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  • How to Open Any Folder as a Project in the NetBeans Platform

    - by Geertjan
    Typically, as described in the NetBeans Project Type Tutorial, you'll define a project type based on the presence of a file (e.g., "project.xml" or "customer.txt" or something like that) in a folder. I.e., if the file is there, then its parent, i.e., the folder that contains the file, is a project and should be opened in your application. However, in some scenarios (as with the HTML5 project type introduced in NetBeans IDE 7.3), the user should be able to open absolutely any folder at all into the application. How to create a project type that is that liberal? Here you go, the only condition that needs to be true is that the selected item in the "Open Project" dialog is a folder, as defined in the "isProject" method below. Nothing else. That's it. If you select a folder, it will be opened in your application, displaying absolutely everything as-is (since below there's no ProjectLogicalView defined): import java.beans.PropertyChangeListener; import java.io.IOException; import javax.swing.Icon; import org.netbeans.api.project.Project; import org.netbeans.api.project.ProjectInformation; import org.netbeans.spi.project.ProjectFactory; import org.netbeans.spi.project.ProjectState; import org.openide.filesystems.FileObject; import org.openide.loaders.DataFolder; import org.openide.loaders.DataObjectNotFoundException; import org.openide.nodes.FilterNode; import org.openide.util.Exceptions; import org.openide.util.ImageUtilities; import org.openide.util.Lookup; import org.openide.util.lookup.Lookups; import org.openide.util.lookup.ServiceProvider; @ServiceProvider(service = ProjectFactory.class) public class FolderProjectFactory implements ProjectFactory { @Override public boolean isProject(FileObject projectDirectory) { return DataFolder.findFolder(projectDirectory) != null; } @Override public Project loadProject(FileObject dir, ProjectState state) throws IOException { return isProject(dir) ? new FolderProject(dir) : null; } @Override public void saveProject(Project prjct) throws IOException, ClassCastException { // leave unimplemented for the moment } private class FolderProject implements Project { private final FileObject projectDir; private Lookup lkp; private FolderProject(FileObject dir) { this.projectDir = dir; } @Override public FileObject getProjectDirectory() { return projectDir; } @Override public Lookup getLookup() { if (lkp == null) { lkp = Lookups.fixed(new Object[]{ new Info(), }); } return lkp; } private final class Info implements ProjectInformation { @Override public Icon getIcon() { Icon icon = null; try { icon = ImageUtilities.image2Icon( new FilterNode(DataFolder.find( getProjectDirectory()).getNodeDelegate()).getIcon(1)); } catch (DataObjectNotFoundException ex) { Exceptions.printStackTrace(ex); } return icon; } @Override public String getName() { return getProjectDirectory().getName(); } @Override public String getDisplayName() { return getName(); } @Override public void addPropertyChangeListener(PropertyChangeListener pcl) { //do nothing, won't change } @Override public void removePropertyChangeListener(PropertyChangeListener pcl) { //do nothing, won't change } @Override public Project getProject() { return FolderProject.this; } } } } Even the ProjectInformation implementation really isn't needed at all, since it provides nothing more than the icon in the "Open Project" dialog, the rest (i.e., the display name in the "Open Project" dialog) is provided by default regardless of whether you have a ProjectInformation implementation or not.

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  • Desktop Applications Versus Web Applications

    Up until the advent of the internet programmers really only developed one type of application used by end-users.  This type of application was called a desktop application. As the name implies, these applications ran strictly from a desktop computer, and were limited by the resources available to the computer. Initially, this type of applications did not need resources outside of the scope of the computer in which they installed. The problem with this type of application is that if multiple end-users need to access the same desktop application, then the application must be installed on the end-user’s computer. In this age of software development security was not as big of a concern as it is today with other types of applications. This is primarily due to the fact that an end-user must have access to the computer where the software is installed in order for them to access the application. In addition, developers could also password protect the application just in case an authorized end-user was able to gain access to the computer. With the birth of the internet a second form of application emerged because developers were trying to solve inherent issues with the preexisting desktop application. One of the solutions to overcome some of the short comings of desktop applications is the web application. Web applications are hosted on a centralized server and clients only need to have network access and a web browser in order to access the application. Because a web application can be installed on a remote server it removes the need for individual installations of the same application on each end-user’s computer.  The main benefits to an application being hosted on a server is increased accessibility to the application due to the fact that nothing has to be installed on a desktop computer for an end-user to be able to access the application. In addition, web applications are much easier to maintain because any change to the application is applied on the server and is inherently applied to any end-user trying to use the application. This removes the time needed to install and maintain individual installations of a desktop application. However with the increased accessibility there are additional costs that are incurred compared to a desktop application because of the additional cost and maintenance of a server hosting the application. Typically, after a desktop application is purchased there are no additional reoccurring fees associated with the application.  When developing a web based application there are additional considerations that must be addressed compared to a desktop application. The added benefit of increased accessibility also now adds a new failure point when trying to gain access to an application. An end-user now must have network connectivity in order to access the application. This issue is not a concern for desktop applications because there resources are typically bound to the computer in which they run. Since the availability of an application is increased with the use of the client-server model in a web based application, additional security concerns now come in to play. As stated before a, desktop application is bound to the accessibility of the end-user to the computer that the application is installed. This is not the case with web based applications because they potentially could have access from anywhere with the proper internet/network connection. Additional security steps are required to insure the integrity of the application and its data. Examples of these steps include and are not limited to the following: Restricted/Password Areas This form of security is used when specific information can only be accessed by end-users based on a set of accessibility rules. IP Restrictions This form of security is used when only specific locations need to access an application. This form of security is applied from within the web server or a firewall. Network Restrictions (Firewalls) This form of security is used to contain access to an application within a specific sub set of a network. Data Encryption This form of security is used transform personally identifiable information in to something unreadable so that it can be stored for future use. Encrypted Protocols (HTTPS) This form of security is used to prevent others from reading messages being sent between applications over a network.

