Search Results

Search found 4593 results on 184 pages for 'constructor injection'.

Page 172/184 | < Previous Page | 168 169 170 171 172 173 174 175 176 177 178 179  | Next Page >

  • Top things web developers should know about the Visual Studio 2013 release

    - by Jon Galloway
    ASP.NET and Web Tools for Visual Studio 2013 Release NotesASP.NET and Web Tools for Visual Studio 2013 Release NotesSummary for lazy readers: Visual Studio 2013 is now available for download on the Visual Studio site and on MSDN subscriber downloads) Visual Studio 2013 installs side by side with Visual Studio 2012 and supports round-tripping between Visual Studio versions, so you can try it out without committing to a switch Visual Studio 2013 ships with the new version of ASP.NET, which includes ASP.NET MVC 5, ASP.NET Web API 2, Razor 3, Entity Framework 6 and SignalR 2.0 The new releases ASP.NET focuses on One ASP.NET, so core features and web tools work the same across the platform (e.g. adding ASP.NET MVC controllers to a Web Forms application) New core features include new templates based on Bootstrap, a new scaffolding system, and a new identity system Visual Studio 2013 is an incredible editor for web files, including HTML, CSS, JavaScript, Markdown, LESS, Coffeescript, Handlebars, Angular, Ember, Knockdown, etc. Top links: Visual Studio 2013 content on the ASP.NET site are in the standard new releases area: http://www.asp.net/vnext ASP.NET and Web Tools for Visual Studio 2013 Release Notes Short intro videos on the new Visual Studio web editor features from Scott Hanselman and Mads Kristensen Announcing release of ASP.NET and Web Tools for Visual Studio 2013 post on the official .NET Web Development and Tools Blog Scott Guthrie's post: Announcing the Release of Visual Studio 2013 and Great Improvements to ASP.NET and Entity Framework Okay, for those of you who are still with me, let's dig in a bit. Quick web dev notes on downloading and installing Visual Studio 2013 I found Visual Studio 2013 to be a pretty fast install. According to Brian Harry's release post, installing over pre-release versions of Visual Studio is supported.  I've installed the release version over pre-release versions, and it worked fine. If you're only going to be doing web development, you can speed up the install if you just select Web Developer tools. Of course, as a good Microsoft employee, I'll mention that you might also want to install some of those other features, like the Store apps for Windows 8 and the Windows Phone 8.0 SDK, but they do download and install a lot of other stuff (e.g. the Windows Phone SDK sets up Hyper-V and downloads several GB's of VM's). So if you're planning just to do web development for now, you can pick just the Web Developer Tools and install the other stuff later. If you've got a fast internet connection, I recommend using the web installer instead of downloading the ISO. The ISO includes all the features, whereas the web installer just downloads what you're installing. Visual Studio 2013 development settings and color theme When you start up Visual Studio, it'll prompt you to pick some defaults. These are totally up to you -whatever suits your development style - and you can change them later. As I said, these are completely up to you. I recommend either the Web Development or Web Development (Code Only) settings. The only real difference is that Code Only hides the toolbars, and you can switch between them using Tools / Import and Export Settings / Reset. Web Development settings Web Development (code only) settings Usually I've just gone with Web Development (code only) in the past because I just want to focus on the code, although the Standard toolbar does make it easier to switch default web browsers. More on that later. Color theme Sigh. Okay, everyone's got their favorite colors. I alternate between Light and Dark depending on my mood, and I personally like how the low contrast on the window chrome in those themes puts the emphasis on my code rather than the tabs and toolbars. I know some people got pretty worked up over that, though, and wanted the blue theme back. I personally don't like it - it reminds me of ancient versions of Visual Studio that I don't want to think about anymore. So here's the thing: if you install Visual Studio Ultimate, it defaults to Blue. The other versions default to Light. If you use Blue, I won't criticize you - out loud, that is. You can change themes really easily - either Tools / Options / Environment / General, or the smart way: ctrl+q for quick launch, then type Theme and hit enter. Signing in During the first run, you'll be prompted to sign in. You don't have to - you can click the "Not now, maybe later" link at the bottom of that dialog. I recommend signing in, though. It's not hooked in with licensing or tracking the kind of code you write to sell you components. It is doing good things, like  syncing your Visual Studio settings between computers. More about that here. So, you don't have to, but I sure do. Overview of shiny new things in ASP.NET land There are a lot of good new things in ASP.NET. I'll list some of my favorite here, but you can read more on the ASP.NET site. One ASP.NET You've heard us talk about this for a while. The idea is that options are good, but choice can be a burden. When you start a new ASP.NET project, why should you have to make a tough decision - with long-term consequences - about how your application will work? If you want to use ASP.NET Web Forms, but have the option of adding in ASP.NET MVC later, why should that be hard? It's all ASP.NET, right? Ideally, you'd just decide that you want to use ASP.NET to build sites and services, and you could use the appropriate tools (the green blocks below) as you needed them. So, here it is. When you create a new ASP.NET application, you just create an ASP.NET application. Next, you can pick from some templates to get you started... but these are different. They're not "painful decision" templates, they're just some starting pieces. And, most importantly, you can mix and match. I can pick a "mostly" Web Forms template, but include MVC and Web API folders and core references. If you've tried to mix and match in the past, you're probably aware that it was possible, but not pleasant. ASP.NET MVC project files contained special project type GUIDs, so you'd only get controller scaffolding support in a Web Forms project if you manually edited the csproj file. Features in one stack didn't work in others. Project templates were painful choices. That's no longer the case. Hooray! I just did a demo in a presentation last week where I created a new Web Forms + MVC + Web API site, built a model, scaffolded MVC and Web API controllers with EF Code First, add data in the MVC view, viewed it in Web API, then added a GridView to the Web Forms Default.aspx page and bound it to the Model. In about 5 minutes. Sure, it's a simple example, but it's great to be able to share code and features across the whole ASP.NET family. Authentication In the past, authentication was built into the templates. So, for instance, there was an ASP.NET MVC 4 Intranet Project template which created a new ASP.NET MVC 4 application that was preconfigured for Windows Authentication. All of that authentication stuff was built into each template, so they varied between the stacks, and you couldn't reuse them. You didn't see a lot of changes to the authentication options, since they required big changes to a bunch of project templates. Now, the new project dialog includes a common authentication experience. When you hit the Change Authentication button, you get some common options that work the same way regardless of the template or reference settings you've made. These options work on all ASP.NET frameworks, and all hosting environments (IIS, IIS Express, or OWIN for self-host) The default is Individual User Accounts: This is the standard "create a local account, using username / password or OAuth" thing; however, it's all built on the new Identity system. More on that in a second. The one setting that has some configuration to it is Organizational Accounts, which lets you configure authentication using Active Directory, Windows Azure Active Directory, or Office 365. Identity There's a new identity system. We've taken the best parts of the previous ASP.NET Membership and Simple Identity systems, rolled in a lot of feedback and made big enhancements to support important developer concerns like unit testing and extensiblity. I've written long posts about ASP.NET identity, and I'll do it again. Soon. This is not that post. The short version is that I think we've finally got just the right Identity system. Some of my favorite features: There are simple, sensible defaults that work well - you can File / New / Run / Register / Login, and everything works. It supports standard username / password as well as external authentication (OAuth, etc.). It's easy to customize without having to re-implement an entire provider. It's built using pluggable pieces, rather than one large monolithic system. It's built using interfaces like IUser and IRole that allow for unit testing, dependency injection, etc. You can easily add user profile data (e.g. URL, twitter handle, birthday). You just add properties to your ApplicationUser model and they'll automatically be persisted. Complete control over how the identity data is persisted. By default, everything works with Entity Framework Code First, but it's built to support changes from small (modify the schema) to big (use another ORM, store your data in a document database or in the cloud or in XML or in the EXIF data of your desktop background or whatever). It's configured via OWIN. More on OWIN and Katana later, but the fact that it's built using OWIN means it's portable. You can find out more in the Authentication and Identity section of the ASP.NET site (and lots more content will be going up there soon). New Bootstrap based project templates The new project templates are built using Bootstrap 3. Bootstrap (formerly Twitter Bootstrap) is a front-end framework that brings a lot of nice benefits: It's responsive, so your projects will automatically scale to device width using CSS media queries. For example, menus are full size on a desktop browser, but on narrower screens you automatically get a mobile-friendly menu. The built-in Bootstrap styles make your standard page elements (headers, footers, buttons, form inputs, tables etc.) look nice and modern. Bootstrap is themeable, so you can reskin your whole site by dropping in a new Bootstrap theme. Since Bootstrap is pretty popular across the web development community, this gives you a large and rapidly growing variety of templates (free and paid) to choose from. Bootstrap also includes a lot of very useful things: components (like progress bars and badges), useful glyphicons, and some jQuery plugins for tooltips, dropdowns, carousels, etc.). Here's a look at how the responsive part works. When the page is full screen, the menu and header are optimized for a wide screen display: When I shrink the page down (this is all based on page width, not useragent sniffing) the menu turns into a nice mobile-friendly dropdown: For a quick example, I grabbed a new free theme off bootswatch.com. For simple themes, you just need to download the boostrap.css file and replace the /content/bootstrap.css file in your project. Now when I refresh the page, I've got a new theme: Scaffolding The big change in scaffolding is that it's one system that works across ASP.NET. You can create a new Empty Web project or Web Forms project and you'll get the Scaffold context menus. For release, we've got MVC 5 and Web API 2 controllers. We had a preview of Web Forms scaffolding in the preview releases, but they weren't fully baked for RTM. Look for them in a future update, expected pretty soon. This scaffolding system wasn't just changed to work across the ASP.NET frameworks, it's also built to enable future extensibility. That's not in this release, but should also hopefully be out soon. Project Readme page This is a small thing, but I really like it. When you create a new project, you get a Project_Readme.html page that's added to the root of your project and opens in the Visual Studio built-in browser. I love it. A long time ago, when you created a new project we just dumped it on you and left you scratching your head about what to do next. Not ideal. Then we started adding a bunch of Getting Started information to the new project templates. That told you what to do next, but you had to delete all of that stuff out of your website. It doesn't belong there. Not ideal. This is a simple HTML file that's not integrated into your project code at all. You can delete it if you want. But, it shows a lot of helpful links that are current for the project you just created. In the future, if we add new wacky project types, they can create readme docs with specific information on how to do appropriately wacky things. Side note: I really like that they used the internal browser in Visual Studio to show this content rather than popping open an HTML page in the default browser. I hate that. It's annoying. If you're doing that, I hope you'll stop. What if some unnamed person has 40 or 90 tabs saved in their browser session? When you pop open your "Thanks for installing my Visual Studio extension!" page, all eleventy billion tabs start up and I wish I'd never installed your thing. Be like these guys and pop stuff Visual Studio specific HTML docs in the Visual Studio browser. ASP.NET MVC 5 The biggest change with ASP.NET MVC 5 is that it's no longer a separate project type. It integrates well with the rest of ASP.NET. In addition to that and the other common features we've already looked at (Bootstrap templates, Identity, authentication), here's what's new for ASP.NET MVC. Attribute routing ASP.NET MVC now supports attribute routing, thanks to a contribution by Tim McCall, the author of http://attributerouting.net. With attribute routing you can specify your routes by annotating your actions and controllers. This supports some pretty complex, customized routing scenarios, and it allows you to keep your route information right with your controller actions if you'd like. Here's a controller that includes an action whose method name is Hiding, but I've used AttributeRouting to configure it to /spaghetti/with-nesting/where-is-waldo public class SampleController : Controller { [Route("spaghetti/with-nesting/where-is-waldo")] public string Hiding() { return "You found me!"; } } I enable that in my RouteConfig.cs, and I can use that in conjunction with my other MVC routes like this: public class RouteConfig { public static void RegisterRoutes(RouteCollection routes) { routes.IgnoreRoute("{resource}.axd/{*pathInfo}"); routes.MapMvcAttributeRoutes(); routes.MapRoute( name: "Default", url: "{controller}/{action}/{id}", defaults: new { controller = "Home", action = "Index", id = UrlParameter.Optional } ); } } You can read more about Attribute Routing in ASP.NET MVC 5 here. Filter enhancements There are two new additions to filters: Authentication Filters and Filter Overrides. Authentication filters are a new kind of filter in ASP.NET MVC that run prior to authorization filters in the ASP.NET MVC pipeline and allow you to specify authentication logic per-action, per-controller, or globally for all controllers. Authentication filters process credentials in the request and provide a corresponding principal. Authentication filters can also add authentication challenges in response to unauthorized requests. Override filters let you change which filters apply to a given action method or controller. Override filters specify a set of filter types that should not be run for a given scope (action or controller). This allows you to configure filters that apply globally but then exclude certain global filters from applying to specific actions or controllers. ASP.NET Web API 2 ASP.NET Web API 2 includes a lot of new features. Attribute Routing ASP.NET Web API supports the same attribute routing system that's in ASP.NET MVC 5. You can read more about the Attribute Routing features in Web API in this article. OAuth 2.0 ASP.NET Web API picks up OAuth 2.0 support, using security middleware running on OWIN (discussed below). This is great for features like authenticated Single Page Applications. OData Improvements ASP.NET Web API now has full OData support. That required adding in some of the most powerful operators: $select, $expand, $batch and $value. You can read more about OData operator support in this article by Mike Wasson. Lots more There's a huge list of other features, including CORS (cross-origin request sharing), IHttpActionResult, IHttpRequestContext, and more. I think the best overview is in the release notes. OWIN and Katana I've written about OWIN and Katana recently. I'm a big fan. OWIN is the Open Web Interfaces for .NET. It's a spec, like HTML or HTTP, so you can't install OWIN. The benefit of OWIN is that it's a community specification, so anyone who implements it can plug into the ASP.NET stack, either as middleware or as a host. Katana is the Microsoft implementation of OWIN. It leverages OWIN to wire up things like authentication, handlers, modules, IIS hosting, etc., so ASP.NET can host OWIN components and Katana components can run in someone else's OWIN implementation. Howard Dierking just wrote a cool article in MSDN magazine describing Katana in depth: Getting Started with the Katana Project. He had an interesting example showing an OWIN based pipeline which leveraged SignalR, ASP.NET Web API and NancyFx components in the same stack. If this kind of thing makes sense to you, that's great. If it doesn't, don't worry, but keep an eye on it. You're going to see some cool things happen as a result of ASP.NET becoming more and more pluggable. Visual Studio Web Tools Okay, this stuff's just crazy. Visual Studio has been adding some nice web dev features over the past few years, but they've really cranked it up for this release. Visual Studio is by far my favorite code editor for all web files: CSS, HTML, JavaScript, and lots of popular libraries. Stop thinking of Visual Studio as a big editor that you only use to write back-end code. Stop editing HTML and CSS in Notepad (or Sublime, Notepad++, etc.). Visual Studio starts up in under 2 seconds on a modern computer with an SSD. Misspelling HTML attributes or your CSS classes or jQuery or Angular syntax is stupid. It doesn't make you a better developer, it makes you a silly person who wastes time. Browser Link Browser Link is a real-time, two-way connection between Visual Studio and all connected browsers. It's only attached when you're running locally, in debug, but it applies to any and all connected browser, including emulators. You may have seen demos that showed the browsers refreshing based on changes in the editor, and I'll agree that's pretty cool. But it's really just the start. It's a two-way connection, and it's built for extensiblity. That means you can write extensions that push information from your running application (in IE, Chrome, a mobile emulator, etc.) back to Visual Studio. Mads and team have showed off some demonstrations where they enabled edit mode in the browser which updated the source HTML back on the browser. It's also possible to look at how the rendered HTML performs, check for compatibility issues, watch for unused CSS classes, the sky's the limit. New HTML editor The previous HTML editor had a lot of old code that didn't allow for improvements. The team rewrote the HTML editor to take advantage of the new(ish) extensibility features in Visual Studio, which then allowed them to add in all kinds of features - things like CSS Class and ID IntelliSense (so you type style="" and get a list of classes and ID's for your project), smart indent based on how your document is formatted, JavaScript reference auto-sync, etc. Here's a 3 minute tour from Mads Kristensen. The previous HTML editor had a lot of old code that didn't allow for improvements. The team rewrote the HTML editor to take advantage of the new(ish) extensibility features in Visual Studio, which then allowed them to add in all kinds of features - things like CSS Class and ID IntelliSense (so you type style="" and get a list of classes and ID's for your project), smart indent based on how your document is formatted, JavaScript reference auto-sync, etc. Lots more Visual Studio web dev features That's just a sampling - there's a ton of great features for JavaScript editing, CSS editing, publishing, and Page Inspector (which shows real-time rendering of your page inside Visual Studio). Here are some more short videos showing those features. Lots, lots more Okay, that's just a summary, and it's still quite a bit. Head on over to http://asp.net/vnext for more information, and download Visual Studio 2013 now to get started!

    Read the article

  • Mulit-tenant ASP.NET MVC – Controllers

    - by zowens
    Part I – Introduction Part II – Foundation   The time has come to talk about controllers in a multi-tenant ASP.NET MVC architecture. This is actually the most critical design decision you will make when dealing with multi-tenancy with MVC. In my design, I took into account the design goals I mentioned in the introduction about inversion of control and what a tenant is to my design. Be aware that this is only one way to achieve multi-tenant controllers.   The Premise MvcEx (which is a sample written by Rob Ashton) utilizes dynamic controllers. Essentially a controller is “dynamic” in that multiple action results can be placed in different “controllers” with the same name. This approach is a bit too complicated for my design. I wanted to stick with plain old inheritance when dealing with controllers. The basic premise of my controller design is that my main host defines a set of universal controllers. It is the responsibility of the tenant to decide if the tenant would like to utilize these core controllers. This can be done either by straight usage of the controller or inheritance for extension of the functionality defined by the controller. The controller is resolved by a StructureMap container that is attached to the tenant, as discussed in Part II.   Controller Resolution I have been thinking about two different ways to resolve controllers with StructureMap. One way is to use named instances. This is a really easy way to simply pull the controller right out of the container without a lot of fuss. I ultimately chose not to use this approach. The reason for this decision is to ensure that the controllers are named properly. If a controller has a different named instance that the controller type, then the resolution has a significant disconnect and there are no guarantees. The final approach, the one utilized by the sample, is to simply pull all controller types and correlate the type with a controller name. This has a bit of a application start performance disadvantage, but is significantly more approachable for maintainability. For example, if I wanted to go back and add a “ControllerName” attribute, I would just have to change the ControllerFactory to suit my needs.   The Code The container factory that I have built is actually pretty simple. That’s really all we need. The most significant method is the GetControllersFor method. This method makes the model from the Container and determines all the concrete types for IController.  The thing you might notice is that this doesn’t depend on tenants, but rather containers. You could easily use this controller factory for an application that doesn’t utilize multi-tenancy. public class ContainerControllerFactory : IControllerFactory { private readonly ThreadSafeDictionary<IContainer, IDictionary<string, Type>> typeCache; public ContainerControllerFactory(IContainerResolver resolver) { Ensure.Argument.NotNull(resolver, "resolver"); this.ContainerResolver = resolver; this.typeCache = new ThreadSafeDictionary<IContainer, IDictionary<string, Type>>(); } public IContainerResolver ContainerResolver { get; private set; } public virtual IController CreateController(RequestContext requestContext, string controllerName) { var controllerType = this.GetControllerType(requestContext, controllerName); if (controllerType == null) return null; var controller = this.ContainerResolver.Resolve(requestContext).GetInstance(controllerType) as IController; // ensure the action invoker is a ContainerControllerActionInvoker if (controller != null && controller is Controller && !((controller as Controller).ActionInvoker is ContainerControllerActionInvoker)) (controller as Controller).ActionInvoker = new ContainerControllerActionInvoker(this.ContainerResolver); return controller; } public void ReleaseController(IController controller) { if (controller != null && controller is IDisposable) ((IDisposable)controller).Dispose(); } internal static IEnumerable<Type> GetControllersFor(IContainer container) { Ensure.Argument.NotNull(container); return container.Model.InstancesOf<IController>().Select(x => x.ConcreteType).Distinct(); } protected virtual Type GetControllerType(RequestContext requestContext, string controllerName) { Ensure.Argument.NotNull(requestContext, "requestContext"); Ensure.Argument.NotNullOrEmpty(controllerName, "controllerName"); var container = this.ContainerResolver.Resolve(requestContext); var typeDictionary = this.typeCache.GetOrAdd(container, () => GetControllersFor(container).ToDictionary(x => ControllerFriendlyName(x.Name))); Type found = null; if (typeDictionary.TryGetValue(ControllerFriendlyName(controllerName), out found)) return found; return null; } private static string ControllerFriendlyName(string value) { return (value ?? string.Empty).ToLowerInvariant().Without("controller"); } } One thing to note about my implementation is that we do not use namespaces that can be utilized in the default ASP.NET MVC controller factory. This is something that I don’t use and have no desire to implement and test. The reason I am not using namespaces in this situation is because each tenant has its own namespaces and the routing would not make sense in this case.   Because we are using IoC, dependencies are automatically injected into the constructor. For example, a tenant container could implement it’s own IRepository and a controller could be defined in the “main” project. The IRepository from the tenant would be injected into the main project’s controller. This is quite a useful feature.   Again, the source code is on GitHub here.   Up Next Up next is the view resolution. This is a complicated issue, so be prepared. I hope that you have found this series useful. If you have any questions about my implementation so far, send me an email or DM me on Twitter. I have had a lot of great conversations about multi-tenancy so far and I greatly appreciate the feedback!

