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• Classification question

  - by adam

  If php and ruby are languages, and cake and rails are frameworks, how do CMS like drupal and joomla fit into the scheme... can you use them in any language and any framework?

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• What is your most useful C/C++ utility?

  - by maddizzyro

  It seems that every project has an "utility" module with various code snippets used throughout other files and which don't fit any particular pattern. What utility classes, functions, and macros do you find most useful in your C/C++ projects? Please keep the entries small (under 100 lines) and give only one example per post.

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• Calculate needed size for a TLabel

  - by Tom

  Ok, here's the problem. I have a label component in a panel. The label is aligned as alClient and has wordwrap enabled. The text can vary from one line to several lines. I would like to re-size the height of the the panel (and the label) to fit all the text. How do I get the necessary height of a label when I know the text and the width of the panel?

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• Lining controls up very precisely

  - by every_answer_gets_a_point

  i have about 50 labels that are each just barely big enough to fit the letter x in them. the labels are on a report. i need to align all the labels very precisely. is there an easier way to do this than trusting my eyes?

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• default xna 4.0 gametime don´t works well for 2D physics

  - by EusKoder

  I am developing a game using Visual Studio 2010 and XNA 4.0, after advancing to some extent with the project (a platform based 2d platformer msdn starter kit) I got to test it on different computers with different hardware (CPU, graphics, etc.) and I found that the speed of movement object of the game is quite different, I implemented the PSK physics msdn that are based on time, /// <summary> /// Updates the player's velocity and position based on input, gravity, etc. /// </summary> public void ApplyPhysics(GameTime gameTime) { float elapsed = (float)gameTime.ElapsedGameTime.TotalSeconds; Vector2 previousPosition = Position; // Base velocity is a combination of horizontal movement control and // acceleration downward due to gravity. velocity.X += movement * MoveAcceleration * elapsed; velocity.Y = MathHelper.Clamp(velocity.Y + GravityAcceleration * elapsed, -MaxFallSpeed, MaxFallSpeed); velocity.Y = DoJump(velocity.Y, gameTime); // Apply pseudo-drag horizontally. if (IsOnGround) velocity.X *= GroundDragFactor; else velocity.X *= GroundDragFactor; //velocity.X *= AirDragFactor; // Prevent the player from running faster than his top speed. velocity.X = MathHelper.Clamp(velocity.X, -MaxMoveSpeed, MaxMoveSpeed); // Apply velocity. Position += velocity *elapsed; Position = new Vector2((float)Math.Round(Position.X), (float)Math.Round(Position.Y)); // If the player is now colliding with the level, separate them. HandleCollisions(gameTime); // If the collision stopped us from moving, reset the velocity to zero. if (Position.X == previousPosition.X) velocity.X = 0; if (Position.Y == previousPosition.Y) { velocity.Y = 0; jumpTime = 0.0f; } } tested eg with a PC (PC1) 2.13GHz Intel Core 2 6400 / ATI Radeon HD 4670 and another one: (pc2) 3.00GHz Intel Pentium D / Intel 82945G Express Chipset Family by displacement difference (moving x axis at supossed (position = velocity * gametime.ElapsedGameTime.TotalSeconds) constant velocity, for example) is 3 seconds in a total of 20 (example: moving pc1 player sprite 6000 pixels in the x-axis at 20 seconds and pc 2 runs the same distance in 17 ). Tested on a 3rd PC: i72700k / Gigabyte GTX 560 TI the results are even worse, after some time after starting the game gets like 3 times slower and showing the number of pixels in each frame moved in a debug window in the game (counting updatespersecond with counter variable for updates cuantity and gametime for counting a second show 63fps), it appears as if the number is always constant ( refreshments lose the Update method?). In this pc if I put the game in fullscreen during the course of the game, the effect of "go slow" is immediate and restore window mode sometimes yield returns to "normal" and sometimes not. Eventually I began to try a new project to test whether the movement is constant in different pc loading only one sprite and its position value in screen printing. Occur The same. I even tried moving a constant amount of pixels explicitly (position + = 5) and different speeds in different pc quantities of pixels moved in x time. I have the game loop as the default (fixedTimeStep=true;SynchronizeWithVerticalRetrace=true;). I've also tried turning off and creating another timestep as discussed in different post (eg http://gafferongames.com/game-physics/fix-your-timestep/ but i can´t achieve the desired result, move the same number of pixels in X seconds on different computers with windows. All pc used for tests use windows 7 enterprise pc1 == x86 the others are x64. The weirdest thing is that I find information about people describing the same problem and that I wear long nights of searches. Thanks for your help.

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• What free space thresholds/limits are advisable for 640 GB and 2 TB hard disk drives with ZEVO ZFS on OS X?

  - by Graham Perrin

  Assuming that free space advice for ZEVO will not differ from advice for other modern implementations of ZFS … Question Please, what percentages or amounts of free space are advisable for hard disk drives of the following sizes? 640 GB 2 TB Thoughts A standard answer for modern implementations of ZFS might be "no more than 96 percent full". However if apply that to (say) a single-disk 640 GB dataset where some of the files most commonly used (by VirtualBox) are larger than 15 GB each, then I guess that blocks for those files will become sub optimally spread across the platters with around 26 GB free. I read that in most cases, fragmentation and defragmentation should not be a concern with ZFS. Sill, I like the mental picture of most fragments of a large .vdi in reasonably close proximity to each other. (Do features of ZFS make that wish for proximity too old-fashioned?) Side note: there might arise the question of how to optimise performance after a threshold is 'broken'. If it arises, I'll keep it separate. Background On a 640 GB StoreJet Transcend (product ID 0x2329) in the past I probably went beyond an advisable threshold. Currently the largest file is around 17 GB –  – and I doubt that any .vdi or other file on this disk will grow beyond 40 GB. (Ignore the purple masses, those are bundles of 8 MB band files.) Without HFS Plus: the thresholds of twenty, ten and five percent that I associate with Mobile Time Machine file system need not apply. I currently use ZEVO Community Edition 1.1.1 with Mountain Lion, OS X 10.8.2, but I'd like answers to be not too version-specific. References, chronological order ZFS Block Allocation (Jeff Bonwick's Blog) (2006-11-04) Space Maps (Jeff Bonwick's Blog) (2007-09-13) Doubling Exchange Performance (Bizarre ! Vous avez dit Bizarre ?) (2010-03-11) … So to solve this problem, what went in 2010/Q1 software release is multifold. The most important thing is: we increased the threshold at which we switched from 'first fit' (go fast) to 'best fit' (pack tight) from 70% full to 96% full. With TB drives, each slab is at least 5GB and 4% is still 200MB plenty of space and no need to do anything radical before that. This gave us the biggest bang. Second, instead of trying to reuse the same primary slabs until it failed an allocation we decided to stop giving the primary slab this preferential threatment as soon as the biggest allocation that could be satisfied by a slab was down to 128K (metaslab_df_alloc_threshold). At that point we were ready to switch to another slab that had more free space. We also decided to reduce the SMO bonus. Before, a slab that was 50% empty was preferred over slabs that had never been used. In order to foster more write aggregation, we reduced the threshold to 33% empty. This means that a random write workload now spread to more slabs where each one will have larger amount of free space leading to more write aggregation. Finally we also saw that slab loading was contributing to lower performance and implemented a slab prefetch mechanism to reduce down time associated with that operation. The conjunction of all these changes lead to 50% improved OLTP and 70% reduced variability from run to run … OLTP Improvements in Sun Storage 7000 2010.Q1 (Performance Profiles) (2010-03-11) Alasdair on Everything » ZFS runs really slowly when free disk usage goes above 80% (2010-07-18) where commentary includes: … OpenSolaris has changed this in onnv revision 11146 … [CFT] Improved ZFS metaslab code (faster write speed) (2010-08-22)

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• Pushing DNSSEC updates with offline keys

  - by eggyal

  In a non-professional capacity, I look after the DNS of some 18 domains: mostly personal/vanity domains for immediate family. I outsource the whole shebang to an inexpensive managed hosting provider with a web interface through which I manage the zones; since the provider also offers DNSSEC, I have successfully deployed that too. These domains are so unimportant that an attack targetted against them seems much less likely than a general compromise of my provider's systems, at which point the records of all their customers might be changed to misdirect traffic (perhaps with extremely long TTLs). DNSSEC could protect against such an attack, but only if the zone's private keys are not held by the hosting provider. So, I wonder: how can one keep DNSSEC private keys offline yet still transfer signed zones to an outsourced DNS host? The most obvious answer (to me, at least) is to run one's own shadow/hidden master (from which the provider can slave) and then copy offline-signed zonefiles to the master as required. The problem is that the only machine I (want to*) control is my personal laptop, which usually connects from a typical home ADSL (behind NAT over a dynamically-assigned IP address). Having them slave from that (e.g. with a very long Expiry time on the zone for periods when my laptop is offline/unavailable) would not only require a Dynamic DNS record from which they can slave (if indeed they can slave from a named host rather than a static IP address), but would also involve me running a DNS server on my laptop and opening both it and my home network up to the incoming zone transfer requests: not ideal. I would prefer a much more push-oriented design, whereby my laptop initiates transfer of offline-signed zonefiles/updates to the provider's servers. I looked into whether nsupdate could fit the bill: documentation is a little sketchy, but my testing (with BIND 9.7) suggests it can indeed update DNSSEC zones, but only where the server holds the keys to perform the zone signing; I have not found a way to have it take an update including the relevant RRSIG/NSEC/etc. records and have the server accept them. Is this a supported use-case? If not, I suspect the only solutions which could fit the bill will involve non-DNS-based transfer of the zone updates and would welcome recommendations that are supported by (hopefully inexpensive) hosting providers: SFTP/SCP? rsync? RDBMS replication? Proprietary API? Finally, what would be the practical implications of such a setup? Key rotation is jumping out at me as being an obvious difficulty, especially if my laptop is offline for extended periods. But the zones are extremely stable, so perhaps I could get away with long-lived ZSKs**...? * Whilst I could run a shadow/hidden master on e.g. an outsourced VPS, I dislike the overhead of having to secure / manage / monitor / maintain yet another system; not to mention the additional financial costs of so doing. ** Okay, this would enable a concerted attacker to replay outdated records—but the risk and impact of such are both tolerable in the case of these domains.

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• File Translator to Export Animated 3D Character from Autodesk Maya as Quake MD2

  - by Andy R

  I'm wondering if anyone knows of a way to export geometry/textures for a rigged, animated character as Quake MD2? I’m developing an app for mobile devices, and I’ve found that MD2 works great for lightweight OpenGL rendering. I have several animated characters, and I’d like to export them as MD2 from Maya. Here are some of the things I have tried: Exporting FBX to 3D Studio Max and using the QTip plugin -- this works, but only if I convert my animation to point cache (pc2) and bring that into Max. When I do that, QTip plugin doesn’t honor the point cache node, and all I get is the model, no animation Exporting OBJ Sequence to Blender, exporting MD2 from there -- I can’t seem to get blender to compile the imported obj sequence into a single animated object Exporting FBX to Milkshape -- the maya rig gets corrupted in the process Bake point cache for animation, export to FBX, import to Milkshape -- again, Milkshape doesn’t honor the geometry cache, so all that appears is a static character. I’m currently writing a plugin for Maya using the blender MD2 export script as reference (but re-writing using the C++ Maya API), but I’m just wondering if anyone has done this before or has any suggestions of how to do this. Also, if anyone has other suggestions for the best format to render a single animated character on an OpenGL ES (Android or iPhone) device, I would be very grateful! I’m open to trying anything to get these animations rendering on device Thanks!

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• Compiling examples for consuming the REST Endpoints for WCF Service using Agatha

