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NerdDinner.com and Two Views of ASP.NET MVC Views

Wednesday, March 11, 2009

Phil and Scott  (and the other Scott) announced the open source Nerddinner.com project and their free ASP.NET MVC eBook today. Actually, the free eBook is a single chapter of 185 pages, which is at least 50 pages longer than any chapter in Tolstoy’s War and Peace (and over half the size of my entire workflow book). Amazing.

In any case, I was looking through the code this evening and a thought struck me. You can divide the nascent world of ASP.NET MVC developers into two camps:

Taxonomy of String People

The people who use strings don’t love to use strings – they just use them to get work done. But the people who hate strings really hate strings. They’d rather be caught using goto label than ever type a string literal, and they exterminate string literals from as many places as possible.

The views in Nerddinner.com are full of strings:

    <label for="Title">Dinner Title:</label>
    <%= Html.TextBox("Title", Model.Dinner.Title) %>
    <%= Html.ValidationMessage("Title", "*") %>

The “Title” string is significant – it has to match up with the name of a controller parameter or the name of a model property when data movies in and out of the controller. A typo in the view, or in a model, can create bugs. Compare the “stringy” views to the views in another open source MVC application - CodeCampServer:

<%=Html.Input(a => a.AttendeeID)%>
<%=Html.Input(a => a.ConferenceID)%>

This is another example of using LINQ expressions to implement “reflection without strings”. A typo here yields a compiler error. The technique is quite powerful and implementations are popping up everywhere, including inside the MVCContrib project.

Errors can be caught with either approach, but you can catch errors earlier and perform safer refactorings if you take Nancy Regan’s advice and Just Say No (to magic strings).

I’m curious – which approach do YOU prefer?