    Read the article

  • AutoMapper MappingFunction from Source Type of NameValueCollection

    - by REA_ANDREW
    I have had a situation arise today where I need to construct a complex type from a source of a NameValueCollection.  A little while back I submitted a patch for the Agatha Project to include REST (JSON and XML) support for the service contract.  I realized today that as useful as it is, it did not actually support true REST conformance, as REST should support GET so that you can use JSONP from JavaScript directly meaning you can query cross domain services.  My original implementation for POX and JSON used the POST method and this immediately rules out JSONP as from reading, JSONP only works with GET Requests. This then raised another issue.  The current operation contract of Agatha and one of its main benefits is that you can supply an array of Request objects in a single request, limiting the about of server requests you need to make.  Now, at the present time I am thinking that this will not be the case for the REST imlementation but will yield the benefits of the fact that : The same Request objects can be used for SOAP and RST (POX, JSON) The construct of the JavaScript functions will be simpler and more readable It will enable the use of JSONP for cross domain REST Services The current contract for the Agatha WcfRequestProcessor is at time of writing the following: [ServiceContract] public interface IWcfRequestProcessor { [OperationContract(Name = "ProcessRequests")] [ServiceKnownType("GetKnownTypes", typeof(KnownTypeProvider))] [TransactionFlow(TransactionFlowOption.Allowed)] Response[] Process(params Request[] requests); [OperationContract(Name = "ProcessOneWayRequests", IsOneWay = true)] [ServiceKnownType("GetKnownTypes", typeof(KnownTypeProvider))] void ProcessOneWayRequests(params OneWayRequest[] requests); }   My current proposed solution, and at the very early stages of my concept is as follows: [ServiceContract] public interface IWcfRestJsonRequestProcessor { [OperationContract(Name="process")] [ServiceKnownType("GetKnownTypes", typeof(KnownTypeProvider))] [TransactionFlow(TransactionFlowOption.Allowed)] [WebGet(UriTemplate = "process/{name}/{*parameters}", BodyStyle = WebMessageBodyStyle.WrappedResponse, ResponseFormat = WebMessageFormat.Json)] Response[] Process(string name, NameValueCollection parameters); [OperationContract(Name="processoneway",IsOneWay = true)] [ServiceKnownType("GetKnownTypes", typeof(KnownTypeProvider))] [WebGet(UriTemplate = "process-one-way/{name}/{*parameters}", BodyStyle = WebMessageBodyStyle.WrappedResponse, ResponseFormat = WebMessageFormat.Json)] void ProcessOneWayRequests(string name, NameValueCollection parameters); }   Now this part I have not yet implemented, it is the preliminart step which I have developed which will allow me to take the name of the Request Type and the NameValueCollection and construct the complex type which is that of the Request which I can then supply to a nested instance of the original IWcfRequestProcessor  and work as it should normally.  To give an example of some of the urls which you I envisage with this method are: http://www.url.com/service.svc/json/process/getweather/?location=london http://www.url.com/service.svc/json/process/getproductsbycategory/?categoryid=1 http://www.url.om/service.svc/json/process/sayhello/?name=andy Another reason why my direction has gone to a single request for the REST implementation is because of restrictions which are imposed by browsers on the length of the url.  From what I have read this is on average 2000 characters.  I think that this is a very acceptable usage limit in the context of using 1 request, but I do not think this is acceptable for accommodating multiple requests chained together.  I would love to be corrected on that one, I really would but unfortunately from what I have read I have come to the conclusion that this is not the case. The mapping function So, as I say this is just the first pass I have made at this, and I am not overly happy with the try catch for detecting types without default constructors.  I know there is a better way but for the minute, it escapes me.  I would also like to know the correct way for adding mapping functions and not using the anonymous way that I have used.  To achieve this I have used recursion which I am sure is what other mapping function use. As you do have to go as deep as the complex type is. public static object RecurseType(NameValueCollection collection, Type type, string prefix) { try { var returnObject = Activator.CreateInstance(type); foreach (var property in type.GetProperties()) { foreach (var key in collection.AllKeys) { if (String.IsNullOrEmpty(prefix) || key.Length > prefix.Length) { var propertyNameToMatch = String.IsNullOrEmpty(prefix) ? key : key.Substring(property.Name.IndexOf(prefix) + prefix.Length + 1); if (property.Name == propertyNameToMatch) { property.SetValue(returnObject, Convert.ChangeType(collection.Get(key), property.PropertyType), null); } else if(property.GetValue(returnObject,null) == null) { property.SetValue(returnObject, RecurseType(collection, property.PropertyType, String.Concat(prefix, property.PropertyType.Name)), null); } } } } return returnObject; } catch (MissingMethodException) { //Quite a blunt way of dealing with Types without default constructor return null; } }   Another thing is performance, I have not measured this in anyway, it is as I say the first pass, so I hope this can be the start of a more perfected implementation.  I tested this out with a complex type of three levels, there is no intended logical meaning to the properties, they are simply for the purposes of example.  You could call this a spiking session, as from here on in, now I know what I am building I would take a more TDD approach.  OK, purists, why did I not do this from the start, well I didn’t, this was a brain dump and now I know what I am building I can. The console test and how I used with AutoMapper is as follows: static void Main(string[] args) { var collection = new NameValueCollection(); collection.Add("Name", "Andrew Rea"); collection.Add("Number", "1"); collection.Add("AddressLine1", "123 Street"); collection.Add("AddressNumber", "2"); collection.Add("AddressPostCodeCountry", "United Kingdom"); collection.Add("AddressPostCodeNumber", "3"); AutoMapper.Mapper.CreateMap<NameValueCollection, Person>() .ConvertUsing(x => { return(Person) RecurseType(x, typeof(Person), null); }); var person = AutoMapper.Mapper.Map<NameValueCollection, Person>(collection); Console.WriteLine(person.Name); Console.WriteLine(person.Number); Console.WriteLine(person.Address.Line1); Console.WriteLine(person.Address.Number); Console.WriteLine(person.Address.PostCode.Country); Console.WriteLine(person.Address.PostCode.Number); Console.ReadLine(); }   Notice the convention that I am using and that this method requires you do use.  Each property is prefixed with the constructed name of its parents combined.  This is the convention used by AutoMapper and it makes sense. I can also think of other uses for this including using with ASP.NET MVC ModelBinders for creating a complex type from the QueryString which is itself is a NameValueCollection. Hope this is of some help to people and I would welcome any code reviews you could give me. References: Agatha : http://code.google.com/p/agatha-rrsl/ AutoMapper : http://automapper.codeplex.com/   Cheers for now, Andrew   P.S. I will have the proposed solution for a more complete REST implementation for AGATHA very soon. 

    Read the article

  • MvcExtensions – Bootstrapping

    - by kazimanzurrashid
    When you create a new ASP.NET MVC application you will find that the global.asax contains the following lines: namespace MvcApplication1 { // Note: For instructions on enabling IIS6 or IIS7 classic mode, // visit http://go.microsoft.com/?LinkId=9394801 public class MvcApplication : System.Web.HttpApplication { public static void RegisterRoutes(RouteCollection routes) { routes.IgnoreRoute("{resource}.axd/{*pathInfo}"); routes.MapRoute( "Default", // Route name "{controller}/{action}/{id}", // URL with parameters new { controller = "Home", action = "Index", id = UrlParameter.Optional } // Parameter defaults ); } protected void Application_Start() { AreaRegistration.RegisterAllAreas(); RegisterRoutes(RouteTable.Routes); } } } As the application grows, there are quite a lot of plumbing code gets into the global.asax which quickly becomes a design smell. Lets take a quick look at the code of one of the open source project that I recently visited: public static void RegisterRoutes(RouteCollection routes) { routes.IgnoreRoute("{resource}.axd/{*pathInfo}"); routes.MapRoute("Default","{controller}/{action}/{id}", new { controller = "Home", action = "Index", id = "" }); } protected override void OnApplicationStarted() { Error += OnError; EndRequest += OnEndRequest; var settings = new SparkSettings() .AddNamespace("System") .AddNamespace("System.Collections.Generic") .AddNamespace("System.Web.Mvc") .AddNamespace("System.Web.Mvc.Html") .AddNamespace("MvcContrib.FluentHtml") .AddNamespace("********") .AddNamespace("********.Web") .SetPageBaseType("ApplicationViewPage") .SetAutomaticEncoding(true); #if DEBUG settings.SetDebug(true); #endif var viewFactory = new SparkViewFactory(settings); ViewEngines.Engines.Add(viewFactory); #if !DEBUG PrecompileViews(viewFactory); #endif RegisterAllControllersIn("********.Web"); log4net.Config.XmlConfigurator.Configure(); RegisterRoutes(RouteTable.Routes); Factory.Load(new Components.WebDependencies()); ModelBinders.Binders.DefaultBinder = new Binders.GenericBinderResolver(Factory.TryGet<IModelBinder>); ValidatorConfiguration.Initialize("********"); HtmlValidationExtensions.Initialize(ValidatorConfiguration.Rules); } private void OnEndRequest(object sender, System.EventArgs e) { if (((HttpApplication)sender).Context.Handler is MvcHandler) { CreateKernel().Get<ISessionSource>().Close(); } } private void OnError(object sender, System.EventArgs e) { CreateKernel().Get<ISessionSource>().Close(); } protected override IKernel CreateKernel() { return Factory.Kernel; } private static void PrecompileViews(SparkViewFactory viewFactory) { var batch = new SparkBatchDescriptor(); batch.For<HomeController>().For<ManageController>(); viewFactory.Precompile(batch); } As you can see there are quite a few of things going on in the above code, Registering the ViewEngine, Compiling the Views, Registering the Routes/Controllers/Model Binders, Settings up Logger, Validations and as you can imagine the more it becomes complex the more things will get added in the application start. One of the goal of the MVCExtensions is to reduce the above design smell. Instead of writing all the plumbing code in the application start, it contains BootstrapperTask to register individual services. Out of the box, it contains BootstrapperTask to register Controllers, Controller Factory, Action Invoker, Action Filters, Model Binders, Model Metadata/Validation Providers, ValueProvideraFactory, ViewEngines etc and it is intelligent enough to automatically detect the above types and register into the ASP.NET MVC Framework. Other than the built-in tasks you can create your own custom task which will be automatically executed when the application starts. When the BootstrapperTasks are in action you will find the global.asax pretty much clean like the following: public class MvcApplication : UnityMvcApplication { public void ErrorLog_Filtering(object sender, ExceptionFilterEventArgs e) { Check.Argument.IsNotNull(e, "e"); HttpException exception = e.Exception.GetBaseException() as HttpException; if ((exception != null) && (exception.GetHttpCode() == (int)HttpStatusCode.NotFound)) { e.Dismiss(); } } } The above code is taken from my another open source project Shrinkr, as you can see the global.asax is longer cluttered with any plumbing code. One special thing you have noticed that it is inherited from the UnityMvcApplication rather than regular HttpApplication. There are separate version of this class for each IoC Container like NinjectMvcApplication, StructureMapMvcApplication etc. Other than executing the built-in tasks, the Shrinkr also has few custom tasks which gets executed when the application starts. For example, when the application starts, we want to ensure that the default users (which is specified in the web.config) are created. The following is the custom task that is used to create those default users: public class CreateDefaultUsers : BootstrapperTask { protected override TaskContinuation ExecuteCore(IServiceLocator serviceLocator) { IUserRepository userRepository = serviceLocator.GetInstance<IUserRepository>(); IUnitOfWork unitOfWork = serviceLocator.GetInstance<IUnitOfWork>(); IEnumerable<User> users = serviceLocator.GetInstance<Settings>().DefaultUsers; bool shouldCommit = false; foreach (User user in users) { if (userRepository.GetByName(user.Name) == null) { user.AllowApiAccess(ApiSetting.InfiniteLimit); userRepository.Add(user); shouldCommit = true; } } if (shouldCommit) { unitOfWork.Commit(); } return TaskContinuation.Continue; } } There are several other Tasks in the Shrinkr that we are also using which you will find in that project. To create a custom bootstrapping task you have create a new class which either implements the IBootstrapperTask interface or inherits from the abstract BootstrapperTask class, I would recommend to start with the BootstrapperTask as it already has the required code that you have to write in case if you choose the IBootstrapperTask interface. As you can see in the above code we are overriding the ExecuteCore to create the default users, the MVCExtensions is responsible for populating the  ServiceLocator prior calling this method and in this method we are using the service locator to get the dependencies that are required to create the users (I will cover the custom dependencies registration in the next post). Once the users are created, we are returning a special enum, TaskContinuation as the return value, the TaskContinuation can have three values Continue (default), Skip and Break. The reason behind of having this enum is, in some  special cases you might want to skip the next task in the chain or break the complete chain depending upon the currently running task, in those cases you will use the other two values instead of the Continue. The last thing I want to cover in the bootstrapping task is the Order. By default all the built-in tasks as well as newly created task order is set to the DefaultOrder(a static property), in some special cases you might want to execute it before/after all the other tasks, in those cases you will assign the Order in the Task constructor. For Example, in Shrinkr, we want to run few background services when the all the tasks are executed, so we assigned the order as DefaultOrder + 1. Here is the code of that Task: public class ConfigureBackgroundServices : BootstrapperTask { private IEnumerable<IBackgroundService> backgroundServices; public ConfigureBackgroundServices() { Order = DefaultOrder + 1; } protected override TaskContinuation ExecuteCore(IServiceLocator serviceLocator) { backgroundServices = serviceLocator.GetAllInstances<IBackgroundService>().ToList(); backgroundServices.Each(service => service.Start()); return TaskContinuation.Continue; } protected override void DisposeCore() { backgroundServices.Each(service => service.Stop()); } } That’s it for today, in the next post I will cover the custom service registration, so stay tuned.

    Read the article

  • 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.

    Read the article

  • Microsoft TypeScript : A Typed Superset of JavaScript

    - by shiju
    JavaScript is gradually becoming a ubiquitous programming language for the web, and the popularity of JavaScript is increasing day by day. Earlier, JavaScript was just a language for browser. But now, we can write JavaScript apps for browser, server and mobile. With the advent of Node.js, you can build scalable, high performance apps on the server with JavaScript. But many developers, especially developers who are working with static type languages, are hating the JavaScript language due to the lack of structuring and the maintainability problems of JavaScript. Microsoft TypeScript is trying to solve some problems of JavaScript when we are building scalable JavaScript apps. Microsoft TypeScript TypeScript is Microsoft's solution for writing scalable JavaScript programs with the help of Static Types, Interfaces, Modules and Classes along with greater tooling support. TypeScript is a typed superset of JavaScript that compiles to plain JavaScript. This would be more productive for developers who are coming from static type languages. You can write scalable JavaScript  apps in TypeScript with more productive and more maintainable manner, and later you can compiles to plain JavaScript which will be run on any browser and any OS. TypeScript will work with browser based JavaScript apps and JavaScript apps that following CommonJS specification. You can use TypeScript for building HTML 5 apps, Node.JS apps, WinRT apps. TypeScript is providing better tooling support with Visual Studio, Sublime Text, Vi, Emacs. Microsoft has open sourced its TypeScript languages on CodePlex at http://typescript.codeplex.com/    Install TypeScript You can install TypeScript compiler as a Node.js package via the NPM or you can install as a Visual Studio 2012 plug-in which will enable you better tooling support within the Visual Studio IDE. Since TypeScript is distributed as a Node.JS package, and it can be installed on other OS such as Linux and MacOS. The following command will install TypeScript compiler via an npm package for node.js npm install –g typescript TypeScript provides a Visual Studio 2012 plug-in as MSI file which will install TypeScript and also provides great tooling support within the Visual Studio, that lets the developers to write TypeScript apps with greater productivity and better maintainability. You can download the Visual Studio plug-in from here Building JavaScript  apps with TypeScript You can write typed version of JavaScript programs with TypeScript and then compiles it to plain JavaScript code. The beauty of the TypeScript is that it is already JavaScript and normal JavaScript programs are valid TypeScript programs, which means that you can write normal  JavaScript code and can use typed version of JavaScript whenever you want. TypeScript files are using extension .ts and this will be compiled using a compiler named tsc. The following is a sample program written in  TypeScript greeter.ts 1: class Greeter { 2: greeting: string; 3: constructor (message: string) { 4: this.greeting = message; 5: } 6: greet() { 7: return "Hello, " + this.greeting; 8: } 9: } 10:   11: var greeter = new Greeter("world"); 12:   13: var button = document.createElement('button') 14: button.innerText = "Say Hello" 15: button.onclick = function() { 16: alert(greeter.greet()) 17: } 18:   19: document.body.appendChild(button) .csharpcode, .csharpcode pre { font-size: small; color: black; font-family: consolas, "Courier New", courier, monospace; background-color: #ffffff; /*white-space: pre;*/ } .csharpcode pre { margin: 0em; } .csharpcode .rem { color: #008000; } .csharpcode .kwrd { color: #0000ff; } .csharpcode .str { color: #006080; } .csharpcode .op { color: #0000c0; } .csharpcode .preproc { color: #cc6633; } .csharpcode .asp { background-color: #ffff00; } .csharpcode .html { color: #800000; } .csharpcode .attr { color: #ff0000; } .csharpcode .alt { background-color: #f4f4f4; width: 100%; margin: 0em; } .csharpcode .lnum { color: #606060; } The above program is compiling with the TypeScript compiler as shown in the below picture The TypeScript compiler will generate a JavaScript file after compiling the TypeScript program. If your TypeScript programs having any reference to other TypeScript files, it will automatically generate JavaScript files for the each referenced files. The following code block shows the compiled version of plain JavaScript  for the above greeter.ts greeter.js 1: var Greeter = (function () { 2: function Greeter(message) { 3: this.greeting = message; 4: } 5: Greeter.prototype.greet = function () { 6: return "Hello, " + this.greeting; 7: }; 8: return Greeter; 9: })(); 10: var greeter = new Greeter("world"); 11: var button = document.createElement('button'); 12: button.innerText = "Say Hello"; 13: button.onclick = function () { 14: alert(greeter.greet()); 15: }; 16: document.body.appendChild(button); .csharpcode, .csharpcode pre { font-size: small; color: black; font-family: consolas, "Courier New", courier, monospace; background-color: #ffffff; /*white-space: pre;*/ } .csharpcode pre { margin: 0em; } .csharpcode .rem { color: #008000; } .csharpcode .kwrd { color: #0000ff; } .csharpcode .str { color: #006080; } .csharpcode .op { color: #0000c0; } .csharpcode .preproc { color: #cc6633; } .csharpcode .asp { background-color: #ffff00; } .csharpcode .html { color: #800000; } .csharpcode .attr { color: #ff0000; } .csharpcode .alt { background-color: #f4f4f4; width: 100%; margin: 0em; } .csharpcode .lnum { color: #606060; } Tooling Support with Visual Studio TypeScript is providing a plug-in for Visual Studio which will provide an excellent support for writing TypeScript  programs within the Visual Studio. The following screen shot shows the Visual Studio template for TypeScript apps   The following are the few screen shots of Visual Studio IDE for TypeScript apps. Summary TypeScript is Microsoft's solution for writing scalable JavaScript apps which will solve lot of problems involved in larger JavaScript apps. I hope that this solution will attract lot of developers who are really looking for writing maintainable structured code in JavaScript, without losing any productivity. TypeScript lets developers to write JavaScript apps with the help of Static Types, Interfaces, Modules and Classes and also providing better productivity. I am a passionate developer on Node.JS and would definitely try to use TypeScript for building Node.JS apps on the Windows Azure cloud. I am really excited about to writing Node.JS apps by using TypeScript, from my favorite development IDE Visual Studio. You can follow me on twitter at @shijucv