  - by REA_ANDREW

  I recently made two contributions to the Agatha Project by Davy Brion over on Google Code, and one of the things I wanted to follow up with was a post showing examples and some, seemingly required tid bits.  The contributions which I made where: To support StructureMap To include REST (JSON and XML) support for the service contract The examples which I have made, I want to format them so they fit in with the current format of examples over on Agatha and hopefully create and submit a third patch which will include these examples to help others who wish to use these additions. Whilst building these examples for both XML and JSON I have learnt a couple of things which I feel are not really well documented, but are extremely good practice and once known make perfect sense.  I have chosen a real basic e-commerce context for my example Requests and Responses, and have also made use of the excellent tool AutoMapper, again on Google Code. Setting the scene I have followed the Pipes and Filters Pattern with the IQueryable interface on my Repository and exposed the following methods to query Products: IQueryable<Product> GetProducts(); IQueryable<Product> ByCategoryName(this IQueryable<Product> products, string categoryName) Product ByProductCode(this IQueryable<Product> products, String productCode) I have an interface for the IProductRepository but for the concrete implementation I have simply created a protected getter which populates a private List<Product> with 100 test products with random data.  Another good reason for following an interface based approach is that it will demonstrate usage of my first contribution which is the StructureMap support.  Finally the two Domain Objects I have made are Product and Category as shown below: public class Product { public String ProductCode { get; set; } public String Name { get; set; } public Decimal Price { get; set; } public Decimal Rrp { get; set; } public Category Category { get; set; } }   public class Category { public String Name { get; set; } }   Requirements for the REST Support One of the things which you will notice with Agatha is that you do not have to decorate your Request and Response objects with the WCF Service Model Attributes like DataContract, DataMember etc… Unfortunately from what I have seen, these are required if you want the same types to work with your REST endpoint.  I have not tried but I assume the same result can be achieved by simply decorating the same classes with the Serializable Attribute.  Without this the operation will fail. Another surprising thing I have found is that it did not work until I used the following Attribute parameters: Name Namespace e.g. [DataContract(Name = "GetProductsRequest", Namespace = "AgathaRestExample.Service.Requests")] public class GetProductsRequest : Request { }   Although I was surprised by this, things kind of explained themselves when I got round to figuring out the exact construct required for both the XML and the REST.  One of the things which you already know and are then reminded of is that each of your Requests and Responses ultimately inherit from an abstract base class respectively. This information needs to be represented in a way native to the format being used.  I have seen this in XML but I have not seen the format which is required for the JSON. JSON Consumer Example I have used JQuery to create the example and I simply want to make two requests to the server which as you will know with Agatha are transmitted inside an array to reduce the service calls.  I have also used a tool called json2 which is again over at Google Code simply to convert my JSON expression into its string format for transmission.  You will notice that I specify the type of Request I am using and the relevant Namespace it belongs to.  Also notice that the second request has a parameter so each of these two object are representing an abstract Request and the parameters of the object describe it. <script type="text/javascript"> var bodyContent = $.ajax({ url: "http://localhost:50348/service.svc/json/processjsonrequests", global: false, contentType: "application/json; charset=utf-8", type: "POST", processData: true, data: JSON.stringify([ { __type: "GetProductsRequest:AgathaRestExample.Service.Requests" }, { __type: "GetProductsByCategoryRequest:AgathaRestExample.Service.Requests", CategoryName: "Category1" } ]), dataType: "json", success: function(msg) { alert(msg); } }).responseText; </script>   XML Consumer Example For the XML Consumer example I have chosen to use a simple Console Application and make a WebRequest to the service using the XML as a request.  I have made a crude static method which simply reads from an XML File, replaces some value with a parameter and returns the formatted XML.  I say crude but it simply shows how XML Templates for each type of Request could be made and then have a wrapper utility in whatever language you use to combine the requests which are required.  The following XML is the same Request array as shown above but simply in the XML Format. <?xml version="1.0" encoding="utf-8" ?> <ArrayOfRequest xmlns="http://schemas.datacontract.org/2004/07/Agatha.Common" xmlns:i="http://www.w3.org/2001/XMLSchema-instance"> <Request i:type="a:GetProductsRequest" xmlns:a="AgathaRestExample.Service.Requests"/> <Request i:type="a:GetProductsByCategoryRequest" xmlns:a="AgathaRestExample.Service.Requests"> <a:CategoryName>{CategoryName}</a:CategoryName> </Request> </ArrayOfRequest>   It is funny because I remember submitting a question to StackOverflow asking whether there was a REST Client Generation tool similar to what Microsoft used for their RestStarterKit but which could be applied to existing services which have REST endpoints attached.  I could not find any but this is now definitely something which I am going to build, as I think it is extremely useful to have but also it should not be too difficult based on the information I now know about the above.  Finally I thought that the Strategy Pattern would lend itself really well to this type of thing so it can accommodate for different languages. I think that is about it, I have included the code for the example Console app which I made below incase anyone wants to have a mooch at the code.  As I said above I want to reformat these to fit in with the current examples over on the Agatha project, but also now thinking about it, make a Documentation Web method…{brain ticking} :-) Cheers for now and here is the final bit of code: static void Main(string[] args) { var request = WebRequest.Create("http://localhost:50348/service.svc/xml/processxmlrequests"); request.Method = "POST"; request.ContentType = "text/xml"; using(var writer = new StreamWriter(request.GetRequestStream())) { writer.WriteLine(GetExampleRequestsString("Category1")); } var response = request.GetResponse(); using(var reader = new StreamReader(response.GetResponseStream())) { Console.WriteLine(reader.ReadToEnd()); } Console.ReadLine(); } static string GetExampleRequestsString(string categoryName) { var data = File.ReadAllText(Path.Combine(Path.GetDirectoryName(Assembly.GetExecutingAssembly().Location), "ExampleRequests.xml")); data = data.Replace("{CategoryName}", categoryName); return data; } }

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• Validation in Silverlight

  - by Timmy Kokke

  Getting started with the basics Validation in Silverlight can get very complex pretty easy. The DataGrid control is the only control that does data validation automatically, but often you want to validate your own entry form. Values a user may enter in this form can be restricted by the customer and have to fit an exact fit to a list of requirements or you just want to prevent problems when saving the data to the database. Showing a message to the user when a value is entered is pretty straight forward as I’ll show you in the following example.     This (default) Silverlight textbox is data-bound to a simple data class. It has to be bound in “Two-way” mode to be sure the source value is updated when the target value changes. The INotifyPropertyChanged interface must be implemented by the data class to get the notification system to work. When the property changes a simple check is performed and when it doesn’t match some criteria an ValidationException is thrown. The ValidatesOnExceptions binding attribute is set to True to tell the textbox it should handle the thrown ValidationException. Let’s have a look at some code now. The xaml should contain something like below. The most important part is inside the binding. In this case the Text property is bound to the “Name” property in TwoWay mode. It is also told to validate on exceptions. This property is false by default.   <StackPanel Orientation="Horizontal"> <TextBox Width="150" x:Name="Name" Text="{Binding Path=Name, Mode=TwoWay, ValidatesOnExceptions=True}"/> <TextBlock Text="Name"/> </StackPanel>   The data class in this first example is a very simplified person class with only one property: string Name. The INotifyPropertyChanged interface is implemented and the PropertyChanged event is fired when the Name property changes. When the property changes a check is performed to see if the new string is null or empty. If this is the case a ValidationException is thrown explaining that the entered value is invalid.   public class PersonData:INotifyPropertyChanged { private string _name; public string Name { get { return _name; } set { if (_name != value) { if(string.IsNullOrEmpty(value)) throw new ValidationException("Name is required"); _name = value; if (PropertyChanged != null) PropertyChanged(this, new PropertyChangedEventArgs("Name")); } } } public event PropertyChangedEventHandler PropertyChanged=delegate { }; } The last thing that has to be done is letting binding an instance of the PersonData class to the DataContext of the control. This is done in the code behind file. public partial class Demo1 : UserControl { public Demo1() { InitializeComponent(); this.DataContext = new PersonData() {Name = "Johnny Walker"}; } }   Error Summary In many cases you would have more than one entry control. A summary of errors would be nice in such case. With a few changes to the xaml an error summary, like below, can be added.           First, add a namespace to the xaml so the control can be used. Add the following line to the header of the .xaml file. xmlns:Controls="clr-namespace:System.Windows.Controls;assembly=System.Windows.Controls.Data.Input"   Next, add the control to the layout. To get the result as in the image showed earlier, add the control right above the StackPanel from the first example. It’s got a small margin to separate it from the textbox a little.   <Controls:ValidationSummary Margin="8"/>   The ValidationSummary control has to be notified that an ValidationException occurred. This can be done with a small change to the xaml too. Add the NotifyOnValidationError to the binding expression. By default this value is set to false, so nothing would be notified. Set the property to true to get it to work.   <TextBox Width="150" x:Name="Name" Text="{Binding Name, Mode=TwoWay, ValidatesOnExceptions=True, NotifyOnValidationError=True}"/>   Data annotation Validating data in the setter is one option, but not my personal favorite. It’s the easiest way if you have a single required value you want to check, but often you want to validate more. Besides, I don’t consider it best practice to write logic in setters. The way used by frameworks like WCF Ria Services is the use of attributes on the properties. Instead of throwing exceptions you have to call the static method ValidateProperty on the Validator class. This call stays always the same for a particular property, not even when you change the attributes on the property. To mark a property “Required” you can use the RequiredAttribute. This is what the Name property is going to look like:   [Required] public string Name { get { return _name; } set { if (_name != value) { Validator.ValidateProperty(value, new ValidationContext(this, null, null){ MemberName = "Name" }); _name = value; if (PropertyChanged != null) PropertyChanged(this, new PropertyChangedEventArgs("Name")); } } }   The ValidateProperty method takes the new value for the property and an instance of ValidationContext. The properties passed to the constructor of the ValidationContextclass are very straight forward. This part is the same every time. The only thing that changes is the MemberName property of the ValidationContext. Property has to hold the name of the property you want to validate. It’s the same value you provide the PropertyChangedEventArgs with. The System.ComponentModel.DataAnnotation contains eight different validation attributes including a base class to create your own. They are: RequiredAttribute Specifies that a value must be provided. RangeAttribute The provide value must fall in the specified range. RegularExpressionAttribute Validates is the value matches the regular expression. StringLengthAttribute Checks if the number of characters in a string falls between a minimum and maximum amount. CustomValidationAttribute Use a custom method to validate the value. DataTypeAttribute Specify a data type using an enum or a custom data type. EnumDataTypeAttribute Makes sure the value is found in a enum. ValidationAttribute A base class for custom validation attributes All of these will ensure that an validation exception is thrown, except the DataTypeAttribute. This attribute is used to provide some additional information about the property. You can use this information in your own code.   [Required] [Range(0,125,ErrorMessage = "Value is not a valid age")] public int Age {   It’s no problem to stack different validation attributes together. For example, when an Age is required and must fall in the range from 0 to 125:   [Required, StringLength(255,MinimumLength = 3)] public string Name {   Or in one row like this, for a required Name with at least 3 characters and a maximum of 255:   Delayed validation Having properties marked as required can be very useful. The only downside to the technique described earlier is that you have to change the value in order to get it validated. What if you start out with empty an empty entry form? All fields are empty and thus won’t be validated. With this small trick you can validate at the moment the user click the submit button.   <TextBox Width="150" x:Name="NameField" Text="{Binding Name, Mode=TwoWay, ValidatesOnExceptions=True, NotifyOnValidationError=True, UpdateSourceTrigger=Explicit}"/>   By default, when a TwoWay bound control looses focus the value is updated. When you added validation like I’ve shown you earlier, the value is validated. To overcome this, you have to tell the binding update explicitly by setting the UpdateSourceTrigger binding property to Explicit:   private void SubmitButtonClick(object sender, RoutedEventArgs e) { NameField.GetBindingExpression(TextBox.TextProperty).UpdateSource(); }   This way, the binding is in two direction but the source is only updated, thus validated, when you tell it to. In the code behind you have to call the UpdateSource method on the binding expression, which you can get from the TextBox.   Conclusion Data validation is something you’ll probably want on almost every entry form. I always thought it was hard to do, but it wasn’t. If you can throw an exception you can do validation. If you want to know anything more in depth about something I talked about in this article let me know. I might write an entire post to that.

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• Robotic Arm &ndash; Hardware

  - by Szymon Kobalczyk

  This is first in series of articles about project I've been building  in my spare time since last Summer. Actually it all began when I was researching a topic of modeling human motion kinematics in order to create gesture recognition library for Kinect. This ties heavily into motion theory of robotic manipulators so I also glanced at some designs of robotic arms. Somehow I stumbled upon this cool looking open source robotic arm: It was featured on Thingiverse and published by user jjshortcut (Jan-Jaap). Since for some time I got hooked on toying with microcontrollers, robots and other electronics, I decided to give it a try and build it myself. In this post I will describe the hardware build of the arm and in later posts I will be writing about the software to control it. Another reason to build the arm myself was the cost factor. Even small commercial robotic arms are quite expensive – products from Lynxmotion and Dagu look great but both cost around USD $300 (actually there is one cheap arm available but it looks more like a toy to me). In comparison this design is quite cheap. It uses seven hobby grade servos and even the cheapest ones should work fine. The structure is build from a set of laser cut parts connected with few metal spacers (15mm and 47mm) and lots of M3 screws. Other than that you’d only need a microcontroller board to drive the servos. So in total it comes a lot cheaper to build it yourself than buy an of the shelf robotic arm. Oh, and if you don’t like this one there are few more robotic arm projects at Thingiverse (including one by oomlout). Laser cut parts Some time ago I’ve build another robot using laser cut parts so I knew the process already. You can grab the design files in both DXF and EPS format from Thingiverse, and there are also 3D models of each part in STL. Actually the design is split into a second project for the mini servo gripper (there is also a standard servo version available but it won’t fit this arm).  I wanted to make some small adjustments, layout, and add measurements to the parts before sending it for cutting. I’ve looked at some free 2D CAD programs, and finally did all this work using QCad 3 Beta with worked great for me (I also tried LibreCAD but it didn’t work that well). All parts are cut from 4 mm thick material. Because I was worried that acrylic is too fragile and might break, I also ordered another set cut from plywood. In the end I build it from plywood because it was easier to glue (I was told acrylic requires a special glue). Btw. I found a great laser cutter service in Kraków and highly recommend it (www.ebbox.com.pl). It cost me only USD $26 for both sets ($16 acrylic + $10 plywood). Metal parts I bought all the M3 screws and nuts at local hardware store. Make sure to look for nylon lock (nyloc) nuts for the gripper because otherwise it unscrews and comes apart quickly. I couldn’t find local store with metal spacers and had to order them online (you’d need 11 x 47mm and 3 x 15mm). I think I paid less than USD $10 for all metal parts. Servos This arm uses five standards size servos to drive the arm itself, and two micro servos are used on the gripper. Author of the project used Modelcraft RS-2 Servo and Modelcraft ES-05 HT Servo. I had two Futaba S3001 servos laying around, and ordered additional TowerPro SG-5010 standard size servos and TowerPro SG90 micro servos. However it turned out that the SG90 won’t fit in the gripper so I had to replace it with a slightly smaller E-Sky EK2-0508 micro servo. Later it also turned out that Futaba servos make some strange noise while working so I swapped one with TowerPro SG-5010 which has higher torque (8kg / cm). I’ve also bought three servo extension cables. All servos cost me USD $45. Assembly The build process is not difficult but you need to think carefully about order of assembling it. You can do the base and upper arm first. Because two servos in the base are close together you need to put first with one piece of lower arm already connected before you put the second servo. Then you connect the upper arm and finally put the second piece of lower arm to hold it together. Gripper and base require some gluing so think it through too. Make sure to look closely at all the photos on Thingiverse (also other people copies) and read additional posts on jjshortcust’s blog: My mini servo grippers and completed robotic arm  Multiply the robotic arm and electronics Here is also Rob’s copy cut from aluminum My assembled arm looks like this – I think it turned out really nice: Servo controller board The last piece of hardware I needed was an electronic board that would take command from PC and drive all seven servos. I could probably use Arduino for this task, and in fact there are several Arduino servo shields available (for example from Adafruit or Renbotics).  However one problem is that most support only up to six servos, and second that their accuracy is limited by Arduino’s timer frequency. So instead I looked for dedicated servo controller and found a series of Maestro boards from Pololu. I picked the Pololu Mini Maestro 12-Channel USB Servo Controller. It has many nice features including native USB connection, high resolution pulses (0.25µs) with no jitter, built-in speed and acceleration control, and even scripting capability. Another cool feature is that besides servo control, each channel can be configured as either general input or output. So far I’m using seven channels so I still have five available to connect some sensors (for example distance sensor mounted on gripper might be useful). And last but important factor was that they have SDK in .NET – what more I could wish for! The board itself is very small – half of the size of Tic-Tac box. I picked one for about USD $35 in this store. Perhaps another good alternative would be the Phidgets Advanced Servo 8-Motor – but it is significantly more expensive at USD $87.30. The Maestro Controller Driver and Software package includes Maestro Control Center program with lets you immediately configure the board. For each servo I first figured out their move range and set the min/max limits. I played with setting the speed an acceleration values as well. Big issue for me was that there are two servos that control position of lower arm (shoulder joint), and both have to be moved at the same time. This is where the scripting feature of Pololu board turned out very helpful. I wrote a script that synchronizes position of second servo with first one – so now I only need to move one servo and other will follow automatically. This turned out tricky because I couldn’t find simple offset mapping of the move range for each servo – I had to divide it into several sub-ranges and map each individually. The scripting language is bit assembler-like but gets the job done. And there is even a runtime debugging and stack view available. Altogether I’m very happy with the Pololu Mini Maestro Servo Controller, and with this final piece I completed the build and was able to move my arm from the Meastro Control program.   The total cost of my robotic arm was: $10 laser cut parts $10 metal parts $45 servos $35 servo controller ----------------------- $100 total So here you have all the information about the hardware. In next post I’ll start talking about the software that I wrote in Microsoft Robotics Developer Studio 4. Stay tuned!

