 Friday, May 30, 2008
New release of Miado
This new release contains significant changes. First and foremost, all the implementation classes have had their public scope removed, so you will now have to program exclusively against the interfaces. I have also moved the IMiadoDao interface to IMiadoRepository in order to encourage composition and not force an inheritance hierarchy. Combined with that change, I also moved the functionality from SimpleSql into IMiadoRepository, as well as making that interface the point where you access an IDbStatement, making the IMiadoRepository the main worker module of Miado. Another change is that you need to use the MiadoRepositoryFactory to create an instance of the IMiadoRepository. Enough with the talk, let's see some code... public AdddressDao { private static readonly string INSERT_ADDRESS_SQL = "insert into Address(Address1, Address2, City, State, ZipCode) " + "values(@Addr1, @Addr2, @City, @State, @ZipCode)"; private static readonly string SELECT_ADDRESS_SQL = "select AddressId, Address1, Address2, City, " + "State, ZipCode " + "from Address "; private static readonly string SELECT_ADDRESS_BY_ID = SELECT_ADDRESS_SQL + "where AddressId = @Id "; private static readonly string SELECT_ADDRESS_BY_ZIP_CODE = SELECT_ADDRESS_SQL + "where ZipCode = @ZipCode "; private static readonly string SELECT_COUNT_BY_STATE = "select count(*) from Address where State = @State ";
// uses MiadoRepositoryFactory.CreateMiadoRepository() public AddressDao() : this(MiadoRepositoryFactory.CreateMiadoRepository( SqlClientFactory.Instance, ConfigurationManager.ConnectionStrings["MyConnection"].ConnectionString)) {}
public AdddressDao(IMiadoRepository repository) { this.MiadoRepository = repository; } protected IMiadoRepository MiadoRepository { get; set; } public void SaveAddress(Address addr) { // uses SQL right in IMiadoRepository this.MiadoRepository .ExecuteNonQuery(INSERT_ADDRESS_SQL, addr.Address1, addr.Address2, addr.City, addr.State, addr.ZipCode) } public ICollection<Address> FindAddressesByZipCode(string zipCode) { // build IDbStatement and do the mapping in a lambda expression ICollection<Address> addresses = this.MiadoRepository .CreateDbStatement(SELECT_ADDRESS_BY_ZIP_CODE) .AddParameter("ZipCode", zipCode) .QueryForResults<Address>( row => new Address() { AddressId = row.GetValue<int>("AddressId"), Address1 = row.GetValue<string>("Address1"), Address2 = row.GetValue<string>("Address2"), City = row.GetValue<string>("City"), State = row.GetValue<string>("State"), ZipCode = row.GetValue<string>("ZipCode") }); return addresses; } public Address LoadAddress(int addrId) { // uses delegate method to do the mapping return this.MiadoRepository .CreateDbStatement(SELECT_ADDRESS_BY_ID) .AddParameter("Id", addrId) .QueryForOne<Address>(CreateAddress); } public int FindCountByState(string state) { return this.MiadoRepository .CreateDbStatement(SELECT_COUNT_BY_STATE) .AddParameter("State", state) .QueryForOne<int>(row => row.GetValue<int>(0)); } private static Address CreateAddress(IResultSetRow row) { return new Address() { AddressId = row.GetValue<int>("AddressId"), Address1 = row.GetValue<string>("Address1"), Address2 = row.GetValue<string>("Address2"), City = row.GetValue<string>("City"), State = row.GetValue<string>("State"), ZipCode = row.GetValue<string>("ZipCode") }; } }
Friday, May 30, 2008 10:57:03 PM (Eastern Standard Time, UTC-05:00) .Net | C# | Miado
 Friday, May 23, 2008
No Fluff Just Stuff recap
This past weekend I attended the No Fluff Just Stuff conference here in Atlanta. If you're not familiar with NFJS, it's a traveling conference that hits most of the major markets here in the US. It's held over weekends so as not to disrupt your daily job, and it covers topics in Java and Agility. I'd been to one NFJS a few years ago here in Atlanta and thought it was well worth it. At that time, Bruce Tate was on the circuit. He was preaching (along with many of the other speakers at the time) about the bloat inherit in J2EE applications, and that Java developers should really be focusing their attention on lighter-weight J2EE alternatives such as Spring and Hibernate. Mind you, this was long before either had become mainstream. Having been a Rod Johnson disciple after reading his first book (the contents of which would eventually become Spring), I guess it's not surprising I enjoyed the conference so much. Interestingly enough, Bruce, along with Stu Halloway and Justin Gehtland (who also spoke at that conference), are now big Ruby-On-Rails guys. Now I've been doing .Net stuff almost exclusively for the last few years, so I had a slight reservation about attending this year's conference, given that I'm not doing Java day-to-day anymore and I wasn't sure how much would be relevant. But given that I'm an independent consultant who should be up on such things, I thought it would be a good idea to at least re-familiarize myself with the goings on in the Java community. I really am technology agnostic, but I do find the language of Java to be extremely noisy, tedious, and verbose anymore, especially coming from C# 3.0. Do you know how many language-level (not library-level) changes have gone into the JVM since 1.1.7? Off the top of my head, I can remember: - the new for loop (finally in 1.5!)