    Read the article

  • Toorcon14

    - by danx
    Toorcon 2012 Information Security Conference San Diego, CA, http://www.toorcon.org/ Dan Anderson, October 2012 It's almost Halloween, and we all know what that means—yes, of course, it's time for another Toorcon Conference! Toorcon is an annual conference for people interested in computer security. This includes the whole range of hackers, computer hobbyists, professionals, security consultants, press, law enforcement, prosecutors, FBI, etc. We're at Toorcon 14—see earlier blogs for some of the previous Toorcon's I've attended (back to 2003). This year's "con" was held at the Westin on Broadway in downtown San Diego, California. The following are not necessarily my views—I'm just the messenger—although I could have misquoted or misparaphrased the speakers. Also, I only reviewed some of the talks, below, which I attended and interested me. MalAndroid—the Crux of Android Infections, Aditya K. Sood Programming Weird Machines with ELF Metadata, Rebecca "bx" Shapiro Privacy at the Handset: New FCC Rules?, Valkyrie Hacking Measured Boot and UEFI, Dan Griffin You Can't Buy Security: Building the Open Source InfoSec Program, Boris Sverdlik What Journalists Want: The Investigative Reporters' Perspective on Hacking, Dave Maas & Jason Leopold Accessibility and Security, Anna Shubina Stop Patching, for Stronger PCI Compliance, Adam Brand McAfee Secure & Trustmarks — a Hacker's Best Friend, Jay James & Shane MacDougall MalAndroid—the Crux of Android Infections Aditya K. Sood, IOActive, Michigan State PhD candidate Aditya talked about Android smartphone malware. There's a lot of old Android software out there—over 50% Gingerbread (2.3.x)—and most have unpatched vulnerabilities. Of 9 Android vulnerabilities, 8 have known exploits (such as the old Gingerbread Global Object Table exploit). Android protection includes sandboxing, security scanner, app permissions, and screened Android app market. The Android permission checker has fine-grain resource control, policy enforcement. Android static analysis also includes a static analysis app checker (bouncer), and a vulnerablity checker. What security problems does Android have? User-centric security, which depends on the user to grant permission and make smart decisions. But users don't care or think about malware (the're not aware, not paranoid). All they want is functionality, extensibility, mobility Android had no "proper" encryption before Android 3.0 No built-in protection against social engineering and web tricks Alternative Android app markets are unsafe. Simply visiting some markets can infect Android Aditya classified Android Malware types as: Type A—Apps. These interact with the Android app framework. For example, a fake Netflix app. Or Android Gold Dream (game), which uploads user files stealthy manner to a remote location. Type K—Kernel. Exploits underlying Linux libraries or kernel Type H—Hybrid. These use multiple layers (app framework, libraries, kernel). These are most commonly used by Android botnets, which are popular with Chinese botnet authors What are the threats from Android malware? These incude leak info (contacts), banking fraud, corporate network attacks, malware advertising, malware "Hackivism" (the promotion of social causes. For example, promiting specific leaders of the Tunisian or Iranian revolutions. Android malware is frequently "masquerated". That is, repackaged inside a legit app with malware. To avoid detection, the hidden malware is not unwrapped until runtime. The malware payload can be hidden in, for example, PNG files. Less common are Android bootkits—there's not many around. What they do is hijack the Android init framework—alteering system programs and daemons, then deletes itself. For example, the DKF Bootkit (China). Android App Problems: no code signing! all self-signed native code execution permission sandbox — all or none alternate market places no robust Android malware detection at network level delayed patch process Programming Weird Machines with ELF Metadata Rebecca "bx" Shapiro, Dartmouth College, NH https://github.com/bx/elf-bf-tools @bxsays on twitter Definitions. "ELF" is an executable file format used in linking and loading executables (on UNIX/Linux-class machines). "Weird machine" uses undocumented computation sources (I think of them as unintended virtual machines). Some examples of "weird machines" are those that: return to weird location, does SQL injection, corrupts the heap. Bx then talked about using ELF metadata as (an uintended) "weird machine". Some ELF background: A compiler takes source code and generates a ELF object file (hello.o). A static linker makes an ELF executable from the object file. A runtime linker and loader takes ELF executable and loads and relocates it in memory. The ELF file has symbols to relocate functions and variables. ELF has two relocation tables—one at link time and another one at loading time: .rela.dyn (link time) and .dynsym (dynamic table). GOT: Global Offset Table of addresses for dynamically-linked functions. PLT: Procedure Linkage Tables—works with GOT. The memory layout of a process (not the ELF file) is, in order: program (+ heap), dynamic libraries, libc, ld.so, stack (which includes the dynamic table loaded into memory) For ELF, the "weird machine" is found and exploited in the loader. ELF can be crafted for executing viruses, by tricking runtime into executing interpreted "code" in the ELF symbol table. One can inject parasitic "code" without modifying the actual ELF code portions. Think of the ELF symbol table as an "assembly language" interpreter. It has these elements: instructions: Add, move, jump if not 0 (jnz) Think of symbol table entries as "registers" symbol table value is "contents" immediate values are constants direct values are addresses (e.g., 0xdeadbeef) move instruction: is a relocation table entry add instruction: relocation table "addend" entry jnz instruction: takes multiple relocation table entries The ELF weird machine exploits the loader by relocating relocation table entries. The loader will go on forever until told to stop. It stores state on stack at "end" and uses IFUNC table entries (containing function pointer address). The ELF weird machine, called "Brainfu*k" (BF) has: 8 instructions: pointer inc, dec, inc indirect, dec indirect, jump forward, jump backward, print. Three registers - 3 registers Bx showed example BF source code that implemented a Turing machine printing "hello, world". More interesting was the next demo, where bx modified ping. Ping runs suid as root, but quickly drops privilege. BF modified the loader to disable the library function call dropping privilege, so it remained as root. Then BF modified the ping -t argument to execute the -t filename as root. It's best to show what this modified ping does with an example: $ whoami bx $ ping localhost -t backdoor.sh # executes backdoor $ whoami root $ The modified code increased from 285948 bytes to 290209 bytes. A BF tool compiles "executable" by modifying the symbol table in an existing ELF executable. The tool modifies .dynsym and .rela.dyn table, but not code or data. Privacy at the Handset: New FCC Rules? "Valkyrie" (Christie Dudley, Santa Clara Law JD candidate) Valkyrie talked about mobile handset privacy. Some background: Senator Franken (also a comedian) became alarmed about CarrierIQ, where the carriers track their customers. Franken asked the FCC to find out what obligations carriers think they have to protect privacy. The carriers' response was that they are doing just fine with self-regulation—no worries! Carriers need to collect data, such as missed calls, to maintain network quality. But carriers also sell data for marketing. Verizon sells customer data and enables this with a narrow privacy policy (only 1 month to opt out, with difficulties). The data sold is not individually identifiable and is aggregated. But Verizon recommends, as an aggregation workaround to "recollate" data to other databases to identify customers indirectly. The FCC has regulated telephone privacy since 1934 and mobile network privacy since 2007. Also, the carriers say mobile phone privacy is a FTC responsibility (not FCC). FTC is trying to improve mobile app privacy, but FTC has no authority over carrier / customer relationships. As a side note, Apple iPhones are unique as carriers have extra control over iPhones they don't have with other smartphones. As a result iPhones may be more regulated. Who are the consumer advocates? Everyone knows EFF, but EPIC (Electrnic Privacy Info Center), although more obsecure, is more relevant. What to do? Carriers must be accountable. Opt-in and opt-out at any time. Carriers need incentive to grant users control for those who want it, by holding them liable and responsible for breeches on their clock. Location information should be added current CPNI privacy protection, and require "Pen/trap" judicial order to obtain (and would still be a lower standard than 4th Amendment). Politics are on a pro-privacy swing now, with many senators and the Whitehouse. There will probably be new regulation soon, and enforcement will be a problem, but consumers will still have some benefit. Hacking Measured Boot and UEFI Dan Griffin, JWSecure, Inc., Seattle, @JWSdan Dan talked about hacking measured UEFI boot. First some terms: UEFI is a boot technology that is replacing BIOS (has whitelisting and blacklisting). UEFI protects devices against rootkits. TPM - hardware security device to store hashs and hardware-protected keys "secure boot" can control at firmware level what boot images can boot "measured boot" OS feature that tracks hashes (from BIOS, boot loader, krnel, early drivers). "remote attestation" allows remote validation and control based on policy on a remote attestation server. Microsoft pushing TPM (Windows 8 required), but Google is not. Intel TianoCore is the only open source for UEFI. Dan has Measured Boot Tool at http://mbt.codeplex.com/ with a demo where you can also view TPM data. TPM support already on enterprise-class machines. UEFI Weaknesses. UEFI toolkits are evolving rapidly, but UEFI has weaknesses: assume user is an ally trust TPM implicitly, and attached to computer hibernate file is unprotected (disk encryption protects against this) protection migrating from hardware to firmware delays in patching and whitelist updates will UEFI really be adopted by the mainstream (smartphone hardware support, bank support, apathetic consumer support) You Can't Buy Security: Building the Open Source InfoSec Program Boris Sverdlik, ISDPodcast.com co-host Boris talked about problems typical with current security audits. "IT Security" is an oxymoron—IT exists to enable buiness, uptime, utilization, reporting, but don't care about security—IT has conflict of interest. There's no Magic Bullet ("blinky box"), no one-size-fits-all solution (e.g., Intrusion Detection Systems (IDSs)). Regulations don't make you secure. The cloud is not secure (because of shared data and admin access). Defense and pen testing is not sexy. Auditors are not solution (security not a checklist)—what's needed is experience and adaptability—need soft skills. Step 1: First thing is to Google and learn the company end-to-end before you start. Get to know the management team (not IT team), meet as many people as you can. Don't use arbitrary values such as CISSP scores. Quantitive risk assessment is a myth (e.g. AV*EF-SLE). Learn different Business Units, legal/regulatory obligations, learn the business and where the money is made, verify company is protected from script kiddies (easy), learn sensitive information (IP, internal use only), and start with low-hanging fruit (customer service reps and social engineering). Step 2: Policies. Keep policies short and relevant. Generic SANS "security" boilerplate policies don't make sense and are not followed. Focus on acceptable use, data usage, communications, physical security. Step 3: Implementation: keep it simple stupid. Open source, although useful, is not free (implementation cost). Access controls with authentication & authorization for local and remote access. MS Windows has it, otherwise use OpenLDAP, OpenIAM, etc. Application security Everyone tries to reinvent the wheel—use existing static analysis tools. Review high-risk apps and major revisions. Don't run different risk level apps on same system. Assume host/client compromised and use app-level security control. Network security VLAN != segregated because there's too many workarounds. Use explicit firwall rules, active and passive network monitoring (snort is free), disallow end user access to production environment, have a proxy instead of direct Internet access. Also, SSL certificates are not good two-factor auth and SSL does not mean "safe." Operational Controls Have change, patch, asset, & vulnerability management (OSSI is free). For change management, always review code before pushing to production For logging, have centralized security logging for business-critical systems, separate security logging from administrative/IT logging, and lock down log (as it has everything). Monitor with OSSIM (open source). Use intrusion detection, but not just to fulfill a checkbox: build rules from a whitelist perspective (snort). OSSEC has 95% of what you need. Vulnerability management is a QA function when done right: OpenVas and Seccubus are free. Security awareness The reality is users will always click everything. Build real awareness, not compliance driven checkbox, and have it integrated into the culture. Pen test by crowd sourcing—test with logging COSSP http://www.cossp.org/ - Comprehensive Open Source Security Project What Journalists Want: The Investigative Reporters' Perspective on Hacking Dave Maas, San Diego CityBeat Jason Leopold, Truthout.org The difference between hackers and investigative journalists: For hackers, the motivation varies, but method is same, technological specialties. For investigative journalists, it's about one thing—The Story, and they need broad info-gathering skills. J-School in 60 Seconds: Generic formula: Person or issue of pubic interest, new info, or angle. Generic criteria: proximity, prominence, timeliness, human interest, oddity, or consequence. Media awareness of hackers and trends: journalists becoming extremely aware of hackers with congressional debates (privacy, data breaches), demand for data-mining Journalists, use of coding and web development for Journalists, and Journalists busted for hacking (Murdock). Info gathering by investigative journalists include Public records laws. Federal Freedom of Information Act (FOIA) is good, but slow. California Public Records Act is a lot stronger. FOIA takes forever because of foot-dragging—it helps to be specific. Often need to sue (especially FBI). CPRA is faster, and requests can be vague. Dumps and leaks (a la Wikileaks) Journalists want: leads, protecting ourselves, our sources, and adapting tools for news gathering (Google hacking). Anonomity is important to whistleblowers. They want no digital footprint left behind (e.g., email, web log). They don't trust encryption, want to feel safe and secure. Whistleblower laws are very weak—there's no upside for whistleblowers—they have to be very passionate to do it. Accessibility and Security or: How I Learned to Stop Worrying and Love the Halting Problem Anna Shubina, Dartmouth College Anna talked about how accessibility and security are related. Accessibility of digital content (not real world accessibility). mostly refers to blind users and screenreaders, for our purpose. Accessibility is about parsing documents, as are many security issues. "Rich" executable content causes accessibility to fail, and often causes security to fail. For example MS Word has executable format—it's not a document exchange format—more dangerous than PDF or HTML. Accessibility is often the first and maybe only sanity check with parsing. They have no choice because someone may want to read what you write. Google, for example, is very particular about web browser you use and are bad at supporting other browsers. Uses JavaScript instead of links, often requiring mouseover to display content. PDF is a security nightmare. Executible format, embedded flash, JavaScript, etc. 15 million lines of code. Google Chrome doesn't handle PDF correctly, causing several security bugs. PDF has an accessibility checker and PDF tagging, to help with accessibility. But no PDF checker checks for incorrect tags, untagged content, or validates lists or tables. None check executable content at all. The "Halting Problem" is: can one decide whether a program will ever stop? The answer, in general, is no (Rice's theorem). The same holds true for accessibility checkers. Language-theoretic Security says complicated data formats are hard to parse and cannot be solved due to the Halting Problem. W3C Web Accessibility Guidelines: "Perceivable, Operable, Understandable, Robust" Not much help though, except for "Robust", but here's some gems: * all information should be parsable (paraphrasing) * if not parsable, cannot be converted to alternate formats * maximize compatibility in new document formats Executible webpages are bad for security and accessibility. They say it's for a better web experience. But is it necessary to stuff web pages with JavaScript for a better experience? A good example is The Drudge Report—it has hand-written HTML with no JavaScript, yet drives a lot of web traffic due to good content. A bad example is Google News—hidden scrollbars, guessing user input. Solutions: Accessibility and security problems come from same source Expose "better user experience" myth Keep your corner of Internet parsable Remember "Halting Problem"—recognize false solutions (checking and verifying tools) Stop Patching, for Stronger PCI Compliance Adam Brand, protiviti @adamrbrand, http://www.picfun.com/ Adam talked about PCI compliance for retail sales. Take an example: for PCI compliance, 50% of Brian's time (a IT guy), 960 hours/year was spent patching POSs in 850 restaurants. Often applying some patches make no sense (like fixing a browser vulnerability on a server). "Scanner worship" is overuse of vulnerability scanners—it gives a warm and fuzzy and it's simple (red or green results—fix reds). Scanners give a false sense of security. In reality, breeches from missing patches are uncommon—more common problems are: default passwords, cleartext authentication, misconfiguration (firewall ports open). Patching Myths: Myth 1: install within 30 days of patch release (but PCI §6.1 allows a "risk-based approach" instead). Myth 2: vendor decides what's critical (also PCI §6.1). But §6.2 requires user ranking of vulnerabilities instead. Myth 3: scan and rescan until it passes. But PCI §11.2.1b says this applies only to high-risk vulnerabilities. Adam says good recommendations come from NIST 800-40. Instead use sane patching and focus on what's really important. From NIST 800-40: Proactive: Use a proactive vulnerability management process: use change control, configuration management, monitor file integrity. Monitor: start with NVD and other vulnerability alerts, not scanner results. Evaluate: public-facing system? workstation? internal server? (risk rank) Decide:on action and timeline Test: pre-test patches (stability, functionality, rollback) for change control Install: notify, change control, tickets McAfee Secure & Trustmarks — a Hacker's Best Friend Jay James, Shane MacDougall, Tactical Intelligence Inc., Canada "McAfee Secure Trustmark" is a website seal marketed by McAfee. A website gets this badge if they pass their remote scanning. The problem is a removal of trustmarks act as flags that you're vulnerable. Easy to view status change by viewing McAfee list on website or on Google. "Secure TrustGuard" is similar to McAfee. Jay and Shane wrote Perl scripts to gather sites from McAfee and search engines. If their certification image changes to a 1x1 pixel image, then they are longer certified. Their scripts take deltas of scans to see what changed daily. The bottom line is change in TrustGuard status is a flag for hackers to attack your site. Entire idea of seals is silly—you're raising a flag saying if you're vulnerable.

    Read the article

  • Multi-tenant ASP.NET MVC - Views

    - by zowens
    Part I – Introduction Part II – Foundation Part III – Controllers   So far we have covered the basic premise of tenants and how they will be delegated. Now comes a big issue with multi-tenancy, the views. In some applications, you will not have to override views for each tenant. However, one of my requirements is to add extra views (and controller actions) along with overriding views from the core structure. This presents a bit of a problem in locating views for each tenant request. I have chosen quite an opinionated approach at the present but will coming back to the “views” issue in a later post. What’s the deal? The path I’ve chosen is to use precompiled Spark views. I really love Spark View Engine and was planning on using it in my project anyways. However, I ran across a really neat aspect of the source when I was having a look under the hood. There’s an easy way to hook in embedded views from your project. There are solutions that provide this, but they implement a special Virtual Path Provider. While I think this is a great solution, I would rather just have Spark take care of the view resolution. The magic actually happens during the compilation of the views into a bin-deployable DLL. After the views are compiled, the are simply pulled out of the views DLL. Each tenant has its own views DLL that just has “.Views” appended after the assembly name as a convention. The list of reasons for this approach are quite long. The primary motivation is performance. I’ve had quite a few performance issues in the past and I would like to increase my application’s performance in any way that I can. My customized build of Spark removes insignificant whitespace from the HTML output so I can some some bandwidth and load time without having to deal with whitespace removal at runtime.   How to setup Tenants for the Host In the source, I’ve provided a single tenant as a sample (Sample1). This will serve as a template for subsequent tenants in your application. The first step is to add a “PostBuildStep” installer into the project. I’ve defined one in the source that will eventually change as we focus more on the construction of dependency containers. The next step is to tell the project to run the installer and copy the DLL output to a folder in the host that will pick up as a tenant. Here’s the code that will achieve it (this belongs in Post-build event command line field in the Build Events tab of settings) %systemroot%\Microsoft.NET\Framework\v4.0.30319\installutil "$(TargetPath)" copy /Y "$(TargetDir)$(TargetName)*.dll" "$(SolutionDir)Web\Tenants\" copy /Y "$(TargetDir)$(TargetName)*.pdb" "$(SolutionDir)Web\Tenants\" The DLLs with a name starting with the target assembly name will be copied to the “Tenants” folder in the web project. This means something like MultiTenancy.Tenants.Sample1.dll and MultiTenancy.Tenants.Sample1.Views.dll will both be copied along with the debug symbols. This is probably the simplest way to go about this, but it is a tad inflexible. For example, what if you have dependencies? The preferred method would probably be to use IL Merge to merge your dependencies with your target DLL. This would have to be added in the build events. Another way to achieve that would be to simply bypass Visual Studio events and use MSBuild.   I also got a question about how I was setting up the controller factory. Here’s the basics on how I’m setting up tenants inside the host (Global.asax) protected void Application_Start() { RegisterRoutes(RouteTable.Routes); // create a container just to pull in tenants var topContainer = new Container(); topContainer.Configure(config => { config.Scan(scanner => { scanner.AssembliesFromPath(Path.Combine(Server.MapPath("~/"), "Tenants")); scanner.AddAllTypesOf<IApplicationTenant>(); }); }); // create selectors var tenantSelector = new DefaultTenantSelector(topContainer.GetAllInstances<IApplicationTenant>()); var containerSelector = new TenantContainerResolver(tenantSelector); // clear view engines, we don't want anything other than spark ViewEngines.Engines.Clear(); // set view engine ViewEngines.Engines.Add(new TenantViewEngine(tenantSelector)); // set controller factory ControllerBuilder.Current.SetControllerFactory(new ContainerControllerFactory(containerSelector)); } The code to setup the tenants isn’t actually that hard. I’m utilizing assembly scanners in StructureMap as a simple way to pull in DLLs that are not in the AppDomain. Remember that there is a dependency on the host in the tenants and a tenant cannot simply be referenced by a host because of circular dependencies.   Tenant View Engine TenantViewEngine is a simple delegator to the tenant’s specified view engine. You might have noticed that a tenant has to define a view engine. public interface IApplicationTenant { .... IViewEngine ViewEngine { get; } } The trick comes in specifying the view engine on the tenant side. Here’s some of the code that will pull views from the DLL. protected virtual IViewEngine DetermineViewEngine() { var factory = new SparkViewFactory(); var file = GetType().Assembly.CodeBase.Without("file:///").Replace(".dll", ".Views.dll").Replace('/', '\\'); var assembly = Assembly.LoadFile(file); factory.Engine.LoadBatchCompilation(assembly); return factory; } This code resides in an abstract Tenant where the fields are setup in the constructor. This method (inside the abstract class) will load the Views assembly and load the compilation into Spark’s “Descriptors” that will be used to determine views. There is some trickery on determining the file location… but it works just fine.   Up Next There’s just a few big things left such as StructureMap configuring controllers with a convention instead of specifying types directly with container construction and content resolution. I will also try to find a way to use the Web Forms View Engine in a multi-tenant way we achieved with the Spark View Engine without using a virtual path provider. I will probably not use the Web Forms View Engine personally, but I’m sure some people would prefer using WebForms because of the maturity of the engine. As always, I love to take questions by email or on twitter. Suggestions are always welcome as well! (Oh, and here’s another link to the source code).

    Read the article

  • Validating a linked item&rsquo;s data template in Sitecore

    - by Kyle Burns
    I’ve been doing quite a bit of work in Sitecore recently and last week I encountered a situation that it appears many others have hit.  I was working with a field that had been configured originally as a grouped droplink, but now needed to be updated to support additional levels of hierarchy in the folder structure.  If you’ve done any work in Sitecore that statement makes sense, but if not it may seem a bit cryptic.  Sitecore offers a number of different field types and a subset of these field types focus on providing links either to other items on the content tree or to content that is not stored in Sitecore.  In the case of the grouped droplink, the field is configured with a “root” folder and each direct descendant of this folder is considered to be a header for a grouping of other items and displayed in a dropdown.  A picture is worth a thousand words, so consider the following piece of a content tree: If I configure a grouped droplink field to use the “Current” folder as its datasource, the control that gets to my content author looks like this: This presents a nicely organized display and limits the user to selecting only the direct grandchildren of the folder root.  It also presents the limitation that struck as we were thinking through the content architecture and how it would hold up over time – the authors cannot further organize content under the root folder because of the structure required for the dropdown to work.  Over time, not allowing the hierarchy to go any deeper would prevent out authors from being able to organize their content in a way that it would be found when needed, so the grouped droplink data type was not going to fit the bill. I needed to look for an alternative data type that allowed for selection of a single item and limited my choices to descendants of a specific node on the content tree.  After looking at the options available for links in Sitecore and considering them against each other, one option stood out as nearly perfect – the droptree.  This field type stores its data identically to the droplink and allows for the selection of zero or one items under a specific node in the content tree.  By changing my data template to use droptree instead of grouped droplink, the author is now presented with the following when selecting a linked item: Sounds great, but a did say almost perfect – there’s still one flaw.  The code intended to display the linked item is expecting the selection to use a specific data template (or more precisely it makes certain assumptions about the fields that will be present), but the droptree does nothing to prevent the author from selecting a folder (since folders are items too) instead of one of the items contained within a folder.  I looked to see if anyone had already solved this problem.  I found many people discussing the problem, but the closest that I found to a solution was the statement “the best thing would probably be to create a custom validator” with no further discussion in regards to what this validator might look like.  I needed to create my own validator to ensure that the user had not selected a folder.  Since so many people had the same issue, I decided to make the validator as reusable as possible and share it here. The validator that I created inherits from StandardValidator.  In order to make the validator more intuitive to developers that are familiar with the TreeList controls in Sitecore, I chose to implement the following parameters: ExcludeTemplatesForSelection – serves as a “deny list”.  If the data template of the selected item is in this list it will not validate IncludeTemplatesForSelection – this can either be empty to indicate that any template not contained in the exclusion list is acceptable or it can contain the list of acceptable templates Now that I’ve explained the parameters and the purpose of the validator, I’ll let the code do the rest of the talking: 1: /// <summary> 2: /// Validates that a link field value meets template requirements 3: /// specified using the following parameters: 4: /// - ExcludeTemplatesForSelection: If present, the item being 5: /// based on an excluded template will cause validation to fail. 6: /// - IncludeTemplatesForSelection: If present, the item not being 7: /// based on an included template will cause validation to fail 8: /// 9: /// ExcludeTemplatesForSelection trumps IncludeTemplatesForSelection 10: /// if the same value appears in both lists. Lists are comma seperated 11: /// </summary> 12: [Serializable] 13: public class LinkItemTemplateValidator : StandardValidator 14: { 15: public LinkItemTemplateValidator() 16: { 17: } 18:   19: /// <summary> 20: /// Serialization constructor is required by the runtime 21: /// </summary> 22: /// <param name="info"></param> 23: /// <param name="context"></param> 24: public LinkItemTemplateValidator(SerializationInfo info, StreamingContext context) : base(info, context) { } 25:   26: /// <summary> 27: /// Returns whether the linked item meets the template 28: /// constraints specified in the parameters 29: /// </summary> 30: /// <returns> 31: /// The result of the evaluation. 32: /// </returns> 33: protected override ValidatorResult Evaluate() 34: { 35: if (string.IsNullOrWhiteSpace(ControlValidationValue)) 36: { 37: return ValidatorResult.Valid; // let "required" validation handle 38: } 39:   40: var excludeString = Parameters["ExcludeTemplatesForSelection"]; 41: var includeString = Parameters["IncludeTemplatesForSelection"]; 42: if (string.IsNullOrWhiteSpace(excludeString) && string.IsNullOrWhiteSpace(includeString)) 43: { 44: return ValidatorResult.Valid; // "allow anything" if no params 45: } 46:   47: Guid linkedItemGuid; 48: if (!Guid.TryParse(ControlValidationValue, out linkedItemGuid)) 49: { 50: return ValidatorResult.Valid; // probably put validator on wrong field 51: } 52:   53: var item = GetItem(); 54: var linkedItem = item.Database.GetItem(new ID(linkedItemGuid)); 55:   56: if (linkedItem == null) 57: { 58: return ValidatorResult.Valid; // this validator isn't for broken links 59: } 60:   61: var exclusionList = (excludeString ?? string.Empty).Split(','); 62: var inclusionList = (includeString ?? string.Empty).Split(','); 63:   64: if ((inclusionList.Length == 0 || inclusionList.Contains(linkedItem.TemplateName)) 65: && !exclusionList.Contains(linkedItem.TemplateName)) 66: { 67: return ValidatorResult.Valid; 68: } 69:   70: Text = GetText("The field \"{0}\" specifies an item which is based on template \"{1}\". This template is not valid for selection", GetFieldDisplayName(), linkedItem.TemplateName); 71:   72: return GetFailedResult(ValidatorResult.FatalError); 73: } 74:   75: protected override ValidatorResult GetMaxValidatorResult() 76: { 77: return ValidatorResult.FatalError; 78: } 79:   80: public override string Name 81: { 82: get { return @"LinkItemTemplateValidator"; } 83: } 84: }   In this blog entry, I have shared some code that I found useful in solving a problem that seemed fairly common.  Hopefully the next person that is looking for this answer finds it useful as well.