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• Best of Breed vs. Suite – Oracle’s SaaS Delivers Both

  - by yaldahhakim

  Normal 0 false false false EN-US X-NONE X-NONE /* Style Definitions */ table.MsoNormalTable {mso-style-name:"Table Normal"; mso-tstyle-rowband-size:0; mso-tstyle-colband-size:0; mso-style-noshow:yes; mso-style-priority:99; mso-style-qformat:yes; mso-style-parent:""; mso-padding-alt:0in 5.4pt 0in 5.4pt; mso-para-margin-top:0in; mso-para-margin-right:0in; mso-para-margin-bottom:10.0pt; mso-para-margin-left:0in; line-height:115%; mso-pagination:widow-orphan; font-size:11.0pt; font-family:"Calibri","sans-serif"; mso-ascii-font-family:Calibri; mso-ascii-theme-font:minor-latin; mso-fareast-font-family:"Times New Roman"; mso-fareast-theme-font:minor-fareast; mso-hansi-font-family:Calibri; mso-hansi-theme-font:minor-latin;} The debate of which is better: “best of breed” business applications vs. an integrated suite is certainly not a new conversation. This has been argued between IT vendors and CIOs for years. It’s also important to clarify that “best of breed” does not necessarily translate into being the richest functionality; rather it’s often about just having the best fit solution to solve a specific business problem or need. So what does cloud have to do with the niche vs. suite debate? Consuming business applications in a cloud or SaaS deployment model can change the best of breed vs. suite discussion - if the cloud is done right. It’s having your cake and eating it too only better: you don’t have to gather all the ingredients or wait to bake your cake, and you can adjust how big of slice you take. Before you eat, it’s worth pausing to recall much of what we learned about IT over the last decade. These basic IT principles still hold true even though the financial model has changed from buying to renting. In other words, what’s under the technology hood still matters. Architecture and development methodologies like building an application based on open standards so it works with other systems - is still important. Data and information silos, complex integrations, and proprietary technologies that lock you in, are still bad. While some may argue that IT no longer matters with cloud, the opposite is actually true. If anything cloud can help return IT back to its rightful place as key strategic asset vs. a liability on the balance sheet. The “I” in CIO was never meant to stand for “integration” yet it’s amazing how much time and money is poured into these types of initiatives for most organizations each year. Rather the “I” needs to stand for “innovation”. This is where Oracle SaaS can uniquely help. Oracle’s application strategy has not really changed over the years. It’s always been about bringing the best and richest functionality across the enterprise to our customers while leveraging a common, standards-based, and enterprise-grade platform. So not jut best fit, but the best capabilities based on the input of thousands of enterprise customers across the globe. Oracle invests billions in R&D every year to add new capabilities to the broadest cloud portfolio in the industry, spanning across functional pillars like CRM, HCM, ERP, etc. And where it makes sense, Oracle combines key strategic acquisitions to complement organic functionality. The result is best of breed delivered in a suite. Again this is not something new. The game changer now with cloud is that it impacts HOW Oracle customers adopt the richest, most modern applications across the business – and continue on getting it. Consuming oracle applications in the cloud means you can adopt new capabilities and updates very quickly and easily. There’s no hardware to buy or software to manage. Oracle does it for you. Low upfront costs and an OpEx financial model is the easy part. Oracle Cloud Applications take it a big step further. For organizations that demand having the latest and richest functionality and accelerating the time to value from their IT investment, Oracle Cloud is the right path. It’s about holistically changing the “hows” and the “whys” of the organization by leveraging transformational innovations like social, mobile, and big data in a consistent and more powerful way. Not just about sales force automation or talent management. These technologies should impact all parts of the company and Oracle Cloud is the enterprise-grade delivery vehicle. Oracle SaaS helps break down barriers of adoption and is eases the headache of upgrades, investing in new supporting hardware, or adding internal expertise to manage it all. With Oracle Cloud, customers can get best of breed capabilities in either a full suite model or a la carte. And because it’s entirely built on open standards, it’s built to co-exist with existing IT investments. Updates can be automatic or delayed based on a customer’s requirements. And it’s complete – a full suite of cross pillar functionality. Even better, if you don’t like it, need more or less, just turn the dial up or down. Just like your utility bill, you pay for what you use, and can consume more or less power whenever you need it. Lower cost, lower investment risk, without compromising on functionality, security, or performance. Technology still matters in the cloud. So our cloud customers also like that when they adopt our cloud applications, they also get the best underlying technology, from the middleware and database platform down to infrastructure and Oracle’s engineered systems. Therefore it’s not just the greatest and latest in application functionality, but everything underneath that makes it work is also the latest and greatest. The best of breed technology stack powering best of breed business applications, and all delivered in a subscription based model. The best of both worlds. Yep, that’s the idea.

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• The APEX of Business Value...or...the Business Value of APEX? Oracle Cloud Takes Oracle APEX to New Heights!

  - by Gene Eun

  The attraction of Oracle Application Express (APEX) has increased tremendously with the recent launch of the Oracle Cloud. APEX already supported departmental development and deployment of business applications with minimal involvement from the IT department. Positioned as the ideal replacement for MS Access, APEX probably has managed better to capture the eye of developers and was used for enterprise application development at least as much as for the kind of tactical applications that Oracle strategically positioned it for. With APEX as PaaS from the Oracle Cloud, a leap is made to a much higher level of business value. Now the IT department is not even needed to make infrastructure available with a database running  on it. All the business needs is a credit card. And the business application that is developed, managed and used from the cloud through a standard browser can now just as easily be accessed by users from around the world as by users from the business department itself. As a bonus – the development of the APEX application is also done in the cloud – with no special demands on the location or the enterprise access privileges of the developers. To sum it up: APEX from Oracle Cloud Database Service get the development environment up and running in minutes no involvement from the internal IT department required (not for infrastructure, platform, or development) superior availability and scalability is offered by Oracle users from anywhere in the world can be invited to access the application developers from anywhere in the world can participate in creating and maintaining the application In addition: because the Oracle Cloud platform is the same as the on-premise platform, you can still decide to move the APEX application between the cloud and the local environment – and back again. The REST-ful services that are available through APEX allow programmatic interaction with the database under the APEX application. That means that this database can be synchronized with on premise databases or data stores in (other) clouds. Through the Oracle Cloud Messaging Service, the APEX application can easily enter into asynchronous conversations with other APEX applications, Fusion Middleware applications (ADF, SOA, BPM) and any other type of REST-enabled application. In my opinion, now, for the first time perhaps, APEX offers the attraction to the business that has been suggested before: because of the cloud, all the business needs is  a credit card (a budget of $175 per month), an internet-connection and a browser. Not like before, with a PC hidden under a desk or a database running somewhere in the data center. No matter how unattended: equipment is needed, power is consumed, the database needs to be kept running and if Oracle Database XE does not suffice, software licenses are required as well. And this set up always has a security challenge associated with it. The cloud fee for the Oracle Cloud Database Service includes infrastructure, power, licenses, availability, platform upgrades, a collection of reusable application components and the development and runtime environments containing the APEX platform. Of course this not only means that business departments can move quickly without having to convince their IT colleagues to move along – it also means that small organizations that do not even have IT colleagues can do the same. Getting tailored applications or applications up and running to get in touch with users and customers all over the world is now within easy reach for small outfits – without any investment. My misunderstanding For a long time, I was under the impression that the essence of APEX was that the business could create applications themselves – meaning that business ‘people’ would actually go into APEX to create the application. To me APEX was too much of a developers’ tool to see that happen – apart from the odd business analyst who missed his or her calling as an IT developer. Having looked at various other cloud based development offerings – including Force.com, Mendix, WaveMaker, WorkXpress, OrangeScape, Caspio and Cordys- I have come to realize my mistake. All these platforms are positioned for 'the business' but require a fair amount of coding and technical expertise. However, they make the business happy nevertheless, because they allow the  business to completely circumvent the IT department. That is the essence. Not having to go through the red tape, not having to wait for IT staff who (justifiably) need weeks or months to provide an environment, not having to deal with administrators (again, justifiably) refusing to take on that 'strange environment'. Being able to think of an initiative and turn into action right away. The business does not have to build the application - it can easily hire some external developers or even that nerdy boy next door. They can get started, get an application up and running and invite users in – especially external users such as customers. They will worry later about upgrades and life cycle management and integration. To get applications up and running quickly and start turning ideas into action and results rightaway. That is the key selling point for all these cloud offerings, including APEX from the Cloud. And it is a compelling story. For APEX probably even more so than for the others. While I consider APEX a somewhat proprietary framework compared with ‘regular’ Java/JEE web development (or even .NET and PHP  development), it is still far more open than most cloud environments. APEX is SQL and PL/SQL based – nothing special about those languages – and can run just as easily on site as in the cloud. It has been around since 2004 (that is not including several predecessors that fed straight into APEX) so it can be considered pretty mature. Oracle as a company seems pretty stable – so investments in its technology are bound to last for some time to come. By the way: neither APEX nor the other Cloud DevaaS offerings are targeted at creating applications with enormous life times. They fit into a trend of agile development and rapid life cycle management, with fairly light weight user interfaces that quickly adapt to taste, technology trends and functional requirements and that are easily replaced. APEX and ADF – a match made in heaven?! (or at least in the sky) Note that using APEX only for cloud based database with REST-ful Services is also a perfectly viable scenario: any UI – mobile or browser based – capable of consuming REST-ful services can be created against such a business tier. Creating an ADF Mobile application for example that runs aginst REST-ful services is a best practice for mobile development. Such REST-ful services can be consumed from any service provider – including the Cloud based APEX powered REST-ful services running against the Oracle Cloud Database Service! The ADF Mobile architecture overview can easily be morphed to fit the APEX services in – allowing for a cloud based mobile app: Want to learn more about Oracle Database Cloud Service or Oracle Cloud, just visit cloud.oracle.com  or oracle.com/cloud. Repost of a blog entry by Rick Greenwald, Director of Product Management, Oracle Database Cloud Service.

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• C# Extension Methods - To Extend or Not To Extend...