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  • Payback Is The Coupon King

    - by Troy Kitch
    PAYBACK GmbH operates the largest marketing and couponing platforms in the world—with more than 50 million subscribers in Germany, Poland, India, Italy, and Mexico.  The Security Challenge Payback handles millions of requests for customer loyalty coupons and card-related transactions per day under tight latency constraints—with up to 1,000 attributes or more for each PAYBACK subscriber. Among the many challenges they solved using Oracle, they had to ensure that storage of sensitive data complied with the company’s stringent privacy standards aimed at protecting customer and purchase information from unintended disclosure. Oracle Advanced Security The company deployed Oracle Advanced Security to achieve reliable, cost-effective data protection for back-up files and gain the ability to transparently encrypt data transfers. By using Oracle Advanced Security, organizations can comply with privacy and regulatory mandates that require encrypting and redacting (display masking) application data, such as credit cards, social security numbers, or personally identifiable information (PII). Learn more about how PAYBACK uses Oracle.

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  • How to resize / enlarge / grow a non-LVM ext4 partition

    - by Mischa
    I have already searched the forums, but couldnt find a good suitable answer: I have an Ubuntu Server 10.04 as KVM Host and a guest system, that also runs 10.04. The host system uses LVM and there are three logical volumes, which are provided to the guest as virtual block devices - one for /, one for /home and one for swap. The guest had been partitioned without LVM. I have already enlarged the logical volume in the host system - the guest successfully sees the bigger virtual disk. However, this virtual disk contains one "good old" partition, which still has the old small size. The output of fdisk -l is me@produktion:/$ LC_ALL=en_US sudo fdisk -l Disk /dev/vda: 32.2 GB, 32212254720 bytes 255 heads, 63 sectors/track, 3916 cylinders Units = cylinders of 16065 * 512 = 8225280 bytes Sector size (logical/physical): 512 bytes / 512 bytes I/O size (minimum/optimal): 512 bytes / 512 bytes Disk identifier: 0x000c8ce7 Device Boot Start End Blocks Id System /dev/vda1 * 1 3917 31455232 83 Linux Disk /dev/vdb: 2147 MB, 2147483648 bytes 244 heads, 47 sectors/track, 365 cylinders Units = cylinders of 11468 * 512 = 5871616 bytes Sector size (logical/physical): 512 bytes / 512 bytes I/O size (minimum/optimal): 512 bytes / 512 bytes Disk identifier: 0x000f2bf7 Device Boot Start End Blocks Id System /dev/vdb1 1 366 2095104 82 Linux swap / Solaris Partition 1 has different physical/logical beginnings (non-Linux?): phys=(0, 32, 33) logical=(0, 43, 28) Partition 1 has different physical/logical endings: phys=(260, 243, 47) logical=(365, 136, 44) Disk /dev/vdc: 225.5 GB, 225485783040 bytes 255 heads, 63 sectors/track, 27413 cylinders Units = cylinders of 16065 * 512 = 8225280 bytes Sector size (logical/physical): 512 bytes / 512 bytes I/O size (minimum/optimal): 512 bytes / 512 bytes Disk identifier: 0x00027f25 Device Boot Start End Blocks Id System /dev/vdc1 1 9138 73398272 83 Linux The output of parted print all is Model: Virtio Block Device (virtblk) Disk /dev/vda: 32.2GB Sector size (logical/physical): 512B/512B Partition Table: msdos Number Start End Size Type File system Flags 1 1049kB 32.2GB 32.2GB primary ext4 boot Model: Virtio Block Device (virtblk) Disk /dev/vdb: 2147MB Sector size (logical/physical): 512B/512B Partition Table: msdos Number Start End Size Type File system Flags 1 1049kB 2146MB 2145MB primary linux-swap(v1) Model: Virtio Block Device (virtblk) Disk /dev/vdc: 225GB Sector size (logical/physical): 512B/512B Partition Table: msdos Number Start End Size Type File system Flags 1 1049kB 75.2GB 75.2GB primary ext4 What I want to achieve is to simply grow or resize the partition /dev/vdc1 so that it uses the whole space provided by the virtual block device /dev/vdc. The problem is, that when I try to do that with parted, it complains: (parted) select /dev/vdc Using /dev/vdc (parted) print Model: Virtio Block Device (virtblk) Disk /dev/vdc: 225GB Sector size (logical/physical): 512B/512B Partition Table: msdos Number Start End Size Type File system Flags 1 1049kB 75.2GB 75.2GB primary ext4 (parted) resize 1 WARNING: you are attempting to use parted to operate on (resize) a file system. parted's file system manipulation code is not as robust as what you'll find in dedicated, file-system-specific packages like e2fsprogs. We recommend you use parted only to manipulate partition tables, whenever possible. Support for performing most operations on most types of file systems will be removed in an upcoming release. Start? [1049kB]? End? [75.2GB]? 224GB Error: File system has an incompatible feature enabled. Compatible features are has_journal, dir_index, filetype, sparse_super and large_file. Use tune2fs or debugfs to remove features. So what can I do? This is a headless production system. What is a safe way to grow this partition? I CAN unmount it, though - so this is not the problem.

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  • Will we ever lose the human touch?