    Read the article

  • Using delegates in C# (Part 2)

    - by rajbk
    Part 1 of this post can be read here. We are now about to see the different syntaxes for invoking a delegate and some c# syntactic sugar which allows you to code faster. We have the following console application. 1: public delegate double Operation(double x, double y); 2:  3: public class Program 4: { 5: [STAThread] 6: static void Main(string[] args) 7: { 8: Operation op1 = new Operation(Division); 9: double result = op1.Invoke(10, 5); 10: 11: Console.WriteLine(result); 12: Console.ReadLine(); 13: } 14: 15: static double Division(double x, double y) { 16: return x / y; 17: } 18: } Line 1 defines a delegate type called Operation with input parameters (double x, double y) and a return type of double. On Line 8, we create an instance of this delegate and set the target to be a static method called Division (Line 15) On Line 9, we invoke the delegate (one entry in the invocation list). The program outputs 5 when run. The language provides shortcuts for creating a delegate and invoking it (see line 9 and 11). Line 9 is a syntactical shortcut for creating an instance of the Delegate. The C# compiler will infer on its own what the delegate type is and produces intermediate language that creates a new instance of that delegate. Line 11 uses a a syntactical shortcut for invoking the delegate by removing the Invoke method. The compiler sees the line and generates intermediate language which invokes the delegate. When this code is compiled, the generated IL will look exactly like the IL of the compiled code above. 1: public delegate double Operation(double x, double y); 2:  3: public class Program 4: { 5: [STAThread] 6: static void Main(string[] args) 7: { 8: //shortcut constructor syntax 9: Operation op1 = Division; 10: //shortcut invoke syntax 11: double result = op1(10, 2); 12: 13: Console.WriteLine(result); 14: Console.ReadLine(); 15: } 16: 17: static double Division(double x, double y) { 18: return x / y; 19: } 20: } C# 2.0 introduced Anonymous Methods. Anonymous methods avoid the need to create a separate method that contains the same signature as the delegate type. Instead you write the method body in-line. There is an interesting fact about Anonymous methods and closures which won’t be covered here. Use your favorite search engine ;-)We rewrite our code to use anonymous methods (see line 9): 1: public delegate double Operation(double x, double y); 2:  3: public class Program 4: { 5: [STAThread] 6: static void Main(string[] args) 7: { 8: //Anonymous method 9: Operation op1 = delegate(double x, double y) { 10: return x / y; 11: }; 12: double result = op1(10, 2); 13: 14: Console.WriteLine(result); 15: Console.ReadLine(); 16: } 17: 18: static double Division(double x, double y) { 19: return x / y; 20: } 21: } We could rewrite our delegate to be of a generic type like so (see line 2 and line 9). You will see why soon. 1: //Generic delegate 2: public delegate T Operation<T>(T x, T y); 3:  4: public class Program 5: { 6: [STAThread] 7: static void Main(string[] args) 8: { 9: Operation<double> op1 = delegate(double x, double y) { 10: return x / y; 11: }; 12: double result = op1(10, 2); 13: 14: Console.WriteLine(result); 15: Console.ReadLine(); 16: } 17: 18: static double Division(double x, double y) { 19: return x / y; 20: } 21: } The .NET 3.5 framework introduced a whole set of predefined delegates for us including public delegate TResult Func<T1, T2, TResult>(T1 arg1, T2 arg2); Our code can be modified to use this delegate instead of the one we declared. Our delegate declaration has been removed and line 7 has been changed to use the Func delegate type. 1: public class Program 2: { 3: [STAThread] 4: static void Main(string[] args) 5: { 6: //Func is a delegate defined in the .NET 3.5 framework 7: Func<double, double, double> op1 = delegate (double x, double y) { 8: return x / y; 9: }; 10: double result = op1(10, 2); 11: 12: Console.WriteLine(result); 13: Console.ReadLine(); 14: } 15: 16: static double Division(double x, double y) { 17: return x / y; 18: } 19: } .NET 3.5 also introduced lambda expressions. A lambda expression is an anonymous function that can contain expressions and statements, and can be used to create delegates or expression tree types. We change our code to use lambda expressions. 1: public class Program 2: { 3: [STAThread] 4: static void Main(string[] args) 5: { 6: //lambda expression 7: Func<double, double, double> op1 = (x, y) => x / y; 8: double result = op1(10, 2); 9: 10: Console.WriteLine(result); 11: Console.ReadLine(); 12: } 13: 14: static double Division(double x, double y) { 15: return x / y; 16: } 17: } C# 3.0 introduced the keyword var (implicitly typed local variable) where the type of the variable is inferred based on the type of the associated initializer expression. We can rewrite our code to use var as shown below (line 7).  The implicitly typed local variable op1 is inferred to be a delegate of type Func<double, double, double> at compile time. 1: public class Program 2: { 3: [STAThread] 4: static void Main(string[] args) 5: { 6: //implicitly typed local variable 7: var op1 = (x, y) => x / y; 8: double result = op1(10, 2); 9: 10: Console.WriteLine(result); 11: Console.ReadLine(); 12: } 13: 14: static double Division(double x, double y) { 15: return x / y; 16: } 17: } You have seen how we can write code in fewer lines by using a combination of the Func delegate type, implicitly typed local variables and lambda expressions.

    Read the article

  • Create PDF document using iTextSharp in ASP.Net 4.0 and MemoryMappedFile

    - by sreejukg
    In this article I am going to demonstrate how ASP.Net developers can programmatically create PDF documents using iTextSharp. iTextSharp is a software component, that allows developers to programmatically create or manipulate PDF documents. Also this article discusses the process of creating in-memory file, read/write data from/to the in-memory file utilizing the new feature MemoryMappedFile. I have a database of users, where I need to send a notice to all my users as a PDF document. The sending mail part of it is not covered in this article. The PDF document will contain the company letter head, to make it more official. I have a list of users stored in a database table named “tblusers”. For each user I need to send customized message addressed to them personally. The database structure for the users is give below. id Title Full Name 1 Mr. Sreeju Nair K. G. 2 Dr. Alberto Mathews 3 Prof. Venketachalam Now I am going to generate the pdf document that contains some message to the user, in the following format. Dear <Title> <FullName>, The message for the user. Regards, Administrator Also I have an image, bg.jpg that contains the background for the document generated. I have created .Net 4.0 empty web application project named “iTextSharpSample”. First thing I need to do is to download the iTextSharp dll from the source forge. You can find the url for the download here. http://sourceforge.net/projects/itextsharp/files/ I have extracted the Zip file and added the itextsharp.dll as a reference to my project. Also I have added a web form named default.aspx to my project. After doing all this, the solution explorer have the following view. In the default.aspx page, I inserted one grid view and associated it with a SQL Data source control that bind data from tblusers. I have added a button column in the grid view with text “generate pdf”. The output of the page in the browser is as follows. Now I am going to create a pdf document when the user clicking on the Generate PDF button. As I mentioned before, I am going to work with the file in memory, I am not going to create a file in the disk. I added an event handler for button by specifying onrowcommand event handler. My gridview source looks like <asp:GridView ID="GridView1" runat="server" AutoGenerateColumns="False" DataSourceID="SqlDataSource1" Width="481px" CellPadding="4" ForeColor="#333333" GridLines="None" onrowcommand="Generate_PDF" > ………………………………………………………………………….. ………………………………………………………………………….. </asp:GridView> In the code behind, I wrote the corresponding event handler. protected void Generate_PDF(object sender, GridViewCommandEventArgs e) { // The button click event handler code. // I am going to explain the code for this section in the remaining part of the article } The Generate_PDF method is straight forward, It get the title, fullname and message to some variables, then create the pdf using these variables. The code for getting data from the grid view is as follows // get the row index stored in the CommandArgument property int index = Convert.ToInt32(e.CommandArgument); // get the GridViewRow where the command is raised GridViewRow selectedRow = ((GridView)e.CommandSource).Rows[index]; string title = selectedRow.Cells[1].Text; string fullname = selectedRow.Cells[2].Text; string msg = @"There are some changes in the company policy, due to this matter you need to submit your latest address to us. Please update your contact details / personnal details by visiting the member area of the website. ................................... "; since I don’t want to save the file in the disk, I am going the new feature introduced in .Net framework 4, called Memory-Mapped Files. Using Memory-Mapped mapped file, you can created non-persisted memory mapped files, that are not associated with a file in a disk. So I am going to create a temporary file in memory, add the pdf content to it, then write it to the output stream. To read more about MemoryMappedFile, read this msdn article http://msdn.microsoft.com/en-us/library/dd997372.aspx The below portion of the code using MemoryMappedFile object to create a test pdf document in memory and perform read/write operation on file. The CreateViewStream() object will give you a stream that can be used to read or write data to/from file. The code is very straight forward and I included comment so that you can understand the code. using (MemoryMappedFile mmf = MemoryMappedFile.CreateNew("test1.pdf", 1000000)) { // Create a new pdf document object using the constructor. The parameters passed are document size, left margin, right margin, top margin and bottom margin. iTextSharp.text.Document d = new iTextSharp.text.Document(PageSize.A4, 72,72,172,72); //get an instance of the memory mapped file to stream object so that user can write to this using (MemoryMappedViewStream stream = mmf.CreateViewStream()) { // associate the document to the stream. PdfWriter.GetInstance(d, stream); /* add an image as bg*/ iTextSharp.text.Image jpg = iTextSharp.text.Image.GetInstance(Server.MapPath("Image/bg.png")); jpg.Alignment = iTextSharp.text.Image.UNDERLYING; jpg.SetAbsolutePosition(0, 0); //this is the size of my background letter head image. the size is in points. this will fit to A4 size document. jpg.ScaleToFit(595, 842); d.Open(); d.Add(jpg); d.Add(new Paragraph(String.Format("Dear {0} {1},", title, fullname))); d.Add(new Paragraph("\n")); d.Add(new Paragraph(msg)); d.Add(new Paragraph("\n")); d.Add(new Paragraph(String.Format("Administrator"))); d.Close(); } //read the file data byte[] b; using (MemoryMappedViewStream stream = mmf.CreateViewStream()) { BinaryReader rdr = new BinaryReader(stream); b = new byte[mmf.CreateViewStream().Length]; rdr.Read(b, 0, (int)mmf.CreateViewStream().Length); } Response.Clear(); Response.ContentType = "Application/pdf"; Response.BinaryWrite(b); Response.End(); } Press ctrl + f5 to run the application. First I got the user list. Click on the generate pdf icon. The created looks as follows. Summary: Creating pdf document using iTextSharp is easy. You will get lot of information while surfing the www. Some useful resources and references are mentioned below http://itextsharp.com/ http://www.mikesdotnetting.com/Article/82/iTextSharp-Adding-Text-with-Chunks-Phrases-and-Paragraphs http://somewebguy.wordpress.com/2009/05/08/itextsharp-simplify-your-html-to-pdf-creation/ Hope you enjoyed the article.

    Read the article

  • Red Gate Coder interviews: Robin Hellen

    - by Michael Williamson
    Robin Hellen is a test engineer here at Red Gate, and is also the latest coder I’ve interviewed. We chatted about debugging code, the roles of software engineers and testers, and why Vala is currently his favourite programming language. How did you get started with programming?It started when I was about six. My dad’s a professional programmer, and he gave me and my sister one of his old computers and taught us a bit about programming. It was an old Amiga 500 with a variant of BASIC. I don’t think I ever successfully completed anything! It was just faffing around. I didn’t really get anywhere with it.But then presumably you did get somewhere with it at some point.At some point. The PC emerged as the dominant platform, and I learnt a bit of Visual Basic. I didn’t really do much, just a couple of quick hacky things. A bit of demo animation. Took me a long time to get anywhere with programming, really.When did you feel like you did start to get somewhere?I think it was when I started doing things for someone else, which was my sister’s final year of university project. She called up my dad two days before she was due to submit, saying “We need something to display a graph!”. Dad says, “I’m too busy, go talk to your brother”. So I hacked up this ugly piece of code, sent it off and they won a prize for that project. Apparently, the graph, the bit that I wrote, was the reason they won a prize! That was when I first felt that I’d actually done something that was worthwhile. That was my first real bit of code, and the ugliest code I’ve ever written. It’s basically an array of pre-drawn line elements that I shifted round the screen to draw a very spikey graph.When did you decide that programming might actually be something that you wanted to do as a career?It’s not really a decision I took, I always wanted to do something with computers. And I had to take a gap year for uni, so I was looking for twelve month internships. I applied to Red Gate, and they gave me a job as a tester. And that’s where I really started having to write code well. To a better standard that I had been up to that point.How did you find coming to Red Gate and working with other coders?I thought it was really nice. I learnt so much just from other people around. I think one of the things that’s really great is that people are just willing to help you learn. Instead of “Don’t you know that, you’re so stupid”, it’s “You can just do it this way”.If you could go back to the very start of that internship, is there something that you would tell yourself?Write shorter code. I have a tendency to write massive, many-thousand line files that I break out of right at the end. And then half-way through a project I’m doing something, I think “Where did I write that bit that does that thing?”, and it’s almost impossible to find. I wrote some horrendous code when I started. Just that principle, just keep things short. Even if looks a bit crazy to be jumping around all over the place all of the time, it’s actually a lot more understandable.And how do you hold yourself to that?Generally, if a function’s going off my screen, it’s probably too long. That’s what I tell myself, and within the team here we have code reviews, so the guys I’m with at the moment are pretty good at pulling me up on, “Doesn’t that look like it’s getting a bit long?”. It’s more just the subjective standard of readability than anything.So you’re an advocate of code review?Yes, definitely. Both to spot errors that you might have made, and to improve your knowledge. The person you’re reviewing will say “Oh, you could have done it that way”. That’s how we learn, by talking to others, and also just sharing knowledge of how your project works around the team, or even outside the team. Definitely a very firm advocate of code reviews.Do you think there’s more we could do with them?I don’t know. We’re struggling with how to add them as part of the process without it becoming too cumbersome. We’ve experimented with a few different ways, and we’ve not found anything that just works.To get more into the nitty gritty: how do you like to debug code?The first thing is to do it in my head. I’ll actually think what piece of code is likely to have caused that error, and take a quick look at it, just to see if there’s anything glaringly obvious there. The next thing I’ll probably do is throw in print statements, or throw some exceptions from various points, just to check: is it going through the code path I expect it to? A last resort is to actually debug code using a debugger.Why is the debugger the last resort?Probably because of the environments I learnt programming in. VB and early BASIC didn’t have much of a debugger, the only way to find out what your program was doing was to add print statements. Also, because a lot of the stuff I tend to work with is non-interactive, if it’s something that takes a long time to run, I can throw in the print statements, set a run off, go and do something else, and look at it again later, rather than trying to remember what happened at that point when I was debugging through it. So it also gives me the record of what happens. I hate just sitting there pressing F5, F5, continually. If you’re having to find out what your code is doing at each line, you’ve probably got a very wrong mental model of what your code’s doing, and you can find that out just as easily by inspecting a couple of values through the print statements.If I were on some codebase that you were also working on, what should I do to make it as easy as possible to understand?I’d say short and well-named methods. The one thing I like to do when I’m looking at code is to find out where a value comes from, and the more layers of indirection there are, particularly DI [dependency injection] frameworks, the harder it is to find out where something’s come from. I really hate that. I want to know if the value come from the user here or is a constant here, and if I can’t find that out, that makes code very hard to understand for me.As a tester, where do you think the split should lie between software engineers and testers?I think the split is less on areas of the code you write and more what you’re designing and creating. The developers put a structure on the code, while my major role is to say which tests we should have, whether we should test that, or it’s not worth testing that because it’s a tiny function in code that nobody’s ever actually going to see. So it’s not a split in the code, it’s a split in what you’re thinking about. Saying what code we should write, but alternatively what code we should take out.In your experience, do the software engineers tend to do much testing themselves?They tend to control the lowest layer of tests. And, depending on how the balance of people is in the team, they might write some of the higher levels of test. Or that might go to the testers. I’m the only tester on my team with three other developers, so they’ll be writing quite a lot of the actual test code, with input from me as to whether we should test that functionality, whereas on other teams, where it’s been more equal numbers, the testers have written pretty much all of the high level tests, just because that’s the best use of resource.If you could shuffle resources around however you liked, do you think that the developers should be writing those high-level tests?I think they should be writing them occasionally. It helps when they have an understanding of how testing code works and possibly what assumptions we’ve made in tests, and they can say “actually, it doesn’t work like that under the hood so you’ve missed this whole area”. It’s one of those agile things that everyone on the team should be at least comfortable doing the various jobs. So if the developers can write test code then I think that’s a very good thing.So you think testers should be able to write production code?Yes, although given most testers skills at coding, I wouldn’t advise it too much! I have written a few things, and I did make a few changes that have actually gone into our production code base. They’re not necessarily running every time but they are there. I think having that mix of skill sets is really useful. In some ways we’re using our own product to test itself, so being able to make those changes where it’s not working saves me a round-trip through the developers. It can be really annoying if the developers have no time to make a change, and I can’t touch the code.If the software engineers are consistently writing tests at all levels, what role do you think the role of a tester is?I think on a team like that, those distinctions aren’t quite so useful. There’ll be two cases. There’s either the case where the developers think they’ve written good tests, but you still need someone with a test engineer mind-set to go through the tests and validate that it’s a useful set, or the correct set for that code. Or they won’t actually be pure developers, they’ll have that mix of test ability in there.I think having slightly more distinct roles is useful. When it starts to blur, then you lose that view of the tests as a whole. The tester job is not to create tests, it’s to validate the quality of the product, and you don’t do that just by writing tests. There’s more things you’ve got to keep in your mind. And I think when you blur the roles, you start to lose that end of the tester.So because you’re working on those features, you lose that holistic view of the whole system?Yeah, and anyone who’s worked on the feature shouldn’t be testing it. You always need to have it tested it by someone who didn’t write it. Otherwise you’re a bit too close and you assume “yes, people will only use it that way”, but the tester will come along and go “how do people use this? How would our most idiotic user use this?”. I might not test that because it might be completely irrelevant. But it’s coming in and trying to have a different set of assumptions.Are you a believer that it should all be automated if possible?Not entirely. So an automated test is always better than a manual test for the long-term, but there’s still nothing that beats a human sitting in front of the application and thinking “What could I do at this point?”. The automated test is very good but they follow that strict path, and they never check anything off the path. The human tester will look at things that they weren’t expecting, whereas the automated test can only ever go “Is that value correct?” in many respects, and it won’t notice that on the other side of the screen you’re showing something completely wrong. And that value might have been checked independently, but you always find a few odd interactions when you’re going through something manually, and you always need to go through something manually to start with anyway, otherwise you won’t know where the important bits to write your automation are.When you’re doing that manual testing, do you think it’s important to do that across the entire product, or just the bits that you’ve touched recently?I think it’s important to do it mostly on the bits you’ve touched, but you can’t ignore the rest of the product. Unless you’re dealing with a very, very self-contained bit, you’re almost always encounter other bits of the product along the way. Most testers I know, even if they are looking at just one path, they’ll keep open and move around a bit anyway, just because they want to find something that’s broken. If we find that your path is right, we’ll go out and hunt something else.How do you think this fits into the idea of continuously deploying, so long as the tests pass?With deploying a website it’s a bit different because you can always pull it back. If you’re deploying an application to customers, when you’ve released it, it’s out there, you can’t pull it back. Someone’s going to keep it, no matter how hard you try there will be a few installations that stay around. So I’d always have at least a human element on that path. With websites, you could probably automate straight out, or at least straight out to an internal environment or a single server in a cloud of fifty that will serve some people. But I don’t think you should release to everyone just on automated tests passing.You’ve already mentioned using BASIC and C# — are there any other languages that you’ve used?I’ve used a few. That’s something that has changed more recently, I’ve become familiar with more languages. Before I started at Red Gate I learnt a bit of C. Then last year, I taught myself Python which I actually really enjoyed using. I’ve also come across another language called Vala, which is sort of a C#-like language. It’s basically a pre-processor for C, but it has very nice syntax. I think that’s currently my favourite language.Any particular reason for trying Vala?I have a completely Linux environment at home, and I’ve been looking for a nice language, and C# just doesn’t cut it because I won’t touch Mono. So, I was looking for something like C# but that was useable in an open source environment, and Vala’s what I found. C#’s got a few features that Vala doesn’t, and Vala’s got a few features where I think “It would be awesome if C# had that”.What are some of the features that it’s missing?Extension methods. And I think that’s the only one that really bugs me. I like to use them when I’m writing C# because it makes some things really easy, especially with libraries that you can’t touch the internals of. It doesn’t have method overloading, which is sometimes annoying.Where it does win over C#?Everything is non-nullable by default, you never have to check that something’s unexpectedly null.Also, Vala has code contracts. This is starting to come in C# 4, but the way it works in Vala is that you specify requirements in short phrases as part of your function signature and they stick to the signature, so that when you inherit it, it has exactly the same code contract as the base one, or when you inherit from an interface, you have to match the signature exactly. Just using those makes you think a bit more about how you’re writing your method, it’s not an afterthought when you’ve got contracts from base classes given to you, you can’t change it. Which I think is a lot nicer than the way C# handles it. When are those actually checked?They’re checked both at compile and run-time. The compile-time checking isn’t very strong yet, it’s quite a new feature in the compiler, and because it compiles down to C, you can write C code and interface with your methods, so you can bypass that compile-time check anyway. So there’s an extra runtime check, and if you violate one of the contracts at runtime, it’s game over for your program, there’s no exception to catch, it’s just goodbye!One thing I dislike about C# is the exceptions. You write a bit of code and fifty exceptions could come from any point in your ten lines, and you can’t mentally model how those exceptions are going to come out, and you can’t even predict them based on the functions you’re calling, because if you’ve accidentally got a derived class there instead of a base class, that can throw a completely different set of exceptions. So I’ve got no way of mentally modelling those, whereas in Vala they’re checked like Java, so you know only these exceptions can come out. You know in advance the error conditions.I think Raymond Chen on Old New Thing says “the only thing you know when you throw an exception is that you’re in an invalid state somewhere in your program, so just kill it and be done with it!”You said you’ve also learnt bits of Python. How did you find that compared to Vala and C#?Very different because of the dynamic typing. I’ve been writing a website for my own use. I’m quite into photography, so I take photos off my camera, post-process them, dump them in a file, and I get a webpage with all my thumbnails. So sort of like Picassa, but written by myself because I wanted something to learn Python with. There are some things that are really nice, I just found it really difficult to cope with the fact that I’m not quite sure what this object type that I’m passed is, I might not ever be sure, so it can randomly blow up on me. But once I train myself to ignore that and just say “well, I’m fairly sure it’s going to be something that looks like this, so I’ll use it like this”, then it’s quite nice.Any particular features that you’ve appreciated?I don’t like any particular feature, it’s just very straightforward to work with. It’s very quick to write something in, particularly as you don’t have to worry that you’ve changed something that affects a different part of the program. If you have, then that part blows up, but I can get this part working right now.If you were doing a big project, would you be willing to do it in Python rather than C# or Vala?I think I might be willing to try something bigger or long term with Python. We’re currently doing an ASP.NET MVC project on C#, and I don’t like the amount of reflection. There’s a lot of magic that pulls values out, and it’s all done under the scenes. It’s almost managed to put a dynamic type system on top of C#, which in many ways destroys the language to me, whereas if you’re already in a dynamic language, having things done dynamically is much more natural. In many ways, you get the worst of both worlds. I think for web projects, I would go with Python again, whereas for anything desktop, command-line or GUI-based, I’d probably go for C# or Vala, depending on what environment I’m in.It’s the fact that you can gain from the strong typing in ways that you can’t so much on the web app. Or, in a web app, you have to use dynamic typing at some point, or you have to write a hell of a lot of boilerplate, and I’d rather use the dynamic typing than write the boilerplate.What do you think separates great programmers from everyone else?Probably design choices. Choosing to write it a piece of code one way or another. For any given program you ask me to write, I could probably do it five thousand ways. A programmer who is capable will see four or five of them, and choose one of the better ones. The excellent programmer will see the largest proportion and manage to pick the best one very quickly without having to think too much about it. I think that’s probably what separates, is the speed at which they can see what’s the best path to write the program in. More Red Gater Coder interviews