  - by James Michael Hare

  I've been thinking a lot about extension methods lately, and I must admit I both love them and hate them. They are a lot like sugar, they taste so nice and sweet, but they'll rot your teeth if you eat them too much.   I can't deny that they aren't useful and very handy. One of the major components of the Shared Component library where I work is a set of useful extension methods. But, I also can't deny that they tend to be overused and abused to willy-nilly extend every living type.   So what constitutes a good extension method? Obviously, you can write an extension method for nearly anything whether it is a good idea or not. Many times, in fact, an idea seems like a good extension method but in retrospect really doesn't fit.   So what's the litmus test? To me, an extension method should be like in the movies when a person runs into their twin, separated at birth. You just know you're related. Obviously, that's hard to quantify, so let's try to put a few rules-of-thumb around them.   A good extension method should:     Apply to any possible instance of the type it extends.     Simplify logic and improve readability/maintainability.     Apply to the most specific type or interface applicable.     Be isolated in a namespace so that it does not pollute IntelliSense.     So let's look at a few examples in relation to these rules.   The first rule, to me, is the most important of all. Once again, it bears repeating, a good extension method should apply to all possible instances of the type it extends. It should feel like the long lost relative that should have been included in the original class but somehow was missing from the family tree.    Take this nifty little int extension, I saw this once in a blog and at first I really thought it was pretty cool, but then I started noticing a code smell I couldn't quite put my finger on. So let's look:       public static class IntExtensinos     {         public static int Seconds(int num)         {             return num * 1000;         }           public static int Minutes(int num)         {             return num * 60000;         }     }     This is so you could do things like:       ...     Thread.Sleep(5.Seconds());     ...     proxy.Timeout = 1.Minutes();     ...     Awww, you say, that's cute! Well, that's the problem, it's kitschy and it doesn't always apply (and incidentally you could achieve the same thing with TimeStamp.FromSeconds(5)). It's syntactical candy that looks cool, but tends to rot and pollute the code. It would allow things like:       total += numberOfTodaysOrders.Seconds();     which makes no sense and should never be allowed. The problem is you're applying an extension method to a logical domain, not a type domain. That is, the extension method Seconds() doesn't really apply to ALL ints, it applies to ints that are representative of time that you want to convert to milliseconds.    Do you see what I mean? The two problems, in a nutshell, are that a) Seconds() called off a non-time value makes no sense and b) calling Seconds() off something to pass to something that does not take milliseconds will be off by a factor of 1000 or worse.   Thus, in my mind, you should only ever have an extension method that applies to the whole domain of that type.   For example, this is one of my personal favorites:       public static bool IsBetween<T>(this T value, T low, T high)         where T : IComparable<T>     {         return value.CompareTo(low) >= 0 && value.CompareTo(high) <= 0;     }   This allows you to check if any IComparable<T> is within an upper and lower bound. Think of how many times you type something like:       if (response.Employee.Address.YearsAt >= 2         && response.Employee.Address.YearsAt <= 10)     {     ...     }     Now, you can instead type:       if(response.Employee.Address.YearsAt.IsBetween(2, 10))     {     ...     }     Note that this applies to all IComparable<T> -- that's ints, chars, strings, DateTime, etc -- and does not depend on any logical domain. In addition, it satisfies the second point and actually makes the code more readable and maintainable.   Let's look at the third point. In it we said that an extension method should fit the most specific interface or type possible. Now, I'm not saying if you have something that applies to enumerables, you create an extension for List, Array, Dictionary, etc (though you may have reasons for doing so), but that you should beware of making things TOO general.   For example, let's say we had an extension method like this:       public static T ConvertTo<T>(this object value)     {         return (T)Convert.ChangeType(value, typeof(T));     }         This lets you do more fluent conversions like:       double d = "5.0".ConvertTo<double>();     However, if you dig into Reflector (LOVE that tool) you will see that if the type you are calling on does not implement IConvertible, what you convert to MUST be the exact type or it will throw an InvalidCastException. Now this may or may not be what you want in this situation, and I leave that up to you. Things like this would fail:       object value = new Employee();     ...     // class cast exception because typeof(IEmployee) != typeof(Employee)     IEmployee emp = value.ConvertTo<IEmployee>();       Yes, that's a downfall of working with Convertible in general, but if you wanted your fluent interface to be more type-safe so that ConvertTo were only callable on IConvertibles (and let casting be a manual task), you could easily make it:         public static T ConvertTo<T>(this IConvertible value)     {         return (T)Convert.ChangeType(value, typeof(T));     }         This is what I mean by choosing the best type to extend. Consider that if we used the previous (object) version, every time we typed a dot ('.') on an instance we'd pull up ConvertTo() whether it was applicable or not. By filtering our extension method down to only valid types (those that implement IConvertible) we greatly reduce our IntelliSense pollution and apply a good level of compile-time correctness.   Now my fourth rule is just my general rule-of-thumb. Obviously, you can make extension methods as in-your-face as you want. I included all mine in my work libraries in its own sub-namespace, something akin to:       namespace Shared.Core.Extensions { ... }     This is in a library called Shared.Core, so just referencing the Core library doesn't pollute your IntelliSense, you have to actually do a using on Shared.Core.Extensions to bring the methods in. This is very similar to the way Microsoft puts its extension methods in System.Linq. This way, if you want 'em, you use the appropriate namespace. If you don't want 'em, they won't pollute your namespace.   To really make this work, however, that namespace should only include extension methods and subordinate types those extensions themselves may use. If you plant other useful classes in those namespaces, once a user includes it, they get all the extensions too.   Also, just as a personal preference, extension methods that aren't simply syntactical shortcuts, I like to put in a static utility class and then have extension methods for syntactical candy. For instance, I think it imaginable that any object could be converted to XML:       namespace Shared.Core     {         // A collection of XML Utility classes         public static class XmlUtility         {             ...             // Serialize an object into an xml string             public static string ToXml(object input)             {                 var xs = new XmlSerializer(input.GetType());                   // use new UTF8Encoding here, not Encoding.UTF8. The later includes                 // the BOM which screws up subsequent reads, the former does not.                 using (var memoryStream = new MemoryStream())                 using (var xmlTextWriter = new XmlTextWriter(memoryStream, new UTF8Encoding()))                 {                     xs.Serialize(xmlTextWriter, input);                     return Encoding.UTF8.GetString(memoryStream.ToArray());                 }             }             ...         }     }   I also wanted to be able to call this from an object like:       value.ToXml();     But here's the problem, if i made this an extension method from the start with that one little keyword "this", it would pop into IntelliSense for all objects which could be very polluting. Instead, I put the logic into a utility class so that users have the choice of whether or not they want to use it as just a class and not pollute IntelliSense, then in my extensions namespace, I add the syntactical candy:       namespace Shared.Core.Extensions     {         public static class XmlExtensions         {             public static string ToXml(this object value)             {                 return XmlUtility.ToXml(value);             }         }     }   So now it's the best of both worlds. On one hand, they can use the utility class if they don't want to pollute IntelliSense, and on the other hand they can include the Extensions namespace and use as an extension if they want. The neat thing is it also adheres to the Single Responsibility Principle. The XmlUtility is responsible for converting objects to XML, and the XmlExtensions is responsible for extending object's interface for ToXml().

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• Workshops, online content show how Oracle infuses simplicity, mobility, extensibility into user experience

  - by mvaughan

  By Kathy Miedema & Misha Vaughan, Oracle Applications User Experience Oracle has made a huge investment into the user experience of its many different software product families, and recent releases showcase big changes and features that aim to promote end user engagement and efficiency by streamlining navigation and simplifying the user interface. But making Oracle’s enterprise software great-looking and usable doesn’t stop when Oracle products go out the door. The Applications User Experience (UX) team recognizes that our customers may need to customize software to fit their work processes. And that’s why we provide tools such as user experience design patterns to help you maintain the Oracle user experience as you tailor your application to fit your business needs. Often, however, customers may need some context around user experience. How has the Oracle user experience been designed and constructed? Why is a good user experience important for users? How does understanding what goes into the user experience benefit the people who purchase the software for users? There’s a short answer to these questions, and you can read about it on Usable Apps. But truly understanding Oracle’s investment and seeing how it applies across product families occasionally requires a deeper dive into the Oracle user experience, especially if you’re an influencer or decision-maker about Oracle products. To help frame these decisions, the Communications & Outreach team has developed several targeted workshops that explore what Oracle means when it talks about user experience, and provides a roadmap into where the Oracle user experience is going. These workshops require non-disclosure agreements, and have been delivered to Oracle sales folks, Oracle partners, Oracle ACE Directors and ACEs, and a few customers. Some of these audience members have been developers or have a technical background; just as many did not. Here’s a breakdown of the kind of training you can get around the Oracle user experience from the OAUX Communications & Outreach team.For Partners: George Papazzian, Principal, Naviscent with Joyce Ohgi, Oracle Oracle Fusion Applications HCM Pre-Sales Seminar:  In concert with Worldwide Alliances  and  Channels under Applications Partner Enablement Director Jonathan Vinoskey’s guidance, the Applications User Experience team delivers a two-day workshop.  Day one focuses on Oracle Fusion Applications HCM and pre-sales strategy, and Day two focuses on positioning and leveraging Oracle’s investment in the Oracle Fusion Applications user experience.  The next workshops will occur on the following dates: December 4-5, 2013 @ Manchester, UK January 29-30, 2014 @ Reston, Virginia February 2014 @ Guadalajara, Mexico (email: Shannon Whiteman) March 11-12, 2014 @ Dubai, United Arab Emirates April 1-2, 2014 @ Chicago, Illinois Partner Advisory Board: A two-day board meeting in the U.S. and U.K. to discuss four main user experience areas for Oracle Fusion Applications: simplicity, visualization & analytics, mobility, & futures. This event is limited to Oracle Diamond Partners, UX bloggers, and key UX influencers and requires legal documentation.  We will be talking about the Oracle applications UX strategy and roadmap. Partner Implementation Training on User Interface: How to Build Great-Looking, Usable Apps:  In this two-day, hands-on workshop built around Oracle’s Application Development Framework, learn how to build desktop and mobile user interfaces and mobile user interfaces based on Oracle’s experience with Fusion Applications. This workshop is for partners with a technology background who are looking for ways to tailor Fusion Applications using ADF, or have built their own custom solutions using ADF. It includes an introduction to UX design patterns and provides tools to build usability-tested UX designs. Nov 5-6, 2013 @ Redwood Shores, CA, USA January 28-29th, 2014 @ Reston, Virginia, USA February 25-26, 2014 @ Guadalajara, Mexico March 9-10, 2014 @ Dubai, United Arab Emirates To register, contact [email protected] Simplified UI Customization & Extensibility:  Pilot workshop:  We will be reviewing the proposed content for communicating the user experience tool kit available with the next release of Oracle Fusion Applications.  Our core focus will be on what toolkit components our system implementors and independent software vendors will need to respond to customer demand, whether they are extending Fusion Applications, or building custom applications, that will need to leverage the simplified UI. Dec 11th, 2013 @ Reading, UK For information: contact [email protected] Private lab tour and demos: Interested in seeing what’s going on in the Apps UX Labs?  If you are headed to the San Francisco Bay Area, let us know. We can arrange a spin through our usability labs at headquarters. OAUX Expo: This open-house forum gives partners a look at what the UX team is working on, and showcases the next-generation user experiences in a demo environment where attendees can see and touch the applications. UX Direct: Use the same methods that Oracle uses to develop its own user experiences. We help you define your users and their needs, and then provide direction on how to tailor the best user experience you can for them. For CustomersAngela Johnston, Gozel Aamoth, Teena Singh, and Yen Chan, Oracle Lab tours: See demos of soon-to-be-released products, and take a spin on usability research equipment such as our eye-tracker. Watch this video to get an idea of what you’ll see. Get our newsletter: Learn about newly released products and see where you can meet us at user group conferences. Participate in a feedback session: Join a focus group or customer feedback session to get an early look at user experience designs for the next generation of software, and provide your thoughts on how well it will work. Join the OUAB: The Oracle Usability Advisory Board meets several times a year to discuss trends in the workforce and provide direction on user experience designs. UX Direct: Use the same methods that Oracle uses to develop its own user experiences. We help you define your users and their needs, and then provide direction on how to tailor the best user experience you can for them. For Developers (customers, partners, and consultants): Plinio Arbizu, SP Solutions, Richard Bingham, Oracle, Balaji Kamepalli, EiSTechnoogies, Praveen Pillalamarri, EiSTechnologies How to Build Great-Looking, Usable Apps: This workshop is for attendees with a strong technology background who are looking for ways to tailor customer software using ADF. It includes an introduction to UX design patterns and provides tools to build usability-tested UX designs.  See above for dates and times. UX design patterns web site: Cut the length of your project down by months. Use these patterns to build out the task flow you need to develop for your users. The patterns have already been usability-tested and represent the best practices that the Oracle UX research team has found in its studies. UX Direct: Use the same methods that Oracle uses to develop its own user experiences. We help you define your users and their needs, and then provide direction on how to tailor the best user experience you can for them. For Oracle Sales Mike Klein, Jeremy Ashley, Brent White, Oracle Contact your local sales person for more information about the Oracle user experience and the training available from the Applications User Experience Communications & Outreach team. See customer-friendly user experience collateral ranging from the new simplified UI in Oracle Fusion Applications Release 7, to E-Business Suite user experience highlights, to Siebel, PeopleSoft, and JD Edwards user experience highlights.   Receive access to the same pre-sales and implementation training we provide to partners. For Oracle Sales only: Oracle-only training on the Oracle Fusion Applications UX Innovation Sales Kit.

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• SQL SERVER – Core Concepts – Elasticity, Scalability and ACID Properties – Exploring NuoDB an Elastically Scalable Database System

  - by pinaldave

  I have been recently exploring Elasticity and Scalability attributes of databases. You can see that in my earlier blog posts about NuoDB where I wanted to look at Elasticity and Scalability concepts. The concepts are very interesting, and intriguing as well. I have discussed these concepts with my friend Joyti M and together we have come up with this interesting read. The goal of this article is to answer following simple questions What is Elasticity? What is Scalability? How ACID properties vary from NOSQL Concepts? What are the prevailing problems in the current database system architectures? Why is NuoDB  an innovative and welcome change in database paradigm? Elasticity This word’s original form is used in many different ways and honestly it does do a decent job in holding things together over the years as a person grows and contracts. Within the tech world, and specifically related to software systems (database, application servers), it has come to mean a few things - allow stretching of resources without reaching the breaking point (on demand). What are resources in this context? Resources are the usual suspects – RAM/CPU/IO/Bandwidth in the form of a container (a process or bunch of processes combined as modules). When it is about increasing resources the simplest idea which comes to mind is the addition of another container. Another container means adding a brand new physical node. When it is about adding a new node there are two questions which comes to mind. 1) Can we add another node to our software system? 2) If yes, does adding new node cause downtime for the system? Let us assume we have added new node, let us see what the new needs of the system are when a new node is added. Balancing incoming requests to multiple nodes Synchronization of a shared state across multiple nodes Identification of “downstate” and resolution action to bring it to “upstate” Well, adding a new node has its advantages as well. Here are few of the positive points Throughput can increase nearly horizontally across the node throughout the system Response times of application will increase as in-between layer interactions will be improved Now, Let us put the above concepts in the perspective of a Database. When we mention the term “running out of resources” or “application is bound to resources” the resources can be CPU, Memory or Bandwidth. The regular approach to “gain scalability” in the database is to look around for bottlenecks and increase the bottlenecked resource. When we have memory as a bottleneck we look at the data buffers, locks, query plans or indexes. After a point even this is not enough as there needs to be an efficient way of managing such large workload on a “single machine” across memory and CPU bound (right kind of scheduling)  workload. We next move on to either read/write separation of the workload or functionality-based sharing so that we still have control of the individual. But this requires lots of planning and change in client systems in terms of knowing where to go/update/read and for reporting applications to “aggregate the data” in an intelligent way. What we ideally need is an intelligent layer which allows us to do these things without us getting into managing, monitoring and distributing the workload. Scalability In the context of database/applications, scalability means three main things Ability to handle normal loads without pressure E.g. X users at the Y utilization of resources (CPU, Memory, Bandwidth) on the Z kind of hardware (4 processor, 32 GB machine with 15000 RPM SATA drives and 1 GHz Network switch) with T throughput Ability to scale up to expected peak load which is greater than normal load with acceptable response times Ability to provide acceptable response times across the system E.g. Response time in S milliseconds (or agreed upon unit of measure) – 90% of the time The Issue – Need of Scale In normal cases one can plan for the load testing to test out normal, peak, and stress scenarios to ensure specific hardware meets the needs. With help from Hardware and Software partners and best practices, bottlenecks can be identified and requisite resources added to the system. Unfortunately this vertical scale is expensive and difficult to achieve and most of the operational people need the ability to scale horizontally. This helps in getting better throughput as there are physical limits in terms of adding resources (Memory, CPU, Bandwidth and Storage) indefinitely. Today we have different options to achieve scalability: Read & Write Separation The idea here is to do actual writes to one store and configure slaves receiving the latest data with acceptable delays. Slaves can be used for balancing out reads. We can also explore functional separation or sharing as well. We can separate data operations by a specific identifier (e.g. region, year, month) and consolidate it for reporting purposes. For functional separation the major disadvantage is when schema changes or workload pattern changes. As the requirement grows one still needs to deal with scale need in manual ways by providing an abstraction in the middle tier code. Using NOSQL solutions The idea is to flatten out the structures in general to keep all values which are retrieved together at the same store and provide flexible schema. The issue with the stores is that they are compromising on mostly consistency (no ACID guarantees) and one has to use NON-SQL dialect to work with the store. The other major issue is about education with NOSQL solutions. Would one really want to make these compromises on the ability to connect and retrieve in simple SQL manner and learn other skill sets? Or for that matter give up on ACID guarantee and start dealing with consistency issues? Hybrid Deployment – Mac, Linux, Cloud, and Windows One of the challenges today that we see across On-premise vs Cloud infrastructure is a difference in abilities. Take for example SQL Azure – it is wonderful in its concepts of throttling (as it is shared deployment) of resources and ability to scale using federation. However, the same abilities are not available on premise. This is not a mistake, mind you – but a compromise of the sweet spot of workloads, customer requirements and operational SLAs which can be supported by the team. In today’s world it is imperative that databases are available across operating systems – which are a commodity and used by developers of all hues. An Ideal Database Ability List A system which allows a linear scale of the system (increase in throughput with reasonable response time) with the addition of resources A system which does not compromise on the ACID guarantees and require developers to learn new paradigms A system which does not force fit a new way interacting with database by learning Non-SQL dialect A system which does not force fit its mechanisms for providing availability across its various modules. Well NuoDB is the first database which has all of the above abilities and much more. In future articles I will cover my hands-on experience with it. Reference: Pinal Dave (http://blog.SQLAuthority.com) Filed under: PostADay, SQL, SQL Authority, SQL Query, SQL Server, SQL Tips and Tricks, T SQL, Technology Tagged: NuoDB