    - by divya.malik
    I was at a conference two weeks ago, which was targeted to sales and marketing professionals. The discussions around the changing scenario in sales was very interesting. More and more of selling is moving to the internet- sales people are delivering more of their presentations online, or via the phone. Budget constraints and new technologies have dramatically decreased the need for face-to-face interactions. At the same time, customers are also researching for products on their own, taking the advice of peers, making up their mind, and then contacting the vendor. That takes care of more than half of the usual selling process. But humans are social animals, and because of that I believe that despite these changing trends and technologies, the need to maintain the human touch will always be necessary. One of the presenters at the conference shared this video, which stayed in my mind.

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  • Open a File Browser From Your Current Command Prompt/Terminal Directory

    - by The Geek
    Ever been doing some work at the command line when you realized… it would be a lot easier if I could just use the mouse for this task? One command later, you’ll have a window open to the same place that you’re at. This same tip works in more than one operating system, so we’ll detail how to do it in every way we know how. Open a File Browser in Windows We’ve actually covered this before when we told you how to open an Explorer window from the command prompt’s current directory, but we’ll briefly review: Just type the follow command into your command prompt: explorer . Note: You could actually just type “start .” instead. And you’ll then see a file browsing window set to the same directory you were previous at. And yes, this screenshot is from Vista, but it works the same in every version of Windows. If that wasn’t good enough, you should really read how you can navigate in the File Open/Save dialogs with just the keyboard—now that’s a Stupid Geek Trick! Open a File Browser in Linux For this exercise, we’re going to assume that you’re using Gnome under a Linux flavor like Ubuntu, because that’s the most common. From your terminal window, just type in the following command: nautilus . And the next thing you know, you’ll have a file browser window open at the current location. You’ll see some type of error message at the prompt, but you can pretty much ignore that. You can also use “gnome-open .” if you want. Open Finder in Mac OS X All the Mac computers in this office are running Linux, so we haven’t had a chance to verify, but you should be able to use the following command on OS X to open Finder in the current terminal location: open . Open Dolphin on Linux KDE4 dolphin . Got any extra tips to help out your fellow readers? How do you do the same thing in KDE3? What about OS X? Leave your savvy advice in the comments, and maybe we’ll update the article. Or not. Either way, it’ll help somebody! Similar Articles Productive Geek Tips Keyboard Ninja: Concatenate Multiple Text Files in WindowsStupid Geek Tricks: Open an Explorer Window from the Command Prompt’s Current DirectoryHow to automate FTP uploads from the Windows Command LineShell Geek: Rename Multiple Files At OnceAdd "Open with gedit" to the right click menu in Ubuntu TouchFreeze Alternative in AutoHotkey The Icy Undertow Desktop Windows Home Server – Backup to LAN The Clear & Clean Desktop Use This Bookmarklet to Easily Get Albums Use AutoHotkey to Assign a Hotkey to a Specific Window Latest Software Reviews Tinyhacker Random Tips DVDFab 6 Revo Uninstaller Pro Registry Mechanic 9 for Windows PC Tools Internet Security Suite 2010 Home Networks – How do they look like & the problems they cause Check Your IMAP Mail Offline In Thunderbird Follow Finder Finds You Twitter Users To Follow Combine MP3 Files Easily QuicklyCode Provides Cheatsheets & Other Programming Stuff Download Free MP3s from Amazon

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  • Arbitrary projection matrix from 6 arbitrary frustum planes

    - by Doub
    A projection matrix represent a tranformation from the camera view space to the rendering system clip space. In other words, it defines the transormation between a 6-sided frustum to the clip cube. The glOrtho and glFrustum use only 6 parameter to define such a projection, but impose several constraints on the frustum that will get projected to the clip cube: the near and far planes are parallel, the left and right planes intersect on a vertical line, and the top and bottom planes intersect on a horizontal lines, both lines being parallel to the near and far planes. I'd like to lift these restrictions. So, from the definition of the 6 frustum side planes (in whatever representation you see fit), how can I compute a general projection matrix?

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  • Game Object Factory: Fixing Memory Leaks

    - by Bunkai.Satori
    Dear all, this is going to be tough: I have created a game object factory that generates objects of my wish. However, I get memory leaks which I can not fix. Memory leaks are generated by return new Object(); in the bottom part of the code sample. static BaseObject * CreateObjectFunc() { return new Object(); } How and where to delete the pointers? I wrote bool ReleaseClassType(). Despite the factory works well, ReleaseClassType() does not fix memory leaks. bool ReleaseClassTypes() { unsigned int nRecordCount = vFactories.size(); for (unsigned int nLoop = 0; nLoop < nRecordCount; nLoop++ ) { // if the object exists in the container and is valid, then render it if( vFactories[nLoop] != NULL) delete vFactories[nLoop](); } return true; } Before taking a look at the code below, let me help you in that my CGameObjectFactory creates pointers to functions creating particular object type. The pointers are stored within vFactories vector container. I have chosen this way because I parse an object map file. I have object type IDs (integer values) which I need to translate them into real objects. Because I have over 100 different object data types, I wished to avoid continuously traversing very long Switch() statement. Therefore, to create an object, I call vFactoriesnEnumObjectTypeID via CGameObjectFactory::create() to call stored function that generates desired object. The position of the appropriate function in the vFactories is identical to the nObjectTypeID, so I can use indexing to access the function. So the question remains, how to proceed with garbage collection and avoid reported memory leaks? #ifndef GAMEOBJECTFACTORY_H_UNIPIXELS #define GAMEOBJECTFACTORY_H_UNIPIXELS //#include "MemoryManager.h" #include <vector> template <typename BaseObject> class CGameObjectFactory { public: // cleanup and release registered object data types bool ReleaseClassTypes() { unsigned int nRecordCount = vFactories.size(); for (unsigned int nLoop = 0; nLoop < nRecordCount; nLoop++ ) { // if the object exists in the container and is valid, then render it if( vFactories[nLoop] != NULL) delete vFactories[nLoop](); } return true; } // register new object data type template <typename Object> bool RegisterClassType(unsigned int nObjectIDParam ) { if(vFactories.size() < nObjectIDParam) vFactories.resize(nObjectIDParam); vFactories[nObjectIDParam] = &CreateObjectFunc<Object>; return true; } // create new object by calling the pointer to the appropriate type function BaseObject* create(unsigned int nObjectIDParam) const { return vFactories[nObjectIDParam](); } // resize the vector array containing pointers to function calls bool resize(unsigned int nSizeParam) { vFactories.resize(nSizeParam); return true; } private: //DECLARE_HEAP; template <typename Object> static BaseObject * CreateObjectFunc() { return new Object(); } typedef BaseObject*(*factory)(); std::vector<factory> vFactories; }; //DEFINE_HEAP_T(CGameObjectFactory, "Game Object Factory"); #endif // GAMEOBJECTFACTORY_H_UNIPIXELS