    Read the article

  • CodePlex Daily Summary for Friday, September 07, 2012

    CodePlex Daily Summary for Friday, September 07, 2012Popular ReleasesUmbraco CMS: Umbraco 4.9.0: Whats newThe media section has been overhauled to support HTML5 uploads, just drag and drop files in, even multiple files are supported on any HTML5 capable browser. The folder content overview is also much improved allowing you to filter it and perform common actions on your media items. The Rich Text Editor’s “Media” button now uses an embedder based on the open oEmbed standard (if you’re upgrading, enable the media button in the Rich Text Editor datatype settings and set TidyEditorConten...menu4web: menu4web 0.4.1 - javascript menu for web sites: This release is for those who believe that global variables are evil. menu4web has been wrapped into m4w singleton object. Added "Vertical Tabs" example which illustrates object notation.WinRT XAML Toolkit: WinRT XAML Toolkit - 1.2.1: WinRT XAML Toolkit based on the Windows 8 RTM SDK. Download the latest source from the SOURCE CODE page. For compiled version use NuGet. You can add it to your project in Visual Studio by going to View/Other Windows/Package Manager Console and entering: PM> Install-Package winrtxamltoolkit Features AsyncUI extensions Controls and control extensions Converters Debugging helpers Imaging IO helpers VisualTree helpers Samples Recent changes NOTE: Namespace changes DebugConsol...iPDC - Free Phasor Data Concentrator: iPDC-v1.3.1: iPDC suite version-1.3.1, Modifications and Bug Fixed (from v 1.3.0) New User Manual for iPDC-v1.3.1 available on websites. Bug resolved : PMU Simulator TCP connection error and hang connection for client (PDC). Now PMU Simulator (server) can communicate more than one PDCs (clients) over TCP and UDP parallely. PMU Simulator is now sending the exact data frames as mentioned in data rate by user. PMU Simulator data rate has been verified by iPDC database entries and PMU Connection Tes...Microsoft SQL Server Product Samples: Database: AdventureWorks OData Feed: The AdventureWorks OData service exposes resources based on specific SQL views. The SQL views are a limited subset of the AdventureWorks database that results in several consuming scenarios: CompanySales Documents ManufacturingInstructions ProductCatalog TerritorySalesDrilldown WorkOrderRouting How to install the sample You can consume the AdventureWorks OData feed from http://services.odata.org/AdventureWorksV3/AdventureWorks.svc. You can also consume the AdventureWorks OData fe...Desktop Google Reader: 1.4.6: Sorting feeds alphabetical is now optional (see preferences window)DotNetNuke® Community Edition CMS: 06.02.03: Major Highlights Fixed issue where mailto: links were not working when sending bulk email Fixed issue where uses did not see friendship relationships Problem is in 6.2, which does not show in the Versions Affected list above. Fixed the issue with cascade deletes in comments in CoreMessaging_Notification Fixed UI issue when using a date fields as a required profile property during user registration Fixed error when running the product in debug mode Fixed visibility issue when...Microsoft Ajax Minifier: Microsoft Ajax Minifier 4.65: Fixed null-reference error in the build task constructor.B INI Sharp Library: B INI Sharp Library v1.0.0.0 Final Realsed: The frist realsedActive Social Migrator: ActiveSocialMigrator 1.0.0 Beta: Beta release for the Active Social Migration tool.EntLib.com????????: ??????demo??-For SQL 2005-2008: EntLibShopping ???v3.0 - ??????demo??,?????SQL SERVER 2005/2008/2008 R2/2012 ??????。 ??(??)??????。 THANKS.Sistem LPK Pemkot Semarang: Panduan Penggunaan Sistem LPK: Panduan cara menggunakan Aplikasi Sistem LPK Bagian Pembangunan Kota SemarangActive Forums for DotNetNuke CMS: Active Forums 5.0.0 RC: RC release of Active Forums 5.0.Droid Explorer: Droid Explorer 0.8.8.7 Beta: Bug in the display icon for apk's, will fix with next release Added fallback icon if unable to get the image/icon from the Cloud Service Removed some stale plugins that were either out dated or incomplete. Added handler for *.ab files for restoring backups Added plugin to create device backups Backups stored in %USERPROFILE%\Android Backups\%DEVICE_ID%\ Added custom folder icon for the android backups directory better error handling for installing an apk bug fixes for the Runn...The Visual Guide for Building Team Foundation Server 2012 Environments: Version 1: --Nearforums - ASP.NET MVC forum engine: Nearforums v8.5: Version 8.5 of Nearforums, the ASP.NET MVC Forum Engine. New features include: Built-in search engine using Lucene.NET Flood control improvements Notifications improvements: sync option and mail body View Roadmap for more details webdeploy package sha1 checksum: 961aff884a9187b6e8a86d68913cdd31f8deaf83WiX Toolset: WiX Toolset v3.6: WiX Toolset v3.6 introduces the Burn bootstrapper/chaining engine and support for Visual Studio 2012 and .NET Framework 4.5. Other minor functionality includes: WixDependencyExtension supports dependency checking among MSI packages. WixFirewallExtension supports more features of Windows Firewall. WixTagExtension supports Software Id Tagging. WixUtilExtension now supports recursive directory deletion. Melt simplifies pure-WiX patching by extracting .msi package content and updating .w...Iveely Search Engine: Iveely Search Engine (0.2.0): ????ISE?0.1.0??,?????,ISE?0.2.0?????????,???????,????????20???follow?ISE,????,??ISE??????????,??????????,?????????,?????????0.2.0??????,??????????。 Iveely Search Engine ?0.2.0?????????“??????????”,??????,?????????,???????,???????????????????,????、????????????。???0.1.0????????????: 1. ??“????” ??。??????????,?????????,???????????????????。??:????????,????????????,??????????????????。??????。 2. ??“????”??。?0.1.0??????,???????,???????????????,?????????????,????????,?0.2.0?,???????...GmailDefaultMaker: GmailDefaultMaker 3.0.0.2: Add QQ Mail BugfixSmart Data Access layer: Smart Data access Layer Ver 3: In this version support executing inline query is added. Check Documentation section for detail.New ProjectsAdding 2013 Jewish Holidays for Outlook2003: Instruction: Copy the outlook.hol file to your compuer where Outlook2003 is installed. Double click the file, choose "Israel" and continue. That's it Agilcont System: Sistema de contabilidad para empresas privadas de preferencia para cajas que trabajan con efectivo en soles, dolares y con el material oroARB (A Request Broker): The idea is something like a Request Broker, but with some additional functionality.BATTLE.NET - SDK: This SDK provides the ability to use the Battle.net (Blizzard) Services for all supported Games such Diablo 3, World of Warcraft. Container Terminal System: SummaryDeclarative UX Streaming Data Language for the Cloud: Bringing a better communication paradigm for media and data..Get User Profile Information from SharePoint UserProfile Service: Used SharePoint object model to get the user profile information from the User Profile Service.Guess The City & State Windows 8 Source Code: Source code for Guess The City & State in Malaysia Windows 8 AppJquery Tree: This project is to demonstrate tree basic functionality.MCEBuddy 2.x: Convert and Remove Commercials for your Windows Media CenterMvcDesign: MvcDesign engine implementation projectMy Task Manager: This is a task manager module for DotNetNuke. I am using it to get started developing modules.MyAppwithbranches: MyAppwithbranchesProjecte prova: rpyGEO: pyGEO is a python package capable of parsing microarray data files. It also has a primitive plotting function.Scarlet Road: Scarlet Road is a top-down shooter. It's you against an unending horde of monsters.simplecounter: A simple counter, cick and counter.SiteEmpires: ????????Soundcloud Loader: Simple Tool for downloading Tracks from Soundcloud.Windows Phone Samples: Windows Phone code samples.

    Read the article

  • Code excavations, wishful invocations, perimeters and domain specific unit test frameworks

    - by RoyOsherove
    One of the talks I did at QCON London was about a subject that I’ve come across fairly recently , when I was building SilverUnit – a “pure” unit test framework for silverlight objects that depend on the silverlight runtime to run. It is the concept of “cogs in the machine” – when your piece of code needs to run inside a host framework or runtime that you have little or no control over for testability related matters. Examples of such cogs and machines can be: your custom control running inside silverlight runtime in the browser your plug-in running inside an IDE your activity running inside a windows workflow your code running inside a java EE bean your code inheriting from a COM+ (enterprise services) component etc.. Not all of these are necessarily testability problems. The main testability problem usually comes when your code actually inherits form something inside the system. For example. one of the biggest problems with testing objects like silverlight controls is the way they depend on the silverlight runtime – they don’t implement some silverlight interface, they don’t just call external static methods against the framework runtime that surrounds them – they actually inherit parts of the framework: they all inherit (in this case) from the silverlight DependencyObject Wrapping it up? An inheritance dependency is uniquely challenging to bring under test, because “classic” methods such as wrapping the object under test with a framework wrapper will not work, and the only way to do manually is to create parallel testable objects that get delegated with all the possible actions from the dependencies.    In silverlight’s case, that would mean creating your own custom logic class that would be called directly from controls that inherit from silverlight, and would be tested independently of these controls. The pro side is that you get the benefit of understanding the “contract” and the “roles” your system plays against your logic, but unfortunately, more often than not, it can be very tedious to create, and may sometimes feel unnecessary or like code duplication. About perimeters A perimeter is that invisible line that your draw around your pieces of logic during a test, that separate the code under test from any dependencies that it uses. Most of the time, a test perimeter around an object will be the list of seams (dependencies that can be replaced such as interfaces, virtual methods etc.) that are actually replaced for that test or for all the tests. Role based perimeters In the case of creating a wrapper around an object – one really creates a “role based” perimeter around the logic that is being tested – that wrapper takes on roles that are required by the code under test, and also communicates with the host system to implement those roles and provide any inputs to the logic under test. in the image below – we have the code we want to test represented as a star. No perimeter is drawn yet (we haven’t wrapped it up in anything yet). in the image below is what happens when you wrap your logic with a role based wrapper – you get a role based perimeter anywhere your code interacts with the system: There’s another way to bring that code under test – using isolation frameworks like typemock, rhino mocks and MOQ (but if your code inherits from the system, Typemock might be the only way to isolate the code from the system interaction.   Ad-Hoc Isolation perimeters the image below shows what I call ad-hoc perimeter that might be vastly different between different tests: This perimeter’s surface is much smaller, because for that specific test, that is all the “change” that is required to the host system behavior.   The third way of isolating the code from the host system is the main “meat” of this post: Subterranean perimeters Subterranean perimeters are Deep rooted perimeters  - “always on” seams that that can lie very deep in the heart of the host system where they are fully invisible even to the test itself, not just to the code under test. Because they lie deep inside a system you can’t control, the only way I’ve found to control them is with runtime (not compile time) interception of method calls on the system. One way to get such abilities is by using Aspect oriented frameworks – for example, in SilverUnit, I’ve used the CThru AOP framework based on Typemock hooks and CLR profilers to intercept such system level method calls and effectively turn them into seams that lie deep down at the heart of the silverlight runtime. the image below depicts an example of what such a perimeter could look like: As you can see, the actual seams can be very far away form the actual code under test, and as you’ll discover, that’s actually a very good thing. Here is only a partial list of examples of such deep rooted seams : disabling the constructor of a base class five levels below the code under test (this.base.base.base.base) faking static methods of a type that’s being called several levels down the stack: method x() calls y() calls z() calls SomeType.StaticMethod()  Replacing an async mechanism with a synchronous one (replacing all timers with your own timer behavior that always Ticks immediately upon calls to “start()” on the same caller thread for example) Replacing event mechanisms with your own event mechanism (to allow “firing” system events) Changing the way the system saves information with your own saving behavior (in silverunit, I replaced all Dependency Property set and get with calls to an in memory value store instead of using the one built into silverlight which threw exceptions without a browser) several questions could jump in: How do you know what to fake? (how do you discover the perimeter?) How do you fake it? Wouldn’t this be problematic  - to fake something you don’t own? it might change in the future How do you discover the perimeter to fake? To discover a perimeter all you have to do is start with a wishful invocation. a wishful invocation is the act of trying to invoke a method (or even just create an instance ) of an object using “regular” test code. You invoke the thing that you’d like to do in a real unit test, to see what happens: Can I even create an instance of this object without getting an exception? Can I invoke this method on that instance without getting an exception? Can I verify that some call into the system happened? You make the invocation, get an exception (because there is a dependency) and look at the stack trace. choose a location in the stack trace and disable it. Then try the invocation again. if you don’t get an exception the perimeter is good for that invocation, so you can move to trying out other methods on that object. in a future post I will show the process using CThru, and how you end up with something close to a domain specific test framework after you’re done creating the perimeter you need.

    Read the article

  • Mocking the Unmockable: Using Microsoft Moles with Gallio

    - by Thomas Weller
    Usual opensource mocking frameworks (like e.g. Moq or Rhino.Mocks) can mock only interfaces and virtual methods. In contrary to that, Microsoft’s Moles framework can ‘mock’ virtually anything, in that it uses runtime instrumentation to inject callbacks in the method MSIL bodies of the moled methods. Therefore, it is possible to detour any .NET method, including non-virtual/static methods in sealed types. This can be extremely helpful when dealing e.g. with code that calls into the .NET framework, some third-party or legacy stuff etc… Some useful collected resources (links to website, documentation material and some videos) can be found in my toolbox on Delicious under this link: http://delicious.com/thomasweller/toolbox+moles A Gallio extension for Moles Originally, Moles is a part of Microsoft’s Pex framework and thus integrates best with Visual Studio Unit Tests (MSTest). However, the Moles sample download contains some additional assemblies to also support other unit test frameworks. They provide a Moled attribute to ease the usage of mole types with the respective framework (there are extensions for NUnit, xUnit.net and MbUnit v2 included with the samples). As there is no such extension for the Gallio platform, I did the few required lines myself – the resulting Gallio.Moles.dll is included with the sample download. With this little assembly in place, it is possible to use Moles with Gallio like that: [Test, Moled] public void SomeTest() {     ... What you can do with it Moles can be very helpful, if you need to ‘mock’ something other than a virtual or interface-implementing method. This might be the case when dealing with some third-party component, legacy code, or if you want to ‘mock’ the .NET framework itself. Generally, you need to announce each moled type that you want to use in a test with the MoledType attribute on assembly level. For example: [assembly: MoledType(typeof(System.IO.File))] Below are some typical use cases for Moles. For a more detailed overview (incl. naming conventions and an instruction on how to create the required moles assemblies), please refer to the reference material above.  Detouring the .NET framework Imagine that you want to test a method similar to the one below, which internally calls some framework method:   public void ReadFileContent(string fileName) {     this.FileContent = System.IO.File.ReadAllText(fileName); } Using a mole, you would replace the call to the File.ReadAllText(string) method with a runtime delegate like so: [Test, Moled] [Description("This 'mocks' the System.IO.File class with a custom delegate.")] public void ReadFileContentWithMoles() {     // arrange ('mock' the FileSystem with a delegate)     System.IO.Moles.MFile.ReadAllTextString = (fname => fname == FileName ? FileContent : "WrongFileName");       // act     var testTarget = new TestTarget.TestTarget();     testTarget.ReadFileContent(FileName);       // assert     Assert.AreEqual(FileContent, testTarget.FileContent); } Detouring static methods and/or classes A static method like the below… public static string StaticMethod(int x, int y) {     return string.Format("{0}{1}", x, y); } … can be ‘mocked’ with the following: [Test, Moled] public void StaticMethodWithMoles() {     MStaticClass.StaticMethodInt32Int32 = ((x, y) => "uups");       var result = StaticClass.StaticMethod(1, 2);       Assert.AreEqual("uups", result); } Detouring constructors You can do this delegate thing even with a class’ constructor. The syntax for this is not all  too intuitive, because you have to setup the internal state of the mole, but generally it works like a charm. For example, to replace this c’tor… public class ClassWithCtor {     public int Value { get; private set; }       public ClassWithCtor(int someValue)     {         this.Value = someValue;     } } … you would do the following: [Test, Moled] public void ConstructorTestWithMoles() {     MClassWithCtor.ConstructorInt32 =            ((@class, @value) => new MClassWithCtor(@class) {ValueGet = () => 99});       var classWithCtor = new ClassWithCtor(3);       Assert.AreEqual(99, classWithCtor.Value); } Detouring abstract base classes You can also use this approach to ‘mock’ abstract base classes of a class that you call in your test. Assumed that you have something like that: public abstract class AbstractBaseClass {     public virtual string SaySomething()     {         return "Hello from base.";     } }      public class ChildClass : AbstractBaseClass {     public override string SaySomething()     {         return string.Format(             "Hello from child. Base says: '{0}'",             base.SaySomething());     } } Then you would set up the child’s underlying base class like this: [Test, Moled] public void AbstractBaseClassTestWithMoles() {     ChildClass child = new ChildClass();     new MAbstractBaseClass(child)         {                 SaySomething = () => "Leave me alone!"         }         .InstanceBehavior = MoleBehaviors.Fallthrough;       var hello = child.SaySomething();       Assert.AreEqual("Hello from child. Base says: 'Leave me alone!'", hello); } Setting the moles behavior to a value of  MoleBehaviors.Fallthrough causes the ‘original’ method to be called if a respective delegate is not provided explicitly – here it causes the ChildClass’ override of the SaySomething() method to be called. There are some more possible scenarios, where the Moles framework could be of much help (e.g. it’s also possible to detour interface implementations like IEnumerable<T> and such…). One other possibility that comes to my mind (because I’m currently dealing with that), is to replace calls from repository classes to the ADO.NET Entity Framework O/R mapper with delegates to isolate the repository classes from the underlying database, which otherwise would not be possible… Usage Since Moles relies on runtime instrumentation, mole types must be run under the Pex profiler. This only works from inside Visual Studio if you write your tests with MSTest (Visual Studio Unit Test). While other unit test frameworks generally can be used with Moles, they require the respective tests to be run via command line, executed through the moles.runner.exe tool. A typical test execution would be similar to this: moles.runner.exe <mytests.dll> /runner:<myframework.console.exe> /args:/<myargs> So, the moled test can be run through tools like NCover or a scripting tool like MSBuild (which makes them easy to run in a Continuous Integration environment), but they are somewhat unhandy to run in the usual TDD workflow (which I described in some detail here). To make this a bit more fluent, I wrote a ReSharper live template to generate the respective command line for the test (it is also included in the sample download – moled_cmd.xml). - This is just a quick-and-dirty ‘solution’. Maybe it makes sense to write an extra Gallio adapter plugin (similar to the many others that are already provided) and include it with the Gallio download package, if  there’s sufficient demand for it. As of now, the only way to run tests with the Moles framework from within Visual Studio is by using them with MSTest. From the command line, anything with a managed console runner can be used (provided that the appropriate extension is in place)… A typical Gallio/Moles command line (as generated by the mentioned R#-template) looks like that: "%ProgramFiles%\Microsoft Moles\bin\moles.runner.exe" /runner:"%ProgramFiles%\Gallio\bin\Gallio.Echo.exe" "Gallio.Moles.Demo.dll" /args:/r:IsolatedAppDomain /args:/filter:"ExactType:TestFixture and Member:ReadFileContentWithMoles" -- Note: When using the command line with Echo (Gallio’s console runner), be sure to always include the IsolatedAppDomain option, otherwise the tests won’t use the instrumentation callbacks! -- License issues As I already said, the free mocking frameworks can mock only interfaces and virtual methods. if you want to mock other things, you need the Typemock Isolator tool for that, which comes with license costs (Although these ‘costs’ are ridiculously low compared to the value that such a tool can bring to a software project, spending money often is a considerable gateway hurdle in real life...).  The Moles framework also is not totally free, but comes with the same license conditions as the (closely related) Pex framework: It is free for academic/non-commercial use only, to use it in a ‘real’ software project requires an MSDN Subscription (from VS2010pro on). The demo solution The sample solution (VS 2008) can be downloaded from here. It contains the Gallio.Moles.dll which provides the here described Moled attribute, the above mentioned R#-template (moled_cmd.xml) and a test fixture containing the above described use case scenarios. To run it, you need the Gallio framework (download) and Microsoft Moles (download) being installed in the default locations. Happy testing…