- the crappy implementation of generics
- annotations
- static imports
- enums
- varargs
That's not a whole lot (or really anything significant) for a language that is over 10 years old. And in case you are not following it, there is a huge debate in the Java world if/how closures should be implemented in the Java language. Have you seen the candidates? Good lord, they make the syntax for anonymous classes look simple! Put me firmly in the camp of leaving Java the language itself good and well alone and concentrate your efforts on other languages that run on the JVM. So given the stale nature of the Java language and the rise of my interest in dynamic languages, I figured this would be an excellent chance for me to explore Groovy and Grails. I attended the sessions by Jeff Brown from G2One on both technologies the first day, and I was hooked right away on both. Groovy compiles to native Java bytecode, and thus can be used interchangeably with standard Java classes (along with the innumerable number of Java frameworks out there). Plus, it has strong support for the things I love in C# 3.0 - properties, extension methods, and closures. Grails is rapid web application framework for Groovy similar to Rails. It favors convention over configuration and uses a classic MVC architecture that allows for easy testability. Under the hood, it uses best of breed Java technologies as plumbing infrastructure (e.g. Spring and Hibernate). Just by creating a new project through scaffolding, it creates a nice project layout structure that provides a beautiful separation of concerns. It really makes it easy for you to write unit tests (no more excuses!). Basically, it creates a solid project architecture that would be roughly close to something a strong Java architect would formulate. I learned of a term from Scott Hanselman called "The Pit Of Success". The concept is that you make it easy for developers to do the right thing and perform best practices. Don't make them have to overcome the language or framework, but rather fall into success by default. That's exactly what Grails does for you. I stayed on the Groovy path the second day of the conference, attending sessions on meta-programming using Groovy. Meta-programming in Groovy is quite powerful, which makes it damn easy to build DSLs. One of the gems of the language is the simplicity in which you can create XML documents using a DSL in its XML builder. If you've ever struggled over a unwieldy ant file (or jumped through hoops just to perform a simple "if" statement in the XML file), you really owe it to yourself to check out Gant. My last day was my Neil Ford day. I attended all four of Neil's sessions the last day. The first two were on Agile project management and metrics while the last two on Ruby/JRuby. Neil is a very entertaining speaker (and Atlanta resident the 10 days a year when he is not traveling). Again, to reference Scott Hanselman, the joke is that Scott got hired on by Microsoft and now gets paid "to be Scott Hanselman". I think Neil is exactly in the same camp. He gets paid "to be Neil Ford". Where do I get the gig "to be Chris Rauber"? One last comment to make on NFJS. One thing I like about Java conferences in general and No Fluff Just Stuff in particular is that they don't seem to favor "technology" over "methodology". NFJS has a strong Agile underpinning, and offers a number of session on practicing Agile methodologies. Where it did offer technology sessions, it seemed that it targeted as how a particular technology implements Agile. For example, I mentioned in a previous post how Sun announced JavaFX at JavaOne this year (again). This was a mere two weeks before the NFJS conference. Yet there was hardly any mention of JavaFX at NFJS. If this were a .Net conference, nearly half the sessions would be about this new technology. Now, you could make the argument that JavaFX isn't really all that appealing to everyday Java developers, and truth to be told, you wouldn't get much argument from me. But I thought it was very interesting nonetheless. The bottom line - if NJFS comes to your town, I would highly recommend checking it out. They really seem interested in providing top-notch speakers and giving you your money's worth in a conference. Now ... anybody looking to hire a Groovy consultant???