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  • How to remove java.sql.BatchUpdateException in Grails? [closed]

    - by aman.nepid
    I have a domain like this: class BusinessOrganization { static hasMany = [organizationBusinessTypes:OrganizationBusinessType] String name String icon static constraints = { name(blank:false,unique:true) icon(unique:true) } String toString() { return "${name}" } } When I save some data for first time it works fine. But when by the next time it shows this error : Error 500: Internal Server Error URI /nLocatePortal/businessOrganization/save Class java.sql.BatchUpdateException Message Batch entry 0 insert into business_organization (version, icon, name, id) values ('0', '', 'dddd', '2') was aborted. Call getNextException to see the cause. **Around line 24 of grails-app/controllers/com/nlocate/portal/BusinessOrganizationController.groovy** 21: 22: def save() { 23: def businessOrganizationInstance = new BusinessOrganization(params) 24: if (!businessOrganizationInstance.save(flush: true)) { 25: render(view: "create", model: [businessOrganizationInstance: businessOrganizationInstance]) 26: return 27: } Please someone help me why this is happening. I am new to Grails. I have not modified the controllers but still I get this error.

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  • ecommerce options for 5-6 products

    - by Calum
    Hi, We're looking to develop a simple e-commerce solution to sell 5-6 products. We'd rather not have to use PayPal's buttons (buy it now!) if there's an existing alternative, but would also for budget/time constraints don't want to roll our own. Are there any small, basic ecommerce solutions available that would allow this? I did look at Foxy Cart but the monthly fee was a bit of a turn off. (I must sound extremely fussy I'm aware!) Something like Zen would just be overkill for our needs. Thanks for any suggestions.

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  • MAAS/Juju architecture and issues

    - by Massimo
    I recently deployed a MAAS/Juju environment based on a six nodes cluster, using Ubuntu 12.04 LTS, to run a "proof of concept". I could appreciate how interesting the architecture is, and I'd like to understand if I can really base my future business on this technology. Therefore I'd like to understand more about any involved limitations, constraints and necessities. In particular I'd like to understand: 1) how can MAAS be made reliable, i.e. deployed over two or more physical nodes able to fail-over ? 2) can the same physical cluster host multiple juju environments, under the assumption openstack/virtualization is not used ? 3) can the same physical node host different charms of the same juju environment, deployed in a standard, reliable way by juju ?

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  • How are minimum system requirements determined?

    - by Michael McGowan
    We've all seen countless examples of software that ships with "minimum system requirements" like the following: Windows XP/Vista/7 1GB RAM 200 MB Storage How are these generally determined? Obviously sometimes there are specific constraints (if the program takes 200 MB on disk then that is a hard requirement). Aside from those situations, many times for things like RAM or processor it turns out that more/faster is better with no hard constraint. How are these determined? Do developers just make up numbers that seem reasonable? Does QA go through some rigorous process testing various requirements until they find the lowest settings with acceptable performance? My instinct says it should be the latter but is often the former in practice.

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  • How to write functionally in a web framework

    - by Kevin Burke
    I love Rich Hickey, Clojure and Haskell and I get it when he talks about functions and the unreliability of side-effecting code. However I work in an environment where nearly all the functions I write have to read from the database, write to the database, make HTTP requests, decrement a user's balance, modify a frontend HTML component based on a click action, return different results based on the URI or the POST body. We also use PHP for the frontend, which is littered with functions like parse_str(), which modifies an object in place. All of these are side-effecting to one degree or another. Given these constraints and the side-effecting nature of the logic I'm coding, what can I do to make my code more reliable and function-able?

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  • RemoveHandler Issues with Custom Events