    Read the article

  • Building extensions for Expression Blend 4 using MEF

    - by Timmy Kokke
    Introduction Although it was possible to write extensions for Expression Blend and Expression Design, it wasn’t very easy and out of the box only one addin could be used. With Expression Blend 4 it is possible to write extensions using MEF, the Managed Extensibility Framework. Until today there’s no documentation on how to build these extensions, so look thru the code with Reflector is something you’ll have to do very often. Because Blend and Design are build using WPF searching the visual tree with Snoop and Mole belong to the tools you’ll be using a lot exploring the possibilities.  Configuring the extension project Extensions are regular .NET class libraries. To create one, load up Visual Studio 2010 and start a new project. Because Blend is build using WPF, choose a WPF User Control Library from the Windows section and give it a name and location. I named mine DemoExtension1. Because Blend looks for addins named *.extension.dll  you’ll have to tell Visual Studio to use that in the Assembly Name. To change the Assembly Name right click your project and go to Properties. On the Application tab, add .Extension to name already in the Assembly name text field. To be able to debug this extension, I prefer to set the output path on the Build tab to the extensions folder of Expression Blend. This means that everything that used to go into the Debug folder is placed in the extensions folder. Including all referenced assemblies that have the copy local property set to false. One last setting. To be able to debug your extension you could start Blend and attach the debugger by hand. I like it to be able to just hit F5. Go to the Debug tab and add the the full path to Blend.exe in the Start external program text field. Extension Class Add a new class to the project.  This class needs to be inherited from the IPackage interface. The IPackage interface can be found in the Microsoft.Expression.Extensibility namespace. To get access to this namespace add Microsoft.Expression.Extensibility.dll to your references. This file can be found in the same folder as the (Expression Blend 4 Beta) Blend.exe file. Make sure the Copy Local property is set to false in this reference. After implementing the interface the class would look something like: using Microsoft.Expression.Extensibility; namespace DemoExtension1 { public class DemoExtension1:IPackage { public void Load(IServices services) { } public void Unload() { } } } These two methods are called when your addin is loaded and unloaded. The parameter passed to the Load method, IServices services, is your main entry point into Blend. The IServices interface exposes the GetService<T> method. You will be using this method a lot. Almost every part of Blend can be accessed thru a service. For example, you can use to get to the commanding services of Blend by calling GetService<ICommandService>() or to get to the Windowing services by calling GetService<IWindowService>(). To get Blend to load the extension we have to implement MEF. (You can get up to speed on MEF on the community site or read the blog of Mr. MEF, Glenn Block.)  In the case of Blend extensions, all that needs to be done is mark the class with an Export attribute and pass it the type of IPackage. The Export attribute can be found in the System.ComponentModel.Composition namespace which is part of the .NET 4 framework. You need to add this to your references. using System.ComponentModel.Composition; using Microsoft.Expression.Extensibility;   namespace DemoExtension1 { [Export(typeof(IPackage))] public class DemoExtension1:IPackage { Blend is able to find your addin now. Adding UI The addin doesn’t do very much at this point. The WPF User Control Library came with a UserControl so lets use that in this example. I just drop a Button and a TextBlock onto the surface of the control to have something to show in the demo. To get the UserControl to work in Blend it has to be registered with the WindowService.  Call GetService<IWindowService>() on the IServices interface to get access to the windowing services. The UserControl will be used in Blend on a Palette and has to be registered to enable it. This is done by calling the RegisterPalette on the IWindowService interface and passing it an identifier, an instance of the UserControl and a caption for the palette. public void Load(IServices services) { IWindowService windowService = services.GetService<IWindowService>(); UserControl1 uc = new UserControl1(); windowService.RegisterPalette("DemoExtension", uc, "Demo Extension"); } After hitting F5 to start debugging Expression Blend will start. You should be able to find the addin in the Window menu now. Activating this window will show the “Demo Extension” palette with the UserControl, style according to the settings of Blend. Now what? Because little is publicly known about how to access different parts of Blend adding breakpoints in Debug mode and browsing thru objects using the Quick Watch feature of Visual Studio is something you have to do very often. This demo extension can be used for that purpose very easily. Add the click event handler to the button on the UserControl. Change the contructor to take the IServices interface and store this in a field. Set a breakpoint in the Button_Click method. public partial class UserControl1 : UserControl { private readonly IServices _services;   public UserControl1(IServices services) { _services = services; InitializeComponent(); }   private void button1_Click(object sender, RoutedEventArgs e) { } } Change the call to the constructor in the load method and pass it the services property. public void Load(IServices services) { IWindowService service = services.GetService<IWindowService>(); UserControl1 uc = new UserControl1(services); service.RegisterPalette("DemoExtension", uc, "Demo Extension"); } Hit F5 to compile and start Blend. Got to the window menu and start show the addin. Click on  the button to hit the breakpoint. Now place the carrot text _services text in the code window and hit Shift+F9 to show the Quick Watch window. Now start exploring and discovering where to find everything you need.  More Information The are no official resources available yet. Microsoft has released one extension for expression Blend that is very useful as a reference, the Microsoft Expression Blend® Add-in Preview for Windows® Phone. This will install a .extension.dll file in the extension folder of Blend. You can load this file with Reflector and have a peek at how Microsoft is building his addins. Conclusion I hope this gives you something to get started building extensions for Expression Blend. Until Microsoft releases the final version, which hopefully includes more information about building extensions, we’ll have to work on documenting it in the community.

    Read the article

  • Wrapping ASP.NET Client Callbacks

    - by Ricardo Peres
    Client Callbacks are probably the less known (and I dare say, less loved) of all the AJAX options in ASP.NET, which also include the UpdatePanel, Page Methods and Web Services. The reason for that, I believe, is it’s relative complexity: Get a reference to a JavaScript function; Dynamically register function that calls the above reference; Have a JavaScript handler call the registered function. However, it has some the nice advantage of being self-contained, that is, doesn’t need additional files, such as web services, JavaScript libraries, etc, or static methods declared on a page, or any kind of attributes. So, here’s what I want to do: Have a DOM element which exposes a method that is executed server side, passing it a string and returning a string; Have a server-side event that handles the client-side call; Have two client-side user-supplied callback functions for handling the success and error results. I’m going to develop a custom control without user interface that does the registration of the client JavaScript method as well as a server-side event that can be hooked by some handler on a page. My markup will look like this: 1: <script type="text/javascript"> 1:  2:  3: function onCallbackSuccess(result, context) 4: { 5: } 6:  7: function onCallbackError(error, context) 8: { 9: } 10:  </script> 2: <my:CallbackControl runat="server" ID="callback" SendAllData="true" OnCallback="OnCallback"/> The control itself looks like this: 1: public class CallbackControl : Control, ICallbackEventHandler 2: { 3: #region Public constructor 4: public CallbackControl() 5: { 6: this.SendAllData = false; 7: this.Async = true; 8: } 9: #endregion 10:  11: #region Public properties and events 12: public event EventHandler<CallbackEventArgs> Callback; 13:  14: [DefaultValue(true)] 15: public Boolean Async 16: { 17: get; 18: set; 19: } 20:  21: [DefaultValue(false)] 22: public Boolean SendAllData 23: { 24: get; 25: set; 26: } 27:  28: #endregion 29:  30: #region Protected override methods 31:  32: protected override void Render(HtmlTextWriter writer) 33: { 34: writer.AddAttribute(HtmlTextWriterAttribute.Id, this.ClientID); 35: writer.RenderBeginTag(HtmlTextWriterTag.Span); 36:  37: base.Render(writer); 38:  39: writer.RenderEndTag(); 40: } 41:  42: protected override void OnInit(EventArgs e) 43: { 44: String reference = this.Page.ClientScript.GetCallbackEventReference(this, "arg", "onCallbackSuccess", "context", "onCallbackError", this.Async); 45: String script = String.Concat("\ndocument.getElementById('", this.ClientID, "').callback = function(arg, context, onCallbackSuccess, onCallbackError){", ((this.SendAllData == true) ? "__theFormPostCollection.length = 0; __theFormPostData = ''; WebForm_InitCallback(); " : String.Empty), reference, ";};\n"); 46:  47: this.Page.ClientScript.RegisterStartupScript(this.GetType(), String.Concat("callback", this.ClientID), script, true); 48:  49: base.OnInit(e); 50: } 51:  52: #endregion 53:  54: #region Protected virtual methods 55: protected virtual void OnCallback(CallbackEventArgs args) 56: { 57: EventHandler<CallbackEventArgs> handler = this.Callback; 58:  59: if (handler != null) 60: { 61: handler(this, args); 62: } 63: } 64:  65: #endregion 66:  67: #region ICallbackEventHandler Members 68:  69: String ICallbackEventHandler.GetCallbackResult() 70: { 71: CallbackEventArgs args = new CallbackEventArgs(this.Context.Items["Data"] as String); 72:  73: this.OnCallback(args); 74:  75: return (args.Result); 76: } 77:  78: void ICallbackEventHandler.RaiseCallbackEvent(String eventArgument) 79: { 80: this.Context.Items["Data"] = eventArgument; 81: } 82:  83: #endregion 84: } And the event argument class: 1: [Serializable] 2: public class CallbackEventArgs : EventArgs 3: { 4: public CallbackEventArgs(String argument) 5: { 6: this.Argument = argument; 7: this.Result = String.Empty; 8: } 9:  10: public String Argument 11: { 12: get; 13: private set; 14: } 15:  16: public String Result 17: { 18: get; 19: set; 20: } 21: } You will notice two properties on the CallbackControl: Async: indicates if the call should be made asynchronously or synchronously (the default); SendAllData: indicates if the callback call will include the view and control state of all of the controls on the page, so that, on the server side, they will have their properties set when the Callback event is fired. The CallbackEventArgs class exposes two properties: Argument: the read-only argument passed to the client-side function; Result: the result to return to the client-side callback function, set from the Callback event handler. An example of an handler for the Callback event would be: 1: protected void OnCallback(Object sender, CallbackEventArgs e) 2: { 3: e.Result = String.Join(String.Empty, e.Argument.Reverse()); 4: } Finally, in order to fire the Callback event from the client, you only need this: 1: <input type="text" id="input"/> 2: <input type="button" value="Get Result" onclick="document.getElementById('callback').callback(callback(document.getElementById('input').value, 'context', onCallbackSuccess, onCallbackError))"/> The syntax of the callback function is: arg: some string argument; context: some context that will be passed to the callback functions (success or failure); callbackSuccessFunction: some function that will be called when the callback succeeds; callbackFailureFunction: some function that will be called if the callback fails for some reason. Give it a try and see if it helps!

    Read the article

  • C#: Optional Parameters - Pros and Pitfalls

    - by James Michael Hare
    When Microsoft rolled out Visual Studio 2010 with C# 4, I was very excited to learn how I could apply all the new features and enhancements to help make me and my team more productive developers. Default parameters have been around forever in C++, and were intentionally omitted in Java in favor of using overloading to satisfy that need as it was though that having too many default parameters could introduce code safety issues.  To some extent I can understand that move, as I’ve been bitten by default parameter pitfalls before, but at the same time I feel like Java threw out the baby with the bathwater in that move and I’m glad to see C# now has them. This post briefly discusses the pros and pitfalls of using default parameters.  I’m avoiding saying cons, because I really don’t believe using default parameters is a negative thing, I just think there are things you must watch for and guard against to avoid abuses that can cause code safety issues. Pro: Default Parameters Can Simplify Code Let’s start out with positives.  Consider how much cleaner it is to reduce all the overloads in methods or constructors that simply exist to give the semblance of optional parameters.  For example, we could have a Message class defined which allows for all possible initializations of a Message: 1: public class Message 2: { 3: // can either cascade these like this or duplicate the defaults (which can introduce risk) 4: public Message() 5: : this(string.Empty) 6: { 7: } 8:  9: public Message(string text) 10: : this(text, null) 11: { 12: } 13:  14: public Message(string text, IDictionary<string, string> properties) 15: : this(text, properties, -1) 16: { 17: } 18:  19: public Message(string text, IDictionary<string, string> properties, long timeToLive) 20: { 21: // ... 22: } 23: }   Now consider the same code with default parameters: 1: public class Message 2: { 3: // can either cascade these like this or duplicate the defaults (which can introduce risk) 4: public Message(string text = "", IDictionary<string, string> properties = null, long timeToLive = -1) 5: { 6: // ... 7: } 8: }   Much more clean and concise and no repetitive coding!  In addition, in the past if you wanted to be able to cleanly supply timeToLive and accept the default on text and properties above, you would need to either create another overload, or pass in the defaults explicitly.  With named parameters, though, we can do this easily: 1: var msg = new Message(timeToLive: 100);   Pro: Named Parameters can Improve Readability I must say one of my favorite things with the default parameters addition in C# is the named parameters.  It lets code be a lot easier to understand visually with no comments.  Think how many times you’ve run across a TimeSpan declaration with 4 arguments and wondered if they were passing in days/hours/minutes/seconds or hours/minutes/seconds/milliseconds.  A novice running through your code may wonder what it is.  Named arguments can help resolve the visual ambiguity: 1: // is this days/hours/minutes/seconds (no) or hours/minutes/seconds/milliseconds (yes) 2: var ts = new TimeSpan(1, 2, 3, 4); 3:  4: // this however is visually very explicit 5: var ts = new TimeSpan(days: 1, hours: 2, minutes: 3, seconds: 4);   Or think of the times you’ve run across something passing a Boolean literal and wondered what it was: 1: // what is false here? 2: var sub = CreateSubscriber(hostname, port, false); 3:  4: // aha! Much more visibly clear 5: var sub = CreateSubscriber(hostname, port, isBuffered: false);   Pitfall: Don't Insert new Default Parameters In Between Existing Defaults Now let’s consider a two potential pitfalls.  The first is really an abuse.  It’s not really a fault of the default parameters themselves, but a fault in the use of them.  Let’s consider that Message constructor again with defaults.  Let’s say you want to add a messagePriority to the message and you think this is more important than a timeToLive value, so you decide to put messagePriority before it in the default, this gives you: 1: public class Message 2: { 3: public Message(string text = "", IDictionary<string, string> properties = null, int priority = 5, long timeToLive = -1) 4: { 5: // ... 6: } 7: }   Oh boy have we set ourselves up for failure!  Why?  Think of all the code out there that could already be using the library that already specified the timeToLive, such as this possible call: 1: var msg = new Message(“An error occurred”, myProperties, 1000);   Before this specified a message with a TTL of 1000, now it specifies a message with a priority of 1000 and a time to live of -1 (infinite).  All of this with NO compiler errors or warnings. So the rule to take away is if you are adding new default parameters to a method that’s currently in use, make sure you add them to the end of the list or create a brand new method or overload. Pitfall: Beware of Default Parameters in Inheritance and Interface Implementation Now, the second potential pitfalls has to do with inheritance and interface implementation.  I’ll illustrate with a puzzle: 1: public interface ITag 2: { 3: void WriteTag(string tagName = "ITag"); 4: } 5:  6: public class BaseTag : ITag 7: { 8: public virtual void WriteTag(string tagName = "BaseTag") { Console.WriteLine(tagName); } 9: } 10:  11: public class SubTag : BaseTag 12: { 13: public override void WriteTag(string tagName = "SubTag") { Console.WriteLine(tagName); } 14: } 15:  16: public static class Program 17: { 18: public static void Main() 19: { 20: SubTag subTag = new SubTag(); 21: BaseTag subByBaseTag = subTag; 22: ITag subByInterfaceTag = subTag; 23:  24: // what happens here? 25: subTag.WriteTag(); 26: subByBaseTag.WriteTag(); 27: subByInterfaceTag.WriteTag(); 28: } 29: }   What happens?  Well, even though the object in each case is SubTag whose tag is “SubTag”, you will get: 1: SubTag 2: BaseTag 3: ITag   Why?  Because default parameter are resolved at compile time, not runtime!  This means that the default does not belong to the object being called, but by the reference type it’s being called through.  Since the SubTag instance is being called through an ITag reference, it will use the default specified in ITag. So the moral of the story here is to be very careful how you specify defaults in interfaces or inheritance hierarchies.  I would suggest avoiding repeating them, and instead concentrating on the layer of classes or interfaces you must likely expect your caller to be calling from. For example, if you have a messaging factory that returns an IMessage which can be either an MsmqMessage or JmsMessage, it only makes since to put the defaults at the IMessage level since chances are your user will be using the interface only. So let’s sum up.  In general, I really love default and named parameters in C# 4.0.  I think they’re a great tool to help make your code easier to read and maintain when used correctly. On the plus side, default parameters: Reduce redundant overloading for the sake of providing optional calling structures. Improve readability by being able to name an ambiguous argument. But remember to make sure you: Do not insert new default parameters in the middle of an existing set of default parameters, this may cause unpredictable behavior that may not necessarily throw a syntax error – add to end of list or create new method. Be extremely careful how you use default parameters in inheritance hierarchies and interfaces – choose the most appropriate level to add the defaults based on expected usage. Technorati Tags: C#,.NET,Software,Default Parameters

    Read the article

  • jBullet Collision/Physics not working correctly

    - by Kenneth Bray
    Below is the code for one of my objects in the game I am creating (yes although this is a cube, I am not making anything remotely like MineCraft), and my issue is I while the cube will display and is does follow the physics if the cube falls, it does not interact with any other objects in the game. If I was to have multiple cubes in screen at once they all just sit there, or shoot off in all directions never stopping. Anyway, I am new to jBullet, and any help would be appreciated. package Object; import static org.lwjgl.opengl.GL11.GL_QUADS; import static org.lwjgl.opengl.GL11.glBegin; import static org.lwjgl.opengl.GL11.glColor3f; import static org.lwjgl.opengl.GL11.glEnd; import static org.lwjgl.opengl.GL11.glPopMatrix; import static org.lwjgl.opengl.GL11.glPushMatrix; import static org.lwjgl.opengl.GL11.glVertex3f; import javax.vecmath.Matrix4f; import javax.vecmath.Quat4f; import javax.vecmath.Vector3f; import com.bulletphysics.collision.shapes.BoxShape; import com.bulletphysics.collision.shapes.CollisionShape; import com.bulletphysics.dynamics.RigidBody; import com.bulletphysics.dynamics.RigidBodyConstructionInfo; import com.bulletphysics.linearmath.DefaultMotionState; import com.bulletphysics.linearmath.Transform; public class Cube { // Cube size/shape variables private float size; boolean cubeCollidable; boolean cubeDestroyable; // Position variables - currently this defines the center of the cube private float posX; private float posY; private float posZ; // Rotation variables - should be between 0 and 359, might consider letting rotation go higher though I can't think of a purpose currently private float rotX; private float rotY; private float rotZ; //collision shape is a box shape CollisionShape fallShape; // setup the motion state for the ball DefaultMotionState fallMotionState; Vector3f fallInertia = new Vector3f(0, 1, 0); RigidBodyConstructionInfo fallRigidBodyCI; public RigidBody fallRigidBody; int mass = 1; // Constructor public Cube(float pX, float pY, float pZ, float pSize) { posX = pX; posY = pY; posZ = pZ; size = pSize; rotX = 0; rotY = 0; rotZ = 0; // define the physics based on the values passed in fallShape = new BoxShape(new Vector3f(size, size, size)); fallMotionState = new DefaultMotionState(new Transform(new Matrix4f(new Quat4f(0, 0, 0, 1), new Vector3f(0, 50, 0), 1f))); fallRigidBodyCI = new RigidBodyConstructionInfo(mass, fallMotionState, fallShape, fallInertia); fallRigidBody = new RigidBody(fallRigidBodyCI); } public void Update() { Transform trans = new Transform(); fallRigidBody.getMotionState().getWorldTransform(trans); posY = trans.origin.x; posX = trans.origin.y; posZ = trans.origin.z; } public void Draw() { fallShape.calculateLocalInertia(mass, fallInertia); // center point posX, posY, posZ float radius = size / 2; //top glPushMatrix(); glBegin(GL_QUADS); { glColor3f(1.0f,0.0f,0.0f); // red glVertex3f(posX + radius, posY + radius, posZ - radius); glVertex3f(posX - radius, posY + radius, posZ - radius); glVertex3f(posX - radius, posY + radius, posZ + radius); glVertex3f(posX + radius, posY + radius, posZ + radius); } glEnd(); glPopMatrix(); //bottom glPushMatrix(); glBegin(GL_QUADS); { glColor3f(1.0f,1.0f,0.0f); // ?? color glVertex3f(posX + radius, posY - radius, posZ + radius); glVertex3f(posX - radius, posY - radius, posZ + radius); glVertex3f(posX - radius, posY - radius, posZ - radius); glVertex3f(posX + radius, posY - radius, posZ - radius); } glEnd(); glPopMatrix(); //right side glPushMatrix(); glBegin(GL_QUADS); { glColor3f(1.0f,0.0f,1.0f); // ?? color glVertex3f(posX + radius, posY + radius, posZ + radius); glVertex3f(posX + radius, posY - radius, posZ + radius); glVertex3f(posX + radius, posY - radius, posZ - radius); glVertex3f(posX + radius, posY + radius, posZ - radius); } glEnd(); glPopMatrix(); //left side glPushMatrix(); glBegin(GL_QUADS); { glColor3f(0.0f,1.0f,1.0f); // ?? color glVertex3f(posX - radius, posY + radius, posZ - radius); glVertex3f(posX - radius, posY - radius, posZ - radius); glVertex3f(posX - radius, posY - radius, posZ + radius); glVertex3f(posX - radius, posY + radius, posZ + radius); } glEnd(); glPopMatrix(); //front side glPushMatrix(); glBegin(GL_QUADS); { glColor3f(0.0f,0.0f,1.0f); //blue glVertex3f(posX + radius, posY + radius, posZ + radius); glVertex3f(posX - radius, posY + radius, posZ + radius); glVertex3f(posX - radius, posY - radius, posZ + radius); glVertex3f(posX + radius, posY - radius, posZ + radius); } glEnd(); glPopMatrix(); //back side glPushMatrix(); glBegin(GL_QUADS); { glColor3f(0.0f,1.0f,0.0f); // green glVertex3f(posX + radius, posY - radius, posZ - radius); glVertex3f(posX - radius, posY - radius, posZ - radius); glVertex3f(posX - radius, posY + radius, posZ - radius); glVertex3f(posX + radius, posY + radius, posZ - radius); } glEnd(); glPopMatrix(); } }