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• Advanced Continuous Delivery to Azure from TFS, Part 1: Good Enough Is Not Great

  - by jasont

  The folks over on the TFS / Visual Studio team have been working hard at releasing a steady stream of new features for their new hosted Team Foundation Service in the cloud. One of the most significant features released was simple continuous delivery of your solution into your Azure deployments. The original announcement from Brian Harry can be found here. Team Foundation Service is a great platform for .Net developers who are used to working with TFS on-premises. I’ve been using it since it became available at the //BUILD conference in 2011, and when I recently came to work at Stackify, it was one of the first changes I made. Managing work items is much easier than the tool we were using previously, although there are some limitations (more on that in another blog post). However, when continuous deployment was made available, it blew my mind. It was the killer feature I didn’t know I needed. Not to say that I wasn’t previously an advocate for continuous delivery; just that it was always a pain to set up and configure. Having it hosted - and a one-click setup – well, that’s just the best thing since sliced bread. It made perfect sense: my source code is in the cloud, and my deployment is in the cloud. Great! I can queue up a build from my iPad or phone and just let it go! I quickly tore through the quick setup and saw it all work… sort of. This will be the first in a three part series on how to take the building block of Team Foundation Service continuous delivery and build a CD model that will actually work for any team deploying something more advanced than a “Hello World” example. Part 1: Good Enough Is Not Great Part 2: A Model That Works: Branching and Multiple Deployment Environments Part 3: Other Considerations: SQL, Custom Tasks, Etc Good Enough Is Not Great There. I’ve said it. I certainly hope no one on the TFS team is offended, but it’s the truth. Let’s take a look under the hood and understand how it works, and then why it’s not enough to handle real world CD as-is. How it works. (note that I’ve skipped a couple of steps; I already have my accounts set up and something deployed to Azure) The first step is to establish some oAuth magic between your Azure management portal and your TFS Instance. You do this via the management portal. Once it’s done, you have a new build process template in your TFS instance. (Image lifted from the documentation) From here, you’ll get the usual prompts for security, allowing access, etc. But you’ll also get to pick which Solution in your source control to build. Here’s what the bulk of the build definition looks like. All I’ve had to do is add in the solution to build (notice that mine is from a specific branch – Release – more on that later) and I’ve changed the configuration. I trigger the build, and voila! I have an Azure deployment a few minutes later. The beauty of this is that it’s all in the cloud and I’m not waiting for my machine to compile and upload the package. (I also had to enable the build definition first – by default it is created in disabled state, probably a good thing since it will trigger on every.single.checkin by default.) I get to see a history of deployments from the Azure portal, and can link into TFS to see the associated changesets and work items. You’ll notice also that this build definition also automatically put my code in the Staging slot of my Azure deployment – more on this soon. For now, I can VIP swap and be in production. (P.S. I hate VIP swap and “production” and “staging” in Azure. More on that later too.) That’s it. That’s the default out-of-box experience. Easy, right? But it’s full of room for improvement, so let’s get into that….   The Problems Nothing is perfect (except my code – it’s always perfect), and neither is Continuous Deployment without a bit of work to help it fit your dev team’s process. So what are the issues? Issue 1: Staging vs QA vs Prod vs whatever other environments your team may have. This, for me, is the big hairy one. Remember how this automatically deployed to staging rather than prod for us? There are a couple of issues with this model: If I want to deliver to prod, it requires intervention on my part after deployment (via a VIP swap). If I truly want to promote between environments (i.e. Nightly Build –> Stable QA –> Production) I likely have configuration changes between each environment such as database connection strings and this process (and the VIP swap) doesn’t account for this. Yet. Issue 2: Branching and delivering on every check-in. As I mentioned above, I have set this up to target a specific branch – Release – of my code. For the purposes of this example, I have adopted the “basic” branching strategy as defined by the ALM Rangers. This basically establishes a “Main” trunk where you branch off Dev and Release branches. Granted, the Release branch is usually the only thing you will deploy to production, but you certainly don’t want to roll to production automatically when you merge to the Release branch and check-in (unless you like the thrill of it, and in that case, I like your style, cowboy….). Rather, you have nightly build and QA environments, or if you’ve adopted the feature-branch model you have environments for those. Those are the environments you want to continuously deploy to. But that takes us back to Issue 1: we currently have a 1:1 solution to Azure deployment target. Issue 3: SQL and other custom tasks. Let’s be honest and address the elephant in the room: I need to get some sleep because I see an elephant in the room. But seriously, I can’t think of an application I have touched in the last 10 years that doesn’t need to consider SQL changes when deploying code and upgrading an environment. Microsoft seems perfectly content to ignore this elephant for now: yes, they’ve added Data Tier Applications. But let’s be honest with ourselves again: no one really uses it, and it’s not suitable for anything more complex than a Hello World sample project database. Why? Because it doesn’t fit well into a great source control story. Developers make stored procedure and table changes all day long while coding complex applications, and if someone forgets to go update the DACPAC before the automated deployment, you have a broken build until it’s completed. Developers – not just DBAs – also like to work with SQL in SQL tools, not in Visual Studio. I’m really picking on SQL because that’s generally the biggest concern that I hear. But we need to account for any custom tasks as well in the build process.   The Solutions… ? We’ve taken a look at how this all works, and addressed the shortcomings. In my next post (which I promise will be very, very soon), I will detail how I’ve overcome these shortcomings and used this foundation to create a mature, flexible model for deploying my app – any version, any time, to any environment.

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• I see no LOBs!

  - by Paul White

  Is it possible to see LOB (large object) logical reads from STATISTICS IO output on a table with no LOB columns? I was asked this question today by someone who had spent a good fraction of their afternoon trying to work out why this was occurring – even going so far as to re-run DBCC CHECKDB to see if any corruption had taken place.  The table in question wasn’t particularly pretty – it had grown somewhat organically over time, with new columns being added every so often as the need arose.  Nevertheless, it remained a simple structure with no LOB columns – no TEXT or IMAGE, no XML, no MAX types – nothing aside from ordinary INT, MONEY, VARCHAR, and DATETIME types.  To add to the air of mystery, not every query that ran against the table would report LOB logical reads – just sometimes – but when it did, the query often took much longer to execute. Ok, enough of the pre-amble.  I can’t reproduce the exact structure here, but the following script creates a table that will serve to demonstrate the effect: IF OBJECT_ID(N'dbo.Test', N'U') IS NOT NULL DROP TABLE dbo.Test GO CREATE TABLE dbo.Test ( row_id NUMERIC IDENTITY NOT NULL,   col01 NVARCHAR(450) NOT NULL, col02 NVARCHAR(450) NOT NULL, col03 NVARCHAR(450) NOT NULL, col04 NVARCHAR(450) NOT NULL, col05 NVARCHAR(450) NOT NULL, col06 NVARCHAR(450) NOT NULL, col07 NVARCHAR(450) NOT NULL, col08 NVARCHAR(450) NOT NULL, col09 NVARCHAR(450) NOT NULL, col10 NVARCHAR(450) NOT NULL, CONSTRAINT [PK dbo.Test row_id] PRIMARY KEY CLUSTERED (row_id) ) ; The next script loads the ten variable-length character columns with one-character strings in the first row, two-character strings in the second row, and so on down to the 450th row: WITH Numbers AS ( -- Generates numbers 1 - 450 inclusive SELECT TOP (450) n = ROW_NUMBER() OVER (ORDER BY (SELECT 0)) FROM master.sys.columns C1, master.sys.columns C2, master.sys.columns C3 ORDER BY n ASC ) INSERT dbo.Test WITH (TABLOCKX) SELECT REPLICATE(N'A', N.n), REPLICATE(N'B', N.n), REPLICATE(N'C', N.n), REPLICATE(N'D', N.n), REPLICATE(N'E', N.n), REPLICATE(N'F', N.n), REPLICATE(N'G', N.n), REPLICATE(N'H', N.n), REPLICATE(N'I', N.n), REPLICATE(N'J', N.n) FROM Numbers AS N ORDER BY N.n ASC ; Once those two scripts have run, the table contains 450 rows and 10 columns of data like this: Most of the time, when we query data from this table, we don’t see any LOB logical reads, for example: -- Find the maximum length of the data in -- column 5 for a range of rows SELECT result = MAX(DATALENGTH(T.col05)) FROM dbo.Test AS T WHERE row_id BETWEEN 50 AND 100 ; But with a different query… -- Read all the data in column 1 SELECT result = MAX(DATALENGTH(T.col01)) FROM dbo.Test AS T ; …suddenly we have 49 LOB logical reads, as well as the ‘normal’ logical reads we would expect. The Explanation If we had tried to create this table in SQL Server 2000, we would have received a warning message to say that future INSERT or UPDATE operations on the table might fail if the resulting row exceeded the in-row storage limit of 8060 bytes.  If we needed to store more data than would fit in an 8060 byte row (including internal overhead) we had to use a LOB column – TEXT, NTEXT, or IMAGE.  These special data types store the large data values in a separate structure, with just a small pointer left in the original row. Row Overflow SQL Server 2005 introduced a feature called row overflow, which allows one or more variable-length columns in a row to move to off-row storage if the data in a particular row would otherwise exceed 8060 bytes.  You no longer receive a warning when creating (or altering) a table that might need more than 8060 bytes of in-row storage; if SQL Server finds that it can no longer fit a variable-length column in a particular row, it will silently move one or more of these columns off the row into a separate allocation unit. Only variable-length columns can be moved in this way (for example the (N)VARCHAR, VARBINARY, and SQL_VARIANT types).  Fixed-length columns (like INTEGER and DATETIME for example) never move into ‘row overflow’ storage.  The decision to move a column off-row is done on a row-by-row basis – so data in a particular column might be stored in-row for some table records, and off-row for others. In general, if SQL Server finds that it needs to move a column into row-overflow storage, it moves the largest variable-length column record for that row.  Note that in the case of an UPDATE statement that results in the 8060 byte limit being exceeded, it might not be the column that grew that is moved! Sneaky LOBs Anyway, that’s all very interesting but I don’t want to get too carried away with the intricacies of row-overflow storage internals.  The point is that it is now possible to define a table with non-LOB columns that will silently exceed the old row-size limit and result in ordinary variable-length columns being moved to off-row storage.  Adding new columns to a table, expanding an existing column definition, or simply storing more data in a column than you used to – all these things can result in one or more variable-length columns being moved off the row. Note that row-overflow storage is logically quite different from old-style LOB and new-style MAX data type storage – individual variable-length columns are still limited to 8000 bytes each – you can just have more of them now.  Having said that, the physical mechanisms involved are very similar to full LOB storage – a column moved to row-overflow leaves a 24-byte pointer record in the row, and the ‘separate storage’ I have been talking about is structured very similarly to both old-style LOBs and new-style MAX types.  The disadvantages are also the same: when SQL Server needs a row-overflow column value it needs to follow the in-row pointer a navigate another chain of pages, just like retrieving a traditional LOB. And Finally… In the example script presented above, the rows with row_id values from 402 to 450 inclusive all exceed the total in-row storage limit of 8060 bytes.  A SELECT that references a column in one of those rows that has moved to off-row storage will incur one or more lob logical reads as the storage engine locates the data.  The results on your system might vary slightly depending on your settings, of course; but in my tests only column 1 in rows 402-450 moved off-row.  You might like to play around with the script – updating columns, changing data type lengths, and so on – to see the effect on lob logical reads and which columns get moved when.  You might even see row-overflow columns moving back in-row if they are updated to be smaller (hint: reduce the size of a column entry by at least 1000 bytes if you hope to see this). Be aware that SQL Server will not warn you when it moves ‘ordinary’ variable-length columns into overflow storage, and it can have dramatic effects on performance.  It makes more sense than ever to choose column data types sensibly.  If you make every column a VARCHAR(8000) or NVARCHAR(4000), and someone stores data that results in a row needing more than 8060 bytes, SQL Server might turn some of your column data into pseudo-LOBs – all without saying a word. Finally, some people make a distinction between ordinary LOBs (those that can hold up to 2GB of data) and the LOB-like structures created by row-overflow (where columns are still limited to 8000 bytes) by referring to row-overflow LOBs as SLOBs.  I find that quite appealing, but the ‘S’ stands for ‘small’, which makes expanding the whole acronym a little daft-sounding…small large objects anyone? © Paul White 2011 email: [email protected] twitter: @SQL_Kiwi

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• Why can I view my site over a 3G connection but not through my wifi?

