Sunday, December 30, 2007
Twelve Days of Refactor! X-mas, Day Eleven: More Refactoring in XML Literals

Mug

Greetings friends! I bring tidings of comfort and joy! That is, you can rest comfortably and joyously, knowing that you don't have to wait for refactorings that leverage the new language features of Visual Studio 2008. These refactorings are available today.

I'm very excited about today's verse. As promised yesterday, I'm back to share some more refactoring possibilities for Visual Basic XML Literals. By the end of the verse, you should have a sense of how powerful these refactorings truly are. If you're a Visual Basic developer, you definitely won't want to miss this!

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

More Refactoring in XML Literals

Yesterday, we saw how our bread-and-butter refactorings can be used on the inner text of XML tags to create new embedded expressions. This is extremely helpful when trying to make the contents of an XML literal more dynamic. Today, we'll take things a step further to see how we can use Refactor! Pro to manipulate the XML tags themselves.

Module TwelveDaysOfXmas
  Sub Main()
    Dim aPrice As Decimal = 0
    Dim lBook = <book isbn="12252007">
                 <title>Refactoring: The True Meaning of X-mas</title>
                 <price><%= aPrice.ToString("C") %></price>
                 <author>
                   <first-name>Dustin</first-name>
                   <last-name>Campbell</last-name>
                 </author>
               </book>
  End Sub
End Module

Consider the code above. Since Refactor! Pro works on XML tags, we can select the entire <price> tag and apply Extract Method to get the following:

Module TwelveDaysOfXmas
  Private Function GetPrice(ByVal aPrice As Decimal) As XElement
    Return <price><%= aPrice.ToString("C") %></price>
  End Function

  Sub Main()
    Dim aPrice As Decimal = 0
    Dim lBook = <book isbn="12252007">
                 <title>Refactoring: The True Meaning of X-mas</title>
                 <%= GetPrice(aPrice) %>
                 <author>
                   <first-name>Dustin</first-name>
                   <last-name>Campbell</last-name>
                 </author>
               </book>
  End Sub
End Module

A potential complication is the use of aPrice in the embedded expression. Fortunately, Extract Method intelligently analyzes this and declares it as a parameter of the new method.

View Screencast to See Extract Method in Action!

Refactor! Pro's ability to manipulate XML tags makes it easy to dynamically build XML. In fact it can save minutes of menial coding labor.

Take another look at the first code example above. Go ahead. I'll wait.

Now, imagine how much effort it would take to transform that code into this:

Module TwelveDaysOfXmas
  Private Function GetTitle(ByVal aTitle As String) As XElement
    Return <title><%= aTitle %></title>
  End Function

  Private Function GetPrice(ByVal aPrice As Decimal) As XElement
    Return <price><%= aPrice.ToString("C") %></price>
  End Function

  Private Function GetAuthor(ByVal aFirstName As String, _
                             ByVal aLastName As String) As XElement
    Return <author>
             <first-name><%= aFirstName %></last-name>
             <last-name><%= aLastName %></last-name>
           </author>
  End Function

  Private Function GetBook(ByVal aPrice As Decimal, _
                           ByVal aIsbn As String, _
                           ByVal aTitle As String, _
                           ByVal aFirstName As String, _
                           ByVal aLastName As String) As XElement
    Return <book isbn=<%= aIsbn %>>
             <%= GetTitle(aTitle) %>
             <%= GetPrice(aPrice) %>
             <%= GetAuthor(aFirstName, aLastName) %>
           </book>
  End Function

  Sub Main()
    Dim lBook = GetBook(0D, _
                  "12252007", _
                  "Refactoring: The True Meaning of X-mas", _
                  "Dustin", _
                  "Campbell")
  End Sub
End Module

That's pretty insane, isn't it? Well, with Refactor! Pro, this is a snap. In fact, most of the effort is spent typing the names of new variables and methods. The refactorings themselves take only seconds to apply.

Don't Believe Me? Check Out This Screencast!

One point I've saved until now is that Refactor! Pro is the very first tool to offer refactorings for Visual Basic XML Literals. That's just one more compelling reason that Refactor! Pro should be a part of your Visual Studio 2008 installation this holiday season.

Happy Holidays!

12 Days of Refactor! | Quality Code | Refactor! | Visual Basic | Visual Studio
posted on Sunday, December 30, 2007 3:58:57 PM (Pacific Standard Time, UTC-08:00)  #    Comments [4]

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Monday, December 31, 2007 3:37:02 AM (Pacific Standard Time, UTC-08:00)
This is a great series Dustin. Now you need to do a counterpart on CodeRush. BTW: You wasted some keystrokes at the end - A ctrl-right from the start of the line would have jumped you to the start of the variable name during all of the inline temps at the end. I know it is not a refactoring or a CodeRush shortcut, but helpful nonetheless.
Joe Brinkman
Monday, December 31, 2007 3:41:25 AM (Pacific Standard Time, UTC-08:00)
FYI: You should check out Camtasia 5. It has several new features and an updated look for your screencasts that is a little more modern.
Joe Brinkman
Monday, December 31, 2007 8:17:13 AM (Pacific Standard Time, UTC-08:00)
More modern? Are you serious? My license of Camtasia Studio 4 is 8 months old. I can't justify shelling out an additional $149.00 until I've used it for at least a year. Camtasia 5 was released in October and I purchased in April. Give me a break.
Dustin Campbell
Tuesday, January 01, 2008 11:15:46 AM (Pacific Standard Time, UTC-08:00)
Dude... Seriously. You are an MVP. Get on the PrivateNews.microsoft.com server and go to the Microsoft.Private.MVP.3rdPartyOffers newsgroup. If Mark can take advantage of NFR offers from "the other tool" company, then surely you should be able to take advantage of NFR offers from TechSmith.
Joe Brinkman
Comments are closed.

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