Friday, May 23, 2008 12:08:33 AM (Eastern Standard Time, UTC-05:00) Conferences | Java
 Wednesday, May 21, 2008
Using LINQ to generate a random confirmation number
Igor Ostrovsky recently published a great blog post about 7 tricks for using LINQ to simplify your programs. Posts like this really make me re-evaluate how I am writing my code in C# 3.0. For example, I had written a piece of code for my current project that generates a random confirmation number for a reservation system. After reading Igor's post, I built off one of his examples and refactored my code to use LINQ to build my confirmation number. I must admit, the refactored code is much more elegant:
private static readonly char[] AVAILABLE_CHARS = "ABCDEFGHIJKLMNOPQRSTUVWXYZ01234567890123456789".ToCharArray();
private static string GenerateConfirmationNumber(int length) { int lastIndex = AVAILABLE_CHARS.length - 1; Random rand = new Random(); var confNbr = Enumerable.Repeat<int>(0, length) // loop N times .Select<int, int>(loopNbr => rand.Next(0, lastIndex)) // get a random index .Select<int, char>(index => AVAILABLE_CHARS[index]) // pull a char .ToArray(); // project the results to a char[] return new String(confNbr); }
I think it's important to remember that LINQ is much, much more than just LINQ-to-SQL (which is what most people immediately think of when you refer to LINQ). In fact, none of the examples in Igor's post have anything to do with SQL. Take a look at his post (and other LINQ examples online) and hopefully it will give you ideas on how to code using more of a dynamic language type syntax.
Wednesday, May 21, 2008 9:42:57 AM (Eastern Standard Time, UTC-05:00) .Net | C# | Linq
 Saturday, May 17, 2008
String extension methods in ASP.Net Ajax
In an earlier post, I showed you how you could add a trim() method to the String class in Javascript. Well, as I found out late last week, if you are using the ASP.Net Ajax framework, they have already done this work for you (as well as a few more methods). Here are the extension methods for the String class that are provided to you:
| Method |
Description |
| endsWith() |
Test to see if the string ends with a particular string |
| format() |
Similar to .Net's String.Format(), it replaces a set of tokens with some replacement values |
| localeFormat() |
Similar to format(), but it uses the current culture to format dates and numbers |
| startsWith() |
Test to see if the string begins with a particular string |
| trim() |
Strips both leading and trailing whitespace from the string |
| trimEnd() |
Strips whitespace from the end of the string |
| trimStart() |
Strips leading whitespace from the string |
One other nice thing it provides is a StringBuilder class similar to .Net's System.Text.StringBuilder class. This is especially nice when creating big chunks of HTML to throw in an innerHTML property. <input type="button" name="btn1" value="Click Me!" onclick="javascript:changeText();"><br /> <span id="myText"></span> <script type="text/javascript">
function changeText() { var sb = new Sys.StringBuilder(); // thank you, ASP.Net Ajax! sb.append('<h1>How cool is this?</h1>'); sb.append('<br />'); sb.append('You just clicked my button. '); sb.append('Now we will change some text');
$get('myText').innerHTML = sb.toString(); }
</script>
Saturday, May 17, 2008 10:32:30 PM (Eastern Standard Time, UTC-05:00) Ajax | ASP.Net | Javascript
 Wednesday, May 14, 2008
C# Extension Methods
In my last post, I showed an example of how you can create an extension method on an existing class in javascript. Well, C# 3.0 has now added the exact same functionality. And it just so happens that today I needed to create one, so I thought I would post an example of how it's done in C#.
public static class StringExtensions { public static byte[] ToByteArray(this string s) { return ASCIIEncoding.UTF8.GetBytes(s); } }
Extension methods act like static methods on existing classes, and as such they can only be declared in static classes. To mark a method as an extension method, you must preface the declaration of the first parameter in the method signature with the keyword "this". The compiler will then add the method to the type of class declared in the first parameter. Any other parameters declared after the first one will become the signature to the extension method.
Now we can call the extension method we added to the String class:
public class Program { public static void Main(string[] args) { string myString = "Foo"; byte[] bytes = myString.ToByteArray(); } }
The other cool thing is that Visual Studio provides full Intellisense on all extension methods! So in the example I provided, ToByteArray() is now offered up as a potential method anytime I reference a string.
Wednesday, May 14, 2008 12:43:26 AM (Eastern Standard Time, UTC-05:00) .Net | C#
 Tuesday, May 13, 2008
Implementing String.trim() in Javascript
Curiously, the String class in javascript does not natively expose a trim() method. Not a problem! Since it is a dynamic language, javascript allows you the ability to crack open a class and add new functionality to it. <script language="javascript" type="text/javascript">
String.prototype.trim = function() { return this.replace(/^\s+/,"").replace(/\s+$/,""); }
var s = new String(" Test me! ").trim();
alert("'" + s + "'");
</script>
The prototype keyword indicates that you are adding functionality to an existing class. In this case, we are adding a method called trim() to the String class that uses regular expressions to find any spaces (\s+ = one or more whitespace characters) at the beginning (^ = match at the START of a line) and then the end ($ = match at the END of a line) of the string, and replace the spaces we find with an empty string ("").
Tuesday, May 13, 2008 11:07:44 AM (Eastern Standard Time, UTC-05:00) Javascript
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