You can pass functions around like any primitives or objects. This is called first class function. In functional programming, your function does not produce side effect i.e. output strings onto screen, change the state of variables outside of its scope. Each function has a copy of its own objects if the objects are passed from the outside, and the copied objects are returned once the function finishes its job. Each function written purely in functional style is completely independent to anything outside of it. Thus, the complexity of the overall system is reduced. This is referred as referential transparency. In functional programming, each function can have its local variables kept its values even after the function exits. This is done by the garbage collector. The value can be reused the next time the function is called again. This is called memoization. A function usually should solve only one thing. It should model only one algorithm to answer a problem. Do you think that a function in a functional language with above properties simulate a Turing Machines? Functions (= algorithms = Turing Machines) are able to be passed around as input and returned as output. TM also accepts and simulate other TMs Memoization models the set of states of a Turing Machine. The memorized variables can be used to determine states of a TM (i.e. which lines to execute, what behavior should it take in a give state ...). Also, you can use memoization to simulate your internal tape storage. In language like C/C++, when a function exits, you lose all of its internal data (unless you store it elsewhere outside of its scope). The set of symbols are the set of all strings in a programming language, which is the higher level and human-readable version of machine code (opcode) Start state is the beginning of the function. However, with memoization, start state can be determined by memoization or if you want, switch/if-else statement in imperative programming language. But then, you can't Final accepting state when the function returns a value, or rejects if an exception happens. Thus, the function (= algorithm = TM) is decidable. Otherwise, it's undecidable. I'm not sure about this. What do you think? Is my thinking true on all of this? The reason I bring function in functional programming because I think it's closer to the idea of TM. What experience with other programming languages do you have which make you feel the idea of TM and the ideas of Computer Science in general? Can you specify how you think?

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  • How can I fix broken i915 drivers for Intel GPUs?

    - by Alen Mujezinovic
    I've got troubles getting the i915 drivers to work correctly on my laptop (HP Pavilion DM4 2101ea). Specifically, the laptop screen goes black and stays black after the splash graphic when booting both from USB key and from harddrive. To get anything on to the display after the splash screen I have to boot either with acpi=off nomodeset i915.modeset=0 I'd rather not turn ACPI off because I like my fans spinning and nomodeset is a bit overkill, so for now I'm booting with i915.modeset=0. Unfortunately, this turns off KMS and my current maximum resolution on the laptop screen is fixed to 1024x768 instead of its real capability. When not setting any of the above boot flags and I plug in an external monitor, the external monitor works fine. When booting with the flags, the external monitor works fine too, but can only do 1024x768 and can't do anything else than mirroring the laptop display. I did upgrade the i915 drivers from 2.17 that ship with Precise to 2.19 which are the most recent ones but without luck of getting anything to display. Here's my lspci output: 00:00.0 Host bridge: Intel Corporation 2nd Generation Core Processor Family DRAM Controller (rev 09) 00:02.0 VGA compatible controller: Intel Corporation 2nd Generation Core Processor Family Integrated Graphics Controller (rev 09) 00:16.0 Communication controller: Intel Corporation 6 Series/C200 Series Chipset Family MEI Controller #1 (rev 04) 00:1a.0 USB controller: Intel Corporation 6 Series/C200 Series Chipset Family USB Enhanced Host Controller #2 (rev 05) 00:1b.0 Audio device: Intel Corporation 6 Series/C200 Series Chipset Family High Definition Audio Controller (rev 05) 00:1c.0 PCI bridge: Intel Corporation 6 Series/C200 Series Chipset Family PCI Express Root Port 1 (rev b5) 00:1c.2 PCI bridge: Intel Corporation 6 Series/C200 Series Chipset Family PCI Express Root Port 3 (rev b5) 00:1c.4 PCI bridge: Intel Corporation 6 Series/C200 Series Chipset Family PCI Express Root Port 5 (rev b5) 00:1d.0 USB controller: Intel Corporation 6 Series/C200 Series Chipset Family USB Enhanced Host Controller #1 (rev 05) 00:1f.0 ISA bridge: Intel Corporation HM65 Express Chipset Family LPC Controller (rev 05) 00:1f.2 SATA controller: Intel Corporation 6 Series/C200 Series Chipset Family 6 port SATA AHCI Controller (rev 05) 00:1f.3 SMBus: Intel Corporation 6 Series/C200 Series Chipset Family SMBus Controller (rev 05) 01:00.0 Network controller: Broadcom Corporation BCM4313 802.11b/g/n Wireless LAN Controller (rev 01) 02:00.0 Unassigned class [ff00]: Realtek Semiconductor Co., Ltd. RTS5116 PCI Express Card Reader (rev 01) 08:00.0 Ethernet controller: Atheros Communications Inc. AR8151 v2.0 Gigabit Ethernet (rev c0) Here's lshw -C video *-display UNCLAIMED description: VGA compatible controller product: 2nd Generation Core Processor Family Integrated Graphics Controller vendor: Intel Corporation physical id: 2 bus info: pci@0000:00:02.0 version: 09 width: 64 bits clock: 33MHz capabilities: msi pm vga_controller bus_master cap_list configuration: latency=0 resources: memory:c0000000-c03fffff memory:b0000000-bfffffff ioport:4000(size=64) Both outputs are generated after booting with i915.modeset=0. Here's a complete Xorg.log file from a boot into a black screen: https://gist.github.com/479ce06454e47d6123e1 The graphics card is a Intel HD 3000 integrated GPU. I've never had problems with Intel hardware on Ubuntu before so this is very surprising. If you could provide a method to make i915 work, suggest alternative drivers a way to boot with i915.modeset=0 but higher resolutions and KMS on or explain what is happening and how to fix it I'll give you an answer badge. :) Thanks