  - by Jonathan

  So, I am sitting in my office with four computers on the same network and internet connection. Two of the computers can visit this particular website. Two of the computer get a message "Google Chrome could not find". I have tried FF and IE also with the same problem. I can view the site 90% of the time on two of the working computers although the site seems slow and sometimes I also get the same errors as the other two computers. I have flushed the DNS, reset the router, tested the site on other peoples computers with success. Is this likely to be a site issue, an ISP issue, a hosting issue? Any advice is greatly appreciated. Here is the ping from the working machine: C:\Users\Jon>ping www.balihaicruises.com Pinging www.balihaicruises.com [208.113.173.102] with 32 bytes of data: Reply from 208.113.173.102: bytes=32 time=331ms TTL=47 Reply from 208.113.173.102: bytes=32 time=327ms TTL=47 Reply from 208.113.173.102: bytes=32 time=326ms TTL=47 Reply from 208.113.173.102: bytes=32 time=329ms TTL=47 Ping statistics for 208.113.173.102: Packets: Sent = 4, Received = 4, Lost = 0 (0% loss), Approximate round trip times in milli-seconds: Minimum = 326ms, Maximum = 331ms, Average = 328ms Traceroute: Tracing route to www.balihaicruises.com [208.113.173.102] over a maximum of 30 hops: 1 1 ms 17 ms 3 ms 192.168.1.1 2 42 ms 37 ms 36 ms 180.254.224.1 3 39 ms 47 ms 40 ms 180.252.1.69 4 36 ms 616 ms 57 ms 61.94.115.221 5 84 ms 76 ms 80 ms 180.240.191.98 6 73 ms 80 ms 72 ms 180.240.191.97 7 157 ms 143 ms 116 ms 180.240.190.82 8 115 ms 113 ms 120 ms ae1-123.hkg11.ip4.tinet.net [183.182.80.93] 9 331 ms 332 ms 335 ms xe-3-2-1.was14.ip4.tinet.net [89.149.184.30] 10 327 ms 330 ms 331 ms internap-gw.ip4.tinet.net [77.67.69.254] 11 437 ms 415 ms 350 ms border10.pc2-bbnet2.wdc002.pnap.net [216.52.127.73] 12 322 ms 823 ms 398 ms dreamhost-2.border10.wdc002.pnap.net [216.52.125.74] 13 328 ms 336 ms 326 ms ip-208-113-156-4.dreamhost.com [208.113.156.4] 14 326 ms 328 ms 336 ms ip-208-113-156-14.dreamhost.com [208.113.156.14] 15 327 ms 331 ms 333 ms apache2-udder.crisp.dreamhost.com [208.113.173.102] And then for the machine that doesn't work: C:\Users\Microsoft>ping www.balihaicruises.com Ping request could not find host www.balihaicruises.com. Please check the name and try again. C:\Users\Microsoft>tracert www.balihaicruises.com Unable to resolve target system name www.balihaicruises.com.

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• PC monitors shut off and system hangs while playing 3D games, but sound continues - Diagnosis?

  - by Jon Schneider

  Two days ago, I started running into a problem with my Windows PC: The PC's two connected monitors simultaneously lose signal and go black (as though the PC had been powered off). The keyboard's Numlock, Capslock, and Scroll Lights will become "stuck" in their current positions, as though the PC is hung. (For example, the Numlock light on the keyboard remains lit regardless of me pressing the Numlock key repeatedly.) No keyboard input does anything. (Ctrl+Alt+Del, Ctrl+Shift+Esc, Ctrl+C, etc.) However -- Whatever sound/music the PC was playing continues to play, and the PC's fans continue running, so the PC hasn't powered itself off or rebooted itself. Opening up the case, the graphics card is pretty hot to the touch. I had this happen 3 times in one evening. In all cases, I was playing a game with 3D graphics when the problem occurred (Torchlight, Minecraft, Magic: The Gathering 2012, Avadon: The Black Fortress demo). I have yet to have the problem happen when I'm not playing a game. This system has been running stable for about 2.5 years prior to this. I didn't make any changes to the system prior to the problem starting to occur. System specs: OS: Windows 7 64-bit Processor: Intel Core 2 Duo E7200 Wolfdale 2.53GHz Video Card: XFX GeForce 9800 GT 512 MB Motherboard: Foxconn P45A-S LGA 775 Intel ATX RAM: Corsair 4 GB (2x 2GB) DDR2-800 (PC2 6400) Full specs: New PC 2008 Troubleshooting tried so far (the problem occurred again after taking each of these steps, one at a time): Updated the video drivers with the latest drivers from NVidia's site. Opened up the case and cleaned out the video card and processor fans (both were pretty dirty). Installed and ran temperature monitor software. The processor idles at about 50 degrees C, and goes up to about 63 degrees C while playing a game (seems on the warm side, but not excessively so?). The software wasn't able to report the temperature of the GPU -- not sure this particular GPU supports software temperature readout? My initial diagnosis is that maybe the GPU is on its last legs (given that it seems to be running pretty hot, and the problem only occurs while playing 3D games). Does this seem likely? Or is it likely that this problem is caused by the processor, RAM, or motherboard? Or could this be a software issue of some kind? Thanks for any advice!

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• An Introduction to ASP.NET Web API

