Wednesday, December 26, 2007

Presents

Season's greetings! We're halfway through my X-mas carol describing how Refactor! Pro can be used to leverage the new features of Visual Studio 2008. Today, I'm sharing a little more Refactor! Pro love by demonstrating a refactoring that literally can save minutes of menial coding. That's right, minutes. Interested? OK, just let me clear my voice...

"On the seventh day of X-mas my true love (DevExpress) gave to me..."

Create Backing Store

A couple of days ago, I showed how Refactor! Pro can transform properties into C# 3.0 Auto-Implemented Properties. However, sometimes the opposite is needed. We need a way to convert from an auto-implemented property to a standard property and field. Consider the following code:

using System;
using System.Drawing;

namespace TwelveDaysOfXmas
{
  class Present
  {
    public Color Color1 { get; set; }
    public Color Color2 { get; set; }
  }
}

Suppose that we want to add logic to both the Color1 and Color2 properties to ensure that they can't be set to the same value. Now, imagine how much effort that would take. An awful lot of keystrokes are needed to get to the code below.

using System;
using System.Drawing;

namespace TwelveDaysOfXmas
{
  class Present
  {
    private Color m_Color1;
    public Color Color1
    {
      get { return m_Color1; }
      set
      {
        if (m_Color2 == value)
          return;
        m_Color1 = value;
      }
    }
    private Color m_Color2;
    public Color Color2
    {
      get { return m_Color2; }
      set
      {
        if (m_Color1 == value)
          return;
        m_Color2 = value;
      }
    }
  }
}

Fortunately, Refactor! Pro provides a refactoring, called Create Backing Store, which converts an auto-implemented property into a standard property with a field backing store. In other words, it transforms this...

public Color Color1 { get; set; }

...into this.

private Color m_Color1;
public Color Color1
{
  get
  {
    return m_Color1;
  }
  set
  {
    m_Color1 = value;
  }
}

That's pretty close to what we want. With the help of two other refactorings, Introduce Setter Guard Clause and Collapse Accessor, we can continue to manipulate the property to get the code below.

private Color m_Color1;
public Color Color1
{
  get { return m_Color1; }
  set
  {
    if (m_Color1 == value)
      return;
    m_Color1 = value;
  }
}

Now we just have to make a minor edit to the guard clause and we're done.

View Screencast of These Refactorings in Action!

And that concludes my verse for today. Remember that the features I'm showing you are available for download this very second. So, if you're tired of waiting for <whisper>the other tool</whisper> to get its act together, Refactor! Pro can have you running laps through Visual Studio 2008 in no time.

posted on Wednesday, December 26, 2007 12:52:42 PM (Pacific Standard Time, UTC-08:00)  #    Comments [0]

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