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  • Should a server "be lenient" in what it accepts and "discard faulty input silently"?

    - by romkyns
    I was under the impression that by now everyone agrees this maxim was a mistake. But I recently saw this answer which has a "be lenient" comment upvoted 137 times (as of today). In my opinion, the leniency in what browsers accept was the direct cause of the utter mess that HTML and some other web standards were a few years ago, and have only recently begun to properly crystallize out of that mess. The way I see it, being lenient in what you accept will lead to this. The second part of the maxim is "discard faulty input silently, without returning an error message unless this is required by the specification", and this feels borderline offensive. Any programmer who has banged their head on the wall when something fails silently will know what I mean. So, am I completely wrong about this? Should my program be lenient in what it accepts and swallow errors silently? Or am I mis-interpreting what this is supposed to mean? The original question said "program", and I take everyone's point about that. It can make sense for programs to be lenient. What I really meant, however, is APIs: interfaces exposed to other programs, rather than people. HTTP is an example. The protocol is an interface that only other programs use. People never directly provide the dates that go into headers like "If-Modified-Since". So, the question is: should the server implementing a standard be lenient and allow dates in several other formats, in addition to the one that's actually required by the standard? I believe the "be lenient" is supposed to apply to this situation, rather than human interfaces. If the server is lenient, it might seem like an overall improvement, but I think in practice it only leads to client implementations that end up relying on the leniency and thus failing to work with another server that's lenient in slightly different ways. So, should a server exposing some API be lenient or is that a very bad idea? Now onto lenient handling of user input. Consider YouTrack (a bug tracking software). It uses a language for text entry that is reminiscent of Markdown. Except that it's "lenient". For example, writing - foo - bar - baz is not a documented way of creating a bulleted list, and yet it worked. Consequently, it ended up being used a lot throughout our internal bugtracker. Next version comes out, and this lenient feature starts working slightly differently, breaking a bunch of lists that (mis)used this (non)feature. The documented way to create bulleted lists still works, of course. So, should my software be lenient in what user inputs it accepts?

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  • 3D terrain map with Hexagon Grids (XNA)