    - by Jeff Certain
    This is a case of things being more complicated that I thought they should be. Since it took a while to figure this one out, I thought it was worth explaining and putting all of the pieces to the answer in one spot. Let me set the stage. Architecturally, I have the notion of generic producers and consumers. These put items onto, and remove items from, a queue. This provides a generic, thread-safe mechanism to load balance the creation and processing of work items in our application. Part of the IProducer(Of T) interface is: 1: Public Interface IProducer(Of T) 2: Event ItemProduced(ByVal sender As IProducer(Of T), ByVal item As T) 3: Event ProductionComplete(ByVal sender As IProducer(Of T)) 4: End Interface Nothing sinister there, is there? In order to simplify our developers’ lives, I wrapped the queue with some functionality to manage the produces and consumers. Since the developer can specify the number of producers and consumers that are spun up, the queue code manages adding event handlers as the producers and consumers are instantiated. Now, we’ve been having some memory leaks and, in order to eliminate the possibility that this was caused by weak references to event handles, I wanted to remove them. This is where it got dicey. My first attempt looked like this: 1: For Each producer As P In Producers 2: RemoveHandler producer.ItemProduced, AddressOf ItemProducedHandler 3: RemoveHandler producer.ProductionComplete, AddressOf ProductionCompleteHandler 4: producer.Dispose() 5: Next What you can’t see in my posted code are the warnings this caused. The 'AddressOf' expression has no effect in this context because the method argument to 'AddressOf' requires a relaxed conversion to the delegate type of the event. Assign the 'AddressOf' expression to a variable, and use the variable to add or remove the method as the handler.  Now, what on earth does that mean? Well, a quick Bing search uncovered a whole bunch of talk about delegates. The first solution I found just changed all parameters in the event handler to Object. Sorry, but no. I used generics precisely because I wanted type safety, not because I wanted to use Object. More searching. Eventually, I found this forum post, where Jeff Shan revealed a missing piece of the puzzle. The other revelation came from Lian_ZA in this post. However, these two only hinted at the solution. Trying some of what they suggested led to finally getting an invalid cast exception that revealed the existence of ItemProducedEventHandler. Hold on a minute! I didn’t create that delegate. There’s nothing even close to that name in my code… except the ItemProduced event in the interface. Could it be? Naaaaah. Hmmm…. Well, as it turns out, there is a delegate created by the compiler for each event. By explicitly creating a delegate that refers to the method in question, implicitly cast to the generated delegate type, I was able to remove the handlers: 1: For Each producer As P In Producers 2: Dim _itemProducedHandler As IProducer(Of T).ItemProducedEventHandler = AddressOf ItemProducedHandler 3: RemoveHandler producer.ItemProduced, _itemProducedHandler 4:  5: Dim _productionCompleteHandler As IProducer(Of T).ProductionCompleteEventHandler = AddressOf ProductionCompleteHandler 6: RemoveHandler producer.ProductionComplete, _productionCompleteHandler 7: producer.Dispose() 8: Next That’s “all” it took to finally be able to remove the event handlers and maintain type-safe code. Hopefully, this will save you the same challenges I had in trying to figure out how to fix this issue!

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  • Is the copy/paste approach professionally viable when working with the Google Maps API?

    - by Ian Campbell
    I find that I understand much of the Javascript concepts used in the Google Maps API code, but then again there is quite a bit that is way over my head in syntax. For example, the geocoder syntax seems to be of Ajax form, though I don't understand what is happening under the hood (especially with lines like results[0].geometry.location). I am able to modify the body of if (status == google.maps.GeocoderStatus.OK) for different purposes though. So, being that I am able to take various code from the Developer's Guide and rework it to an extent for my own purposes, all the while not fully understanding what Google Maps is actually doing, does this make me a copy-paste programmer? Is this a bad practice, or is this professionally viable? I am, of course, interested in learning as much as I can, but what if time-constraints outweigh the learning process?

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  • Server side random selection of players

    - by Ron
    Assuming I have a simple client-server game, where the server picks random players on a very frequent base, I was wondering what is the best way to select a random player (According to the following constraints): Solution must be high performance and highly scalable Random spread should be relatively even (meaning if I have 3 players and pick 99 times, they will all be picked 33 times more or less) Should only pick players who were active in the past X days (optional, but a big bonus) The actual DB or data model used to store players isn't an issue here, as we'll select the technology in accordance to our needs. However, high performance and scalability is (at the moment we have over 60,000 unique daily active players, and we plan on growing even more). Thanks!

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  • Retrofit Certification

    - by Bill Evjen
    Impact of Regulations on Cabin Systems Installation John Courtright, Structural Integrity Engineering There are “heightened” FAA attention to technical issues related to IFE and Wi-Fi Systems Installations The Aging Aircraft Safety Rule – EWIS & Damage Tolerance Analysis The Challenge: Maximize Flight Safety While Minimizing Costs Issue Papers & Testing, Testing, Testing The role of Airworthiness Directives (ADs) on the design of many IFE systems and all antenna systems. Goal is safety AND cost-effective maintenance intervals and inspection techniques The STC Process Briefly Stated Type Certifications (TC) Supplemental Type Certifications (STC) The STC Process Project Specific Certification Plan (PSCP) Managed by FAA Aircraft Certification Office (ACO) Type of Project (Electrical/Mechanical Systems or Structural) Specific Type of Aircraft Being Modified Schedule Design & Installation Location What does the STC Plan (PSCP) Cover? System Description – What does the system do? System qualification – Are the components qualified? Certification requirements – What FARs are applicable? Installation detail – what is being modified? Prototype installation – What is new? Functional hazard Assessment (FHA) – is it safe? EZAP-EWIS Requirements – Any aging aircraft issues? Certification Data – How is compliance achieved? Delegation and FAA involvement – Who is doing the work? Proposed certification schedule – When is the installation? Certification documentation – What the FAA Expects to see Cabin Systems Certification Concerns In addition to meeting the requirements for DO-160, Cabin System Certification needs to address issues related to: Power management: Generally, IFE and Wi-Fi Systems are classified as “Non-Essential Equipment” from a certification viewpoint. Connected to “non-essential” power buses Must be able to shed IFE & Wi-Fi Systems in a smoke/fire event or Other electrical emergency (FAA Policy 00-111-160) FAA is more relaxed with testing wi-fi. It used to be that you had to have 150 seats with laptops running wi-fi, but now it is down to around 50. Aging aircraft concerns – electrical and structural Issue papers addressing technical concerns involving: “Structural Certification Criteria for Large Antenna Installations” Antenna “Vibration/Buffeting Compliance Criteria” DO-160 : Environmental Test Procedures DO 160 – “Environmental Conditions and Test Procedures for Airborne Equipment”, Issued by RTCA Provides guidance to equipment manufacturers as to testing requirements Temperature: –40C to +55C Vibration and Shock Contaminant susceptibility – fluids and dust Electro-magnetic Interference Cabin systems are generally classified as “non-essential” Swissair 111 crashed (in part) due to non-standard wiring practices. EWIS Design Implications Installation design must take EWIS Requirements into account. This generally means: Aircraft surveys are needed to identify proper wire routing Ensure existing wiring diagrams are correct Identify primary/Secondary/Tertiary bus locations Verify proper separation of wire bundles exist Required separation from fuel quantity indicator system (FQIS) to prevent fuel tang ignition Enhanced Zonal Analysis Procedure (EZAP) Performed EZAP was developed by the Aging Transport Systems Rulemaking Advisory Committee (ATSRAC) EZAP is the method for analyzing airplane zones with an emphasis on evaluating wiring systems and the existence of combustibles  in the cabin. Certification Considerations for Wi-Fi Systems Electrical – All existing DO 160 testing required Issue papers required Onboard EMI testing – any interference with aircraft systems when multiple wi-fi users are logged on? Vibration/Buffeting compliance criteria – what is the effect of the antenna on aircraft flight characteristics? Structural certification criteria – what are the stress loads on the aircraft at the antenna location and what is the impact on maintenance inspection criteria for the airline? Damage tolerance analysis required Goal – minimize maintenance inspection intervals

