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The Cornball goes to Brunch with Chaplin

Lately I've been working pretty hard on different projects but not really stumbling upon anything blogworthy. The most recent project is quite interesting though, a single page, touch friendly, web application using the latest and greatest technologies. We've ended up with using Brunch with Chaplin , which is a very neat way of setting up a Backbone based single page web project with Brunch and Chaplin . Aside from this, I have my own little project that has lived on for almost 15 years already, The Cornball . From being a plain Windows application written i C an Win32 API, it has been ported to .NET using WPF, and is currently a Silverlight application hosted on Windows Azure. I could not find a better time to reanimate this project and create a new web based version, touch friendly, super optimized, awesome in any way. So I did... So please follow my journey at Github . It's going to take a while, I assure you, but I already have some ground work done. Meanwhile,
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jQuery file upload with Bootstrap progress bar

Performing an asynchronous file upload from the browser is a common problem with almost as many solutions as there are developers. The following solution is the best fit for my needs, and also works well with most popular browsers. Backwards compatibility is not an issue in this case which is great, because I can use the new technologies as they are supposed to be used. Everything is put together in JSFiddle for a working example . I will continue to explain the parts below... First, the input field needs to be styled as a button. The form tag is only present for us to be able to reset the file input field later on. <form>     <span class="fileUpload btn btn-default">         <span class="glyphicon glyphicon-upload"></span> Upload file         <input type="file" id="uploadFile" />     </span> </form> .fileUpload { position: relative; overflow: hidden; } .fileUpload input { position: a

Using ASP.NET MVC with MEF

I wrote this post almost a year ago, but never published it for some reason. Anyway, here is a little MVC/MEF magic. By default a controller in MVC must have a parameterless constructor. When using MEF a good practice is to inject the services via constructor parameters. These two in combination obviously creates an issue where the following scenario will not work out of the box, since there is no parameterless constructor for  MVC  to use. Note that the PartCreationPolicy is set to NonShared since a new controller have to be initialized for each request. [Export] [PartCreationPolicy(CreationPolicy.NonShared)] public class HomeController : Controller {     private readonly IServiceClient _service;     [ImportingConstructor]     public HomeController(IServiceClient service)     {         _service = service;     }     public ActionResult Index()     {         return View();     } } For this scenario to work we need to override the default controller factory with a custom imp

Bindable RichTextBox with HTML conversion in WPF

In WPF , the RichTextBox  control is not really like other controls. Due to its flexible nature, there is no built in way of binding a property to the content. In this case, I wanted a simple  RichTextBox  control with a binding to an HTML formatted string to be able to use the built-in formatting features of the  RichTextBox  and allow users to create simple HTML formatted content. First, doing the conversion on-the-fly proved to have major performance issues, so I ended up binding the content to a XAML string. The XAML to HTML conversion can be performed at any time. I created a UserControl with a bindable Text-property. The view contains a  RichTextBox  control. <RichTextBox x:Name="richTextBox" TextChanged="OnRichTextBoxChanged"> The source code for the user control contains the Text property and the methods to handle the binding. public static readonly DependencyProperty TextProperty = DependencyProperty.Register( "Text", typeof(st

Using Bootstrap Tooltip to show Parsley validation errors

I'm currently working on a web application using a variety of different frameworks, such as Backbone for the back-end, Bootstrap for the front-end and Parsley for client side form validation.  Parsley is a really powerful validation toolkit, but it takes some tweaking to make it blend with the Bootstrap front-end. Fortunately this is a one time fix, which can be re-used all over our project. Since there will be some custom options in our  Parsley  object, we can't use the default parsley-validate attribute on the form. Instead we have to initialize the validation with the jQuery syntax: $('#my-form').parsley(parsleyOptions); The options are were the magic happens, and in our case we have a global options object that our forms use to get the same experience all over the application. Here's what it looks like: var parsleyOptions = {  // Sets success and error class to Bootstrap class names  successClass: 'has-success',  errorClass: 'has-er

Proper initialize/dispose with WCF and MEF

Initialization and disposing of services in a WCF application is a bit of a hassle to control when running on an IIS instance, since the application starts and stops every now and then based on server requests. It doesnt make it easier when using an IOC, as in our case MEF. To have total control of the startup and shutdown events we began with adding a service factory to all our WCF services. <%@ ServiceHost Language="C#" Debug="true" Service="WcfService" Factory="CustomServiceHostFactory" %> When ever the application gets woke up by a request to any of the services, the service factory will be used to instantiate the service. This means we can add any logic to these methods to have full control of the WCF application initialization. Here is what a service factory class could look like. (Composition is a static class containing a reference to the MEF container) public class CustomServiceHostFactory : ServiceHostFactory { priva

Custom DataAnnotation validation on multiple properties

There are a few cases where you want to be able to validate a property value based on the value of another property. As always there are a bunch of different solutions to this problem, but the cleanest way of doing so is to create a custom DataAnnotaion validation attribute. It is as easy as creating a class derived from ValidationAttribute and overriding the IsValid-method, but instead of the usual IsValid(object value) we will be overriding the IsValid(object value, ValidationContext validationContext) method. The ValidationContext contains information about the current object beeing validated and makes it possible to get the values of related properties. By including the related properties and values in our validation class constructor. All in all, it could look like this, even though the validation logic does not really make sense in a real world context it explains the idea pretty good. [AttributeUsage(AttributeTargets.Property)] public class CustomValidationAttribute : Val