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Archive for May, 2011

Bubble Sort algorithm developed with TDD. Code Kata.

16/05/2011 2 comments

After I’ve been on a three day course with Uncle Bob in Copehangen, I got inspired by the code kata concept. And now want to do Kata from time to time to train coding.

I’ve wanted to start with something simple so I chose to do a sort algorithm. I was trying to make a video out of it, but got stuck with quicktime. Hoping to get it to work in the future. So for now you will have to settle with the testcases and code. I’m trying to use the guidelines from Clean Code so no comments will be in the code, functions and variable names should reveal their purpose.  How the code works should be visible from the Testcases.

Test cases.


package Sort;

import junit.framework.Assert;
import org.junit.Test;

import java.util.Arrays;

public class SorterTest {
  @Test
  public void SortEmptyList_ShouldReturnEmptyList() {
    Assert.assertTrue(Arrays.equals(new int[]{},
                        Sorter.Sort(new int[]{})));
 }

 @Test
 public void SortListWithOneElement_ShouldReturnSortedList() {
   Assert.assertTrue(Arrays.equals(new int[]{1},
                       Sorter.Sort(new int[]{1})));
 }

 @Test
 public void SortListWithTwoElementsInCorrectOrder_ShouldReturnSameList() {
   Assert.assertTrue(Arrays.equals(new int[]{1, 2},
                       Sorter.Sort(new int[]{1, 2})));
 }

 @Test
 public void SortListWithTwoElementsInReverseOrder_ShouldReturnSortedList() {
   Assert.assertTrue(Arrays.equals(new int[]{1, 2},
                       Sorter.Sort(new int[]{2, 1})));
 }

 @Test
 public void SortListWithSameTwoElementsr_ShouldReturnSortedList() {
   Assert.assertTrue(Arrays.equals(new int[]{2, 2},
                       Sorter.Sort(new int[]{2, 2})));
 }

 @Test
 public void SortListWithThreeElementsInCorrectOrder_ShouldReturnSortedList() {
   Assert.assertTrue(Arrays.equals(new int[]{1, 2, 3},
                       Sorter.Sort(new int[]{1, 2, 3})));
 }

 @Test
 public void SortListWithThreeElementsFirstTwoSwapped_ShouldReturnSortedList() {
   Assert.assertTrue(Arrays.equals(new int[]{1, 2, 3},
                       Sorter.Sort(new int[]{2, 1, 3})));
 }

 @Test
 public void SortListWithThreeElementslastTwoSwapped_ShouldReturnSortedList() {
   Assert.assertTrue(Arrays.equals(new int[]{1, 2, 3},
                       Sorter.Sort(new int[]{1, 3, 2})));
 }

 @Test
 public void SortListWithThreeElementslReverseOrder_ShouldReturnSortedList() {
   Assert.assertTrue(Arrays.equals(new int[]{1, 2, 3},
                       Sorter.Sort(new int[]{3, 2, 1})));
 }

 @Test
 public void SortListWithNElementaRandomOrder_ShouldReturnSortedList() {
   Assert.assertTrue(Arrays.equals(new int[]{1, 2, 3, 4, 5, 6, 6, 7, 8},
                       Sorter.Sort(new int[]{3, 2, 7, 6, 4, 8, 6, 1, 5})));
 }
}

And now to the refactored code.


package Sort;

public class Sorter {
  public static int[] Sort(int[] unSortedList) {
    if (unSortedList.length > 1)
      SortList(unSortedList);
    return unSortedList;
 }

 private static void SortList(int[] unSortedList) {
   int unsortedLength = unSortedList.length;
   while (unsortedLength > 0) {
     PlacedLargestElementAtEndOfList(unSortedList);
     unsortedLength--;
   }
 }

 private static void PlacedLargestElementAtEndOfList(int[] unSortedList) {
   for (int j = 0; j < i.length - 1; j++)
     SortElements(unSortedList, j);
 }

 private static void SortElements(int[] unSortedList, int j) {
   if (unSortedList[j] > unSortedList[j + 1])
     SwapElements(unSortedList, j);
 }

 private static void SwapElements(int[] unSortedList, int j) {
   int backupelement = unSortedList[j];
   unSortedList[j] = unSortedList[j + 1];
   unSortedList[j + 1] = backupelement;
 }
}
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Categories: Java Tags: , ,

CMS Friendly URL With MVC (Simple)

04/05/2011 Leave a comment

I currently working on HUGE MVC project for a customer through Pentia. They are rebuilding their entire website from .Net webforms to MVC 3 with Razer.

So one of the first task was to build som simpel functionality tha could resolve their url delivered from the underlying CMS.Instead of register specific routes for the different pagetypes in the CMS

I came up with this solution shown in this blogpost.

To begin with I registered a new “CMS route in global.asax”. All URL shoul hit this route, ofcourse you could make other routes before this.


//RouteMap for CMS content
routes.MapRoute("CMSRoute", "{*url*}").RouteHandler = new CmsRouteHandler();

Now to the simple CmsRouteHandler implementation it simply calls the CmsHttpHandler a relying on the handler to find a correct controller to desplaying the current request.

public class CmsRouteHandler : IRouteHandler
{
public IHttpHandler GetHttpHandler(RequestContext requestContext)
{
return new CmsHttpHandler(requestContext);
}
}

Now the CMSHttpHandle which for this blogpost is simplyfied to always returning the
frontpage. This should offcourse by matching the url to a page i DB and displaying the
and resolve it to the correct controller.


public class CmsHttpHandler : IHttpHandler
{
private RequestContext RequestContext { get; set; }
private IControllerFactory ControllerFactory { get; set; }
private IController Controller { get; set; }

public CmsHttpHandler(RequestContext requestContext)
{
RequestContext = requestContext;
}

public void ProcessRequest(HttpContext context)
{
HttpContext = context;
InstantiateControllerFactory();
InstantiateController();
SetupRequestContext();
Controller.Execute(RequestContext);
}

private HttpContext HttpContext { get; set; }

private void InstantiateControllerFactory()
{
ControllerFactory = ControllerBuilder.Current.GetControllerFactory();
}

private void InstantiateController()
{
Controller = ControllerFactory.CreateController(RequestContext, Pagetype);
}

private void SetupRequestContext()
{
RequestContext.RouteData.Values.Add("controller", Pagetype);
//Always render Index action, all pagetype controllers must implement Index action
RequestContext.RouteData.Values.Add("action", "Index");

AppendQueryStrings();
}

private void AppendQueryStrings()
{
foreach (string name in HttpContext.Request.QueryString)
RequestContext.RouteData.Values.Add(name, HttpContext.Request.QueryString[name]);
}

private static string ResolvePagetypeFromUrl()
{


//Should return apgetype from db/URL
return Pagetype


}

private string _pageType;
private string Pagetype
{
get
{
//Resolve pagetype from DB fx
//For now we will just return the frontpage
/return string should match controller name
return "frontpage";
}
}

public bool IsReusable
{
get
{
throw new NotImplementedException();
}
}
}

Hope you find it usefull..

Categories: C# Tags: ,