    Read the article

  • Security Issues with Single Page Apps

    - by Stephen.Walther
    Last week, I was asked to do a code review of a Single Page App built using the ASP.NET Web API, Durandal, and Knockout (good stuff!). In particular, I was asked to investigate whether there any special security issues associated with building a Single Page App which are not present in the case of a traditional server-side ASP.NET application. In this blog entry, I discuss two areas in which you need to exercise extra caution when building a Single Page App. I discuss how Single Page Apps are extra vulnerable to both Cross-Site Scripting (XSS) attacks and Cross-Site Request Forgery (CSRF) attacks. This goal of this blog post is NOT to persuade you to avoid writing Single Page Apps. I’m a big fan of Single Page Apps. Instead, the goal is to ensure that you are fully aware of some of the security issues related to Single Page Apps and ensure that you know how to guard against them. Cross-Site Scripting (XSS) Attacks According to WhiteHat Security, over 65% of public websites are open to XSS attacks. That’s bad. By taking advantage of XSS holes in a website, a hacker can steal your credit cards, passwords, or bank account information. Any website that redisplays untrusted information is open to XSS attacks. Let me give you a simple example. Imagine that you want to display the name of the current user on a page. To do this, you create the following server-side ASP.NET page located at http://MajorBank.com/SomePage.aspx: <%@Page Language="C#" %> <html> <head> <title>Some Page</title> </head> <body> Welcome <%= Request["username"] %> </body> </html> Nothing fancy here. Notice that the page displays the current username by using Request[“username”]. Using Request[“username”] displays the username regardless of whether the username is present in a cookie, a form field, or a query string variable. Unfortunately, by using Request[“username”] to redisplay untrusted information, you have now opened your website to XSS attacks. Here’s how. Imagine that an evil hacker creates the following link on another website (hackers.com): <a href="/SomePage.aspx?username=<script src=Evil.js></script>">Visit MajorBank</a> Notice that the link includes a query string variable named username and the value of the username variable is an HTML <SCRIPT> tag which points to a JavaScript file named Evil.js. When anyone clicks on the link, the <SCRIPT> tag will be injected into SomePage.aspx and the Evil.js script will be loaded and executed. What can a hacker do in the Evil.js script? Anything the hacker wants. For example, the hacker could display a popup dialog on the MajorBank.com site which asks the user to enter their password. The script could then post the password back to hackers.com and now the evil hacker has your secret password. ASP.NET Web Forms and ASP.NET MVC have two automatic safeguards against this type of attack: Request Validation and Automatic HTML Encoding. Protecting Coming In (Request Validation) In a server-side ASP.NET app, you are protected against the XSS attack described above by a feature named Request Validation. If you attempt to submit “potentially dangerous” content — such as a JavaScript <SCRIPT> tag — in a form field or query string variable then you get an exception. Unfortunately, Request Validation only applies to server-side apps. Request Validation does not help in the case of a Single Page App. In particular, the ASP.NET Web API does not pay attention to Request Validation. You can post any content you want – including <SCRIPT> tags – to an ASP.NET Web API action. For example, the following HTML page contains a form. When you submit the form, the form data is submitted to an ASP.NET Web API controller on the server using an Ajax request: <!DOCTYPE html> <html xmlns="http://www.w3.org/1999/xhtml"> <head> <title></title> </head> <body> <form data-bind="submit:submit"> <div> <label> User Name: <input data-bind="value:user.userName" /> </label> </div> <div> <label> Email: <input data-bind="value:user.email" /> </label> </div> <div> <input type="submit" value="Submit" /> </div> </form> <script src="Scripts/jquery-1.7.1.js"></script> <script src="Scripts/knockout-2.1.0.js"></script> <script> var viewModel = { user: { userName: ko.observable(), email: ko.observable() }, submit: function () { $.post("/api/users", ko.toJS(this.user)); } }; ko.applyBindings(viewModel); </script> </body> </html> The form above is using Knockout to bind the form fields to a view model. When you submit the form, the view model is submitted to an ASP.NET Web API action on the server. Here’s the server-side ASP.NET Web API controller and model class: public class UsersController : ApiController { public HttpResponseMessage Post(UserViewModel user) { var userName = user.UserName; return Request.CreateResponse(HttpStatusCode.OK); } } public class UserViewModel { public string UserName { get; set; } public string Email { get; set; } } If you submit the HTML form, you don’t get an error. The “potentially dangerous” content is passed to the server without any exception being thrown. In the screenshot below, you can see that I was able to post a username form field with the value “<script>alert(‘boo’)</script”. So what this means is that you do not get automatic Request Validation in the case of a Single Page App. You need to be extra careful in a Single Page App about ensuring that you do not display untrusted content because you don’t have the Request Validation safety net which you have in a traditional server-side ASP.NET app. Protecting Going Out (Automatic HTML Encoding) Server-side ASP.NET also protects you from XSS attacks when you render content. By default, all content rendered by the razor view engine is HTML encoded. For example, the following razor view displays the text “<b>Hello!</b>” instead of the text “Hello!” in bold: @{ var message = "<b>Hello!</b>"; } @message   If you don’t want to render content as HTML encoded in razor then you need to take the extra step of using the @Html.Raw() helper. In a Web Form page, if you use <%: %> instead of <%= %> then you get automatic HTML Encoding: <%@ Page Language="C#" %> <% var message = "<b>Hello!</b>"; %> <%: message %> This automatic HTML Encoding will prevent many types of XSS attacks. It prevents <script> tags from being rendered and only allows &lt;script&gt; tags to be rendered which are useless for executing JavaScript. (This automatic HTML encoding does not protect you from all forms of XSS attacks. For example, you can assign the value “javascript:alert(‘evil’)” to the Hyperlink control’s NavigateUrl property and execute the JavaScript). The situation with Knockout is more complicated. If you use the Knockout TEXT binding then you get HTML encoded content. On the other hand, if you use the HTML binding then you do not: <!-- This JavaScript DOES NOT execute --> <div data-bind="text:someProp"></div> <!-- This Javacript DOES execute --> <div data-bind="html:someProp"></div> <script src="Scripts/jquery-1.7.1.js"></script> <script src="Scripts/knockout-2.1.0.js"></script> <script> var viewModel = { someProp : "<script>alert('Evil!')<" + "/script>" }; ko.applyBindings(viewModel); </script>   So, in the page above, the DIV element which uses the TEXT binding is safe from XSS attacks. According to the Knockout documentation: “Since this binding sets your text value using a text node, it’s safe to set any string value without risking HTML or script injection.” Just like server-side HTML encoding, Knockout does not protect you from all types of XSS attacks. For example, there is nothing in Knockout which prevents you from binding JavaScript to a hyperlink like this: <a data-bind="attr:{href:homePageUrl}">Go</a> <script src="Scripts/jquery-1.7.1.min.js"></script> <script src="Scripts/knockout-2.1.0.js"></script> <script> var viewModel = { homePageUrl: "javascript:alert('evil!')" }; ko.applyBindings(viewModel); </script> In the page above, the value “javascript:alert(‘evil’)” is bound to the HREF attribute using Knockout. When you click the link, the JavaScript executes. Cross-Site Request Forgery (CSRF) Attacks Cross-Site Request Forgery (CSRF) attacks rely on the fact that a session cookie does not expire until you close your browser. In particular, if you visit and login to MajorBank.com and then you navigate to Hackers.com then you will still be authenticated against MajorBank.com even after you navigate to Hackers.com. Because MajorBank.com cannot tell whether a request is coming from MajorBank.com or Hackers.com, Hackers.com can submit requests to MajorBank.com pretending to be you. For example, Hackers.com can post an HTML form from Hackers.com to MajorBank.com and change your email address at MajorBank.com. Hackers.com can post a form to MajorBank.com using your authentication cookie. After your email address has been changed, by using a password reset page at MajorBank.com, a hacker can access your bank account. To prevent CSRF attacks, you need some mechanism for detecting whether a request is coming from a page loaded from your website or whether the request is coming from some other website. The recommended way of preventing Cross-Site Request Forgery attacks is to use the “Synchronizer Token Pattern” as described here: https://www.owasp.org/index.php/Cross-Site_Request_Forgery_%28CSRF%29_Prevention_Cheat_Sheet When using the Synchronizer Token Pattern, you include a hidden input field which contains a random token whenever you display an HTML form. When the user opens the form, you add a cookie to the user’s browser with the same random token. When the user posts the form, you verify that the hidden form token and the cookie token match. Preventing Cross-Site Request Forgery Attacks with ASP.NET MVC ASP.NET gives you a helper and an action filter which you can use to thwart Cross-Site Request Forgery attacks. For example, the following razor form for creating a product shows how you use the @Html.AntiForgeryToken() helper: @model MvcApplication2.Models.Product <h2>Create Product</h2> @using (Html.BeginForm()) { @Html.AntiForgeryToken(); <div> @Html.LabelFor( p => p.Name, "Product Name:") @Html.TextBoxFor( p => p.Name) </div> <div> @Html.LabelFor( p => p.Price, "Product Price:") @Html.TextBoxFor( p => p.Price) </div> <input type="submit" /> } The @Html.AntiForgeryToken() helper generates a random token and assigns a serialized version of the same random token to both a cookie and a hidden form field. (Actually, if you dive into the source code, the AntiForgeryToken() does something a little more complex because it takes advantage of a user’s identity when generating the token). Here’s what the hidden form field looks like: <input name=”__RequestVerificationToken” type=”hidden” value=”NqqZGAmlDHh6fPTNR_mti3nYGUDgpIkCiJHnEEL59S7FNToyyeSo7v4AfzF2i67Cv0qTB1TgmZcqiVtgdkW2NnXgEcBc-iBts0x6WAIShtM1″ /> And here’s what the cookie looks like using the Google Chrome developer toolbar: You use the [ValidateAntiForgeryToken] action filter on the controller action which is the recipient of the form post to validate that the token in the hidden form field matches the token in the cookie. If the tokens don’t match then validation fails and you can’t post the form: public ActionResult Create() { return View(); } [ValidateAntiForgeryToken] [HttpPost] public ActionResult Create(Product productToCreate) { if (ModelState.IsValid) { // save product to db return RedirectToAction("Index"); } return View(); } How does this all work? Let’s imagine that a hacker has copied the Create Product page from MajorBank.com to Hackers.com – the hacker grabs the HTML source and places it at Hackers.com. Now, imagine that the hacker trick you into submitting the Create Product form from Hackers.com to MajorBank.com. You’ll get the following exception: The Cross-Site Request Forgery attack is blocked because the anti-forgery token included in the Create Product form at Hackers.com won’t match the anti-forgery token stored in the cookie in your browser. The tokens were generated at different times for different users so the attack fails. Preventing Cross-Site Request Forgery Attacks with a Single Page App In a Single Page App, you can’t prevent Cross-Site Request Forgery attacks using the same method as a server-side ASP.NET MVC app. In a Single Page App, HTML forms are not generated on the server. Instead, in a Single Page App, forms are loaded dynamically in the browser. Phil Haack has a blog post on this topic where he discusses passing the anti-forgery token in an Ajax header instead of a hidden form field. He also describes how you can create a custom anti-forgery token attribute to compare the token in the Ajax header and the token in the cookie. See: http://haacked.com/archive/2011/10/10/preventing-csrf-with-ajax.aspx Also, take a look at Johan’s update to Phil Haack’s original post: http://johan.driessen.se/posts/Updated-Anti-XSRF-Validation-for-ASP.NET-MVC-4-RC (Other server frameworks such as Rails and Django do something similar. For example, Rails uses an X-CSRF-Token to prevent CSRF attacks which you generate on the server – see http://excid3.com/blog/rails-tip-2-include-csrf-token-with-every-ajax-request/#.UTFtgDDkvL8 ). For example, if you are creating a Durandal app, then you can use the following razor view for your one and only server-side page: @{ Layout = null; } <!DOCTYPE html> <html> <head> <title>Index</title> </head> <body> @Html.AntiForgeryToken() <div id="applicationHost"> Loading app.... </div> @Scripts.Render("~/scripts/vendor") <script type="text/javascript" src="~/App/durandal/amd/require.js" data-main="/App/main"></script> </body> </html> Notice that this page includes a call to @Html.AntiForgeryToken() to generate the anti-forgery token. Then, whenever you make an Ajax request in the Durandal app, you can retrieve the anti-forgery token from the razor view and pass the token as a header: var csrfToken = $("input[name='__RequestVerificationToken']").val(); $.ajax({ headers: { __RequestVerificationToken: csrfToken }, type: "POST", dataType: "json", contentType: 'application/json; charset=utf-8', url: "/api/products", data: JSON.stringify({ name: "Milk", price: 2.33 }), statusCode: { 200: function () { alert("Success!"); } } }); Use the following code to create an action filter which you can use to match the header and cookie tokens: using System.Linq; using System.Net.Http; using System.Web.Helpers; using System.Web.Http.Controllers; namespace MvcApplication2.Infrastructure { public class ValidateAjaxAntiForgeryToken : System.Web.Http.AuthorizeAttribute { protected override bool IsAuthorized(HttpActionContext actionContext) { var headerToken = actionContext .Request .Headers .GetValues("__RequestVerificationToken") .FirstOrDefault(); ; var cookieToken = actionContext .Request .Headers .GetCookies() .Select(c => c[AntiForgeryConfig.CookieName]) .FirstOrDefault(); // check for missing cookie or header if (cookieToken == null || headerToken == null) { return false; } // ensure that the cookie matches the header try { AntiForgery.Validate(cookieToken.Value, headerToken); } catch { return false; } return base.IsAuthorized(actionContext); } } } Notice that the action filter derives from the base AuthorizeAttribute. The ValidateAjaxAntiForgeryToken only works when the user is authenticated and it will not work for anonymous requests. Add the action filter to your ASP.NET Web API controller actions like this: [ValidateAjaxAntiForgeryToken] public HttpResponseMessage PostProduct(Product productToCreate) { // add product to db return Request.CreateResponse(HttpStatusCode.OK); } After you complete these steps, it won’t be possible for a hacker to pretend to be you at Hackers.com and submit a form to MajorBank.com. The header token used in the Ajax request won’t travel to Hackers.com. This approach works, but I am not entirely happy with it. The one thing that I don’t like about this approach is that it creates a hard dependency on using razor. Your single page in your Single Page App must be generated from a server-side razor view. A better solution would be to generate the anti-forgery token in JavaScript. Unfortunately, until all browsers support a way to generate cryptographically strong random numbers – for example, by supporting the window.crypto.getRandomValues() method — there is no good way to generate anti-forgery tokens in JavaScript. So, at least right now, the best solution for generating the tokens is the server-side solution with the (regrettable) dependency on razor. Conclusion The goal of this blog entry was to explore some ways in which you need to handle security differently in the case of a Single Page App than in the case of a traditional server app. In particular, I focused on how to prevent Cross-Site Scripting and Cross-Site Request Forgery attacks in the case of a Single Page App. I want to emphasize that I am not suggesting that Single Page Apps are inherently less secure than server-side apps. Whatever type of web application you build – regardless of whether it is a Single Page App, an ASP.NET MVC app, an ASP.NET Web Forms app, or a Rails app – you must constantly guard against security vulnerabilities.

    Read the article

  • Using JDialog with Tabbed Pane to draw different pictures [migrated]

    - by Bryam Ulloa
    I am using NetBeans, and I have a class that extends to JDialog, inside that Dialog box I have created a Tabbed Pane. The Tabbed Pane contains 6 different tabs, with 6 different panels of course. What I want to do is when I click on the different tabs, a diagram is supposed to be drawn with the paint method. My question is how can I draw on the different panels with just one paint method in another class being called from the Dialog class? Here is my code for the Dialog class: package GUI; public class NewJDialog extends javax.swing.JDialog{ /** * Creates new form NewJDialog */ public NewJDialog(java.awt.Frame parent, boolean modal) { super(parent, modal); initComponents(); } /** * This method is called from within the constructor to initialize the form. * WARNING: Do NOT modify this code. The content of this method is always * regenerated by the Form Editor. */ @SuppressWarnings("unchecked") // <editor-fold defaultstate="collapsed" desc="Generated Code"> private void initComponents() { jTabbedPane1 = new javax.swing.JTabbedPane(); jPanel1 = new javax.swing.JPanel(); jPanel2 = new javax.swing.JPanel(); jPanel3 = new javax.swing.JPanel(); jPanel4 = new javax.swing.JPanel(); jPanel5 = new javax.swing.JPanel(); jPanel6 = new javax.swing.JPanel(); jPanel7 = new javax.swing.JPanel(); jLabel1 = new javax.swing.JLabel(); jLabel2 = new javax.swing.JLabel(); setDefaultCloseOperation(javax.swing.WindowConstants.DISPOSE_ON_CLOSE); javax.swing.GroupLayout jPanel1Layout = new javax.swing.GroupLayout(jPanel1); jPanel1.setLayout(jPanel1Layout); jPanel1Layout.setHorizontalGroup( jPanel1Layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING) .addGap(0, 466, Short.MAX_VALUE) ); jPanel1Layout.setVerticalGroup( jPanel1Layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING) .addGap(0, 242, Short.MAX_VALUE) ); jTabbedPane1.addTab("FCFS", jPanel1); javax.swing.GroupLayout jPanel2Layout = new javax.swing.GroupLayout(jPanel2); jPanel2.setLayout(jPanel2Layout); jPanel2Layout.setHorizontalGroup( jPanel2Layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING) .addGap(0, 466, Short.MAX_VALUE) ); jPanel2Layout.setVerticalGroup( jPanel2Layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING) .addGap(0, 242, Short.MAX_VALUE) ); jTabbedPane1.addTab("SSTF", jPanel2); javax.swing.GroupLayout jPanel3Layout = new javax.swing.GroupLayout(jPanel3); jPanel3.setLayout(jPanel3Layout); jPanel3Layout.setHorizontalGroup( jPanel3Layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING) .addGap(0, 466, Short.MAX_VALUE) ); jPanel3Layout.setVerticalGroup( jPanel3Layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING) .addGap(0, 242, Short.MAX_VALUE) ); jTabbedPane1.addTab("LOOK", jPanel3); javax.swing.GroupLayout jPanel4Layout = new javax.swing.GroupLayout(jPanel4); jPanel4.setLayout(jPanel4Layout); jPanel4Layout.setHorizontalGroup( jPanel4Layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING) .addGap(0, 466, Short.MAX_VALUE) ); jPanel4Layout.setVerticalGroup( jPanel4Layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING) .addGap(0, 242, Short.MAX_VALUE) ); jTabbedPane1.addTab("LOOK C", jPanel4); javax.swing.GroupLayout jPanel5Layout = new javax.swing.GroupLayout(jPanel5); jPanel5.setLayout(jPanel5Layout); jPanel5Layout.setHorizontalGroup( jPanel5Layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING) .addGap(0, 466, Short.MAX_VALUE) ); jPanel5Layout.setVerticalGroup( jPanel5Layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING) .addGap(0, 242, Short.MAX_VALUE) ); jTabbedPane1.addTab("SCAN", jPanel5); javax.swing.GroupLayout jPanel6Layout = new javax.swing.GroupLayout(jPanel6); jPanel6.setLayout(jPanel6Layout); jPanel6Layout.setHorizontalGroup( jPanel6Layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING) .addGap(0, 466, Short.MAX_VALUE) ); jPanel6Layout.setVerticalGroup( jPanel6Layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING) .addGap(0, 242, Short.MAX_VALUE) ); jTabbedPane1.addTab("SCAN C", jPanel6); getContentPane().add(jTabbedPane1, java.awt.BorderLayout.CENTER); jLabel1.setText("Distancia:"); jLabel2.setText("___________"); javax.swing.GroupLayout jPanel7Layout = new javax.swing.GroupLayout(jPanel7); jPanel7.setLayout(jPanel7Layout); jPanel7Layout.setHorizontalGroup( jPanel7Layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING) .addGroup(jPanel7Layout.createSequentialGroup() .addGap(21, 21, 21) .addComponent(jLabel1) .addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.RELATED) .addComponent(jLabel2) .addContainerGap(331, Short.MAX_VALUE)) ); jPanel7Layout.setVerticalGroup( jPanel7Layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING) .addGroup(jPanel7Layout.createSequentialGroup() .addContainerGap() .addGroup(jPanel7Layout.createParallelGroup(javax.swing.GroupLayout.Alignment.BASELINE) .addComponent(jLabel1) .addComponent(jLabel2)) .addContainerGap(15, Short.MAX_VALUE)) ); getContentPane().add(jPanel7, java.awt.BorderLayout.PAGE_START); pack(); }// </editor-fold> /** * @param args the command line arguments */ public static void main(String args[]) { /* Set the Nimbus look and feel */ //<editor-fold defaultstate="collapsed" desc=" Look and feel setting code (optional) "> /* If Nimbus (introduced in Java SE 6) is not available, stay with the default look and feel. * For details see http://download.oracle.com/javase/tutorial/uiswing/lookandfeel/plaf.html */ try { for (javax.swing.UIManager.LookAndFeelInfo info : javax.swing.UIManager.getInstalledLookAndFeels()) { if ("Nimbus".equals(info.getName())) { javax.swing.UIManager.setLookAndFeel(info.getClassName()); break; } } } catch (ClassNotFoundException ex) { java.util.logging.Logger.getLogger(NewJDialog.class.getName()).log(java.util.logging.Level.SEVERE, null, ex); } catch (InstantiationException ex) { java.util.logging.Logger.getLogger(NewJDialog.class.getName()).log(java.util.logging.Level.SEVERE, null, ex); } catch (IllegalAccessException ex) { java.util.logging.Logger.getLogger(NewJDialog.class.getName()).log(java.util.logging.Level.SEVERE, null, ex); } catch (javax.swing.UnsupportedLookAndFeelException ex) { java.util.logging.Logger.getLogger(NewJDialog.class.getName()).log(java.util.logging.Level.SEVERE, null, ex); } //</editor-fold> /* Create and display the dialog */ java.awt.EventQueue.invokeLater(new Runnable() { public void run() { NewJDialog dialog = new NewJDialog(new javax.swing.JFrame(), true); dialog.addWindowListener(new java.awt.event.WindowAdapter() { @Override public void windowClosing(java.awt.event.WindowEvent e) { System.exit(0); } }); dialog.setVisible(true); } }); } // Variables declaration - do not modify private javax.swing.JLabel jLabel1; private javax.swing.JLabel jLabel2; private javax.swing.JPanel jPanel1; private javax.swing.JPanel jPanel2; private javax.swing.JPanel jPanel3; private javax.swing.JPanel jPanel4; private javax.swing.JPanel jPanel5; private javax.swing.JPanel jPanel6; private javax.swing.JPanel jPanel7; private javax.swing.JTabbedPane jTabbedPane1; // End of variables declaration } This is another class that I have created for the paint method: package GUI; import java.awt.Graphics; import javax.swing.JPanel; /** * * @author TOSHIBA */ public class Lienzo { private int width = 5; private int height = 5; private int y = 5; private int x = 0; private int x1 = 0; public Graphics Draw(Graphics g, int[] pistas) { //Im not sure if this is the correct way to do it //The diagram gets drawn according to values from an array //The array is not always the same thats why I used the different Panels for (int i = 0; i < pistas.length; i++) { x = pistas[i]; x1 = pistas[i + 1]; g.drawOval(x, y, width, height); g.drawString(Integer.toString(x), x, y); g.drawLine(x, y, x1, y); } return g; } } I hope you guys understand what I am trying to do with my program.

