aspZone.com

mvccontrib - PermanentRedirectResult and PermanentRedirectToActionResult

john — Fri, 04 Sep 2009 21:40:00 GMT

A few days ago I submitted a contribution to mvccontrib, and it got committed.

What I added was two new ActionResults. PermanentRedirectResult and PermanentRedirectToActionResult. I've had to code the same basic thing for several different projects already, I figured it was time to stop repeating myself.

This was my first use of git. I have a bit to learn, as I am not used to thinking about source control in the way that git forces you to think, but I'll figure it out. Turns out there are a few UI bugs on github in IE 8. I had to use firefox in order to submit a pull request to get my code included into the main project.

jQuery File Upload in ASP.NET MVC without using Flash

john — Thu, 20 Aug 2009 21:00:00 GMT

In this post, I will show how to implement jQuery File Upload in ASP.NET MVC without using any Flash components.

Why bother? Why not just use Flash?

That was my first thought. So I started down the path of using SWFUpload. It did not take me long to realize that I would run into a well known bug where non-IE browsers will not pass cookies properly. There are several fixes available that require you to hack the server side code. This worked fine for things like ASP.NET session state, forms authentication cookie, etc, but this project needed to work in conjunction with an single sign-on ISAPI filter that I could not modify. Since users of this site needed to be authenticated by the corporate ISAPI filter, I was unable to use Flash.

So what to use if Flash is not an option?

I googled around a bit, and found several plug-ins. But I did not really want to import yet another script library into my already complicated page. Since I was already using the jQuery Form Plugin for other features, the choice was easy.

Use jQuery Form Plugin

From the jQuery Form Plugin website, some important information about how to get a JsonResult back to the browser:

Since it is not possible to upload files using the browser's XMLHttpRequest object, the Form Plugin uses a hidden iframe element to help with the task. This is a common technique, but it has inherent limitations. The iframe element is used as the target of the form's submit operation which means that the server response is written to the iframe. This is fine if the response type is HTML or XML^[1], but doesn't work as well if the response type is script or JSON, both of which often contain characters that need to be represented using entity references when found in HTML markup.

To account for the challenges of script and JSON responses, the Form Plugin allows these responses to be embedded in a textarea element and it is recommended that you do so for these response types when used in conjuction with file uploads. Please note, however, that if a file has not been selected by the user for the file input then the request uses normal XHR to submit the form (not an iframe). This puts the burden on your server code to know when to use a textarea and when not to. If you like, you can use the iframe option of the plugin to force it to always use an iframe mode and then your server can always embed the response in a textarea. The following response shows how a script should be returned from the server:

The easiest way to do this in ASP.NET MVC, is to create a new class that inherits from JsonResult:

public class FileUploadJsonResult : JsonResult
{
    public override void ExecuteResult(ControllerContext context)
    {
        this.ContentType = "text/html";
        context.HttpContext.Response.Write("<textarea>");
        base.ExecuteResult(context);
        context.HttpContext.Response.Write("</textarea>");
    }
}

And here is how to code your controller method:

public FileUploadJsonResult AjaxUpload(HttpPostedFileBase file)
{
    // TODO: Add your business logic here and/or save the file
  
    // Return JSON
    return new FileUploadJsonResult { Data = new { message = string.Format("{0} uploaded successfully.", System.IO.Path.GetFileName(file.FileName)) } };
}

And here is the view:

<script type="text/javascript">   1:  
    $(function() {
  
        $("#ajaxUploadForm").ajaxForm({
            iframe: true,
            dataType: "json",
            beforeSubmit: function() {
                $("#ajaxUploadForm").block({ message: '<h1><img src="/Content/busy.gif" /> Uploading file...</h1>' });
            },
            success: function(result) {
                $("#ajaxUploadForm").unblock();
                $("#ajaxUploadForm").resetForm();
                $.growlUI(null, result.message);
            },
            error: function(xhr, textStatus, errorThrown) {
                $("#ajaxUploadForm").unblock();
                $("#ajaxUploadForm").resetForm();
                $.growlUI(null, 'Error uploading file');
            }
        });
    });
</script>
  
<form id="ajaxUploadForm" action="<%= Url.Action("AjaxUpload", "Upload")%>" method="post" enctype="multipart/form-data">
    <fieldset>
        <legend>Upload a file</legend>
        <label>File to Upload: <input type="file" name="file" />(100MB max size)</label>
        <input id="ajaxUploadButton" type="submit" value="Submit" />
        </fieldset>
</form>

You can download a the full source project from here.

Remote Desktop on a Second Monitor

john — Thu, 09 Jul 2009 15:22:00 GMT

I am blogging this link so that when I forget (again) how to do it, I can find it more easily.

ASP.NET MVC File Upload

john — Sun, 26 Apr 2009 14:35:00 GMT

This very short blog post will show you how to add support for uploading files to an ASP.NET MVC application.

Add a controller action

Add a controller action that accepts a parameter of type HttpPostedFileBase. In the example below, I save the file to my App_Data folder. I would highly recommend that you redirect the browser to another action when done.

public ActionResult Upload(HttpPostedFileBase file)
{
    var fileName = Path.Combine(Request.MapPath("~/App_Data"), Path.GetFileName(file.FileName));
    file.SaveAs(fileName);
    return RedirectToAction("Index");
}

Add an upload form

Add an upload form. Set the action to your upload controller action, the method to post, and very important, the enctype to multipart/form-data.

<form action="/Home/Upload" method="post" enctype="multipart/form-data">
    <label>Filename: <input type="file" name="file" /></label>
    <input type="submit" value="Submit" />
</form>

You’re done

That is all that is needed. Compile your app and give it a try. You browse or checkout the full source code from my googlecode repository.

