Meanwhile, Back At CodePlex…

Just a quick update — I’ve been working on Flow Based MVC Controllers some more and hope to do a blog post about them in the next couple days…

For now, I’ve moved some of my other MVC projects onto CodePlex so there is a better home for them (than my own website of course :))

Mvc Content Marker

A few months ago I wrote some code that allowed you to write to different parts of the page using inline code — You probably know it isn’t easy to add a stylesheet or script to a different part of the page since after render code has finished you can’t go back and write over it.

This code makes it so you can place a marker on the page and then write back to it no matter where you are at. It also supports forward looking markers (meaning markers that haven’t been added to the page yet) so it makes it easy to add scripts to the footer of your page from higher up in the document.

As it turns out Spark has something similar to this — but if you aren’t ready to jump into Spark then this still might be handy for you. (Spark is cool, don’t get me wrong though)

Mvc WebForm

Mvc WebForm does exactly what you think it does — It lets you place a WebForm inline with your Mvc code. I isn’t perfect at all and in all honestly was just to see if it was possible. As it turns out you can have basic event handling, button clicks, data grids — whatever — and it works directly in your Mvc Views. Neat stuff even if it is evil.

I expected to be shunned by the development community with this but surprisingly I got several ‘thank you’s and ‘good job’s — Funny how that works out sometimes.

Combining WebServices with MVC

I always liked the concept behind WebServices. Having a single place to store a bunch of complex but commonly used functions is a great way to decrease complexity of other programs that all sit on the same network. If you’re like me and tend to do a lot of intranet applications, a web service can prevent a lot of duplicate code.

My only real problem with WebServices was having to use SOAP. Adding a Web Reference to a project wasn’t that big of a deal but if you ever wanted to just call a function real quick, say from a script file (yes, I do VBScript occasionally… ick) then it isn’t quite as I’d prefer. You end up spending more time making sure your XML is well formed and less time on the logic inside your quick script.

MVC helps get around that problem by allowing you to perform normal HTTP calls and plug all your arguments into the query string or the body of the request – something much easier to do. The problem, however, is that you end up losing the convenience of using a WebService with other applications.

A Simple Solution

The idea here is to create a controller that acts as a wrapper to a WebService. By doing this we can override a few methods on our Controller that use reflection to invoke the matching method on the WebService. Also, because the Controller is still a unique class, we can still attach any number of Actions to it as we normally would. Below is some code that I wrote the other day. It isn’t battle tested so if you use it be sure to verify it does everything that you need it to do.

using System;
using System.Collections.Generic;
using System.Linq;
using System.Web;
using System.Web.Services;
using System.Web.Mvc;
using System.Reflection;
using System.Xml.Serialization;
using System.Xml.Linq;
using System.IO;

namespace Interface.Controllers {

    /// <summary>
    /// Abstract wrapper that handles calling WebService methods on behalf of a controller
    /// </summary
    public abstract class WebServiceControllerWrapper<T> : Controller where T : WebService {

        #region Constructors

        /// <summary>
        /// Creates a new Controller Wrapper for a WebService
        /// </summary>
        public WebServiceControllerWrapper() {
            this.Service = Activator.CreateInstance<T>();
        }

        #endregion

        #region Properties

        //The service that is being used for this call
        private T Service { get; set; }

        #endregion

        #region Overriding Methods

        //finds the correct method for the WebService method
        protected override void HandleUnknownAction(string actionName) {

            //find if the method exists
            MethodInfo method = this.Service
                .GetType()
                .GetMethods()
                .Where(found =>
                    found.IsPublic &&
                    found.Name.Equals(actionName, StringComparison.OrdinalIgnoreCase) &&
                    found.GetCustomAttributes(typeof(WebMethodAttribute), true).Count() > 0
                    )
                    .FirstOrDefault();

            //if no method was found, just give up
            if (method == null) { return; }

            //check if all the arguments were found
            List<object> arguments = new List<object>();
            ParameterInfo[] parameters = method.GetParameters();
            foreach (ParameterInfo param in parameters) {