    - by Rob
    I'm working on a hobby project (I'm a web/backend developer by day) and I want to create a 3D Tile (terrain) engine. I'm using XNA, but I can use MonoGame, OpenGL, or straight DirectX, so the answer does not have to be XNA specific. I'm more looking for some high level advice on how to approach this problem. I know about creating height maps and such, there are thousands of references out there on the net for that, this is a bit more specific. I'm more concerned with is the approach to get a 3D hexagon tile grid out of my terrain (since the terrain, and all 3d objects, are basically triangles). The first approach I thought about is to basically draw the triangles on the screen in the following order (blue numbers) to give me the triangles for terrain (black triangles) and then make hexes out of the triangles (red hex). http://screencast.com/t/ebrH2g5V This approach seems complicated to me since i'm basically having to draw 4 different types of triangles. The next approach I thought of was to use the existing triangles like I did for a square grid and get my hexes from 6 triangles as follows http://screencast.com/t/w9b7qKzVJtb8 This seems like the easier approach to me since there are only 2 types of triangles (i would have to play with the heights and widths to get a "perfect" hexagon, but the idea is the same. So I'm looking for: 1) Any suggestions on which approach I should take, and why. 2) How would I translate mouse position to a hexagon grid position (especially when moving the camera around), for example in the second image if the mouse pointer were the green circle, how would I determine to highlight that hexagon and then translating that into grid coordinates (assuming it is 0,0)? 3) Any references, articles, books, etc - to get me going in the right direction. Note: I've done hex grid's and mouse-grid coordinate conversion before in 2d. looking for some pointers on how to do the same in 3d. The result I would like to achieve is something similar to the following: http :// www. youtube .com / watch?v=Ri92YkyC3fw (sorry about the youtube link, but it will only let me post 2 links in this post... same rep problem i mention below...) Thanks for any help! P.S. Sorry for not posting the images inline, I apparently don't have enough rep on this stack exchange site.

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  • Sweden Azure Group with Michele Laroux Bustamente &amp; Maartin Balliauw Thursday 22nd May

    - by Alan Smith
    Originally posted on: http://geekswithblogs.net/asmith/archive/2014/05/19/156418.aspxSweden Azure Group (SWAG) has the privilege of welcoming Michele Laroux Bustamente and Maartin Balliauw to present sessions at our meeting this Thursday. Michele and Maartin are two of the world’s leading experts in Cloud Computing and Azure, and will be taking time out from their busy schedules to share their ideas with us, and answer any questions. Knowit Stockholm are kindly hosting the event at their offices, and providing food and refreshments. It should be a great evening. You can register for the event here. Azure Q & A - Michele Leroux Bustamante In this interactive Q & A session Michele Leroux Bustamante will be on hand to share her wealth of experience on Azure related issues. If you are new to Azure and wanting some tips to get started, or an experienced developer needing to negotiate the legal and political protocols related to Cloud Computing Michele will have been there, done that, and be willing to share her experiences. This session will be entirely driven by that attendees, so please come prepared with questions. Reducing latency on the web with the Windows Azure CDN – Maarten Balliauw Serving up content on the Internet is something our web sites do daily. But are we doing this in the fastest way possible? How are users in faraway countries experiencing our apps? Why do we have three webservers serving the same content over and over again? In this session, we’ll explore the Windows Azure Content Delivery Network or CDN, a service which makes it easy to serve up blobs, videos and other content from servers close to our users. We’ll explore simple file serving as well as some more advanced, dynamic edge caching scenarios. Michele Leroux Bustamante Michele Leroux Bustamante is CIO at Solliance (solliance.net), cofounder of Snapboard (snapboard.com), and is recognized as a Microsoft Regional Director and MVP. Michele is a thought leader with over 20 years specializing in building scalable and secure end-to-end system design, identity and access management, and cloud computing technologies – for companies of all sizes. In recent years Michele has also helped launch several startup business ventures and has been a mentor to startups in several accelerator programs – providing both technical and business guidance. Michele shares her experiences through presentations and keynotes all over the world, and has been publishing regularly in technology journals. Maarten Balliauw Maarten Balliauw is a Technical Evangelist at JetBrains. His interests are all web: ASP.NET MVC, PHP and Windows Azure. He’s a Microsoft Most Valuable Professional (MVP) for Azure and an ASPInsider. He has published many articles in both PHP and .NET literature such as MSDN magazine and PHP architect. Maarten is a frequent speaker at various national and international events such as MIX (Las Vegas), TechDays, DPC, …

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  • How does rc job work / order of (contradicting) "start on ..." and "stop on ..." stanzas