    Read the article

  • C#/.NET Little Wonders: The Timeout static class

    - by James Michael Hare
    Once again, in this series of posts I look at the parts of the .NET Framework that may seem trivial, but can help improve your code by making it easier to write and maintain. The index of all my past little wonders posts can be found here. When I started the “Little Wonders” series, I really wanted to pay homage to parts of the .NET Framework that are often small but can help in big ways.  The item I have to discuss today really is a very small item in the .NET BCL, but once again I feel it can help make the intention of code much clearer and thus is worthy of note. The Problem - Magic numbers aren’t very readable or maintainable In my first Little Wonders Post (Five Little Wonders That Make Code Better) I mention the TimeSpan factory methods which, I feel, really help the readability of constructed TimeSpan instances. Just to quickly recap that discussion, ask yourself what the TimeSpan specified in each case below is 1: // Five minutes? Five Seconds? 2: var fiveWhat1 = new TimeSpan(0, 0, 5); 3: var fiveWhat2 = new TimeSpan(0, 0, 5, 0); 4: var fiveWhat3 = new TimeSpan(0, 0, 5, 0, 0); You’d think they’d all be the same unit of time, right?  After all, most overloads tend to tack additional arguments on the end.  But this is not the case with TimeSpan, where the constructor forms are:     TimeSpan(int hours, int minutes, int seconds);     TimeSpan(int days, int hours, int minutes, int seconds);     TimeSpan(int days, int hours, int minutes, int seconds, int milliseconds); Notice how in the 4 and 5 parameter version we suddenly have the parameter days slipping in front of hours?  This can make reading constructors like those above much harder.  Fortunately, there are TimeSpan factory methods to help make your intention crystal clear: 1: // Ah! Much clearer! 2: var fiveSeconds = TimeSpan.FromSeconds(5); These are great because they remove all ambiguity from the reader!  So in short, magic numbers in constructors and methods can be ambiguous, and anything we can do to clean up the intention of the developer will make the code much easier to read and maintain. Timeout – Readable identifiers for infinite timeout values In a similar way to TimeSpan, let’s consider specifying timeouts for some of .NET’s (or our own) many methods that allow you to specify timeout periods. For example, in the TPL Task class, there is a family of Wait() methods that can take TimeSpan or int for timeouts.  Typically, if you want to specify an infinite timeout, you’d just call the version that doesn’t take a timeout parameter at all: 1: myTask.Wait(); // infinite wait But there are versions that take the int or TimeSpan for timeout as well: 1: // Wait for 100 ms 2: myTask.Wait(100); 3:  4: // Wait for 5 seconds 5: myTask.Wait(TimeSpan.FromSeconds(5); Now, if we want to specify an infinite timeout to wait on the Task, we could pass –1 (or a TimeSpan set to –1 ms), which what the .NET BCL methods with timeouts use to represent an infinite timeout: 1: // Also infinite timeouts, but harder to read/maintain 2: myTask.Wait(-1); 3: myTask.Wait(TimeSpan.FromMilliseconds(-1)); However, these are not as readable or maintainable.  If you were writing this code, you might make the mistake of thinking 0 or int.MaxValue was an infinite timeout, and you’d be incorrect.  Also, reading the code above it isn’t as clear that –1 is infinite unless you happen to know that is the specified behavior. To make the code like this easier to read and maintain, there is a static class called Timeout in the System.Threading namespace which contains definition for infinite timeouts specified as both int and TimeSpan forms: Timeout.Infinite An integer constant with a value of –1 Timeout.InfiniteTimeSpan A static readonly TimeSpan which represents –1 ms (only available in .NET 4.5+) This makes our calls to Task.Wait() (or any other calls with timeouts) much more clear: 1: // intention to wait indefinitely is quite clear now 2: myTask.Wait(Timeout.Infinite); 3: myTask.Wait(Timeout.InfiniteTimeSpan); But wait, you may say, why would we care at all?  Why not use the version of Wait() that takes no arguments?  Good question!  When you’re directly calling the method with an infinite timeout that’s what you’d most likely do, but what if you are just passing along a timeout specified by a caller from higher up?  Or perhaps storing a timeout value from a configuration file, and want to default it to infinite? For example, perhaps you are designing a communications module and want to be able to shutdown gracefully, but if you can’t gracefully finish in a specified amount of time you want to force the connection closed.  You could create a Shutdown() method in your class, and take a TimeSpan or an int for the amount of time to wait for a clean shutdown – perhaps waiting for client to acknowledge – before terminating the connection.  So, assume we had a pub/sub system with a class to broadcast messages: 1: // Some class to broadcast messages to connected clients 2: public class Broadcaster 3: { 4: // ... 5:  6: // Shutdown connection to clients, wait for ack back from clients 7: // until all acks received or timeout, whichever happens first 8: public void Shutdown(int timeout) 9: { 10: // Kick off a task here to send shutdown request to clients and wait 11: // for the task to finish below for the specified time... 12:  13: if (!shutdownTask.Wait(timeout)) 14: { 15: // If Wait() returns false, we timed out and task 16: // did not join in time. 17: } 18: } 19: } We could even add an overload to allow us to use TimeSpan instead of int, to give our callers the flexibility to specify timeouts either way: 1: // overload to allow them to specify Timeout in TimeSpan, would 2: // just call the int version passing in the TotalMilliseconds... 3: public void Shutdown(TimeSpan timeout) 4: { 5: Shutdown(timeout.TotalMilliseconds); 6: } Notice in case of this class, we don’t assume the caller wants infinite timeouts, we choose to rely on them to tell us how long to wait.  So now, if they choose an infinite timeout, they could use the –1, which is more cryptic, or use Timeout class to make the intention clear: 1: // shutdown the broadcaster, waiting until all clients ack back 2: // without timing out. 3: myBroadcaster.Shutdown(Timeout.Infinite); We could even add a default argument using the int parameter version so that specifying no arguments to Shutdown() assumes an infinite timeout: 1: // Modified original Shutdown() method to add a default of 2: // Timeout.Infinite, works because Timeout.Infinite is a compile 3: // time constant. 4: public void Shutdown(int timeout = Timeout.Infinite) 5: { 6: // same code as before 7: } Note that you can’t default the ShutDown(TimeSpan) overload with Timeout.InfiniteTimeSpan since it is not a compile-time constant.  The only acceptable default for a TimeSpan parameter would be default(TimeSpan) which is zero milliseconds, which specified no wait, not infinite wait. Summary While Timeout.Infinite and Timeout.InfiniteTimeSpan are not earth-shattering classes in terms of functionality, they do give you very handy and readable constant values that you can use in your programs to help increase readability and maintainability when specifying infinite timeouts for various timeouts in the BCL and your own applications. Technorati Tags: C#,CSharp,.NET,Little Wonders,Timeout,Task

    Read the article

  • SortedDictionary and SortedList

    - by Simon Cooper
    Apart from Dictionary<TKey, TValue>, there's two other dictionaries in the BCL - SortedDictionary<TKey, TValue> and SortedList<TKey, TValue>. On the face of it, these two classes do the same thing - provide an IDictionary<TKey, TValue> interface where the iterator returns the items sorted by the key. So what's the difference between them, and when should you use one rather than the other? (as in my previous post, I'll assume you have some basic algorithm & datastructure knowledge) SortedDictionary We'll first cover SortedDictionary. This is implemented as a special sort of binary tree called a red-black tree. Essentially, it's a binary tree that uses various constraints on how the nodes of the tree can be arranged to ensure the tree is always roughly balanced (for more gory algorithmical details, see the wikipedia link above). What I'm concerned about in this post is how the .NET SortedDictionary is actually implemented. In .NET 4, behind the scenes, the actual implementation of the tree is delegated to a SortedSet<KeyValuePair<TKey, TValue>>. One example tree might look like this: Each node in the above tree is stored as a separate SortedSet<T>.Node object (remember, in a SortedDictionary, T is instantiated to KeyValuePair<TKey, TValue>): class Node { public bool IsRed; public T Item; public SortedSet<T>.Node Left; public SortedSet<T>.Node Right; } The SortedSet only stores a reference to the root node; all the data in the tree is accessed by traversing the Left and Right node references until you reach the node you're looking for. Each individual node can be physically stored anywhere in memory; what's important is the relationship between the nodes. This is also why there is no constructor to SortedDictionary or SortedSet that takes an integer representing the capacity; there are no internal arrays that need to be created and resized. This may seen trivial, but it's an important distinction between SortedDictionary and SortedList that I'll cover later on. And that's pretty much it; it's a standard red-black tree. Plenty of webpages and datastructure books cover the algorithms behind the tree itself far better than I could. What's interesting is the comparions between SortedDictionary and SortedList, which I'll cover at the end. As a side point, SortedDictionary has existed in the BCL ever since .NET 2. That means that, all through .NET 2, 3, and 3.5, there has been a bona-fide sorted set class in the BCL (called TreeSet). However, it was internal, so it couldn't be used outside System.dll. Only in .NET 4 was this class exposed as SortedSet. SortedList Whereas SortedDictionary didn't use any backing arrays, SortedList does. It is implemented just as the name suggests; two arrays, one containing the keys, and one the values (I've just used random letters for the values): The items in the keys array are always guarenteed to be stored in sorted order, and the value corresponding to each key is stored in the same index as the key in the values array. In this example, the value for key item 5 is 'z', and for key item 8 is 'm'. Whenever an item is inserted or removed from the SortedList, a binary search is run on the keys array to find the correct index, then all the items in the arrays are shifted to accomodate the new or removed item. For example, if the key 3 was removed, a binary search would be run to find the array index the item was at, then everything above that index would be moved down by one: and then if the key/value pair {7, 'f'} was added, a binary search would be run on the keys to find the index to insert the new item, and everything above that index would be moved up to accomodate the new item: If another item was then added, both arrays would be resized (to a length of 10) before the new item was added to the arrays. As you can see, any insertions or removals in the middle of the list require a proportion of the array contents to be moved; an O(n) operation. However, if the insertion or removal is at the end of the array (ie the largest key), then it's only O(log n); the cost of the binary search to determine it does actually need to be added to the end (excluding the occasional O(n) cost of resizing the arrays to fit more items). As a side effect of using backing arrays, SortedList offers IList Keys and Values views that simply use the backing keys or values arrays, as well as various methods utilising the array index of stored items, which SortedDictionary does not (and cannot) offer. The Comparison So, when should you use one and not the other? Well, here's the important differences: Memory usage SortedDictionary and SortedList have got very different memory profiles. SortedDictionary... has a memory overhead of one object instance, a bool, and two references per item. On 64-bit systems, this adds up to ~40 bytes, not including the stored item and the reference to it from the Node object. stores the items in separate objects that can be spread all over the heap. This helps to keep memory fragmentation low, as the individual node objects can be allocated wherever there's a spare 60 bytes. In contrast, SortedList... has no additional overhead per item (only the reference to it in the array entries), however the backing arrays can be significantly larger than you need; every time the arrays are resized they double in size. That means that if you add 513 items to a SortedList, the backing arrays will each have a length of 1024. To conteract this, the TrimExcess method resizes the arrays back down to the actual size needed, or you can simply assign list.Capacity = list.Count. stores its items in a continuous block in memory. If the list stores thousands of items, this can cause significant problems with Large Object Heap memory fragmentation as the array resizes, which SortedDictionary doesn't have. Performance Operations on a SortedDictionary always have O(log n) performance, regardless of where in the collection you're adding or removing items. In contrast, SortedList has O(n) performance when you're altering the middle of the collection. If you're adding or removing from the end (ie the largest item), then performance is O(log n), same as SortedDictionary (in practice, it will likely be slightly faster, due to the array items all being in the same area in memory, also called locality of reference). So, when should you use one and not the other? As always with these sort of things, there are no hard-and-fast rules. But generally, if you: need to access items using their index within the collection are populating the dictionary all at once from sorted data aren't adding or removing keys once it's populated then use a SortedList. But if you: don't know how many items are going to be in the dictionary are populating the dictionary from random, unsorted data are adding & removing items randomly then use a SortedDictionary. The default (again, there's no definite rules on these sort of things!) should be to use SortedDictionary, unless there's a good reason to use SortedList, due to the bad performance of SortedList when altering the middle of the collection.

    Read the article

  • xml file save/read error (making a highscore system for XNA game)

    - by Eddy
    i get an error after i write player name to the file for second or third time (An unhandled exception of type 'System.InvalidOperationException' occurred in System.Xml.dll Additional information: There is an error in XML document (18, 17).) (in highscores load method In data = (HighScoreData)serializer.Deserialize(stream); it stops) the problem is that some how it adds additional "" at the end of my .dat file could anyone tell me how to fix this? the file before save looks: <?xml version="1.0"?> <HighScoreData xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:xsd="http://www.w3.org/2001/XMLSchema"> <PlayerName> <string>neil</string> <string>shawn</string> <string>mark</string> <string>cindy</string> <string>sam</string> </PlayerName> <Score> <int>200</int> <int>180</int> <int>150</int> <int>100</int> <int>50</int> </Score> <Count>5</Count> </HighScoreData> the file after save looks: <?xml version="1.0"?> <HighScoreData xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:xsd="http://www.w3.org/2001/XMLSchema"> <PlayerName> <string>Nick</string> <string>Nick</string> <string>neil</string> <string>shawn</string> <string>mark</string> </PlayerName> <Score> <int>210</int> <int>210</int> <int>200</int> <int>180</int> <int>150</int> </Score> <Count>5</Count> </HighScoreData>> the part of my code that does all of save load to xml is: DECLARATIONS PART [Serializable] public struct HighScoreData { public string[] PlayerName; public int[] Score; public int Count; public HighScoreData(int count) { PlayerName = new string[count]; Score = new int[count]; Count = count; } } IAsyncResult result = null; bool inputName; HighScoreData data; int Score = 0; public string NAME; public string HighScoresFilename = "highscores.dat"; Game1 constructor public Game1() { graphics = new GraphicsDeviceManager(this); Content.RootDirectory = "Content"; Width = graphics.PreferredBackBufferWidth = 960; Height = graphics.PreferredBackBufferHeight =640; GamerServicesComponent GSC = new GamerServicesComponent(this); Components.Add(GSC); } Inicialize function (end of it) protected override void Initialize() { //other game code base.Initialize(); string fullpath =Path.Combine(HighScoresFilename); if (!File.Exists(fullpath)) { //If the file doesn't exist, make a fake one... // Create the data to save data = new HighScoreData(5); data.PlayerName[0] = "neil"; data.Score[0] = 200; data.PlayerName[1] = "shawn"; data.Score[1] = 180; data.PlayerName[2] = "mark"; data.Score[2] = 150; data.PlayerName[3] = "cindy"; data.Score[3] = 100; data.PlayerName[4] = "sam"; data.Score[4] = 50; SaveHighScores(data, HighScoresFilename); } } all methods for loading saving and output public static void SaveHighScores(HighScoreData data, string filename) { // Get the path of the save game string fullpath = Path.Combine("highscores.dat"); // Open the file, creating it if necessary FileStream stream = File.Open(fullpath, FileMode.OpenOrCreate); try { // Convert the object to XML data and put it in the stream XmlSerializer serializer = new XmlSerializer(typeof(HighScoreData)); serializer.Serialize(stream, data); } finally { // Close the file stream.Close(); } } /* Load highscores */ public static HighScoreData LoadHighScores(string filename) { HighScoreData data; // Get the path of the save game string fullpath = Path.Combine("highscores.dat"); // Open the file FileStream stream = File.Open(fullpath, FileMode.OpenOrCreate, FileAccess.Read); try { // Read the data from the file XmlSerializer serializer = new XmlSerializer(typeof(HighScoreData)); data = (HighScoreData)serializer.Deserialize(stream);//this is the line // where program gives an error } finally { // Close the file stream.Close(); } return (data); } /* Save player highscore when game ends */ private void SaveHighScore() { // Create the data to saved HighScoreData data = LoadHighScores(HighScoresFilename); int scoreIndex = -1; for (int i = 0; i < data.Count ; i++) { if (Score > data.Score[i]) { scoreIndex = i; break; } } if (scoreIndex > -1) { //New high score found ... do swaps for (int i = data.Count - 1; i > scoreIndex; i--) { data.PlayerName[i] = data.PlayerName[i - 1]; data.Score[i] = data.Score[i - 1]; } data.PlayerName[scoreIndex] = NAME; //Retrieve User Name Here data.Score[scoreIndex] = Score; // Retrieve score here SaveHighScores(data, HighScoresFilename); } } /* Iterate through data if highscore is called and make the string to be saved*/ public string makeHighScoreString() { // Create the data to save HighScoreData data2 = LoadHighScores(HighScoresFilename); // Create scoreBoardString string scoreBoardString = "Highscores:\n\n"; for (int i = 0; i<5;i++) { scoreBoardString = scoreBoardString + data2.PlayerName[i] + "-" + data2.Score[i] + "\n"; } return scoreBoardString; } when ill make this work i will start this code when i call game over (now i start it when i press some buttons, so i could test it faster) public void InputYourName() { if (result == null && !Guide.IsVisible) { string title = "Name"; string description = "Write your name in order to save your Score"; string defaultText = "Nick"; PlayerIndex playerIndex = new PlayerIndex(); result= Guide.BeginShowKeyboardInput(playerIndex, title, description, defaultText, null, null); // NAME = result.ToString(); } if (result != null && result.IsCompleted) { NAME = Guide.EndShowKeyboardInput(result); result = null; inputName = false; SaveHighScore(); } } this where i call output to the screen (ill call this in highscores meniu section when i am done with debugging) spriteBatch.DrawString(Font1, "" + makeHighScoreString(),new Vector2(500,200), Color.White); }

    Read the article

  • Anatomy of a .NET Assembly - CLR metadata 1

    - by Simon Cooper
    Before we look at the bytes comprising the CLR-specific data inside an assembly, we first need to understand the logical format of the metadata (For this post I only be looking at simple pure-IL assemblies; mixed-mode assemblies & other things complicates things quite a bit). Metadata streams Most of the CLR-specific data inside an assembly is inside one of 5 streams, which are analogous to the sections in a PE file. The name of each section in a PE file starts with a ., and the name of each stream in the CLR metadata starts with a #. All but one of the streams are heaps, which store unstructured binary data. The predefined streams are: #~ Also called the metadata stream, this stream stores all the information on the types, methods, fields, properties and events in the assembly. Unlike the other streams, the metadata stream has predefined contents & structure. #Strings This heap is where all the namespace, type & member names are stored. It is referenced extensively from the #~ stream, as we'll be looking at later. #US Also known as the user string heap, this stream stores all the strings used in code directly. All the strings you embed in your source code end up in here. This stream is only referenced from method bodies. #GUID This heap exclusively stores GUIDs used throughout the assembly. #Blob This heap is for storing pure binary data - method signatures, generic instantiations, that sort of thing. Items inside the heaps (#Strings, #US, #GUID and #Blob) are indexed using a simple binary offset from the start of the heap. At that offset is a coded integer giving the length of that item, then the item's bytes immediately follow. The #GUID stream is slightly different, in that GUIDs are all 16 bytes long, so a length isn't required. Metadata tables The #~ stream contains all the assembly metadata. The metadata is organised into 45 tables, which are binary arrays of predefined structures containing information on various aspects of the metadata. Each entry in a table is called a row, and the rows are simply concatentated together in the file on disk. For example, each row in the TypeRef table contains: A reference to where the type is defined (most of the time, a row in the AssemblyRef table). An offset into the #Strings heap with the name of the type An offset into the #Strings heap with the namespace of the type. in that order. The important tables are (with their table number in hex): 0x2: TypeDef 0x4: FieldDef 0x6: MethodDef 0x14: EventDef 0x17: PropertyDef Contains basic information on all the types, fields, methods, events and properties defined in the assembly. 0x1: TypeRef The details of all the referenced types defined in other assemblies. 0xa: MemberRef The details of all the referenced members of types defined in other assemblies. 0x9: InterfaceImpl Links the types defined in the assembly with the interfaces that type implements. 0xc: CustomAttribute Contains information on all the attributes applied to elements in this assembly, from method parameters to the assembly itself. 0x18: MethodSemantics Links properties and events with the methods that comprise the get/set or add/remove methods of the property or method. 0x1b: TypeSpec 0x2b: MethodSpec These tables provide instantiations of generic types and methods for each usage within the assembly. There are several ways to reference a single row within a table. The simplest is to simply specify the 1-based row index (RID). The indexes are 1-based so a value of 0 can represent 'null'. In this case, which table the row index refers to is inferred from the context. If the table can't be determined from the context, then a particular row is specified using a token. This is a 4-byte value with the most significant byte specifying the table, and the other 3 specifying the 1-based RID within that table. This is generally how a metadata table row is referenced from the instruction stream in method bodies. The third way is to use a coded token, which we will look at in the next post. So, back to the bytes Now we've got a rough idea of how the metadata is logically arranged, we can now look at the bytes comprising the start of the CLR data within an assembly: The first 8 bytes of the .text section are used by the CLR loader stub. After that, the CLR-specific data starts with the CLI header. I've highlighted the important bytes in the diagram. In order, they are: The size of the header. As the header is a fixed size, this is always 0x48. The CLR major version. This is always 2, even for .NET 4 assemblies. The CLR minor version. This is always 5, even for .NET 4 assemblies, and seems to be ignored by the runtime. The RVA and size of the metadata header. In the diagram, the RVA 0x20e4 corresponds to the file offset 0x2e4 Various flags specifying if this assembly is pure-IL, whether it is strong name signed, and whether it should be run as 32-bit (this is how the CLR differentiates between x86 and AnyCPU assemblies). A token pointing to the entrypoint of the assembly. In this case, 06 (the last byte) refers to the MethodDef table, and 01 00 00 refers to to the first row in that table. (after a gap) RVA of the strong name signature hash, which comes straight after the CLI header. The RVA 0x2050 corresponds to file offset 0x250. The rest of the CLI header is mainly used in mixed-mode assemblies, and so is zeroed in this pure-IL assembly. After the CLI header comes the strong name hash, which is a SHA-1 hash of the assembly using the strong name key. After that comes the bodies of all the methods in the assembly concatentated together. Each method body starts off with a header, which I'll be looking at later. As you can see, this is a very small assembly with only 2 methods (an instance constructor and a Main method). After that, near the end of the .text section, comes the metadata, containing a metadata header and the 5 streams discussed above. We'll be looking at this in the next post. Conclusion The CLI header data doesn't have much to it, but we've covered some concepts that will be important in later posts - the logical structure of the CLR metadata and the overall layout of CLR data within the .text section. Next, I'll have a look at the contents of the #~ stream, and how the table data is arranged on disk.

    Read the article

< Previous Page | 168 169 170 171 172 173 174 175 176 177 178 179  | Next Page >