nIgnuSharp.NET

NHibernate and jQuery slides and code from Chicago Code Camp

Len Smith — Sun, 31 May 2009 21:46:35 GMT

Here’re the code and slides from my talks on NHibernate and jQuery.

And some links mentioned during my talks:

NHibernate:

jQuery:

Converting HQL to NHibernate LINQ

Len Smith — Thu, 28 May 2009 22:46:10 GMT

I was playing around with converting some HQL and Criteria queries to LINQ, and the result is pretty slick:

All I had to do was reference NHibernate.Linq and I went from:

        public IList<Stay> GetCurrentStays()
        {                       
            string hql = @"FROM Stay WHERE CheckinDate <= :now 
                    AND (CheckoutDate IS NULL OR CheckoutDate >= :now)";

            var query = getQuery(hql);
            query.SetDateTime("now", DateTime.Now);
            return query.List<Stay>();
        }
to:     
        public IList<Stay> GetCurrentStays()
        {
            var query = from stay in session.Linq<Stay>()
                        where stay.CheckinDate <= DateTime.Now &&
                              stay.CheckoutDate >= DateTime.Now
                        select stay;
            return query.ToList();
        }

Goodbye Magic Strings.  Goodbye having to teach my team a another esoteric API and syntax.

Speaking at Chicago Code Camp – May 30th

Len Smith — Wed, 27 May 2009 18:24:44 GMT

This Saturday I’ll be speaking at Chicago Code Camp which to my initial dismay is not actually in Chicago but an hour or so north. This is probably best since I’ll feel less nerdy for talking about technology all weekend instead of checking out the city.

I’ll be giving two presentation:

jQuery Magic

Get Rolling with NHibernate

If you haven’t signed up yet, there’s still time!

Creating software in two days: GiveCamp Retrospective Part 1

Len Smith — Sun, 24 May 2009 13:33:56 GMT

At Lansing GiveCamp I was chosen to lead a team tasked with creating a guest registration system for Ronald McDonald House of Mid-Michigan. Ronald McDonald House wanted to get off their current system, paper, to streamline their processes and report on their data. The event started around 7:00PM on Friday and ended with 3:00PM on Sunday. That’s 44 hours.

At first it seemed too simple and I wondered if Microsoft Access wouldn’t have been sufficient for their needs. That is until Jay Harris met with the client/charity and hammered out the Business Requirements. Whew, there were a lot.

Friday night came and we start the project. First, we defined the domain entities. We had no time to lose so with the domain defined Jay started creating business entity classes while I talked with Dave Giard and Eric Vogel more about the system architecture.

With the business entities ready and three developers wanting to get started at once, how do we get everyone productive? There’s no database, no DAL… This is where Inversion of Control paid out nicely. I whipped up some fakes to return some hard-coded objects so the team could consume those until the actual database was ready.

    public class FakeStaffMemberService : IStaffMemberService {

        private List<StaffMember> staffMembers = new List<StaffMember>() {
            new StaffMember() {Id=1, UserName="JSmith", FirstName="John", LastName="Smith",

                Type=StaffType.Admin},

        // ...

     
        public IList<StaffMember> GetAll() {return _staffMembers; }
        
        // ...

Then I told our IoC Container, StructureMap, to return a FakeStaffMemberService whenever an IStaffMemberService was requested. And yes, with proper Inversion of Control and TDD, it doesn’t matter that the database doesn’t exist in your controllers and middle-tier classes, but we had a lot of views and JavaScript to get written so it was important to hit F5 and see our website.