StructureMap/Ninject + log4net

john — Tue, 07 Apr 2009 15:25:00 GMT

One fine day, my task was to refactor my classes so they did not have a dependency on log4net.

The first thing I did was to create an ILogger interface in my core library, and an Log4NetLogger class in my infrastructure library. Followed by adding a line to my IoC container bootstrapper class. Finally, I added an ILogger constructor argument to each of my classes that needed logging. Finished in no time, or so I thought.

The Problem

I quickly realized that the contents of my log files had lost one important piece of information that nearly rendered them useless.

2009-04-07 07:10:15,810 [1] DEBUG aspZone.LoggingExample.Log4NetLogger – Called Foo.DoSomething
2009-04-07 07:10:15,843 [1] DEBUG aspZone.LoggingExample.Log4NetLogger – Called Bar.DoSomething

In my Log4NetLogger constructor, I had called LogManager.GetLogger as per common practice:

public Log4NetLogger()
{
    this.logger = log4net.LogManager.GetLogger(
        System.Reflection.MethodBase.GetCurrentMethod().DeclaringType);
}

As a result, there was no way to filter my log entries by which logger they came from. Every single log entry looked like it came from Log4NetLogger. This had to change.

The Solution

After a bunch of searching and a few tweets, I found what I think is a very neat solution.

I changed my ILogger interface to ILogger<T>:

using System;
  
namespace aspZone.LoggingExample
{
    public interface ILogger<T>
    {
        void Debug(object message);
        // ...
    }
}

And I modified my Log4NetLogger like this:

using System;
using log4net;
  
namespace aspZone.LoggingExample
{
    public class Log4NetLogger<T> : ILogger<T>
    {
        private readonly ILog logger;
  
        public Log4NetLogger()
        {
            this.logger = LogManager.GetLogger(typeof(T));
        }
  
        // ...
    }
}

And using generic type inference, a syntax I was previously unaware of, to register the types in StructureMap:

using StructureMap.Configuration.DSL;
  
namespace aspZone.LoggingExample
{
    public class ExampleRegistry : Registry
    {
        public ExampleRegistry()
        {
            ForRequestedType(typeof(ILogger<>))
                .TheDefaultIsConcreteType(typeof(Log4NetLogger<>));
            // ...
        }
    }
}

The syntax for Ninject is very similar:

   1: Bind(typeof(ILogger<>)).To(typeof(Log4NetLogger<>));

Conclusion

My log entries are filterable like they were before.

2009-04-07 07:10:15,810 [1] DEBUG aspZone.LoggingExample.Foo – Called Foo.DoSomething
2009-04-07 07:10:15,843 [1] DEBUG aspZone.LoggingExample.Bar – Called Bar.DoSomething

And now I have much better separation of concerns.

ALT.NET Programming Contest

john — Fri, 06 Mar 2009 15:17:00 GMT

Last weekend, I went to the ALT.NET Seattle Open Spaces event. It was an awesome experience to talk with all my blogging heroes.

On Saturday night, they held a programming contest. I won!

http://codebetter.com/blogs/aaron.jensen/archive/2009/03/05/the-alt-net-programming-contest.aspx

Is this a good way to wire up NHibernate using StructureMap?

john — Sat, 28 Feb 2009 00:18:00 GMT

I am blogging this code snippet in order to ask some people at altnetseattle if this is a good implementation or not.

I want to know whether or not this is considered a good way of wiring up NHibernate using StructureMap. I am making use of the registry DSL feature, this code would get called somewhere in my bootstrapper.

Elsewhere in my code, my Repositories simply have a constructor dependency on ISession.

NHibernateConfiguration is my class that does all configuration of NHibernate using FluentNHibernate.

        1: public class DataAccessRegistry : Registry

       2: {

       3:     public DataAccessRegistry()

       4:     {

       5:         // NHibernate ISessionFactory

       6:         ForRequestedType<ISessionFactory>()

       7:             .CacheBy(InstanceScope.Singleton)

       8:             .TheDefault.Is.ConstructedBy(() => new NHibernateConfiguration().BuildSessionFactory());

       9:  

      10:         // NHibernate ISession

      11:         ForRequestedType<ISession>()

      12:             .CacheBy(InstanceScope.Hybrid)

      13:             .TheDefault.Is.ConstructedBy(() => ObjectFactory.GetInstance<ISessionFactory>().OpenSession());

      14:     }

      15: }

02/24/09 Tank Photos

john — Wed, 25 Feb 2009 01:56:00 GMT

How NHibernate saved my day

john — Thu, 08 Jan 2009 19:42:00 GMT

I am working on an ecommerce site as a personal learning project. Rob Conery’s MVC Storefront series of blog posts was my inspiration. However, I am following a different path. I am using NHibernate instead of Linq-To-Sql.

I determined that the hosting budget for this little project would be exceeded by any reputable hosting provider that offers Microsoft SQL server. I did find, however, several hosting providers that offered MySql at an acceptable rate.

After a half hour or so of fumbling around with installing MySql on my dev box for the very first time, and setting up an empty database, it was time to migrate my code over.

A couple of NHibernate configuration changes, and a couple of minor tweaks (and I mean very minor), my entire project was working against MySql. My database integration tests export the schema to the database, so I didn’t even have to create any tables manually. Migrating my code from one database vendor to another took less than 5 minutes.

I sat back and said to myself, “Wow!”

I shared this experience with a couple of co-workers, and they said the same thing.

Using the Code Behind in MVC causes blindness

john — Fri, 12 Dec 2008 18:37:00 GMT

LOL for the funny post title. Derik wrote a great post with a great list of tips to live by:

Keep your Code Behind empty
Keep your Views simple
Keep your Controllers light
Keep your Model fat (domain model that is)