  - by Rick Strahl

  Microsoft recently released ASP.NET MVC 4.0 and .NET 4.5 and along with it, the brand spanking new ASP.NET Web API. Web API is an exciting new addition to the ASP.NET stack that provides a new, well-designed HTTP framework for creating REST and AJAX APIs (API is Microsoft’s new jargon for a service, in case you’re wondering). Although Web API ships and installs with ASP.NET MVC 4, you can use Web API functionality in any ASP.NET project, including WebForms, WebPages and MVC or just a Web API by itself. And you can also self-host Web API in your own applications from Console, Desktop or Service applications. If you're interested in a high level overview on what ASP.NET Web API is and how it fits into the ASP.NET stack you can check out my previous post: Where does ASP.NET Web API fit? In the following article, I'll focus on a practical, by example introduction to ASP.NET Web API. All the code discussed in this article is available in GitHub: https://github.com/RickStrahl/AspNetWebApiArticle [republished from my Code Magazine Article and updated for RTM release of ASP.NET Web API] Getting Started To start I’ll create a new empty ASP.NET application to demonstrate that Web API can work with any kind of ASP.NET project. Although you can create a new project based on the ASP.NET MVC/Web API template to quickly get up and running, I’ll take you through the manual setup process, because one common use case is to add Web API functionality to an existing ASP.NET application. This process describes the steps needed to hook up Web API to any ASP.NET 4.0 application. Start by creating an ASP.NET Empty Project. Then create a new folder in the project called Controllers. Add a Web API Controller Class Once you have any kind of ASP.NET project open, you can add a Web API Controller class to it. Web API Controllers are very similar to MVC Controller classes, but they work in any kind of project. Add a new item to this folder by using the Add New Item option in Visual Studio and choose Web API Controller Class, as shown in Figure 1. Figure 1: This is how you create a new Controller Class in Visual Studio   Make sure that the name of the controller class includes Controller at the end of it, which is required in order for Web API routing to find it. Here, the name for the class is AlbumApiController. For this example, I’ll use a Music Album model to demonstrate basic behavior of Web API. The model consists of albums and related songs where an album has properties like Name, Artist and YearReleased and a list of songs with a SongName and SongLength as well as an AlbumId that links it to the album. You can find the code for the model (and the rest of these samples) on Github. To add the file manually, create a new folder called Model, and add a new class Album.cs and copy the code into it. There’s a static AlbumData class with a static CreateSampleAlbumData() method that creates a short list of albums on a static .Current that I’ll use for the examples. Before we look at what goes into the controller class though, let’s hook up routing so we can access this new controller. Hooking up Routing in Global.asax To start, I need to perform the one required configuration task in order for Web API to work: I need to configure routing to the controller. Like MVC, Web API uses routing to provide clean, extension-less URLs to controller methods. Using an extension method to ASP.NET’s static RouteTable class, you can use the MapHttpRoute() (in the System.Web.Http namespace) method to hook-up the routing during Application_Start in global.asax.cs shown in Listing 1.using System; using System.Web.Routing; using System.Web.Http; namespace AspNetWebApi { public class Global : System.Web.HttpApplication { protected void Application_Start(object sender, EventArgs e) { RouteTable.Routes.MapHttpRoute( name: "AlbumVerbs", routeTemplate: "albums/{title}", defaults: new { symbol = RouteParameter.Optional, controller="AlbumApi" } ); } } } This route configures Web API to direct URLs that start with an albums folder to the AlbumApiController class. Routing in ASP.NET is used to create extensionless URLs and allows you to map segments of the URL to specific Route Value parameters. A route parameter, with a name inside curly brackets like {name}, is mapped to parameters on the controller methods. Route parameters can be optional, and there are two special route parameters – controller and action – that determine the controller to call and the method to activate respectively. HTTP Verb Routing Routing in Web API can route requests by HTTP Verb in addition to standard {controller},{action} routing. For the first examples, I use HTTP Verb routing, as shown Listing 1. Notice that the route I’ve defined does not include an {action} route value or action value in the defaults. Rather, Web API can use the HTTP Verb in this route to determine the method to call the controller, and a GET request maps to any method that starts with Get. So methods called Get() or GetAlbums() are matched by a GET request and a POST request maps to a Post() or PostAlbum(). Web API matches a method by name and parameter signature to match a route, query string or POST values. In lieu of the method name, the [HttpGet,HttpPost,HttpPut,HttpDelete, etc] attributes can also be used to designate the accepted verbs explicitly if you don’t want to follow the verb naming conventions. Although HTTP Verb routing is a good practice for REST style resource APIs, it’s not required and you can still use more traditional routes with an explicit {action} route parameter. When {action} is supplied, the HTTP verb routing is ignored. I’ll talk more about alternate routes later. When you’re finished with initial creation of files, your project should look like Figure 2.   Figure 2: The initial project has the new API Controller Album model   Creating a small Album Model Now it’s time to create some controller methods to serve data. For these examples, I’ll use a very simple Album and Songs model to play with, as shown in Listing 2. public class Song { public string AlbumId { get; set; } [Required, StringLength(80)] public string SongName { get; set; } [StringLength(5)] public string SongLength { get; set; } } public class Album { public string Id { get; set; } [Required, StringLength(80)] public string AlbumName { get; set; } [StringLength(80)] public string Artist { get; set; } public int YearReleased { get; set; } public DateTime Entered { get; set; } [StringLength(150)] public string AlbumImageUrl { get; set; } [StringLength(200)] public string AmazonUrl { get; set; } public virtual List<Song> Songs { get; set; } public Album() { Songs = new List<Song>(); Entered = DateTime.Now; // Poor man's unique Id off GUID hash Id = Guid.NewGuid().GetHashCode().ToString("x"); } public void AddSong(string songName, string songLength = null) { this.Songs.Add(new Song() { AlbumId = this.Id, SongName = songName, SongLength = songLength }); } } Once the model has been created, I also added an AlbumData class that generates some static data in memory that is loaded onto a static .Current member. The signature of this class looks like this and that's what I'll access to retrieve the base data:public static class AlbumData { // sample data - static list public static List<Album> Current = CreateSampleAlbumData(); /// <summary> /// Create some sample data /// </summary> /// <returns></returns> public static List<Album> CreateSampleAlbumData() { … }} You can check out the full code for the data generation online. Creating an AlbumApiController Web API shares many concepts of ASP.NET MVC, and the implementation of your API logic is done by implementing a subclass of the System.Web.Http.ApiController class. Each public method in the implemented controller is a potential endpoint for the HTTP API, as long as a matching route can be found to invoke it. The class name you create should end in Controller, which is how Web API matches the controller route value to figure out which class to invoke. Inside the controller you can implement methods that take standard .NET input parameters and return .NET values as results. Web API’s binding tries to match POST data, route values, form values or query string values to your parameters. Because the controller is configured for HTTP Verb based routing (no {action} parameter in the route), any methods that start with Getxxxx() are called by an HTTP GET operation. You can have multiple methods that match each HTTP Verb as long as the parameter signatures are different and can be matched by Web API. In Listing 3, I create an AlbumApiController with two methods to retrieve a list of albums and a single album by its title .public class AlbumApiController : ApiController { public IEnumerable<Album> GetAlbums() { var albums = AlbumData.Current.OrderBy(alb => alb.Artist); return albums; } public Album GetAlbum(string title) { var album = AlbumData.Current .SingleOrDefault(alb => alb.AlbumName.Contains(title)); return album; }} To access the first two requests, you can use the following URLs in your browser: http://localhost/aspnetWebApi/albumshttp://localhost/aspnetWebApi/albums/Dirty%20Deeds Note that you’re not specifying the actions of GetAlbum or GetAlbums in these URLs. Instead Web API’s routing uses HTTP GET verb to route to these methods that start with Getxxx() with the first mapping to the parameterless GetAlbums() method and the latter to the GetAlbum(title) method that receives the title parameter mapped as optional in the route. Content Negotiation When you access any of the URLs above from a browser, you get either an XML or JSON result returned back. The album list result for Chrome 17 and Internet Explorer 9 is shown Figure 3. Figure 3: Web API responses can vary depending on the browser used, demonstrating Content Negotiation in action as these two browsers send different HTTP Accept headers.   Notice that the results are not the same: Chrome returns an XML response and IE9 returns a JSON response. Whoa, what’s going on here? Shouldn’t we see the same result in both browsers? Actually, no. Web API determines what type of content to return based on Accept headers. HTTP clients, like browsers, use Accept headers to specify what kind of content they’d like to see returned. Browsers generally ask for HTML first, followed by a few additional content types. Chrome (and most other major browsers) ask for: Accept: text/html, application/xhtml+xml,application/xml; q=0.9,*/*;q=0.8 IE9 asks for: Accept: text/html, application/xhtml+xml, */* Note that Chrome’s Accept header includes application/xml, which Web API finds in its list of supported media types and returns an XML response. IE9 does not include an Accept header type that works on Web API by default, and so it returns the default format, which is JSON. This is an important and very useful feature that was missing from any previous Microsoft REST tools: Web API automatically switches output formats based on HTTP Accept headers. Nowhere in the server code above do you have to explicitly specify the output format. Rather, Web API determines what format the client is requesting based on the Accept headers and automatically returns the result based on the available formatters. This means that a single method can handle both XML and JSON results.. Using this simple approach makes it very easy to create a single controller method that can return JSON, XML, ATOM or even OData feeds by providing the appropriate Accept header from the client. By default you don’t have to worry about the output format in your code. Note that you can still specify an explicit output format if you choose, either globally by overriding the installed formatters, or individually by returning a lower level HttpResponseMessage instance and setting the formatter explicitly. More on that in a minute. Along the same lines, any content sent to the server via POST/PUT is parsed by Web API based on the HTTP Content-type of the data sent. The same formats allowed for output are also allowed on input. Again, you don’t have to do anything in your code – Web API automatically performs the deserialization from the content. Accessing Web API JSON Data with jQuery A very common scenario for Web API endpoints is to retrieve data for AJAX calls from the Web browser. Because JSON is the default format for Web API, it’s easy to access data from the server using jQuery and its getJSON() method. This example receives the albums array from GetAlbums() and databinds it into the page using knockout.js.$.getJSON("albums/", function (albums) { // make knockout template visible $(".album").show(); // create view object and attach array var view = { albums: albums }; ko.applyBindings(view); }); Figure 4 shows this and the next example’s HTML output. You can check out the complete HTML and script code at http://goo.gl/Ix33C (.html) and http://goo.gl/tETlg (.js). Figu Figure 4: The Album Display sample uses JSON data loaded from Web API.   The result from the getJSON() call is a JavaScript object of the server result, which comes back as a JavaScript array. In the code, I use knockout.js to bind this array into the UI, which as you can see, requires very little code, instead using knockout’s data-bind attributes to bind server data to the UI. Of course, this is just one way to use the data – it’s entirely up to you to decide what to do with the data in your client code. Along the same lines, I can retrieve a single album to display when the user clicks on an album. The response returns the album information and a child array with all the songs. The code to do this is very similar to the last example where we pulled the albums array:$(".albumlink").live("click", function () { var id = $(this).data("id"); // title $.getJSON("albums/" + id, function (album) { ko.applyBindings(album, $("#divAlbumDialog")[0]); $("#divAlbumDialog").show(); }); }); Here the URL looks like this: /albums/Dirty%20Deeds, where the title is the ID captured from the clicked element’s data ID attribute. Explicitly Overriding Output Format When Web API automatically converts output using content negotiation, it does so by matching Accept header media types to the GlobalConfiguration.Configuration.Formatters and the SupportedMediaTypes of each individual formatter. You can add and remove formatters to globally affect what formats are available and it’s easy to create and plug in custom formatters.The example project includes a JSONP formatter that can be plugged in to provide JSONP support for requests that have a callback= querystring parameter. Adding, removing or replacing formatters is a global option you can use to manipulate content. It’s beyond the scope of this introduction to show how it works, but you can review the sample code or check out my blog entry on the subject (http://goo.gl/UAzaR). If automatic processing is not desirable in a particular Controller method, you can override the response output explicitly by returning an HttpResponseMessage instance. HttpResponseMessage is similar to ActionResult in ASP.NET MVC in that it’s a common way to return an abstract result message that contains content. HttpResponseMessage s parsed by the Web API framework using standard interfaces to retrieve the response data, status code, headers and so on[MS2] . Web API turns every response – including those Controller methods that return static results – into HttpResponseMessage instances. Explicitly returning an HttpResponseMessage instance gives you full control over the output and lets you mostly bypass WebAPI’s post-processing of the HTTP response on your behalf. HttpResponseMessage allows you to customize the response in great detail. Web API’s attention to detail in the HTTP spec really shows; many HTTP options are exposed as properties and enumerations with detailed IntelliSense comments. Even if you’re new to building REST-based interfaces, the API guides you in the right direction for returning valid responses and response codes. For example, assume that I always want to return JSON from the GetAlbums() controller method and ignore the default media type content negotiation. To do this, I can adjust the output format and headers as shown in Listing 4.public HttpResponseMessage GetAlbums() { var albums = AlbumData.Current.OrderBy(alb => alb.Artist); // Create a new HttpResponse with Json Formatter explicitly var resp = new HttpResponseMessage(HttpStatusCode.OK); resp.Content = new ObjectContent<IEnumerable<Album>>( albums, new JsonMediaTypeFormatter()); // Get Default Formatter based on Content Negotiation //var resp = Request.CreateResponse<IEnumerable<Album>>(HttpStatusCode.OK, albums); resp.Headers.ConnectionClose = true; resp.Headers.CacheControl = new CacheControlHeaderValue(); resp.Headers.CacheControl.Public = true; return resp; } This example returns the same IEnumerable<Album> value, but it wraps the response into an HttpResponseMessage so you can control the entire HTTP message result including the headers, formatter and status code. In Listing 4, I explicitly specify the formatter using the JsonMediaTypeFormatter to always force the content to JSON.  If you prefer to use the default content negotiation with HttpResponseMessage results, you can create the Response instance using the Request.CreateResponse method:var resp = Request.CreateResponse<IEnumerable<Album>>(HttpStatusCode.OK, albums); This provides you an HttpResponse object that's pre-configured with the default formatter based on Content Negotiation. Once you have an HttpResponse object you can easily control most HTTP aspects on this object. What's sweet here is that there are many more detailed properties on HttpResponse than the core ASP.NET Response object, with most options being explicitly configurable with enumerations that make it easy to pick the right headers and response codes from a list of valid codes. It makes HTTP features available much more discoverable even for non-hardcore REST/HTTP geeks. Non-Serialized Results The output returned doesn’t have to be a serialized value but can also be raw data, like strings, binary data or streams. You can use the HttpResponseMessage.Content object to set a number of common Content classes. Listing 5 shows how to return a binary image using the ByteArrayContent class from a Controller method. [HttpGet] public HttpResponseMessage AlbumArt(string title) { var album = AlbumData.Current.FirstOrDefault(abl => abl.AlbumName.StartsWith(title)); if (album == null) { var resp = Request.CreateResponse<ApiMessageError>( HttpStatusCode.NotFound, new ApiMessageError("Album not found")); return resp; } // kinda silly - we would normally serve this directly // but hey - it's a demo. var http = new WebClient(); var imageData = http.DownloadData(album.AlbumImageUrl); // create response and return var result = new HttpResponseMessage(HttpStatusCode.OK); result.Content = new ByteArrayContent(imageData); result.Content.Headers.ContentType = new MediaTypeHeaderValue("image/jpeg"); return result; } The image retrieval from Amazon is contrived, but it shows how to return binary data using ByteArrayContent. It also demonstrates that you can easily return multiple types of content from a single controller method, which is actually quite common. If an error occurs - such as a resource can’t be found or a validation error – you can return an error response to the client that’s very specific to the error. In GetAlbumArt(), if the album can’t be found, we want to return a 404 Not Found status (and realistically no error, as it’s an image). Note that if you are not using HTTP Verb-based routing or not accessing a method that starts with Get/Post etc., you have to specify one or more HTTP Verb attributes on the method explicitly. Here, I used the [HttpGet] attribute to serve the image. Another option to handle the error could be to return a fixed placeholder image if no album could be matched or the album doesn’t have an image. When returning an error code, you can also return a strongly typed response to the client. For example, you can set the 404 status code and also return a custom error object (ApiMessageError is a class I defined) like this:return Request.CreateResponse<ApiMessageError>( HttpStatusCode.NotFound, new ApiMessageError("Album not found") );   If the album can be found, the image will be returned. The image is downloaded into a byte[] array, and then assigned to the result’s Content property. I created a new ByteArrayContent instance and assigned the image’s bytes and the content type so that it displays properly in the browser. There are other content classes available: StringContent, StreamContent, ByteArrayContent, MultipartContent, and ObjectContent are at your disposal to return just about any kind of content. You can create your own Content classes if you frequently return custom types and handle the default formatter assignments that should be used to send the data out . Although HttpResponseMessage results require more code than returning a plain .NET value from a method, it allows much more control over the actual HTTP processing than automatic processing. It also makes it much easier to test your controller methods as you get a response object that you can check for specific status codes and output messages rather than just a result value. Routing Again Ok, let’s get back to the image example. Using the original routing we have setup using HTTP Verb routing there's no good way to serve the image. In order to return my album art image I’d like to use a URL like this: http://localhost/aspnetWebApi/albums/Dirty%20Deeds/image In order to create a URL like this, I have to create a new Controller because my earlier routes pointed to the AlbumApiController using HTTP Verb routing. HTTP Verb based routing is great for representing a single set of resources such as albums. You can map operations like add, delete, update and read easily using HTTP Verbs. But you cannot mix action based routing into a an HTTP Verb routing controller - you can only map HTTP Verbs and each method has to be unique based on parameter signature. You can't have multiple GET operations to methods with the same signature. So GetImage(string id) and GetAlbum(string title) are in conflict in an HTTP GET routing scenario. In fact, I was unable to make the above Image URL work with any combination of HTTP Verb plus Custom routing using the single Albums controller. There are number of ways around this, but all involve additional controllers.  Personally, I think it’s easier to use explicit Action routing and then add custom routes if you need to simplify your URLs further. So in order to accommodate some of the other examples, I created another controller – AlbumRpcApiController – to handle all requests that are explicitly routed via actions (/albums/rpc/AlbumArt) or are custom routed with explicit routes defined in the HttpConfiguration. I added the AlbumArt() method to this new AlbumRpcApiController class. For the image URL to work with the new AlbumRpcApiController, you need a custom route placed before the default route from Listing 1.RouteTable.Routes.MapHttpRoute( name: "AlbumRpcApiAction", routeTemplate: "albums/rpc/{action}/{title}", defaults: new { title = RouteParameter.Optional, controller = "AlbumRpcApi", action = "GetAblums" } ); Now I can use either of the following URLs to access the image: Custom route: (/albums/rpc/{title}/image)http://localhost/aspnetWebApi/albums/PowerAge/image Action route: (/albums/rpc/action/{title})http://localhost/aspnetWebAPI/albums/rpc/albumart/PowerAge Sending Data to the Server To send data to the server and add a new album, you can use an HTTP POST operation. Since I’m using HTTP Verb-based routing in the original AlbumApiController, I can implement a method called PostAlbum()to accept a new album from the client. Listing 6 shows the Web API code to add a new album.public HttpResponseMessage PostAlbum(Album album) { if (!this.ModelState.IsValid) { // my custom error class var error = new ApiMessageError() { message = "Model is invalid" }; // add errors into our client error model for client foreach (var prop in ModelState.Values) { var modelError = prop.Errors.FirstOrDefault(); if (!string.IsNullOrEmpty(modelError.ErrorMessage)) error.errors.Add(modelError.ErrorMessage); else error.errors.Add(modelError.Exception.Message); } return Request.CreateResponse<ApiMessageError>(HttpStatusCode.Conflict, error); } // update song id which isn't provided foreach (var song in album.Songs) song.AlbumId = album.Id; // see if album exists already var matchedAlbum = AlbumData.Current .SingleOrDefault(alb => alb.Id == album.Id || alb.AlbumName == album.AlbumName); if (matchedAlbum == null) AlbumData.Current.Add(album); else matchedAlbum = album; // return a string to show that the value got here var resp = Request.CreateResponse(HttpStatusCode.OK, string.Empty); resp.Content = new StringContent(album.AlbumName + " " + album.Entered.ToString(), Encoding.UTF8, "text/plain"); return resp; } The PostAlbum() method receives an album parameter, which is automatically deserialized from the POST buffer the client sent. The data passed from the client can be either XML or JSON. Web API automatically figures out what format it needs to deserialize based on the content type and binds the content to the album object. Web API uses model binding to bind the request content to the parameter(s) of controller methods. Like MVC you can check the model by looking at ModelState.IsValid. If it’s not valid, you can run through the ModelState.Values collection and check each binding for errors. Here I collect the error messages into a string array that gets passed back to the client via the result ApiErrorMessage object. When a binding error occurs, you’ll want to return an HTTP error response and it’s best to do that with an HttpResponseMessage result. In Listing 6, I used a custom error class that holds a message and an array of detailed error messages for each binding error. I used this object as the content to return to the client along with my Conflict HTTP Status Code response. If binding succeeds, the example returns a string with the name and date entered to demonstrate that you captured the data. Normally, a method like this should return a Boolean or no response at all (HttpStatusCode.NoConent). The sample uses a simple static list to hold albums, so once you’ve added the album using the Post operation, you can hit the /albums/ URL to see that the new album was added. The client jQuery code to call the POST operation from the client with jQuery is shown in Listing 7. var id = new Date().getTime().toString(); var album = { "Id": id, "AlbumName": "Power Age", "Artist": "AC/DC", "YearReleased": 1977, "Entered": "2002-03-11T18:24:43.5580794-10:00", "AlbumImageUrl": http://ecx.images-amazon.com/images/…, "AmazonUrl": http://www.amazon.com/…, "Songs": [ { "SongName": "Rock 'n Roll Damnation", "SongLength": 3.12}, { "SongName": "Downpayment Blues", "SongLength": 4.22 }, { "SongName": "Riff Raff", "SongLength": 2.42 } ] } $.ajax( { url: "albums/", type: "POST", contentType: "application/json", data: JSON.stringify(album), processData: false, beforeSend: function (xhr) { // not required since JSON is default output xhr.setRequestHeader("Accept", "application/json"); }, success: function (result) { // reload list of albums page.loadAlbums(); }, error: function (xhr, status, p3, p4) { var err = "Error"; if (xhr.responseText && xhr.responseText[0] == "{") err = JSON.parse(xhr.responseText).message; alert(err); } }); The code in Listing 7 creates an album object in JavaScript to match the structure of the .NET Album class. This object is passed to the $.ajax() function to send to the server as POST. The data is turned into JSON and the content type set to application/json so that the server knows what to convert when deserializing in the Album instance. The jQuery code hooks up success and failure events. Success returns the result data, which is a string that’s echoed back with an alert box. If an error occurs, jQuery returns the XHR instance and status code. You can check the XHR to see if a JSON object is embedded and if it is, you can extract it by de-serializing it and accessing the .message property. REST standards suggest that updates to existing resources should use PUT operations. REST standards aside, I’m not a big fan of separating out inserts and updates so I tend to have a single method that handles both. But if you want to follow REST suggestions, you can create a PUT method that handles updates by forwarding the PUT operation to the POST method:public HttpResponseMessage PutAlbum(Album album) { return PostAlbum(album); } To make the corresponding $.ajax() call, all you have to change from Listing 7 is the type: from POST to PUT. Model Binding with UrlEncoded POST Variables In the example in Listing 7 I used JSON objects to post a serialized object to a server method that accepted an strongly typed object with the same structure, which is a common way to send data to the server. However, Web API supports a number of different ways that data can be received by server methods. For example, another common way is to use plain UrlEncoded POST  values to send to the server. Web API supports Model Binding that works similar (but not the same) as MVC's model binding where POST variables are mapped to properties of object parameters of the target method. This is actually quite common for AJAX calls that want to avoid serialization and the potential requirement of a JSON parser on older browsers. For example, using jQUery you might use the $.post() method to send a new album to the server (albeit one without songs) using code like the following:$.post("albums/",{AlbumName: "Dirty Deeds", YearReleased: 1976 … },albumPostCallback); Although the code looks very similar to the client code we used before passing JSON, here the data passed is URL encoded values (AlbumName=Dirty+Deeds&YearReleased=1976 etc.). Web API then takes this POST data and maps each of the POST values to the properties of the Album object in the method's parameter. Although the client code is different the server can both handle the JSON object, or the UrlEncoded POST values. Dynamic Access to POST Data There are also a few options available to dynamically access POST data, if you know what type of data you're dealing with. If you have POST UrlEncoded values, you can dynamically using a FormsDataCollection:[HttpPost] public string PostAlbum(FormDataCollection form) { return string.Format("{0} - released {1}", form.Get("AlbumName"),form.Get("RearReleased")); } The FormDataCollection is a very simple object, that essentially provides the same functionality as Request.Form[] in ASP.NET. Request.Form[] still works if you're running hosted in an ASP.NET application. However as a general rule, while ASP.NET's functionality is always available when running Web API hosted inside of an  ASP.NET application, using the built in classes specific to Web API makes it possible to run Web API applications in a self hosted environment outside of ASP.NET. If your client is sending JSON to your server, and you don't want to map the JSON to a strongly typed object because you only want to retrieve a few simple values, you can also accept a JObject parameter in your API methods:[HttpPost] public string PostAlbum(JObject jsonData) { dynamic json = jsonData; JObject jalbum = json.Album; JObject juser = json.User; string token = json.UserToken; var album = jalbum.ToObject<Album>(); var user = juser.ToObject<User>(); return String.Format("{0} {1} {2}", album.AlbumName, user.Name, token); } There quite a few options available to you to receive data with Web API, which gives you more choices for the right tool for the job. Unfortunately one shortcoming of Web API is that POST data is always mapped to a single parameter. This means you can't pass multiple POST parameters to methods that receive POST data. It's possible to accept multiple parameters, but only one can map to the POST content - the others have to come from the query string or route values. I have a couple of Blog POSTs that explain what works and what doesn't here: Passing multiple POST parameters to Web API Controller Methods Mapping UrlEncoded POST Values in ASP.NET Web API   Handling Delete Operations Finally, to round out the server API code of the album example we've been discussin, here’s the DELETE verb controller method that allows removal of an album by its title:public HttpResponseMessage DeleteAlbum(string title) { var matchedAlbum = AlbumData.Current.Where(alb => alb.AlbumName == title) .SingleOrDefault(); if (matchedAlbum == null) return new HttpResponseMessage(HttpStatusCode.NotFound); AlbumData.Current.Remove(matchedAlbum); return new HttpResponseMessage(HttpStatusCode.NoContent); } To call this action method using jQuery, you can use:$(".removeimage").live("click", function () { var $el = $(this).parent(".album"); var txt = $el.find("a").text(); $.ajax({ url: "albums/" + encodeURIComponent(txt), type: "Delete", success: function (result) { $el.fadeOut().remove(); }, error: jqError }); }   Note the use of the DELETE verb in the $.ajax() call, which routes to DeleteAlbum on the server. DELETE is a non-content operation, so you supply a resource ID (the title) via route value or the querystring. Routing Conflicts In all requests with the exception of the AlbumArt image example shown so far, I used HTTP Verb routing that I set up in Listing 1. HTTP Verb Routing is a recommendation that is in line with typical REST access to HTTP resources. However, it takes quite a bit of effort to create REST-compliant API implementations based only on HTTP Verb routing only. You saw one example that didn’t really fit – the return of an image where I created a custom route albums/{title}/image that required creation of a second controller and a custom route to work. HTTP Verb routing to a controller does not mix with custom or action routing to the same controller because of the limited mapping of HTTP verbs imposed by HTTP Verb routing. To understand some of the problems with verb routing, let’s look at another example. Let’s say you create a GetSortableAlbums() method like this and add it to the original AlbumApiController accessed via HTTP Verb routing:[HttpGet] public IQueryable<Album> SortableAlbums() { var albums = AlbumData.Current; // generally should be done only on actual queryable results (EF etc.) // Done here because we're running with a static list but otherwise might be slow return albums.AsQueryable(); } If you compile this code and try to now access the /albums/ link, you get an error: Multiple Actions were found that match the request. HTTP Verb routing only allows access to one GET operation per parameter/route value match. If more than one method exists with the same parameter signature, it doesn’t work. As I mentioned earlier for the image display, the only solution to get this method to work is to throw it into another controller. Because I already set up the AlbumRpcApiController I can add the method there. First, I should rename the method to SortableAlbums() so I’m not using a Get prefix for the method. This also makes the action parameter look cleaner in the URL - it looks less like a method and more like a noun. I can then create a new route that handles direct-action mapping:RouteTable.Routes.MapHttpRoute( name: "AlbumRpcApiAction", routeTemplate: "albums/rpc/{action}/{title}", defaults: new { title = RouteParameter.Optional, controller = "AlbumRpcApi", action = "GetAblums" } ); As I am explicitly adding a route segment – rpc – into the route template, I can now reference explicit methods in the Web API controller using URLs like this: http://localhost/AspNetWebApi/rpc/SortableAlbums Error Handling I’ve already done some minimal error handling in the examples. For example in Listing 6, I detected some known-error scenarios like model validation failing or a resource not being found and returning an appropriate HttpResponseMessage result. But what happens if your code just blows up or causes an exception? If you have a controller method, like this:[HttpGet] public void ThrowException() { throw new UnauthorizedAccessException("Unauthorized Access Sucka"); } You can call it with this: http://localhost/AspNetWebApi/albums/rpc/ThrowException The default exception handling displays a 500-status response with the serialized exception on the local computer only. When you connect from a remote computer, Web API throws back a 500  HTTP Error with no data returned (IIS then adds its HTML error page). The behavior is configurable in the GlobalConfiguration:GlobalConfiguration .Configuration .IncludeErrorDetailPolicy = IncludeErrorDetailPolicy.Never; If you want more control over your error responses sent from code, you can throw explicit error responses yourself using HttpResponseException. When you throw an HttpResponseException the response parameter is used to generate the output for the Controller action. [HttpGet] public void ThrowError() { var resp = Request.CreateResponse<ApiMessageError>( HttpStatusCode.BadRequest, new ApiMessageError("Your code stinks!")); throw new HttpResponseException(resp); } Throwing an HttpResponseException stops the processing of the controller method and immediately returns the response you passed to the exception. Unlike other Exceptions fired inside of WebAPI, HttpResponseException bypasses the Exception Filters installed and instead just outputs the response you provide. In this case, the serialized ApiMessageError result string is returned in the default serialization format – XML or JSON. You can pass any content to HttpResponseMessage, which includes creating your own exception objects and consistently returning error messages to the client. Here’s a small helper method on the controller that you might use to send exception info back to the client consistently:private void ThrowSafeException(string message, HttpStatusCode statusCode = HttpStatusCode.BadRequest) { var errResponse = Request.CreateResponse<ApiMessageError>(statusCode, new ApiMessageError() { message = message }); throw new HttpResponseException(errResponse); } You can then use it to output any captured errors from code:[HttpGet] public void ThrowErrorSafe() { try { List<string> list = null; list.Add("Rick"); } catch (Exception ex) { ThrowSafeException(ex.Message); } }   Exception Filters Another more global solution is to create an Exception Filter. Filters in Web API provide the ability to pre- and post-process controller method operations. An exception filter looks at all exceptions fired and then optionally creates an HttpResponseMessage result. Listing 8 shows an example of a basic Exception filter implementation.public class UnhandledExceptionFilter : ExceptionFilterAttribute { public override void OnException(HttpActionExecutedContext context) { HttpStatusCode status = HttpStatusCode.InternalServerError; var exType = context.Exception.GetType(); if (exType == typeof(UnauthorizedAccessException)) status = HttpStatusCode.Unauthorized; else if (exType == typeof(ArgumentException)) status = HttpStatusCode.NotFound; var apiError = new ApiMessageError() { message = context.Exception.Message }; // create a new response and attach our ApiError object // which now gets returned on ANY exception result var errorResponse = context.Request.CreateResponse<ApiMessageError>(status, apiError); context.Response = errorResponse; base.OnException(context); } } Exception Filter Attributes can be assigned to an ApiController class like this:[UnhandledExceptionFilter] public class AlbumRpcApiController : ApiController or you can globally assign it to all controllers by adding it to the HTTP Configuration's Filters collection:GlobalConfiguration.Configuration.Filters.Add(new UnhandledExceptionFilter()); The latter is a great way to get global error trapping so that all errors (short of hard IIS errors and explicit HttpResponseException errors) return a valid error response that includes error information in the form of a known-error object. Using a filter like this allows you to throw an exception as you normally would and have your filter create a response in the appropriate output format that the client expects. For example, an AJAX application can on failure expect to see a JSON error result that corresponds to the real error that occurred rather than a 500 error along with HTML error page that IIS throws up. You can even create some custom exceptions so you can differentiate your own exceptions from unhandled system exceptions - you often don't want to display error information from 'unknown' exceptions as they may contain sensitive system information or info that's not generally useful to users of your application/site. This is just one example of how ASP.NET Web API is configurable and extensible. Exception filters are just one example of how you can plug-in into the Web API request flow to modify output. Many more hooks exist and I’ll take a closer look at extensibility in Part 2 of this article in the future. Summary Web API is a big improvement over previous Microsoft REST and AJAX toolkits. The key features to its usefulness are its ease of use with simple controller based logic, familiar MVC-style routing, low configuration impact, extensibility at all levels and tight attention to exposing and making HTTP semantics easily discoverable and easy to use. Although none of the concepts used in Web API are new or radical, Web API combines the best of previous platforms into a single framework that’s highly functional, easy to work with, and extensible to boot. I think that Microsoft has hit a home run with Web API. Related Resources Where does ASP.NET Web API fit? Sample Source Code on GitHub Passing multiple POST parameters to Web API Controller Methods Mapping UrlEncoded POST Values in ASP.NET Web API Creating a JSONP Formatter for ASP.NET Web API Removing the XML Formatter from ASP.NET Web API Applications© Rick Strahl, West Wind Technologies, 2005-2012Posted in Web Api   Tweet !function(d,s,id){var js,fjs=d.getElementsByTagName(s)[0];if(!d.getElementById(id)){js=d.createElement(s);js.id=id;js.src="//platform.twitter.com/widgets.js";fjs.parentNode.insertBefore(js,fjs);}}(document,"script","twitter-wjs"); (function() { var po = document.createElement('script'); po.type = 'text/javascript'; po.async = true; po.src = 'https://apis.google.com/js/plusone.js'; var s = document.getElementsByTagName('script')[0]; s.parentNode.insertBefore(po, s); })();