For the Data Access Layer, I grabbed Fluent NHibernate and fumbled getting automapping to do what I wanted. It was one of those situations where I couldn’t tell if I was five minutes or five hours away from getting the thing to work... so I tossed it and went with normal Fluent NHibernate mappings. It was somewhat tedious but a predictable and manageable task. With a greenfield database, Fluent NHibernate is perfect. Were we dealt existing schema, I would’ve feared a situation arising I couldn’t map with Fluent, but this wasn’t an issue here. Fluent NHibernate makes the mappings strongly typed and trivial/beautiful while providing helpers for testing your mappings. Along with that, I created a “test”, set to run explicitly, to create the schema and populate the database. This let us never need to open SQL Server or even think about its existence. In order to persist a new property, we simply had to add it to the mapping and add a line in our integration test for verification. This led to a less than ideal schema but functioning software was our concern. Later, when the dust settled and product was delivered, Eric and I wrote a script to optimize the schema.

This infrastructure allowed us to just rip through code all day Saturday… which was good because we were hindered by multiple power outages, a restocking trip required by myself to replace clothes and toiletries stolen from my car the night before and some fumbling trying to figure out an ASP.NET MVC binder solution.

With an hour and a half to go to our demo, I realized I had well over two hours of work to do. The main feature of our application, recording a patient’s support people and their stays was not going to be complete. I still had to code the binder and the JavaScript to handle multiple support people. I was sure trying to explain what I needed to someone would be insufficient for them to comprehend and return what I wanted. I started plowing through it, hoping maybe I could come in under the wire when I saw an out. I knew what the Act and Assert was in my Unit Test. I wrote them, checked it in and asked Dennis Burton for an hour of his time to fill out the Arrange part of the test along with the implementation. There were three failing tests and I needed them all to be green. He downloaded the project and because of our use of Inversion of Control he did not need to set up the database or know anything about the rest of the domain. An hour later he checked in the code and because all of the tests passed I didn’t even care about looking at his implementation. Dropping it into the project was the missing piece and we were done with about fifteen minutes to spare.

In this part I talked about what went right. In Part 2 I’ll talk about what didn’t.

(First photo by David Giard)

Slides and code from Central Ohio Day of .NET

Len Smith — Sat, 18 Apr 2009 14:49:15 GMT

Central Ohio Day of .NET was awesome.

As promised, here are my code and slides from my talk, Test Driven Development with Inversion of Control.

However, ignore them. I have my preferred TDD stack available at http://github.com/ignu/specish, complete with a sample test project.

Frictionless IOC in ASP.NET MVC with Windsor/Binsor

Len Smith — Mon, 15 Dec 2008 17:59:35 GMT

For the past four months my controllers have had two constructors: one that received my dependencies and one parameterless that called Windsor directly, because parameterless constructors are a requirement for the default MVC ControllerFactory. (These constructors did have a huge //HACK comment on them.)

Wiring up IOC with zero friction was quite simple.

First, we need to make a new ControllerFactory. In it, we will ask Windsor to give us the controller.

    public class CastleWindsorControllerFactory : DefaultControllerFactory
    {
        public override IController CreateController(RequestContext context, string controllerName)
        {
            return Container.Resolve<IController>(controllerName);                         
        }
    }

Then we just need to set this as the default ControllerFactory in our global.asax:

        protected void Application_Start()
        {            
            RegisterRoutes(RouteTable.Routes);            
            ControllerBuilder.Current.SetControllerFactory(new CastleWindsorControllerFactory());

Then, if you like friction, you can stop here... you'll just need to add a line to your Windsor config everytime you add a new Controller. You will forget to do this and your code will break every time you add a new Controller.

If you want to never think about your controller's IOC again, we can use Binsor and programmatically register all of our controllers using reflection.

For every type in our Web assembly, we'll see if a type is a controller. If it is a controller, we'll register it.

    for type in Assembly.Load("Web").GetTypes():    
        if typeof(IController).IsAssignableFrom(type):            
            Component(type.Name.Replace("Controller", String.Empty), IController, type, LifestyleType.Transient)

Don't forget to include LifestyleType.Transient. By default, Windsor will return a singleton. We do not want our controllers to be singletons.

And that's it. You can just start creating controllers and never have to worry about wiring up their dependencies again.