    - by Binarus
    Hi, I just can't understand how Upstart's rc job definition in Natty 11.04 works. To illustrate the problem, here is the definition (empty lines and comments are left out): start on runlevel [0123456] stop on runlevel [!$RUNLEVEL] export RUNLEVEL export PREVLEVEL console output env INIT_VERBOSE task exec /etc/init.d/rc $RUNLEVEL Let's suppose we currently are in runlevel 2 and the rc job is stopped (that is exactly the situation after booting my box and logging in via SSH). Now, let's assume that the system switches to runlevel 3, for example due to a command like "telinit 3" given by root. What will happen to the rc job? Obviously, the rc job will be started since it is currently stopped and the event runlevel 3 is matching the start events. But from now on, things are unclear to me: According to the manual $RUNLEVEL evaluates to the new runlevel when the job is started (that means 3 in our example). Therefore, the next stanza "stop on runlevel [!$RUNLEVEL]" translates to "stop on runlevel [!3]"; that means we have a first stanza which will trigger the job, but the second stanza will never stop the job and seems to be useless. Since I know that the Ubuntu / Upstart people won't do useless things, I must be heavily misunderstanding something. I would be grateful for any explanation. While trying to understand this, an additional question came to my mind. If I had contradicting start and stop triggers, for example start on foo stop on foo what would happen? I swear I never will do that, but I am nevertheless very interested in how Upstart handles that on the theoretical level. Thank you very much! Editing the question as a reaction on geekosaur's first answer: I can see the parallelism, but it is not that easy (at least, not to me). Let's assume the job aurrently is still running, and a new runlevel event comes in (of course, the new runlevel is different from the current one). Then, the following should happen: 1) The job is single instance. That means that "start on ..." won't be triggered since the job is currently running; $RUNLEVEL is not touched. 2) "stop on ..." will be triggered since the new runlevel is different from $RUNLEVEL, so the job will be aborted. 3) Now, the job is stopped and waiting. I can't see how it is restarted with the new runlevel. AFAIK, initctl emits events only once, so "start on ..." won't be triggered and the new runlevel won't be entered. I know that I still misunderstanding something, and I am grateful for explanations. Thank you very much!

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  • Do I need to create my own or use a commercial server for the features and matchmaking options I want my game to support?

    - by baptzmoffire
    So I'm developing an indie turn-based game for iOS and, in coding up a Game Center matchmaking class, I'm starting to question whether Game Center is even the best choice for what I want this game to do. I need to figure out whether I need to create my own server, invest in a preexisting client or server service, or if I even need to use a server at all. If I do need to use a ready-made service other than Game Center, which server would accomodate my game's needs best? I have limited resources and funds. Here is the list of features I want my game to support, ideally: Turn-based gameplay (a la "with Friends" and "with Buddies" games) Smart matchmaking (matching users up with other players of comparable skill/achievements) Random matchmaking Facebook matchmaking Specific username matchmaking Contact list matchmaking A way to select what "type" of match you want to challenge an opponent to. (In random, smart, and Facebook matchmaking, there will be different "wagers" the player can make. [e.g. "I wanna play a random opponent for 1000 points. Now, I wanna play my Facebook buddy for 1,000,000 points."] There will be a predetermined range of amounts you can play for. It won't be customizable.) Buddies list capability (Game-buddies, as opposed to contacts and Facebook) A higher concurrent game cap than Game Center offers (which I still can't really find a straight answer on) Scalability (it should support 2 or 20,000,000 players) Objective-C compatibility Flexibility (for all the stuff I haven't thought of yet) Am I dreaming, here? Is there even a service that can handle all of these features? Do I need to invest months in learning a networking language to build my own? If so, how much would I need to spend on hardware? I've been looking around all morning and, so far, the only seemingly viable option is SmartFox. Under "Everything and the kitchen sink" section here, it says they support "virtual world with Zones, Rooms and RoomGroups, create complex game challenges, send invitations, manage buddy lists, create custom permission profiles, oversee the security aspects and tons more." http://www.smartfoxserver.com/overview/platform Is there an option that Im just overlooking? Thanks for any help anyone can provide. Sorry for the long poast. One last question: Does anyone know which server Dice with Buddies uses? I was experimenting with how many concurrent games I could get going and my ADHD kicked in at about 80 games. 80 concurrent games would be great for my game, but again, I need the other features I mentioned too. Thanks again.

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  • Would someone please explain Octree Collisions to me?