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  • Learn Many Languages

    - by Jeff Foster
    My previous blog, Deliberate Practice, discussed the need for developers to “sharpen their pencil” continually, by setting aside time to learn how to tackle problems in different ways. However, the Sapir-Whorf hypothesis, a contested and somewhat-controversial concept from language theory, seems to hold reasonably true when applied to programming languages. It states that: “The structure of a language affects the ways in which its speakers conceptualize their world.” If you’re constrained by a single programming language, the one that dominates your day job, then you only have the tools of that language at your disposal to think about and solve a problem. For example, if you’ve only ever worked with Java, you would never think of passing a function to a method. A good developer needs to learn many languages. You may never deploy them in production, you may never ship code with them, but by learning a new language, you’ll have new ideas that will transfer to your current “day-job” language. With the abundant choices in programming languages, how does one choose which to learn? Alan Perlis sums it up best. “A language that doesn‘t affect the way you think about programming is not worth knowing“ With that in mind, here’s a selection of languages that I think are worth learning and that have certainly changed the way I think about tackling programming problems. Clojure Clojure is a Lisp-based language running on the Java Virtual Machine. The unique property of Lisp is homoiconicity, which means that a Lisp program is a Lisp data structure, and vice-versa. Since we can treat Lisp programs as Lisp data structures, we can write our code generation in the same style as our code. This gives Lisp a uniquely powerful macro system, and makes it ideal for implementing domain specific languages. Clojure also makes software transactional memory a first-class citizen, giving us a new approach to concurrency and dealing with the problems of shared state. Haskell Haskell is a strongly typed, functional programming language. Haskell’s type system is far richer than C# or Java, and allows us to push more of our application logic to compile-time safety. If it compiles, it usually works! Haskell is also a lazy language – we can work with infinite data structures. For example, in a board game we can generate the complete game tree, even if there are billions of possibilities, because the values are computed only as they are needed. Erlang Erlang is a functional language with a strong emphasis on reliability. Erlang’s approach to concurrency uses message passing instead of shared variables, with strong support from both the language itself and the virtual machine. Processes are extremely lightweight, and garbage collection doesn’t require all processes to be paused at the same time, making it feasible for a single program to use millions of processes at once, all without the mental overhead of managing shared state. The Benefits of Multilingualism By studying new languages, even if you won’t ever get the chance to use them in production, you will find yourself open to new ideas and ways of coding in your main language. For example, studying Haskell has taught me that you can do so much more with types and has changed my programming style in C#. A type represents some state a program should have, and a type should not be able to represent an invalid state. I often find myself refactoring methods like this… void SomeMethod(bool doThis, bool doThat) { if (!(doThis ^ doThat)) throw new ArgumentException(“At least one arg should be true”); if (doThis) DoThis(); if (doThat) DoThat(); } …into a type-based solution, like this: enum Action { DoThis, DoThat, Both }; void SomeMethod(Action action) { if (action == Action.DoThis || action == Action.Both) DoThis(); if (action == Action.DoThat || action == Action.Both) DoThat(); } At this point, I’ve removed the runtime exception in favor of a compile-time check. This is a trivial example, but is just one of many ideas that I’ve taken from one language and implemented in another.

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  • When do you use float and when do you use double

    - by Jakub Zaverka
    Frequently in my programming experience I need to make a decision whether I should use float or double for my real numbers. Sometimes I go for float, sometimes I go for double, but really this feels more subjective. If I would be confronted to defend my decision, I would probably not give sound reasons. When do you use float and when do you use double? Do you always use double, only when memory constraints are present you go for float? Or you use always float unless the precision requirement requires you to use double? Are there some substantial differences regarding computational complexity of basic arithemtics between float and double? What are the pros and cons of using float or double? And have you even used long double?