Low impact Ajax with jQuery and ASP.NET MVC

Len Smith — Sun, 09 Nov 2008 21:37:01 GMT

Here's a simple way to avoid postbacks in your site, still be SEO friendly and degrade gracefully to JavaScript free browsers (and handle middle clicks and copy&paste) in ASP.NET MVC using jQuery.

First, we'll create an alternate MasterPage called No.master with no content, only one ContentPlaceHolder:

<asp:ContentPlaceHolder ID="MainContent" runat="server" />

Now, we're able to tell via HTTP Headers if a Request is an Ajax Request, so we'll write a new method in our Controller Base class to toggle the master page:

protected string GetMasterPageName()
{
     if (this.IsAjaxRequest())
         return "No";

     return "Site";
}

And now, whenever we return a View in our Controllers, we'll use the overload that takes in the name of a View

return View("Edit", GetMasterPageName(), postServices.GetByID(id))

So when a request comes in normally, we are returned full mark-up. If the request is AJAX, we only return HTML for that view.

We won't modify the url of our links, however we'll give them all a class so we can grab then in jQuery.

<a href="/Post/Show/<%=post.ID %>" class="ajaxLink"><%= post.Subject %></a>

Then we'll wire a method called displayLink to all our ajaxLinks' click event handlers:

$('.ajaxLink').click(displayLink);

And in that function we'll make an AJAX call to the link's target (its href attribute value) using the jQuery $.get method, update our main content area and return false in order to cancel the click event of the link:

displayLink = function() {
    $.get($(this).attr('href'), function(response) {
        $('#mainContent').html(response);
    });
    return false;
};

And that's it. I would (and did) refactor the JavaScript and add a loading graphic, but I'm just awestruck at how you can Ajaxify an application in ~12 lines of code.

Have I mentioned loving Extension Methods?

Len Smith — Thu, 06 Nov 2008 13:00:19 GMT

Here's my new favorite:

public static string AppSetting(this string parameter)
{
   return System.Configuration.ConfigurationManager.AppSettings[parameter];
}

Now I can simply call

"BaseUrl".AppSetting();

Beautiful.

Writing a jQuery plugin to filter a table on keypress

Len Smith — Sun, 19 Oct 2008 20:12:51 GMT

I recently had a requirement to filter a table as the user was typing.

I was able to write a jQuery plugin to do this in just six lines of code.

I want to use jQuery to add a keyup handler to my search box, and target table(s) via a selector parameter.

First, in order to extend functionality onto a selector, we add a new function to $.fn

$.fn.tableFilter = function(tableSelector) {

Then we want to get a reference to the table we're going to filter:

table = $(tableSelector);

and we'll write a function that will actually perform the filtering:

updateTable = function() {

now, on every keypress we need a blank slate. lets hide all the rows besides the header:

table.find('tr:gt(0)').hide();

then, we'll display the rows that match the text we've typed:

table.find('td:contains("' + $(this).val() + '")').parents('tr').show();

}

and we'll assign the keypress of event of our textbox to our new filterfing function:

$(this).keyup(updateTable);

}

and bam! we're done:

$.fn.tableFilter = function(tableSelector) {

table = $(tableSelector);

updateTable = function() {

table.find('tr:gt(0)').hide();

table.find('td:contains("' + $(this).val() + '")').parents('tr').show();

}

$(this).keyup(updateTable);

}

The we just wire up our plugin like this

$("#filter").tableFilter("#ProductGrid");

View the plugin in action here.

Note that this is case sensitive. You can see how to add a case insensitive selector here: http://www.ericmmartin.com/creating-a-custom-jquery-selector/.

Ann Arbor Day of .NET code and slides

Len Smith — Sat, 18 Oct 2008 12:00:11 GMT

Ann Arbor Day of .NET is a blast.

Here's just a quick update to share my code and slides from my talk, Browser Magic with jQuery.

Slides

Demo 1 (Filtering a table of Northwind Products)

Demo 2 (Adding AJAX to an existing MVC application)

I swear I'll actually update this blog with more in depth posts about my demos within the week.