                //check if this argument was found
                object arg = this.ValueProvider[param.Name].ConvertTo(param.ParameterType);
                arguments.Add(arg);
            }

            //with the arguments try and call the result
            object result = method.Invoke(this.Service, arguments.ToArray());

            //if there is a return value, serialize it and write it
            this.Response.ContentType = "text/xml";
            if (method.ReturnType != null) {

                //if this is an XElement of some kind, just use it as is
                if (result is XObject) {

                    //write the string
                    using (StreamWriter writer = new StreamWriter(this.Response.OutputStream)) {
                        writer.Write(result.ToString());
                    }

                }
                else {

                    //try and serialize it
                    XmlSerializer serialize = new XmlSerializer(result.GetType());
                    serialize.Serialize(this.Response.OutputStream, result);
                }

            }

        }

        #endregion

    }

}

The idea here is to inherit this class instead of the standard Controller class and provide the name of the WebService we want to wrap around as our Generic argument. For example…

//that's about it - actions are mapped automatically to the correct method on the webservice
public class AccountController : WebServiceControllerWrapper<AccountWebService> { }

By doing this, when our controller receives an Action, is checks the WebService instance for the same method and then tries to call the method with the arguments it finds as part of the request!

And that’s it! A quick and simple way to map incoming actions to a matching method on a Web Service!

The Return Type

I’m not sure the best way to handle the return type at this time. It seems to me that the XmlSerializer should be sufficient for object with the exception of Xml which should probably just be written out as a string. If you have a suggestion on a better way to respond to incoming requests, please let me know. 🙂

Remember: This is just some quick and dirty code – This needs some more polish and exception handling before I’d use it in a real project, but at least it might help you get going in the right direction.

New Hugoware.net Site

For the longest time now Hugoware.net has basically been the home for jLinq. Lately, I’ve been working on a new version of my site — one that represents all of the stuff I do and not just one of my projects. After working on the site for about a week I’ve updated with a brand new look and grouped all of my projects together into one site.

I’d love to get some feedback — so use the ‘Contact Me’ section to tell me if you think something could be improved.

And of course, there is my Twitter Bird (he’s open source as well :))

There isn’t much to talk about with the new site. Basically it is an ASP.NET MVC site with personal information and projects on it.

However, I’m always interested in hearing feedback. If you think something about the site is missing or could be improved, please let me know!

Software Design For Audiences – General versus Specific

So here is the problem — I’ve got limited key presses on my keyboard to make something awesome happen — even then, the awesome factor is debatable. I won’t be around forever so I need to build something the right way with as few mistakes as possible.

Which leads me to a problem I’ve found with every project I’ve worked on — Who is my target audience?

I know I’m not the first person to run into it, but I still have a hard time committing to a design until I’ve passed this hurdle — which I’m still stuck on as I write this.

General versus Specific

It’s a tough question. On one hand you can try to target a very broad audience — for example Yahoo Answers. You might get a lot more traffic because you cater to a much larger group of internet users. However, at the same time it seems that the more general you are, then the more competition you have — most likely with more programming resources on their side.

On the other hand you could try to hit a specific audience — for example StackOverflow.com. Same general idea, but more attractive to a specific group of people because they know that the content they are going to find is going to coincide with their interests. But unless your that specific group cares then you’re left with a product that no one cares about.

Is Specific Less Competition?

I was speaking with a guy where I work at the other day and we started talking about one of his friends who made it big in software development. He made big bucks selling a software package he had designed and was living it up in style while he worked on his next project. What was the software? Office management tools? A Facebook/Myspace style application?

No — Surprisingly it was software to manage State Fairs — You know, those carnivals that show up in your city from time to time. The thing was that there wasn’t any software out there already. Instead, the market was completely empty and ready for someone to swoop in and grab up all the customers.

Does “specific” targets equal to “less competition” — I’m not really sure, but it certainly seems that way.

Still Stuck

I’m still stuck trying to decide what to do in this situation. Do I go for the bigger audience, knowing that I have a higher amounts of competition — or the specific group where I have a much higher chance missing my mark?

What do you think — which audience should be the target of programmers with limited resources?