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• Prevent RDP logon brute force in mikrotik router via winbox

  - by holian

  Masters, I need help, how to config our router to block RDP brute force attacks I would like to set our router to only allow RDP connection from a specified country (our specified IP ranges), plus i need to set up router to block (take ips to black list) and drop brute force attepmst to specified port numbers. I try to set this with changeing the ftp port to rdp port. http://wiki.mikrotik.com/wiki/Bruteforce_login_prevention_%28FTP_%26_SSH Any suggestion tnx. H Current configuration: I try to configure the router via Winbox. I set some NAT rules (from dyndns to local address, rdp port) In the filter rules tab: I'm not sure this configuration should do the trick?! Is the content text "530 login incorrect" is fit for RDP connection to? Because in the tutorial used for filtering FTP connection. How to set router to allow RDP attempts from specified IP ranges? Thank you // New config

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• How would you apply a BIOS update for a Dell M610 blade with VMware ESXi installed?

  - by Guamaniac

  Hello, all. We've got a Dell M610 blade with VMware ESXi 4 installed and we need to update it's BIOS to the latest version. Unfortunately, Dell only makes available a Windows (.exe) and Linux (.bin) versions of the BIOS update program (as well as a bootable DOS floppy version that is too big to fit on a 1.44MB floppy!). We've tried using various "LiveCD" versions of linux distributions but keep running into errors. Anyone out there with experience with Dell blades who could give us a hint or two to get this working? Thanks a lot, in advance. Joe

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• Upgrading from Vista Home Basic to Vista Business

  - by miracle2k

  I have a PC that came with Vista Home Basic, and I now have some need for Remote Desktop, which is not included in Home Basic, so I'd like to upgrade. Now, there is apparently some hack to get Remote Desktop working in Home Premium, and obviously, it's in Ultimate, but really, the Business Edition would be the best fit for us. Unfortunately, Windows Anytime Upgrade does not provide a path from Home Basic to Business. My question is, if I were to buy a standalone Vista Business license, could I use it to do an upgrade from my current Home Basic installation? Would it be simply entering the new license key?

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• Recommendations on laptops - long battery life, slim, Windows 7

  - by molecule

  Hi, I have been looking at a couple of laptops... The most important requirement is long battery life, slim & light, and runs Windows 7. One that seems to fit the bill is the Sony Vaio Z series laptops. They claim to have long battery life, have some really impressive specs (on paper) and a very nice design. They are not on sale where I am yet but has seen/used them? Second would be the Lenovo Thinkpad IBM x301 For business users, Thinkpad seems to be the way to go. I have also considered Dell Alienware M11x but may not be completely appropriate for business use? What would you recommend with a budget of USD1500-2000?

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