    - by A-Type
    I've been reading everything I can find on the subject and I feel like the pieces are just about to fall into place, but I just can't quite get it. I'm making a space game, where collisions will occur between planets, ships, asteroids, and the sun. Each of these objects can be subdivided into 'chunks', which I have implemented to speed up rendering (the vertices can and will change often at runtime, so I've separated the buffers). These subdivisions also have bounding primitives to test for collision. All of these objects are made of blocks (yeah, it's that kind of game). Blocks can also be tested for rough collisions, though they do not have individual bounding primitives for memory reasons. I think the rough testing seems to be sufficient, though. So, collision needs to be fairly precise; at block resolution. Some functions rely on two blocks colliding. And, of course, attacking specific blocks is important. Now what I am struggling with is filtering my collision pairs. As I said, I've read a lot about Octrees, but I'm having trouble applying it to my situation as many tutorials are vague with very little code. My main issues are: Are Octrees recalculated each frame, or are they stored in memory and objects are shuffled into different divisions as they move? Despite all my reading I still am not clear on this... the vagueness of it all has been frustrating. How far do Octrees subdivide? Planets in my game are quite large, while asteroids are smaller. Do I subdivide to the size of the planet, or asteroid (where planet is in multiple divisions)? Or is the limit something else entirely, like number of elements in the division? Should I load objects into the octrees as 'chunks' or in the whole, then break into chunks later? This could be specific to my implementation, I suppose. I was going to ask about how big my root needed to be, but I did manage to find this question, and the second answer seems sufficient for me. I'm afraid I don't really get what he means by adding new nodes and doing subdivisions upon adding new objects, probably because I'm confused about whether the tree is maintained in memory or recalculated per-frame.

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  • iTorque for a simple arcade game

    - by Herfus
    I have a basic understanding of programming, but I am no programmer. I've had a couple of a semesters with java programming, so we're talking pretty basic here. I have some scripting experience with game editors where I've created a few (simple) encounters, boss AI, abilities, events and so on. I've mostly done level design with UDK, Source and several other toolsets for a few years now, but I'd like to divert some of the focus to iphone-development. I've participated in a few development projects (source, udk, daot) where I've had a variety of roles (yet never beyond simple scripting). I have just finished prototyping an Iphone game (using game maker) and begun a bit more precise planning on what I'll have to do for the real version. The game is fairly simple, perhaps the best comparison in scope and complexity would be Doodlejump for iPhone. The reason I created the prototype was not just to answer a few questions about the gameplay, but to get some insight into what kind of problems I might face when trying to develop the real thing. I've been looking for engines that I can use for this. iTorque looks, so far, like the best option with a scripting language and WYSIWYG-editor. However the price is fairly steep and I'd like to prepare myself as much as possible before jumping into this, which is why I'm going to ask a few questions here. What kind of difficulties do you think I might run into, considering what you've read so far? Not just with torque, but development in general. I'm making this question mostly to have someone to reality check me. I usually achieve to do what I'm trying to do with scripting, but something tells me there's a very big difference between scripting an AI or an event and creating game logic. Will it be too much of a leap? Just how simple is it to use the Torque scripting language? Obviously I don't expect to be prepared, I expect it to be a learning process. However, I'd still like to be at least a bit confident on the time I'll have to dedicate to this first.

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  • Understanding clojure keywords

    - by tjb1982
    I'm taking my first steps with Clojure. Otherwise, I'm somewhat competent with JavaScript, Python, Java, and a little C. I was reading this artical that describes destructuring vectors and maps. E.g. => (def point [0 0]) => (let [[x y] point] => (println "the coordinates are:" x y)) the coordinates are: 0 0 but I'm having a difficult time understanding keywords. At first glance, they seem really simple, as they just evaluate to themselves: => :test :test But they seem to be used is so many different ways and I don't understand how to think about them. E.g., you can also do stuff like this: => (defn full-name [& {first :first last :last}] => (println first last)) => (full-name :first "Tom" :last "Brennan") Tom Brennan nil This doesn't seem intuitive to me. I would have guessed the arguments should have been something more like: (full-name {:first "Tom" :last "Brennan"}) because it looks like in the function definition that you're saying "no required arguments, but a variable number of arguments comes in the form of a single map". But it seems more like you're saying "no required arguments, but a variable number of arguments comes which should be a list of alternating keywords and values... ?" I'm not really sure how to wrap my brain around this. Also, things like this confuse me too: => (def population {:humans 5 :zombies 1000}) => (:zombies population) 1000 => (population :zombies) 1000 How do maps and keywords suddenly become functions? If I could get some clarification on the use of keywords in these two examples, that would be really helpful. Update I've also seen http://stackoverflow.com/questions/3337888/clojure-named-arguments and while the accepted answer is a great demonstration of how to use keywords with destructuring and named arguments, I'm really looking more for understanding how to think about them--why the language is designed this way and how I can best internalize their use.

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