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  • Resolving a collision between point and moving line

    - by Conundrumer
    I am designing a 2d physics engine that uses Verlet integration for moving points (velocities mentioned below can be derived), constraints to represent moving line segments, and continuous collision detection to resolve collisions between moving points and static lines, and collisions between moving/static points and moving lines. I already know how to calculate the Time of Impact for both types of collision events, and how to resolve moving point static line collisions. However, I can't figure out how to resolve moving/static point moving line collisions. Here are the initial conditions in a point and moving line collision event. We have a line segment joined by two points, A and B. At this instant, point P is touching/colliding with line AB. These points have unit mass and some might have an initial velocity, unless point P is static. The line is massless and has no explicit rotational component, since points A and B could freely move around, extending or contracting the line as a result (which will be fixed later by the constraint solver). Collision is inelastic. What are the final velocities of the points after collision?

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  • WIF-less claim extraction from ACS: JWT

    - by Elton Stoneman
    ACS support for JWT still shows as "beta", but it meets the spec and it works nicely, so it's becoming the preferred option as SWT is losing favour. (Note that currently ACS doesn’t support JWT encryption, if you want encrypted tokens you need to go SAML). In my last post I covered pulling claims from an ACS token without WIF, using the SWT format. The JWT format is a little more complex, but you can still inspect claims just with string manipulation. The incoming token from ACS is still presented in the BinarySecurityToken element of the XML payload, with a TokenType of urn:ietf:params:oauth:token-type:jwt: <t:RequestSecurityTokenResponse xmlns:t="http://schemas.xmlsoap.org/ws/2005/02/trust">   <t:Lifetime>     <wsu:Created xmlns:wsu="http://docs.oasis-open.org/wss/2004/01/oasis-200401-wss-wssecurity-utility-1.0.xsd">2012-08-31T07:39:55.337Z</wsu:Created>     <wsu:Expires xmlns:wsu="http://docs.oasis-open.org/wss/2004/01/oasis-200401-wss-wssecurity-utility-1.0.xsd">2012-08-31T09:19:55.337Z</wsu:Expires>   </t:Lifetime>   <wsp:AppliesTo xmlns:wsp="http://schemas.xmlsoap.org/ws/2004/09/policy">     <EndpointReference xmlns="http://www.w3.org/2005/08/addressing">       <Address>http://localhost/x.y.z</Address>     </EndpointReference>   </wsp:AppliesTo>   <t:RequestedSecurityToken>     <wsse:BinarySecurityToken wsu:Id="_1eeb5cf4-b40b-40f2-89e0-a3343f6bd985-6A15D1EED0CDB0D8FA48C7D566232154" ValueType="urn:ietf:params:oauth:token-type:jwt" EncodingType="http://docs.oasis-open.org/wss/2004/01/oasis-200401-wss-soap-message-security-1.0#Base64Binary" xmlns:wsu="http://docs.oasis-open.org/wss/2004/01/oasis-200401-wss-wssecurity-utility-1.0.xsd" xmlns:wsse="http://docs.oasis-open.org/wss/2004/01/oasis-200401-wss-wssecurity-secext-1.0.xsd">[ base64string ] </wsse:BinarySecurityToken>   </t:RequestedSecurityToken>   <t:TokenType>urn:ietf:params:oauth:token-type:jwt</t:TokenType>   <t:RequestType>http://schemas.xmlsoap.org/ws/2005/02/trust/Issue</t:RequestType>   <t:KeyType>http://schemas.xmlsoap.org/ws/2005/05/identity/NoProofKey</t:KeyType> </t:RequestSecurityTokenResponse> The token as a whole needs to be base-64 decoded. The decoded value contains a header, payload and signature, dot-separated; the parts are also base-64, but they need to be decoded using a no-padding algorithm (implementation and more details in this MSDN article on validating an Exchange 2013 identity token). The values are then in JSON; the header contains the token type and the hashing algorithm: "{"typ":"JWT","alg":"HS256"}" The payload contains the same data as in the SWT, but JSON rather than querystring format: {"aud":"http://localhost/x.y.z" "iss":"https://adfstest-bhw.accesscontrol.windows.net/" "nbf":1346398795 "exp":1346404795 "http://schemas.microsoft.com/ws/2008/06/identity/claims/authenticationinstant":"2012-08-31T07:39:53.652Z" "http://schemas.microsoft.com/ws/2008/06/identity/claims/authenticationmethod":"http://schemas.microsoft.com/ws/2008/06/identity/authenticationmethod/windows" "http://schemas.microsoft.com/ws/2008/06/identity/claims/windowsaccountname":"xyz" "http://schemas.xmlsoap.org/ws/2005/05/identity/claims/emailaddress":"[email protected]" "http://schemas.xmlsoap.org/ws/2005/05/identity/claims/upn":"[email protected]" "identityprovider":"http://fs.svc.x.y.z.com/adfs/services/trust"} The signature is in the third part of the token. Unlike SWT which is fixed to HMAC-SHA-256, JWT can support other protocols (the one in use is specified as the "alg" value in the header). How to: Validate an Exchange 2013 identity token contains an implementation of a JWT parser and validator; apart from the custom base-64 decoding part, it’s very similar to SWT extraction. I've wrapped the basic SWT and JWT in a ClaimInspector.aspx page on gitHub here: SWT and JWT claim inspector. You can drop it into any ASP.Net site and set the URL to be your redirect page in ACS. Swap ACS to issue SWT or JWT, and using the same page you can inspect the claims that come out.

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  • PHP code works on Chrome, but not on Firefox or IE (send email via HTML form) [on hold]

    - by Cachirro
    My brother has this form: <form id="lista" action="lista2.php" method="post"> <input name="cf_name" type="text" size="50" hidden="yes" class="obscure"> <input name="cf_email" type="text" size="50" hidden="yes" class="obscure"> <textarea name="cf_message" cols="45" rows="10" hidden="yes" class="obscure"> </textarea> <input type="image" name="submit" value="Enviar Lista por Email" src="imagens/lista_email.png" width="40" height="40" onclick="this.form.elements['cf_message'].value = lista_mail;this.form.elements['cf_name'].value = prompt('Escreva o seu nome:', '');this.form.elements['cf_email'].value = prompt('Escreva o seu email:', '');"> <input name="submit2" type="submit" value="Enviar" hidden="yes" class="obscure"> </form> That calls this PHP file: <?php if ( isset($_POST['submit']) ) { // Dados de autenticacao SMTP $smtpinfo['host'] = 'localhost'; $smtpinfo['port'] = '25'; $smtpinfo['auth'] = true; $smtpinfo['username'] = 'xxx'; $smtpinfo['password'] = 'xxx'; // Dados recebidos do formulario $nome = $_POST['cf_name']; $email = $_POST['cf_email']; $mensagem = $_POST['cf_message']; // Inclusão de ficheiro PEAR. Certifique-se que o PEAR está activado no seu alojamento require_once "Mail.php"; // Corpo da mensagem $body = "Nome: ".$nome; $body.= "\n\n"; $body.= nl2br($mensagem); $headers = array ('From' => $email, 'To' => $smtpinfo["username"], 'Subject' => 'Encomenda Website'); $mail_object = Mail::factory('smtp', $smtpinfo); $mail = $mail_object->send($smtpinfo["username"], $headers, $body); if ( PEAR::isError($mail) ) { echo ("<p>" . $mail->getMessage() . "</p>"); } else { echo ('<b><font color="FFFF00">Mensagem enviada com sucesso.<br><br></b>Seu email: ' . $email . '<br><br></font>'); }} ?> This basically sends an email with some selected products, name and email. The problem is that it works perfectly on Chrome, but not on FF or IE. When the submit image is pressed, the URL changes to the PHP file, but it displays a blank page. After display errors activated: ini_set('display_errors',1); ini_set('display_startup_errors',1); error_reporting(-1) FF/IE display blank page and email isn't sent, Chrome sends the email and displays this: Strict Standards: Non-static method Mail::factory() should not be called statically in /var/www/vhosts/[site url]/httpdocs/lista2.php on line 33 Strict Standards: Non-static method PEAR::isError() should not be called statically, assuming $this from incompatible context in /usr/share/php/Mail/smtp.php , dont know if it helps So, what is causing the email to be sent on chrome and not on FF or IE? Thank you.

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  • Modeling Websites and Native Code

    I've blogged previously about the Architecture tools in Visual Studio 2010. These tools offer a fantastic way to understand an existing application, design some new functionality, and validate an implementation against architectural rules and constraints. Recently, we announced the availability of the Visualization and Modeling Feature Pack for MSDN subscribers, which complements the Architecture tools in Visual Studio 2010 by adding support for: C/C++ code visualization Website visualization Improved...Did you know that DotNetSlackers also publishes .net articles written by top known .net Authors? We already have over 80 articles in several categories including Silverlight. Take a look: here.

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  • Modeling Websites and Native Code

    I've blogged previously about the Architecture tools in Visual Studio 2010. These tools offer a fantastic way to understand an existing application, design some new functionality, and validate an implementation against architectural rules and constraints. Recently, we announced the availability of the Visualization and Modeling Feature Pack for MSDN subscribers, which complements the Architecture tools in Visual Studio 2010 by adding support for: C/C++ code visualization Website visualization Improved...Did you know that DotNetSlackers also publishes .net articles written by top known .net Authors? We already have over 80 articles in several categories including Silverlight. Take a look: here.

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  • Checking form input data on submit with pure PHP [migrated]

    - by Leron
    I have some experience with PHP but I have never even try to do this wit pure PHP, but now a friend of mine asked me to help him with this task so I sat down and write some code. What I'm asking is for opinion if this is the right way to do this when you want to use only PHP and is there anything I can change to make the code better. Besides that I think the code is working at least with the few test I made with it. Here it is: <?php session_start(); // define variables and initialize with empty values $name = $address = $email = ""; $nameErr = $addrErr = $emailErr = ""; $_SESSION["name"] = $_SESSION["address"] = $_SESSION["email"] = ""; $_SESSION["first_page"] = false; if ($_SERVER["REQUEST_METHOD"] == "POST") { if (empty($_POST["name"])) { $nameErr = "Missing"; } else { $_SESSION["name"] = $_POST["name"]; $name = $_POST["name"]; } if (empty($_POST["address"])) { $addrErr = "Missing"; } else { $_SESSION["address"] = $_POST["address"]; $address = $_POST["address"]; } if (empty($_POST["email"])) { $emailErr = "Missing"; } else { $_SESSION["email"] = $_POST["email"]; $email = $_POST["email"]; } } if ($_SESSION["name"] != "" && $_SESSION["address"] != "" && $_SESSION["email"] != "") { $_SESSION["first_page"] = true; header('Location: http://localhost/formProcessing2.php'); //echo $_SESSION["name"]. " " .$_SESSION["address"]. " " .$_SESSION["email"]; } ?> <DCTYPE! html> <head> <style> .error { color: #FF0000; } </style> </head> <body> <form method="POST" action="<?php echo htmlspecialchars($_SERVER["PHP_SELF"]);?>"> Name <input type="text" name="name" value="<?php echo htmlspecialchars($name);?>"> <span class="error"><?php echo $nameErr;?></span> <br /> Address <input type="text" name="address" value="<?php echo htmlspecialchars($address);?>"> <span class="error"><?php echo $addrErr;?></span> <br /> Email <input type="text" name="email" value="<?php echo htmlspecialchars($email);?>"> <span class="error"><?php echo $emailErr;?></span> <br /> <input type="submit" name="submit" value="Submit"> </form> </body> </html>

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